Exam 1 Flashcards
contaminant vs. pollutant
Contaminants - anything added to the environment that causes a deviation from the average composition that a particular phase of environment would have in the absence of human activity
We call contaminants pollutants when they adversely affect something we value, and is present in high enough concentration to do so.
What is the 1970 U.S. Clean Air Act?
Air quality criteria documents (books) that provide a summary of what is known about:
1. Sulfur oxides
2. Particulates
3. Oxidants
4. Carbon monoxide
5. Hydrocarbons (VOCs)
6. Nitrogen oxides
Why should we care about global warming?
Global warming will have an overwhelming negative impact on human and ecological life:
1. Rise in sea level
- extinctions of species
- spread of disease
2. Extreme weather patterns
- harm ozone layer
- extreme storms
- droughts
- fires
Describe the history of Carbon Dioxide (CO2) as a pollutant
Until 35 years ago, the goal was to break down pollutants to carbon dioxide; it was not a pollutant itself
Now, carbon dioxide is a greenhouse gas and is our most concerning pollutant due to global warming and climate change
How has COVID-19 impacted air pollution?
The COVID-19 lockdown has led to cleaner air, but will do little to address the issue of air pollution in the long run.
People living with poor air quality may be more susceptible to COVID.
What groups are at the greatest risk for air pollution?
Describe the air pollution problem before the Industrial Revolution
Chimneys were a major problem, with many complaining. In 1273, English Parliament passed a law - “don’t burn peat while in session, burn coal instead.”
Metallurgy, ceramics, and preservation of animal products in the bronze and iron ages led to bad air.
Smoke and ash from burning fossil fuels and coal by powerplants, trains, and ships in 18th and 19th centuries.
British Parliament studies in the 19th century recognized that there was lots of dirty air, but nothing was done about it.
Describe the Smoke Abatement Era in the U.S. (1880-1940s)
Initially there were no penalties for violations, but smoke abatement ordinances with penalties were prevalent starting in 1940s.
There was a shift from coal to natural gas, accompanied by the belief that natural gas = clean fuel (which was partially true, gas > coal)
What is the Meuse Valley, Belgium, incident (1930), and what were its effects?
This was the first modern air pollution disaster. In the densely populated, highly industrialized river valley, industrial pollutants combined with thermal temperature inversion to create a highly dangerous fog. The Meuse Valley’s natural geography amplified the effect of temperature inversion, effectively trapping the polluted air close to the ground.
Note: this is very similar to the Donora, PA, incident in 1948.
Pollution by:
- SO2, sulfur dioxide
- H2O
- SO4, sulfuric acid mist
Impact:
- 63 deaths (mostly elderly)
- Sore throats, shortness of breath, cough, phlegm, nausea, vomiting
- Cattle, birds, and rats died
- Received little news coverage
What is a temperature inversion?
a temperature inversion occurs when a layer of warm air traps cooler air near the ground, preventing pollutants from dispersing upward, effectively trapping them
Example: Meuse Valley, Donora, Poza Rico, London incidents
What is the Donora, Pennsylvania, incident (1948), and what were its effects?
In the Monongahela River Valley in October 1948, industrial pollutants combined with a temperature inversion to trap fog for 4.5 days. The industrial town + steep hills surrounding the valley amplified this effect.
Note: this is very similar to the Meuse Valley, Belgium, incident in 1930.
The air reeked of sulfur dioxide and the fog was a motionless, dense smoke. The smell in Donora is normal, but this time it was much more extreme.
Pollutants:
- Sulfur gases + particulates
- SO4, sulfuric acid mist
Impact:
- 6000/14000 people ill
- 20 deaths
- U.S. public health service called in - first time air pollution was recognized as public health problem
What is the Poza Rico, Mexico, incident (1950), and what were its effects?
High sulfur crude oil released hydrogen sulfide (H2S), and a temperature inversion in the valley trapped the H2S as a pollutant.
Impact:
- 22 sudden deaths
- 320 hospitalized (all ages)
What is the Great London Smog (1952), and what were its effects?
In Dec 1952 - Factories and power plants in London burned coal, and these pollutants combined with a cold front led to a hazardous temperature inversion resulting in “5 days of the worst smog the city had ever seen.” Pollution levels were 5-19x above current regulatory standards.
Impact:
- ~12,000 deaths
- Much lung and heart disease
- Rise in smoke associated w/ rise in deaths
- New studies found particulates in 1952 lungs
- Public transportation stopped
- Concerts cancelled (people couldn’t see the stage)
What is the Worldwide Air Pollution Episode?
November 27-December 10, 1962 - thousands of deaths in many cities including NYC, London, Boston, and Paris.
Oct-Nov 1958 - many asthma deaths in New Orleans
What is the Seveso, Italy, incident (1976), and what were its effects?
On July 10, 1976, north of Milan, Italy, in Seveso, a valve broke at a chemical plant, releasing a cloud of Dioxin (TCDD) that traveled southwest through Seveso toward Milan.
Dioxin is a contaminant of herbicide (Agent Orange).
Impact:
- 38k people exposed
- 4% of farm animals dropped dead
- 80k animals killed
- Italian government covered it up
What is Dioxin (TCDD)?
contaminant of herbicide (Agent Orange) that can cause a slew of symptoms including liver necrosis, GI bleeding, and ulcers
Dioxin was the pollutant in the Seveso, Italy, incident of 1976.
What is the Bhopal, India, incident (1984), and what were its effects?
On Dec 3, 1984, pesticide plant leak releases Methyl isocyanate (MIC), an irritant to the lungs that causes edema and bronchospasms. Labeled as the “worst industrial accident in history.”
Impact:
- 2,000 deaths
- 350k injured
- 100k permanently disabled
What is MIC?
Methyl isocyanate (MIC) is a lung irritant formed from phosgene + methylamine that causes edema and bronchospasms.
MIC was the main pollutant in the Bhopal, India, incident of 1984.
7 similarities among prominent air pollution disasters
- Winter months
- Dense population
- Heavy industrialization
- Often in a valley
- Temperature inversion
- Stagnant air
- Accident, or mixtures from non-accidents
What is the Asian Brown Cloud?
a large atmospheric brown cloud that occurs annually over Asia during the winter as a result of aerosol pollution
risk assessment vs. risk management
Risk assessment - the use of research to define the probability of some harm as a result of exposure to a substance or situation
Risk management - the public process of deciding what to do where risk has been determined to exist
What are polychlorinated biphenyls (PCBs)?
-mixtures of up to 209 indiviudal chlorinated compounds; PCBs are a fat-soluble, water-insoluble hydrocarbon containing 1 to 10 chlorine atoms
- either oily liquids or solids, colorless, no smell/taste
- carcinogenic to humans
3 components of risk assessment
- Hazard identification
- Dose-response assessment
- What is the relationship between dose and incidence in humans? - Exposure assessment
- What exposures are currently experienced or anticipated under different conditions?
What is epidemiology?
the study of the distribution and causes of health and illness in human populations using observational data
the “patient” of epidemiologists is the population
What is environmental epidemiology?
branch of epidemiology that asks: “Is a given exposure hazardous to human health?”
In what way was 9/11 an air pollution disaster?
Asbestos in NYC skyscrapers led to elevated deaths in NYC post 9/11; it penetrated the masks of first responders
The extent of the disaster was so severe that many developed respiratory and pulmonary problems and cancer, leading to the creation of the World Trade Center Health Program for those affected.
How did the EPA mislead the public on 9/11 information?
The White House ordered false assurances on air quality, using light microscopy (a poor detector of asbestos) when surveying NYC
Was there asbestos in the World Trade Center?
Yes, 5000 tons in lower 40 floors of North Tower. Builders said asbestos would prevent “towering inferno” and help keep buildings standing.
This introduced a major issue during 9/11 due to asbestos pollution in the air.
What is the World Trade Center Health Program?
federal health program that provides no-cost medical care for certified WTC-related health conditions to those directly affected by 9/11
What is toxicology?
The study of harmful actions of chemicals on biological tissue; the study of poisons
What is the impact of 9/11 on cancer?
The WTC Health Program reported elevations in all cancer sites combined, including prostate cancer, thyroid cancer, and leukemia
What is the Paracelcus view of poisons (dose response)?
“All things are poisons, for there is nothing without poisonous qualities. It is only the dose which makes a thing a poison.”
How do we interpret a dose-response curve?
things that work at a lower dose are more toxic (lower LD50)
4 problems in extrapolating dose response information from animals to man
- Species differences in susceptibility
- Interactions with other exposures
- Latent period
- Low dose problem
measuring risk vs. judging safety
Measuring risk - calculating the probability and severity of public health harm; it is an empirical scientific activity
Judging safety - judging the safety of risks; is a normative, political, economical, and value laden activity
What is de minimus with regard to epidemiology?
idea that there is an acceptable small amount of each substance (never zero); there is also no such thing as zero risk, its simply dose dependent
Example: EPA and FDA acceptable lifetime cancer risk (de minimus) is one in a million
What is the precautionary principle?
“When an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically”
What is the basic premise of epidemiology?
Disease occurrence (or its outcome) is NOT random, but can vary depending on a variety of characteristics and predisposing factors.
What is an incubation period?
time between exposure to an infectious agent and onset of symptoms; typical for each infectious disease but varies depending on dose, route, replication rate, host responses
Note: same as latent period, but latent period is for non-infectious ailments (e.g., cancer, heart disease) and has no multiplicative causative agent
What is a latent period?
Time between non-infectious (e.g., cancer, heart disease) disease acquisition and onset of symptoms; typical for each disease but varies depending on type of disease, etc.
No multiplication of causative agent is involved, rather multiple low-dose exposures (some chemicals).
Note: same as incubation period, but incubation period is for infectious ailments (e.g., caused by viruses) and has a multiplicative causative agent
What is descriptive epidemiology, and what is its purpose?
the person, place, and time of disease occurrence, tracking what is going on in the world, nation, state, community
Purpose:
1. Helps form etiologic (what is causing) hypotheses
2. Helps form public health policy
What is an epidemic?
the occurrence in a community or region of cases of an illness or health-related event clearly in excess of normal expectancy
What is the #1 cause of death?
Heart disease
What are DALYs and QALYs?
Disability Adjusted Life-Years and Quality Adjusted Life-Years; both are attempts to express burden of a disease in a single quantification (higher DALYs = greater burden)
How is disease prevalence rate calculated?
Prevalence rate = (# of cases of disease in population at a specified time)/(# of persons in the population at that specified time)
How is disease incidence rate calculated?
Incidence rate = (# of new cases of a disease in population during a specified period of time)/(# of persons exposed to risk of developing the disease during that period of time)
How has cause of death changed over time?
In 1900, the leading causes of death were mainly infectious diseases like influenza and TB
In 1970, the leading cause of death was heart disease, with infectious disease mortality significantly decreasing
What is peculiar about the U.S. cancer epidemic?
the cancer epidemic was arguably just a lung cancer epidemic, with a major spike in lung cancer prevalence due to cigarettes; the prevalence of other cancers has also changed but not to the same extent
What is a neoplasm?
autonomous growth of tissue that has escaped the normal restraints on cell proliferation; usually appears as a tumor made of mass of cells and are generally irreversible
AKA “abnormal growth of cells” or “unlimited growth of cells”
A malignant neoplasm is cancer
What is cancer?
the malignant unrestrained proliferation of somatic cells (cells other than germ/reproductive cells); i.e., a malignant neoplasm
What is invasion (RE: cancer)?
malignant tumors (cancer) are capable of invasion, which is the spread of the neoplasms into adjacent structures
What is metastasis (RE: cancer)?
malignant tumors (cancer) are capable of metastasis, which is the implantation of the neoplasms into noncontiguous sites
How does the lung cancer epidemic compare in males vs. females?
epidemic of lung cancer in males was much greater than that of females, likely due to heightened smoking rates among men
2 possible reasons for changes in mortality trends over time
- Artifactual
- errors in the numerator or denominator during calculation - Real
- changes in demographics, survivorship, or disease incidence
People hypothesize artifactual, but the reality is likely real
What is the Agent-Host-Environment model?
triad model used to understand the dynamics of infectious disease transmission and propagation that is based on the interactions of the agent (pathogen or poison), host, and environment
How do death rate and incidence rate compare between males and females?
Males always die at higher rates than females, even in the womb…however, females have higher condition incidence rate (report more sickness)
How does death rate compare on the basis of race?
Non-whites have greater maternal mortality rates than whites in the U.S.
How have stomach cancer incidence/death rates changed over time?
Stomach cancer used to be very prevalent in the 1950s, but now it is rare; we don’t know why rates used to be higher than they are now
What are retrospective and prospective studies?
Retrospective - study looking for past exposure to a factor
Prospective - study that classifies exposure to a factor then follows cohort to see if disease develops
descriptive vs. analytic epidemiology studies
Descriptive:
- Mortality
- Morbidity
Analytic:
- Case-control
- Cohort (historical for occupation)
- Clinical trials
5 weaknesses of indirect studies
- Possibility of indirect association (e.g., alcohol —> stomach cancer is flawed b/c not direct study)
- Interpretation of negative results
- Often look at agents one at a time
- Comparability of data by place and time
- Mobility problem
Why can’t we say that alcohol causes stomach cancer even though Wisconsin has highest rates of both alcohol consumption and stomach cancer?
It’s an indirect association, which cannot assess causality
What is air pollution?
the presence in the air (outdoor atmosphere) of one or more contaminants or combinations thereof in such quantities and of such durations as may be or tend to be injurious to human, animal, or plant life, or property, or which unreasonably interferes with the comfortable enjoyment of life or property or conduct of business
Of clean, dry air, what is the air made of? (GUARANTEED TEST QUESTION)
~80% nitrogen and ~20% oxygen
Of clean, dry air, what percent is carbon dioxide?
0.4% and growing
How has atmospheric carbon dioxide changed over time?
Since the start of the industrial revolution we have endured a massive spike in CO2, and now it is >400ppm
What is LA Photochemical Smog?
smog in Los Angeles due to ground level ozone; NOx + VOCs (hydrocarbons) = ozone precursors + sunlight = ozone
What is the significance of the factory cigarette rolling machine?
American Tobacco Company gambled that American smokers would buy machine made cigarettes, and it worked. This led to a massive increase in cigarette smoking.
How did advertising play a role in the cigarette epidemic?
Ads were extremely personalized and companies spend lots of money making them extravagant and enticing. These ads are infamous for advertising health benefits of cigarette ads.
What was the first research study detailing negative effects of cigarettes, and how was it interpreted?
1924 “On the cancer-producing factors in tar” - it was largely ignored
What was the significance of “Tobacco and longevity” from 1938, and how was the work interpreted?
Showed that non-cig smokers lived longer than cig smokers, but the author had many controversial views, causing many to dismiss his work
What was the Wynder and Graham paper from 1950, and what was its significance?
First major case-control study (retrospective) of cigs and lung cancer.
Physician authors interviewed 684 cases of lung cancer on previous smoking, occupation, etc. Due to many problems in the study (different interviewers, no blinding, etc.), results hard to interpret.
However, two non-medical investigators also interviewed 100 lung cancer patients and 186 patients with other chest diseases (controls), correcting these problems.
Found higher rates of lung cancer proportional to amount smoked.
What did the first case-control studies (retrospective) of lung cancer and cigarette smoking find?
29 studies as of 1964 all with the same result, confirming the association
5 primary critiques of the original case-control studies of lung cancer and cigarette smoking
- Studies limited to hospitalized lung cancer patients (not all lung cancer patients)
- Control groups were hospital patients who may not be representative of the general population with respect to smoking habits
- The ascertainment of smoking habits may be inaccurate
- Numerous other important variables were not investigated
- Association was shown but not relative risk
What was the Doll & Hill British Doctors Study of lung cancer and cigarette smoking, and what was its significance?
First cohort (prospective) study of lung cancer and cigarettes.
In Oct. 1951, questionnaires on smoking habits were sent to all British physicians. 40k replies received, patients followed for deaths. Confirmed association between smoking and lung cancer/death.
Found that the longer its been since you quit smoking, the higher your survival rate.
How did smoking prevalence change among doctors?
Starting in 1950, doctors began to steadily stop smoking cigarettes; at the same time, death rate among doctors decreased 38%
What was the Hammond & Horn ACS study, and what was its significance?
Cancer research solicitors had men fill out smoking questionnaire once per year. Received 187k replies. Asked about inhalation practices (how deep), packs/day, death status, etc.
Found that smoker has ~10x risk of lung cancer death than non-smokers. Also, deeper inhalation = higher death rate and quitting for longer = lower death rate.
What is the risk of lung cancer for smokers relative to non-smokers?
Male smokers have ~23x greater risk and women have ~13x greater risk of lung cancer death than non-smokers
How do emotions and life patterns differ for smokers relative to non-smokers?
Smokers are more emotionally unstable and have more hectic lives (more marriages, more accidents, etc.) than non-smokers
How did levels of tar and nicotine in factory cigarettes change over time?
From 1957-87 the amounts of both tar and nicotine in cigarettes decreased
What is the major cancer-causing agent in cigarettes?
benzo(a)pyrene
How addictive are cigarettes?
According to one study, “the pharmacologic and bahvioral processes that determine tobacco addiction are similar to those that determine addiction to drugs such as heroin and cocaine”
Describe the theft of documents from Big Tobacco
The 7 Big Tobacco companies were internally aware of the risks of cigarettes yet hid this info from the public. A scientist stole documents entailing how cigarettes are addictive and cause cancer, leading to the development of a major court case.
Stolen docs are not viable in court, so the scientist placed the documents in public library at UCSF, allowing them to be used in court.
How are the spouses of smokers affected by smoking?
Study found that spouses of smokers were at greater risk for lung cancer than spouses of nonsmokers due to sidestream smoke; “smoking kills others”
How does the carcinogenic content of sidestream smoke differ from mainstream smoke?
Sidestream smoke contains more bezno(a)pyrene than mainstream smoke
How does sidestream smoke affect children?
Causes the lungs of children to not develop properly
How does sidestream smoke affect the heart?
Causes heart disease
How does maternal smoking affect the fetus?
Women who smoke make smaller, unhealthier babies
What is The Master Settlement Agreement?
Agreement reached between states and the 7 major cigarette manufacturers after Big Tobacco was exposed for concealing the dangers of cigarettes from the public.
The 7 heads had to give money to each state in a settlement after being sued.
What percentage of lung cancer is caused by cigarettes?
~85-90% of lung cancer is caused by cigarettes
What is the relative risk of active smoking compared to other activities?
Active smoking causes the most fatalities by far, much more than alcohol, accident, or disease. It is the leading cause of preventable death
Is smoking still a problem?
Yes, cigarette smoking is down but 34 million American adults still smoke
How many deaths are attributable to cigarettes?
Cigarette smoking accounts for 1 of 5 deaths in the U.S.
More than 10 times as many citizens have died prematurely from cigarette smoking than have died in all the wars fought by the U.S.
More deaths are caused each year by cigs than by all deaths from HIV, illegal drug use, alcohol use, motor vehicle injuries, suicides, and murders combines
What are the cardiovascular effects of cigarette smoking?
- Cigarette smokers are 2-4x more likely to develop coronary heart disease (CHD) than nonsmokers
- Smoking doubles risk for stroke
- Smokers 10x more likely to develop peripheral vascular disease
Is smoking a major cancer risk of just the lungs?
More cancer risk than just the lungs, also increases risk of cancers of the bladder, oral cavity, pharynx, larynx, esophagus, cervix, kidney, pancreas, stomach, acute myeloid leukemia
What is the relationship of cigarette smoking and COPD?
10x increase in the risk of dying from COPD. 90% of COPD deaths are from cig smoking
What are the reproductive and early childhood effects of cigarette smoking?
Increased risk for:
- infertility
- preterm birth
- stillbirth
- low birth weight
- sudden infant death syndrome (SIDS)
What is the relationship of cigarette smoking and bone density?
Postmenopausal women who smoke have lower bone density than women who never smoked; women who smoked consequently have an increased risk for hip fracture
How many deaths per year are caused by cigarettes?
Tobacco causes 4 million deaths per year, a figure that will increase to 10 million per year by the late 2020s
Why is cigarette smoking cessation so important?
“Smoking cessation has major and immediate health benefits, including decreasing the risk of lung and other cancers, heart attack, stroke, and chronic lung disease.”
The longer someone has been off cigarettes, greater survival rates.
What was the impact of cigarette product placement?
Placing cigarettes in movies like “Rocky” generated much revenue for Big Tobacco
4-Step Public Health Approach
- Define the burden
- Find the causes
- Develop effective solutions
- Close the gap between the science and practice
What is the major source of environmental tobacco smoke (ETS)?
The home. Children in these homes have higher levels of cotinine (biological marker of secondhand smoke exposure)
What is cotinine?
biological marker of secondhand smoke exposure; reliable because only cig smoke elevates serum cotinine
5 major conclusions of the 2006 Surgeon General Report of environmental tobacco smoke (ETS)
- Secondhand smoke causes premature death and disability
- Children are especially vulnerable to the poisons in secondhand smoke
- Exposure has immediate effects and causes serious disease
- There is no risk-free level of exposure
- Eliminating smoking indoors is the only way to reduce the risk from exposure
5 major health effects of tobacco smoke on children
- Increased risk for sudden infant death syndrome (SIDS)
- Acute respiratory infections
- Ear infections
- More severe asthma
- Slows lung growth
How does exposure to environmental tobacco smoke (ETS) affect the risk of heart disease and cancer in nonsmokers?
- Increased risk of developing heart disease by 25-30%
- Increased risk of developing lung cancer by 20-30%
Is there a risk-free level of secondhand smoke?
No…
- Immediate effects occur in cardiovascular system, increasing risk of heart attack
- Also irritates and damages the lining of the airways
What is the cost of nonsmokers’ exposure to secondhand smoke?
The effects of secondhand smoke on nonsmokers in the U.S. costs nearly $6 billion/year
What was the result of the 1998 U.S. Federal Court hearing on the EPA classification of environmental tobacco smoke (ETS) as a carcinogen?
Judge voided much of the EPA’s smoking danger findings. He stated that the EPA had overstepped its authority and that its report on the dangers of secondhand smoke was not supported by substantial evidence.
ETS had many critics that this decision appeased, but it does not invalidate the dangers of secondhand smoke.
How many people die as a result of secondhand smoke exposure?
1 person for every 52 smokers; about one million people worldwide each year
Is ventilation an effective means of reducing the health risks of secondhand smoke?
No…
- Air handling systems circulate secondhand smoke throughout the building
- Air cleaning reduces smells but not the hazardous small particles or gases found in secondhand smoke
The only effective public health approach to ETS is banning indoor cigarette smoking.
How have cigarette smoking trends changed in the U.S. over time?
Following the advent of the factory cigarette rolling machine, smoking gradually boomed. After the 1st Surgeon General’s Report on Smoking and Health, it experienced a gradual decline.
When was the first report on secondhand smoke released to the public?
1986 Surgeon General’s Report on Secondhand Smoke
When is law and policy used as a public health approach?
Often used if education fails to achieve the intended outcome. We tend to follow the notion that we can compromise individual rights to benefit the collective good. This is the case with indoor cigarette smoking.
When was restaurant smoking banned in Madison?
In 1992, Madison adopts a plan to phase in a restaurant smoking ban. Restaurants are 100% smoke-free three years later. Second municipality to do so in the state. Bars still legal to smoke in.
Who is Ira Sharenow?
Anti-smoking activist in Madison who was a major player in the Madison indoor smoking ban in the 1990s
Who is Carol Thompson?
Anti-anti-smoker who believed that banning indoor smoking was a violation of human rights. She attacked the government and numerous other agencies in her fight for “smoking rights.”
What led to a smoking ban in bars in Madison?
Local coalition composed of UW students circulated a petition and teamed with The Smoke Free Madison Organization to push for 100% smoke-free environments in the city.
In 2004, smoking in bars was banned in Madison.
How have general trends in environmental tobacco smoke (ETS) exposure changed over time?
What is the effect of secondhand smoke on hospitality workers?
Of bartenders and waitstaff, 50% greater risk of lung cancer than the general public, 74% report respiratory symptoms.
Current big problem is casino workers.
What is an e-cigarette?
Electronic device that replicates a cigarette, cigar, or other smoking pipes; activated by inhaling the device, which activates the heating element and releases vapor
What liquid is commonly used in vapes?
Propylene glycol
What is the atomization chamber of a vape?
This is the element that heats up and vaporizes the liquid, creating vapor-like smoke. It is significant because it gives the nicotine of real tobacco but without the tars (e.g., benzo(a)pyrene).
In newer vapes, atomizer and cart are a combined “cartomizer.”
What makes the Juul special?
The primary feature of the Juul is the fact that its e-liquid contains nicotine salts extracted from leaf-based tobacco
What are the physiological effects of nicotine?
Restricts blood vessels and consequently increases blood pressure
Is vaping less harmful than smoking?
Yes, because it gives the nicotine of real tobacco but without the tars (e.g., benzo(a)pyrene), but it’s still not safe. Vapes are still associated with lung and cardiopulmonary problems.
Are there toxins/carcinogens in vapes?
The FDA indicated that there are toxic chemicals including a carcinogen known to cause cancer in humans produced by vapes.
There are also specific toxicants in cinnamon-flavored e-liquids.
In 2014 there were 215 poison center calls involving vapes, with half involving children.
Are vapes an official nicotine replacement tool?
No, according to WHO, e-cigs are not currently used for Nicotine Replacement Therapy due to lack of peer-reviewed studies
How have trends in vapes compared with trends in cigarettes?
- Number of vapes is increasing while number of cigarettes is decreasing
- Vape profit pool is increasing while cigarette profit pool is decreasing
It is thought that consumption of vapes could surpass consumption of tobacco within the next decade.
Do vapes cause health issues?
Research suggests vaping is bad for the heart and lungs, but there are many unknowns. Seems like health issues largely with THC carts.
Can vapes be smoked indoors in Madison?
No, vaping is part of the indoor smoking ban
What is the loophole in the vape flavor ban?
Disposables can have flavors, but refillables cannot
How does vaping relate to COVID-19?
Teens and young adults who vape face a much higher risk of COVID-19 than those who do not vape
How has the FDA approached vapes?
FDA denied marketing applications for millions of vaping products because they lacked sufficient evidence on the benefits for adult smokers
What is a chemical of concern in vapes?
Vitamin E Acetate, a thickening agent often used in THC vapes; found in all lung fluid samples of EVALI patients (those injured while vaping)
Are there respiratory effects of smoking marijuana?
No good epidemiology studies, but as a rule of thumb, eat a brownie or cookie, don’t smoke it. Smoking in general damages the lungs and can cause cardiovascular problems.
Vaping THC carts is associated with lung injury and heart problems.
How does marijuana affect brain development?
Using marijuana during adolescence may affect how the brain builds connections for functions like attention, memory, and learning
2 phases of breathing
- Inspiration - process of taking in air
- Expiration - process of blowing out air
5 major functions of the upper respiratory tract
- Passageway for respiration
- Receptors for smell
- Filters incoming air for larger foreign material
- Moistens air and warms incoming air
- Has resonating chambers for voice
What is the function of the nose/naval cavity?
warms, moistens, and filters air as it is inhaled
What is the function of the pharynx (throat)?
passageway for air, leads to the trachea
What is the function of the larynx?
the voice box, where vocal chords are located
What is the function of the trachea (windpipe)?
keeps the windpipe “open;” lined with fine hairs called cilia which filter air before it reaches the lungs
What is the function of the bronchi?
two branches at end of the trachea, each lead to a lung
What is the function of the bronchioles?
a network of smaller branches leading from the bronchi into the lung tissue and ultimately to air sacs
What is the function of the alveoli?
the functional respiratory units in the lung where gases (O2 and CO2) are exchanged
How does gas exchange between the blood and alveoli work?
oxygen from inhaled air diffuses into the bloodstream from alveoli, and carbon dioxide from the blood diffuses into the alveoli to be exhaled
Where are small particles deposited in the respiratory system?
Small particles make it deeper into the lungs, being deposited in the alveoli as well as the trachea and bronchi
What is asthma?
severe allergic reaction characterized by the constriction of bronchioles
What is bronchitis?
inflammation of the lining of the bronchiole
What is emphysema?
condition in which the alveoli deteriorate, causing the lungs to lose their elasticity
What is pneumonia?
condition in which the alveoli become filled with fluid, preventing the exchange of gases
What is lung cancer?
irregular and uncontrolled growth of tumors in the lung tissue
What are alveolar macrophages?
specialized immune cells in the lungs that surround foreign particles in the lungs and attempt to dissolve them; attempt to clear deposited small particles
What components of the respiratory system are responsible for the clearance of deposited particles?
- Mucociliary system (escalator)
- Alveolar macrophages
What is the mucociliary escalator?
defense mechanism of the respiratory system where cilia lining the airways move mucus, along with trapped particles and pathogens, upward toward the throat to be swallowed or expelled; attempts to clear deposited small particles
What makes asbestos “magic?”
It doesn’t burn, it’s like an eternal flame; also has very thin fibers that can be easily woven
What makes asbestos especially dangerous relative to other hazards?
It has no warning properties: no foul smell, no skin irritation, etc.
Where does asbestos come from?
thin fibers come from an ore
Why does everyone have asbestos in their lungs?
Asbestos used to be used in a multitude of things, including insulation, tiles, shingles, and even hair dryers
Why can asbestos be found everywhere in urban cities?
Demolition and construction of buildings led to asbestos pollution throughout many cities
How do we calculate asbestos disease risk?
Disease risk = exposure duration x intensity
Exposure to asbestos is defined as inhaled dust
How does asbestos cause asbestosis?
the body tries to “cover” asbestos by scarring, leading to scarring of the lungs (AKA asbestosis)
4 main asbestos related diseases
- Asbestosis
- Lung cancer
- Mesothelioma
- Tumors
How have asbestosis deaths trended over time?
Starting in 1968, asbestosis deaths gradually increased
What is malignant mesothelioma of the pleura?
a rare and aggressive cancer primarily caused by asbestos exposure, affecting the thin tissue layer (pleura) lining the lungs
What is adenocarcinoma of the lung?
type of non-small cell lung cancer that originates in the mucus-producing glandular cells of the lung; caused by asbestos exposure
How does asbestos exposure correlate with mesothelioma prevalence?
How does asbestos affect insulation workers?
Among 17,800 asbestos insulation workers, actual deaths (1008) exceeded expected deaths (268.68)
If we know that asbestos is bad and causes many illnesses, why are workers still getting sick?
- Prisoners of the past
- latency period - Unstudied problems
How does asbestos exposure affect family members?
35% of family members of asbestos workers had asbestos-related abnormalities; household exposure and neighborhood exposure are both risks
What is the Libby, MT Vermiculite Ore situation?
An ore contaminated with asbestiform minerals was processed by 300 U.S. facilities, releasing tons of particulate matter in 1988
What is the chief source of mercury?
mineral cinnabar, HgS, but it sometimes occurs in nature as a free metal
Describe mercury (Hg) as an element
Heavy, silver-gray, metallic element, atomic number 80, relative atomic mass 200.59
Dense, mobile liquid with low melting point
AKA “inorganic” and “quicksilver”
Why is mercury inhalation dangerous?
Inhalation route gives higher exposure
How does mercury enter the environment?
- Occurs naturally in soil and atmosphere from volcanic emissions
- Extracted and used in industry, then enters air or water from pollution
- Formerly in some medications, causing direct exposure
How was mercury used with regard to syphilis?
rubbed on syphilis sores to cure syphilis, but left those treated with nasty side effects
How does mercury relate to Ancient Egypt?
Mercury was found in mummies; possibly because doctors trying to administer mercury as treatment in end-of-life care
How does mercury relate to dental fillings?
Mercury + silver is used in many amalgams (dental fillings). The dose is high in mouth, but low to the body. There is a real scientific controversy in this regard.
How did mercury help coin the term “Mad as a Hatter?”
Mercury was used in making black felt hats, and the people making the hats were called crazy, likely due to mercury poisoning
What occupations have a historical connection to mercury exposure?
- Gold mining
- Felt industry
- “Mad as a Hatter”
Inorganic vs. Organic Mercury
Inorganic:
Hg, Quick Silver, elemental
Organic:
HgCH3, Methylmercury (MeHg)
Why is methylmercury especially dangerous?
Methylmercury (organic) is far more toxic than other forms and is well absorbed when ingested
How is methylmercury content measured?
blood and hair
What is the Minamata Bay, Japan, mercury incident?
In 1953 in Minamata Bay, there was an outbreak of Polio-like disease among coastal fishing villages. At this same time, there was a startup of acetaldehyde production at a coastal factory using mercuric oxide as a catalyst.
Stray cats went crazy after eating fish, and years later in 1968, mercury diagnosed as cause of 2,000 disease victims.
Led to coining of “Minamata Disease.”
4 ways Minamata disease affected infants
- Mental retardation
- Abnormal reflexes, ataxia, involuntary movements
- Cerebral palsy
- Developmental delays - some didn’t walk until age 7
How did Minamata disease affect adults?
- Parasthesia - “pins and needles”
- Cerebellar atacia, tremors
- Constriction of visual fields and loss of smell
- Loss of hearing, dizziness, insomnia
- Dysarthria - speech disorder
- Cognitive impairments
How are humans exposed to mercury through fish (biotransformation and bioaccumulation)?
- Inorganic mercury (Hg) is biotransformed to methylmercury (MeHg) by bacteria
- Bacteria are eaten by mollusks, crustaceans, etc.
- Methylmercury is poorly eliminated so it concentrates up the food chain and is bioaccumulated by a number of species, including fish. The biggest and oldest predators at the top of the food chain have highest MeHg levels
- Methylmercury is evenly distributed throughout the fish and is not changed by cooking
What is the Iraq mercury incident, and how did it occur?
- Mercury compounds can be applied to seed grain as an antifungal agent. Instead of planting it, Iraqis made bread directly from the seed grain.
- Warning labels were in English (uncomprehendable to them) and the skull and crossbones poison label has no meaning in the Arab world. Red dye was also added as a warning, but Iraqis washed it out thinking it was then safe.
What are the neurobehavioral effects of methylmercury poisoning?
- Blindness and deafness
- Cerebral palsy
- Abnormal reflexes
- Retarded motor development
4 main effects of methylmercury on the brain
- Decrease in brain size
- Cell loss
- Disorganization of cells
- Cell migration failures
How does methylmercury poisoning affect the fetus?
Birth defects may be due to brief exposure during critical periods of fetal development; affected fetuses may spontaneously abort
However, relationship between exposure and outcome is difficult to establish
5 major environmental sources of mercury
- Natural degassing of the earth
- Combustion of fossil fuel
- Industrial discharges and wastes
- Incineration and crematories
- Dental amalgams
How do coal fired plants relate to mercury emissions?
Coal fired plants are one of the prominent sources of mercury emissions
How can gold mining cause mercury poisoning?
- Sediments of a river are run through sluice boxes with mercury in them.
- The gold sticks to the mercury and then the mercury-gold goop is cooked over a fire to drive off the mercury, causing the mercury to go to the water and air
This is a problem in the Amazon, causing children to have altered vision
What is the main source of environmental mercury release?
50-75% of mercury released in the environment relates to human activities, though there is lots of mercury in the soil from millions of years ago
Describe the Chippewa Indian mercury study
- Chippewa Indian spearfishers thought they were poisoning themselves via their fish consumption
- Indians were randomly sampled and/or volunteered, and blood was drawn to assess methylmercury levels.
- Participants were also surveyed on fish consumption.
- Found very low blood mercury levels in Chippewa Indians, but it was still higher than white fishing guides after Chippewa yearly spearfishing
Conclusions: Mercury levels in the Chippewa are directly related to fish consumption, but current mercury levels are below the levels with known health effects. No changes to current practices recommended.
Describe the three large prospective cohort studies of fish consumption and mercury toxicity
- Study in The Seychelles found no adverse neurologic effects on offspring related to level of mercury exposure
- Study in the Faroe Islands found that some adverse outcomes correlate with degree of mercury exposure (and PCB exposure)
- Study in New Zealand found that abnormalities in newborn exams correlated with high maternal mercury levels
Therefore, 2 of 3 studies found abnormalities correlated with mercury levels
What fish have high/low methylmercury levels?
High:
Levels are higher in long-lived predator fish and some fish may have higher levels based on regional environmental pollution
Low:
- Small fish, mollusks, and crustaceans have low levels unless in polluted waters
- Ocean fish usually “cleaner” than lake fish
- Fish that are NOT predators
- Salmon
What current mercury fishing advisories exist?
In 2000, 41 states have over 2000 fish consumption advisories. In general, pregnant women, nursing mothers, women who intend to have children, and children under 15 should be wary.
What is the “fine line” of fish consumption?
Fish are a rich source of protein and omega 3 fatty acids, BUT have to weigh adverse effects of mercury and PCB contaminated fish
What are the methylmercury (MeHg) consumption limits?
- US EPA - 0.1 ug/kg per day
- US FDA - 0.5 ug/kg per day
According to no observed adverse effect level (NOAEL) studies, the consumption limit should actually be 0.025 ug/kg per day
How does mercury relate to heart attacks?
One study found higher mercury in men who had heart attacks vs. controls.
Another review of studies links methylmercury to heart attacks
Can vaccines containing thimerosal (ethyl mercury) cause autism?
Science studies say no
What was the Wakefield Lancet 1998 MMR study?
Infamous, unethical study of 12 children with faked data. NO evidence that MMR vaccine leads to autism, but his false study started the “anti-vaccine” movement
What are the primary and secondary goals of the National Ambient Air Quality Standards (NAAQS)?
Primary: to prevent human health effects
Secondary: to prevent welfare (materials, plants, animals) effects
What did the U.S. EPA 1970 Clean Air Act do?
Implemented the National Ambient Air Quality Standards (NAAQS)
What are “criteria pollutants?”
Exact same thing as NAAQS; ambient standards established by the U.S. EPA and reviewed every 5 years
6 main NAAQS/criteria pollutants
- Particulate matter
- Ozone
- NOx
- SO2
- CO
- Lead (Pb)
What is the dominant source of air emissions?
Coal-fired power plants generate the vast majority of emissions:
95% of SO2
90% of NOx
83% of CO2
What is sulfur dioxide SO2?
Sulfur oxide that is prevalent in fossil fuels; 65% of SO2 emissions in the U.S. are from electric utilities (coal burning)
What is “clean” coal?
Coal that has sulfur oxides and carbon dioxide removed to reduce pollution
How is nitrogen dioxide NO2 formed?
Clean air is 80% nitrogen, and this nitrogen combines with oxygen to make NO2; NO2 is a major emission of coal-fired power plants
Is carbon dioxide CO2 a NAAQS/criteria pollutant?
No
How is acid rain formed?
SO2 and NOx from burning coal combine with oxygen multiple times (SO3, NO3), which combines with water vapor to produce sulfuric acid and nitric acid (acid rain) and even ammonium sulfate.
What are other (not coal-fired plants) sources of sulfur dioxide SO2?
- Industrial facilities that derive their products from raw materials like metallic ore, coal, and crude oil, or that burn coal to produce process heat
- Trains, large ships, nonroad diesel equipment
2 main problems with sulfur dioxide SO2
- Contributes to respiratory illness, particularly in children and the elderly, and aggravates existing heart and lung diseases. Harmful to those with asthma.
- Contributes to the formation of acid rain, which damages trees, crops, historic buildings, and makes soils, lakes, and streams acidic
Can sulfur dioxide SO2 travel long distances?
Yes, SO2 can be transported over long distances, which is why we have seen acid rain in areas lacking a large number of coal-fired plants or other proponents of acid rain
How are sulfates formed?
SO2 + H2O = SO3 + SO4
Sulfur dioxide emissions combine with water vapor in the air
Can acid aerosols (sulfates and nitrates) travel long distances?
Yes, sulfates (SO3) and nitrates (NO3) can be transported over long distances, which is why we have seen acid rain in areas lacking a large number of coal-fired plants or other proponents of acid rain
Why is “the solution to pollution is dilution” an incorrect statement with regard to acid rain?
E.g., increasing chimney heights thought to disperse pollution, but really just led to international acid rain.
Chimneys are some of the tallest human-made structures, accentuating this acid rain issue.
What is “clean rain?”
Rain with a pH of at least 5.6. Rain with a pH below this is acid rain
2 ways acid rain affects lakes
- Acid rain lowers the pH of lakes, and leaching into soil can harm ecosystems
- Acid rain has killed off many species living in lakes, leading to “dead lakes.” This is because most species thrive at ~pH = 7, not acidic pH levels
How does acid rain affect buildings/monuments?
Acid rain has damaged many historical structures and monuments, for sulfur oxide decays building materials, including stone; i.e., by burning coal, we are destroying our heritage
How does acid rain affect agriculture?
Acid rain is extremely harmful to crops, resulting in a major financial burden and loss of food
What is unique about sulfur dioxide SO2 with regard to other pollutants in this class?
SO2 is the one pollutant in this course that doesn’t go deep into the lungs because it is water soluble. Instead, it is absorbed in the upper respiratory tract.
This is not to say it has no health effects, as it irritates existing conditions, especially asthma.
SO2 in upper tract + particulates in lower tract (alveoli) is a harmful combination
Why is quantifying particulate exposure important?
Particulate exposure is one of the most important factors in determining lifespan. A Buffalo study found that higher particulate exposure correlated with higher deaths
What are the health effects of sulfur dioxide SO2?
Contributes to respiratory illness, particularly in children and the elderly, and aggravates existing heart and lung diseases (long term exposure).
People with asthma are particularly affected by peak levels of SO2 (short term exposure).
What are sulfate particles, and what are their respiratory effects?
Sulfate particles are formed from SO2 reacting with other chemicals in the air and are associated with severe respiratory illness, including difficulty breathing and premature death.
Particulate exposure is one of the most important factors in determining lifespan.
What is the Harvard Six-Cities Study?
30 year study investigating the health effects of air pollution across six U.S. cities. It found a significant correlation between fine particulate matter and increased mortality. The study greatly influenced stricter U.S. air quality regulations.
How have wildfires posed a major health problem?
Because of climate change, wildfires have become increasingly prevalent, tainting the air with small particulates
How have sulfur dioxide (SO2) and NOx emissions changed over time, and why?
Steadily decreased over time across all industries, including power plants. This is largely due to acid rain programs and the implementation of preventative measures such as the scrubber.
What is a scrubber?
Preventative measure used in coal-fired power plants and other industries to remove SO2 from exhaust gases. It produces pH-neutral calcium sulphate that can be removed from the scrubber.
How has the U.S. approached the acid rain issue?
NAAQS dictated that power plants must clean up their act to reduce sulfur oxides, and this legislation has been successful as a result of preventative measures such as the scrubber. We have experienced major progress with regard to acid rain as a result of acid rain programs.
All in all, acid rain has largely been controlled by the Clean Air Act (cap and trade between utilities, lowering total amount that reaches Canada)
What is cap and trade?
Environmental policy tool designed to control and reduce pollution by providing economic incentives; this was implemented by the NAAQS of the Clean Air Act, greatly reducing acid rain by putting a “cap” on number of emitted pollutants and allowing for “trade” with other industries to ensure limits are not exceeded.
3 eras of air pollution and death epidemiology
- 1950s-1970: Urban Rural Effect
- 1980-1995: Particles less than 10 microns led to increased respiratory deaths
- 1995-today: Particles less than 25 microns and soot lead to further increased deaths including heart disease
5 major ambient air carcinogens
- Particulate matter
- Asbestos
- Certain VOCs - benzene, carbon tetrachloride, chloroform, vinyl chloride
- Aliphatic hydrocarbons
- Radon
What are polycyclic aromatic hydrocarbons (PAHs)?
Group of organic compounds that consist of multiple aromatic rings and persist in the environment; an example is benzo(a)pyrene
What is benzo(a)pyrene (BAP)?
A polycyclic aromatic hydrocarbon (PAH) that is the main carcinogen of cigarettes and is also found in the ambient air from burning fossil fuels and some occupational settings (coke oven in steel industry; specifically top side):
Top side of coke oven —> cancer, bottom side —> no cancer
Is also emitted by diesel vehicles. Black smoke = bad smoke
Explain the relationship between soot and scrotum cancer
In 1776 it was noticed that many were developing scrotum cancer in chimney sweeps. It was confirmed that soot exposure led to scrotum cancer by using rabbit and mouse skin.
Who is exposed to the greatest levels of benzo(a)pyrene?
Those in urban areas, likely due to emissions from automobiles
Why are diesel vehicles so problematic?
They emit:
1. Benzo(a)pyrene
2. Nearly half of all nitrogen oxides
3. 2/3 of all particulate emissions
This is largely a diesel problem. Black smoke = highly toxic
Why was the catalytic converter necessary for emissions?
Because automobiles (mainly diesel) emit many toxic pollutants, including benzo(a)pyrene, nitrogen oxides, and small particulates
What is the Urban-Rural Effect?
There are higher lung cancer rates in urban environments>suburban environments>rural areas
Increasing lung cancer rates with population density.
Likely due to fact that U.S. transportation sources emit a large number of pollutants.
What is particulate matter composed of?
A complex mixture of extremely small particles and liquid droplets
Does air pollution kill?
Yes, panel found that diseases caused by pollution were responsible for 9 million premature deaths, 16% of all global deaths
What is the “paradox” of ozone?
Ozone in the stratosphere protects human health and the enviornment, but ground level ozone (tropospheric ozone) is a harmful pollutant to human health
What is the troposphere?
The lowest layer of Earth’s atmosphere; most of the mass of the atmosphere is here, and almost all weather occurs here.
Tropospheric ozone is dangerous ozone
What is “good” ozone?
Stratospheric ozone, or ozone that is located 10-30 miles above the earth’s surface, away from the troposphere.
This ozone protects the planet from harmful UV radiation
2 types of UV that are proven to contribute to the risk for skin cancer
- UVA - has longer wavelength and is associated with skin aging
- UVB - has shorter wavelength and is associated with skin burning
When did the ozone hole appear, and where is it located?
First appeared in the early 1980s above the South Pole; it begins to develop each August, fully developed by October, and is broken up in early December
What is the Dobson?
Unit of measurement for ozone
Example: “Average” UV amount is about 300 Dobsons
4 main negative effects of UV radiation on health
- Skin cancer
- Eye cataracts
- Reduced immune response
- Increased skin aging & keratoses
Non-melanoma vs. malignant melanoma skin cancers
Non-melanoma skin cancers: not normally fatal, but treatment can be costly, painful, and disfiguring
Malignant melanoma skin cancer: far less common, but the major cause of death from skin cancer
What is the major environmental risk factor in skin cancers?
Solar UVB exposure
Who in the U.S. is primarily affected by skin cancer?
The Southeast
What would be the effect of decreasing the amount of ozone in the stratosphere by just 10%?
Could cause an estimated 300,000 extra non-melanoma skin cancers, 4,500 extra melanoma cancers, and 1.6-1.75 million extra eye cataracts, worldwide, every year
How does UV exposure affect the marine food chain and fish stocks?
- UV can damage early developmental stages of fish, shrimp, marine mammals, and other organisms
- Higher UV reduces production of phytoplankton (primary element in food chains in oceans), reducing fish stocks
How does UV exposure affect plants and forests?
UV can alter plant development, plant diseases, how nutrients are distributed, and biogeochemical cycles
How does UV exposure affect outdoor materials?
- UV degrades many materials used outdoors, reducing their useful lifetimes (e.g., some plastics, rubber, textiles, wood products)
- Chemical additives can make materials somewhat resistant to UV, but increased UV reduces product lifetimes, bringing greater costs
What caused the ozone hole to develop?
Chlorofluorocarbons; the ozone hole is man-made
CFCs react with UV to generate free Cl, and it is this free Cl that damages the ozone layer
What are chlorofluorocarbons?
Cl + F + C
They do not directly harm health, but they destroy stratospheric ozone, which is why the ozone hole formed
6 examples of ozone-depleting substances (ODS)
- Chlorofluorocarbons (CFCs) - refrigerants, solvents, medical sterilants, foam
- Hydrochlorofluorocarbons (HCFCs) - refrigerants, propellants, foam
- Other halocarbons - refrigerants, propellants
- Halons - fire suppression
- Methyl chloroform, carbon tetrachloride - chemical processing, solvents
- Methyl bromide - fumigant, produce and soil sterilant
What is the Montreal Protocol?
1987 treaty that enacted many methods to reduce the production and emission of ozone depleting chemicals; it controls 96 ozone-depleting substances, including CFCs and HCFCs
How has global ozone changed over time?
How do ozone-depleting substances (ODS) relate to greenhouse gases?
Many ODS are greenhouse gases, with Global Warming Potentials varying from small to large (CFCs large)
What are some impediments to ozone recovery?
The ozone layer remains vulnerable for a long time:
- long lifetime of many ODS
- cold weather as catalyst for action of Cl and Br
- HCFCs still produced
- Volcanic eruption could deplete ozone
The recovery of the ozone layer depends on full compliance with the Montreal Protocol’s restrictions on ODS, if not it would delay, or even prevent, the ozone layer’s recovery.
How does ground level ozone (tropospheric ozone) form?
Volatile Organic Compounds (VOCs) + Nitrogen oxides (NOx) + sunlight = ground level ozone
VOCs come primarily from cars and industrial sources.
NOx comes from automobiles, trucks, buses, and power plants.
When is tropospheric ozone pollution primarily a concern?
During the summer months when the weather conditions to form it normally occur (i.e., lots of sun, which is an “ingredient” for ozone); ground level ozone is low in the winter
4 main health effects of ground level (tropospheric) ozone?
- “Sunburns” the lungs, may cause permanent lung damage; particularly harmful for people with asthma, as inhaling ozone can trigger an asthma attack
- Most common symptom is pain from taking a deep breath
- Long term exposure may lead to premature aging of the lungs
- Causes eye irritation
What are volatile organic compounds (VOCs)?
A primary component of ground level ozone that both forms naturally and comes from gasoline (cars), paint, solvents, pesticides, and lighter fluid
Who is at risk for ozone poisoning?
- Elderly
- Children
- Adults who are active outdoors
- People with respiratory diseases
How did reducing traffic during the 1996 Olympics affect those with asthma?
40% decrease in amount of asthma attacks due to less vehicles on the road; this is hypothesized to be a result of less VOCs and consequently less ground level ozone
How does ground level ozone affect plants?
Attacks cells and modifies proteins, leading to cell breakdown and collapse; also bleaches and kills leaves
How can we avoid and prevent ground level ozone?
- Check local air quality forecast
- limit physical exertion outdoors in afternoon and early evening - On ozone action days…
- conserve energy
- avoid driving or filling up tank
- avoid using lawn mower or other two-stroke powered equipment
How many people are killed by ground level ozone?
Best estimate is 282k to 362k cardiopulmonary mortalities annually
How many people are killed by particulate matter?
Best estimate is 1.3 to 2.4 million cardiopulmonary and lung cancer mortalities annually
What is the Lake Michigan Ozone Study?
Study that found that high ozone levels may be far from the source, meaning ground level ozone can travel far distances
Why were the Clean Air Act Amendments of 1990 significant with regard to ozone?
Introduced ozone control strategies similar to the Montreal Protocol; sought to control industrial precursor emissions and automotive precursor emissions. Precursor emissions being VOCs and NOx.
Introduced reformulated gasoline as part of these efforts.
What is methyl tertiary butyl ether (MTBE)?
Part of “reformulated gasoline” from the 1990 Clean Air Act. It is a suspected carcinogen, leading to reformulated gasoline being phased out. There is debate over whether it actually caused health effects or whether public response was due to hysteria via media.
Was MTBE causing health effects as part of reformulated gasoline?
According to some surveys, it would seem so; however, likely an example of media influencing hysteria.
Conclusions were that exposure to reformulated gas fumes is not associated with serious, acute health effects.
Explain MTBE and water contamination
Santa Monica and other sites indicated widespread MTBE presence in groundwater wells; EPA recommended decreased MTBE use
What is TSP?
Total Suspended Particulate Matter, or the sum of all particles with diameters less than 50 micrometers
What is PM10?
Particulate matter with aerodynamic diameters less than 10 micrometers; mechanically generated from soil debris, tiling, construction, or road dust
What is PM2.5?
Particulate matter with aerodynamic diameters less than 2.5 micrometers; fine particles that are combustion generated
These are secondary particles.
What are ultrafine particles?
Particulate matter with diameters less than 50nm; combustion generated, not much else is known about these
What is primary particulate matter?
Particles directly emitted into the atmosphere from air pollution sources, such as motor vehicles, food cooking, wood burning
What is secondary particulate matter?
Particles that are formed in the atmosphere by gas-phase chemical reactions that form condensable products, such as sulfate, nitrate, or secondary organic compounds
What is natural particulate matter?
Particles from natural source that is not impacted by human activity, such as sea spray, wind blown dust, forest fires, etc.
What is anthropogenic particulate matter?
Particles resulting from human activity, such as from motor vehicles, wood burning, tiling, etc.
How does particulate matter affect visibility?
High PM can make it extremely difficult to see (think China)
How does particulate matter affect materials?
PM deposits itself on many historical building and structures, often damaging the material. An example is the discoloration of the Taj Mahal.
How does particulate matter affect the ecosystem?
“Ozone injury” is when plants essentially become bleached. This leads to death of leaves. There are no known controls for ozone injury.
How does particulate matter relate to climate change?
PM is not evenly distributed across the earth, so it forms heating and cooling zones that impact the environment
Why is clean air important from a business standpoint?
Clean air attracts international investment; many agencies such as Forbes rank cities on how “toxic” or polluted they are, and these rankings influence investment and location decisions by major firms
2 biological pathways for air pollution impacts
- Local inflammation - can lead to asthma, COPD, fibrosis, or cancer
- Systemic inflammation - can lead to atherosclerosis, heart attack, or stroke
Which disease has the strongest environmental contribution?
Stroke; 42% environmental contribution
What is the pathway for particulate matter injury?
Unlikely that same components and sources impact all pathways on injury, but oxidative stress is an important pathway for many impacts
Describe the Milwaukee PM2.5 Example
Milwaukee was found to be in compliance with US EPA standards for PM2.5 as the result of a decrease in the frequency of 24 hour exceedances
How are roadway emissions problematic?
Large number of studies show adverse health effects associated with distance to roadways; roadway emissions come from tailpipe emissions, tire wear, and brake wear
Describe the lung transplantation road traffic pollution study
Study found that those with transplanted lungs who live closer to a roadway have a significantly decreased survival rate
Why is particulate matter in Lahore, Pakistan more dangerous than in the U.S.?
Particle concentration and biological activity both much higher; more toxic components w/ lack of government regulations
How does indoor air pollution affect blood pressure?
In China, found that high levels of pollution lead to a significant increase in blood pressure for women over 50; small/no effect for younger women
When was radioactivity discovered, and who discovered it?
February 24, 1896 by Antoine Henry Becquerel
Who coined the term “radioactivity,” and how?
Marie Curie…
1. Discovered that if you have a certain amount of uranium, you get a certain amount of ray intensity no matter what you did to the material
2. Discovered there was something going on inside the atom that created the rays and named this effect “radioactivity”
What were the discoveries of Marie Curie?
- Coined the term “radioactivity” by discovering that if you have a certain amount of uranium, you get a certain amount of ray intensity no matter what you did to the material
- Discovered that the only known elements that were radioactive were uranium and thorium
- Extracted Polonium for the first time
- Discovered Radium (most famous discovery)
- Found that radium gave out heat and light and can damage living flesh
What are the properties of radium?
Silver-white in color, used in small amounts as a cancer treatment and in fluorescent paint
What awards did Marie Curie receive?
- Nobel Prize in physics in 1903 for her work with X-rays
- Nobel Prize in chemistry in 1911 for her work with radium
4 types of ionizing radiation
Particulate:
1. Alpha
2. Beta
Electromagentic:
1. Gamma
2. X-Ray
Alpha particles vs. beta particles
Alpha particles are positively charged particles that are made up of two neutrons and two protons bound together (identical to a helium nucleus); they are slow moving and are the least penetrating
Beta particles are high speed electrons from the nucleus that are not very penetrating
What is alpha decay?
Type of ionizing radiation that involves the emission of an alpha particle (a helium nucleus)
What is beta decay?
Type of ionizing radiation that involves the conversion of a neutron to a proton and electron, and subsequent electron ejection
I.e., loss of a beta particle
What is radioactivity?
Spontaneous emission of particles/energy from unstable nuclei; discovered by Antoine Henry Becquerel and coined by Marie Curie
What are gamma rays?
Not particles, but a type of radiation that is very similar to light rays; easily penetrate human tissue
What does the Curie (Ci) measure?
Activity; rate of radioactive decay in a given sample of radioactive material
Becquerel (Bq) also measures this
What does the becquerel (Bq) measure?
Activity; rate of radioactive decay in a given sample of radioactive material
Curie (Ci) also measures this
What does the rad unit measure?
Energy absorbed in material exposed to radiation
Gray (Gy) also measures this
What does the gray (Gy) measure?
Energy absorbed in material exposed to radiation
Rad also measures this
What does the rem unit measure?
Radiation dose in terms of its biological effect
Sievert (Sv) also measures this
What does the sievert (Sv) measure?
Radiation dose in terms of its biological effect
Rem also measures this
Is fusion real?
As of now, fusion is science fiction
How is electric power generated by an electric plant?
- Fuel boils water
- Steam drives turbine
- Turbine drives generator
- Transformer boosts voltage
How is nuclear power generated by a nuclear power plant?
Essentially a controlled nuclear chain reaction
What did Fermi/Szilard do in 1942?
Harnessed the first self sustaining nuclear chain reaction at a Racquetball court below Stagg Field; this event served as the forerunner of nuclear power/weapons
What is the role of graphite control rods in a nuclear power plant?
Graphite control rods act as a moderator and coolant for the reaction
What is a liquid metal fastbreeder reactor (LMFBR)?
A nuclear reactor that converts Uranium238 —> Plutonium239
4 potential dangers of nuclear plants
- Radiation leaks to air and water
- China Syndrome (meltdown where reactor components melt through the earth)
- Potential for big explosion w/ lots of radiation release
- Nuclear fuel reprocessing, waste disposal, and long term storage are issues
Describe salt mine waste disposal
Refers to the disposal of radioactive waste from nuclear plants in salt mines
How is nuclear fuel reprocessed?
- Unfissioned, reusable U-235 is separated from the waste
- K-85 to air, H-3 (tritium) to water
Do nuclear power plants pose a risk to human health?
Not really; the frequency of nuclear plant accidents is extremely low, especially relative to other accidents
How did the nuclear power industry change around the time of the Three Mile Island incident?
Initially there was a nuclear power “boom,” with many orders for reactors. Following Three Mile, however, many plants decommissioned, cancelling their orders.
How much of the sources of exposure to ionizing radiation is man-made?
About 18% and primarily medical
What is the greatest source of exposure to ionizing radiation?
Radon comprises about half of all exposure sources; man-made is about 18% (primarily medical)
What is the half-life of radon?
3.85 days
How is radioactive exposure applicable to flying in planes?
We are exposed to cosmic radiation while flying
How is radioactive exposure related to buildings?
Many building materials contain detectable levels of radiation
How is radioactive exposure related to coal mining?
Coal often contains uranium and thorium
Can food be a source of radioactive exposure?
Yes, but radiation levels are low except in Brazil Nuts, which are concerningly radioactive
3 factors that influence the biological effects of radiation
- Type and energy of radiation
- Critical organ effected (Thyroid mainly)
- Biological half-life
2 types of health effects of ionizing radiation
- Deterministic (nonstochastic) - effect is guaranteed to occur
- e.g., Acute Radiation Syndrome - Probablistic (stochastic) - may or may not occur; difficult to predict at individual level, but effects clear at population level
- e.g., cancer after radiation exposure
What is the nonstochastic (definitely will happen) biological effect of ionizing radiation?
Acute Radiation Syndrome
Describe the sequence of events after harmful levels of radiation exposure
- Physical effect - ionization
- Chemical effect
- Biological effect - cell death, mutation, cancer, germ cell impact, organism death
3 principal long-term hazards of ionizing radiation
- Genetic effects
- Carcinogenic effects
- Effects on the developing embryo/fetus
How does radium relate to bone cancer?
There is a dose-response between amount of radium exposure and number of bone cancer cases
4 stages of nuclear bomb detonation
- Blast - flattens everything
- Fireball
- Electromagnetic pulse
- Radiation
Describe the Atomic Bomb Casualty Commission Study of Atomic Bomb Survivors
87,000 A-bomb survivors followed…7,800 cancer deaths observed vs. 7,400 expected; therefore, 400 excess cancers
How was the Hiroshima atomic bomb a “dirty bomb?”
It contained 20% neutrons (vs. 2% in Nagasaki), making its radiation more harmful
What was the impact of the Hiroshima and Nagasaki atomic bombs on cancer rates?
An instant spike in leukemia was observed, and other cancers began to increase in prevalence years later
What is microcephaly?
A severe birth defect that was prominent in Hiroshima as a result of radiation from the atomic bomb
How did in-utero radiation exposure affect A-bomb survivors?
Often led to microcephaly, a severe birth defect; there was a 40% risk of being mentally retarded if exposed to radiation in-utero
2 factors influencing probability of teratogenic effects after radiation exposure
- Dose to embryo/fetus
- Stage of gestation at time of exposure
What are the teratogenic risks following radiation exposure?
Moderate doses of radiation can produce catastrophic effects on the developing embryo and fetus, namely microcephaly and mental retardation
What are the death estimates of Chernobyl?
32,000 total deaths
How did Chernobyl impact neighboring countries?
Winds carried radioactive cloud from Chernobyl; this is how other countries realized a disaster had occurred
How does Chernobyl relate to thyroid cancer?
First reports of an increase in thyroid cancer came in 1990, particularly among children
What were the health effects of Chernobyl?
- Only proven radiobiological effect on health of the population around the plant has been increase in thyroid cancer in those exposed as children
- One report suggests that the most serious health effect of the accident was psychological, not physical
What do recent findings on Chernobyl reveal?
29 years later, recent findings suggest:
1. An increase of leukemia risk among Chernobyl liquidators
2. An increase in the incidence of pre-menopausal breast cancer
3. Possible low-dose effects on risk of cataracts and cardiovascular diseases
What are “downwinders?”
Soldiers that stood away from nuclear blast tests to see the effects…this led to 17,000 cancer cases in the U.S. alone
What are the health effects of U.S. above-ground nuclear tests?
1977 - Leukemia doubled is exposed soldiers
1978 - Utah children 2x leukemia
1962 - Strontium-90 build up in the food chain, creating radioactive milk
How did U.S. above-ground nuclear testing affect the entire U.S. population?
Winds carried radiation to every continental state
What is the “most polluted site in the U.S.,” and why is it dubbed this?
Hanford Atomic Facilities in Washington; this was a lab that generated fuel for nuclear reactors and bombs and had many leaks
One study found that workers who got cancer had higher film badge doses than control workers
Who discovered X-rays?
W.C. Rontgen in 1895; the first x-ray image ever taken was of his wife’s hand, and she ended up getting bone cancer and dying
What is the hierarchy of radiation risks?
Teratogenic risks orders or magnitude larger than carcinogenic risks orders of magnitude larger than hereditary risks
Does radiation lead to genetic mutations?
Radiation does not produce new, unique mutations, but simply increases the incidence of the same mutations that occur spontaneously
Are there heritable effects of the A-bomb attacks?
Children of the survivors of A-bomb attacks have been studied for:
1. Untoward pregnancy outcomes
2. Death of live-born children
3. Sex chromosome abnormalities
4. Electrophoretic variants of blood proteins
…but no statistically significant effects have been observed
3 principal effects of radiation on the developing embryo/fetus
- Growth retardation
- Embryonic, neonatal, or fetal death
- Congenital malformations and functional impairment, such as mental retardation
What are the “worst” pollutants covered in class so far?
Small particulates and ozone —> solely because they are the hardest to control
Who gave the lecture on particulate matter?
Dr. James J. Schauer
Who gave the lecture on asbestos?
Dr. Henry Anderson
Who gave the lecture on the lungs?
Dr. Do Pico
Who gave the lecture on cigarette smoking?
Dr. Patrick Remington
What was the Fukushima nuclear accident?
Following a massive earthquake and subsequent tsunami in March 2011, the Fukushima Daiichi Nuclear Power Plant in Japan suffered major damage, leading to the meltdown of three of its six reactors. The incident released radioactive materials, making it the most severe nuclear accident since the Chernobyl disaster in 1986.
