Chapter 8: Environmental Health and Toxicology Flashcards
Who are the WHO?
World Health Organization
What are the factors that can contribute to disease?
Poor diet and nutrition Infectious agents Toxic substances Genetics Trauma Stress
What is the difference between morbidity and mortality?
Morbidity means illness while mortality
means death
What person and what book started the environmental health movement?
Rachel Carson with Silent Spring
What percentage of all deaths are due to chronic diseases?
60%
What disease does WHO predict will be the number one disease in 2020?
Heart disease
What are pathogens and what are some examples of some?
Pathogens are disease-causing agents
Ex. viruses, bacteria, protozoans (single-celled organisms),
parasitic worms and flukes.
What was the greatest cause of death in 1918?
An influenza pandemic
What are emergent diseases and what are some examples?
Those diseases previously unknown or not seen within the past 20 years.
Ex. Ebola, Marburg fever, West Nile Virus
What are ecological diseases and what are some examples?
Sudden widespread epidemics experienced by domestic animals and wildlife.
Ex. Ebola, Chronic Wasting Disease (CWD), and TSE related to mad cow disease
What is Conservation Medicine?
studies how environmental changes affect our health and natural communities we depend on for ecological services.
What is Toxicology?
The study of toxins or poisons
What are the top four most toxic and hazardous chemicals?
Arsenic
Lead
Mercury
Vinyl chloride
What are Allergens?
Substances that trigger an immune response (activates the immune system).
What is Sick Building Syndrome?
Environmental triggers cause immune system health concerns.
What are Endocrine Disrupters?
Chemicals that disrupt normal hormone functions.
What are Neurotoxins?
Special class of metabolic poisons that attach nerve cells (neurons).
What are Mutagens?
Substances that induce mutations (the altering of DNA), chemicals and radiation are sources.
What are Teratogens?
Substances that induce birth defects.
Ex. Alcohol (fetal alcohol syndrome).
What are Carcinogens?
Substances that cause cancer.
What are toxicity amounts dependent on?
Route of entry
Timing of exposure
Sensitivity of the organism
What is Sick Building Syndrome?
Environmental triggers cause immune system health concerns
Who tends to be the most susceptible to contract toxins?
Young children and the elderly
How are airborne toxins absorbed?
Can be breathed in and are generally the most hazardous, causing the most ill effects.
What things are important for determining how toxic a chemical is?
How a substance is delivered, at what rate, through what route of entry and in what medium
What is bioaccumulation?
The selective absorption and concentration of molecules by cells.
What is biomagnification?
increase in concentration of certain stable chemicals in successively higher trophic levels of a food chain or food web
Example: Mercury biomagnification
What are POP’s?
Persistent Organic Pollutants;
They accumulate in food webs and can reach toxic concentrations in long-living organisms (humans, raptors, sharks, bears, etc.).
What are the most dangerous POP’s?
PBDE (polybrominated diphenyl ethers):
flame retarding chemicals, now banned in Europe
PFOS (perfluorooctane sulfonate) and C8 :
chemicals used for non-stick and stain-resistant surfaces
What are phthalates?
Found in cosmetics, deodorants, and plastics
What is perchlorate?
A waterborne contaminant found in propellants and rocket fuel
What a Bisphenol A (BPA)?
Prime ingredient in many plastics, it is an environmental estrogen
What is atrazine?
Most widely used herbicide in America
What is a body burden?
Name given to persistent toxins that have accumulated in our bodies
What is synergism?
Interaction in which one substance exacerbates the effects of another.
Ex. Smoking increases potential rate of lung cancer
What is a toxin?
Even in dilute concentrations; poisonous chemicals that react to kill cells or alter normal growth and development.
What is a poison?
Any substance that can cause severe distress or death if ingested, breathed in, or absorbed through the skin.
What is a fundamental concept of toxicology?
Any material can become poisonous under some conditions, but most materials have a safe level. Most toxins can be broken down over time. (POPs do not deteriorate)
What do enzymes do?
Process waste products to reduce their toxicity
Where are most enzymes located?
In the liver
What does “The dose makes the poison” mean?
Everything is toxic at some level
What is a common example of “The dose makes the poison”?
Table salt is essential to life in small doses. It is toxic in
high doses
What is a common measurement test?
Expose a population of lab animals to specific measured doses of a specific substance under controlled conditions
What are problems of a common measurement test?
Expensive, time-consuming, and painful or deadly to the animals tested
What is LD50?
Describes the toxicity of a substance by which 50 percent of the test population is sensitive.
What does “LD” mean?
A modern toxin takes 1 gram per kilogram of body weight to make a lethal dose
Very toxic substances take 1/10th that amount.
Extremely toxic substances take 1/100th that amount
Supertoxic substances are lethal in a few micrograms
What is an acute dose?
Effects caused by a single exposure to a toxin and result in an immediate health crisis.
Example: Being
bitten by a poisonous snake
What is a chronic dose?
Effects may be caused by a single exposure or multiple exposures over a long period of time. Symptoms may be long-lasting.
Example: Lung cancer resulting from a lifetime of smoking
What are EPA standards?
For water, air, soil, etc.
Levels set by the Environmental Protection
Agency or DEP, Department of Environmental
Protection are not necessarily harmful. They
just serve as a “boundary” of acceptable
quantities.
What are the EPA standard quality level units?
ppm, ppt, ppb, ppq, etc. parts per million parts per trillion parts per billion parts per quadrillion
What is risk?
Possibility of harm or loss
What is risk assessment?
Process of estimating the threat particular hazards pose to human health.
What are some factors in risk and risk assessment?
Political, social, economic interests of people
Understanding probabilities
Personal experience
Exaggerated view of our ability to control media bias
Irrational fear of technologies or activities
(nuclear)
What is risk management?
Combines the principles of environmental health and toxicology with regulatory decisions based on economic, technical, and political considerations.
Example: Endocrine Disrupter Screening Program
After 13 years if testing and 76 million
dollars, no disrupters have been found
What do we need to consider when setting standards for environmental toxins?
Combined effects of exposure to sources of
damage
Different sensitivities of population members
Effects of chronic vs. acute exposures
