Exam 3 Flashcards
what was one of the most significant measures to enhance the safety of water
chlorination of drinking water which resulted in reduction of waterborne infections
main sources of drinking water
surface water: water in rivers and lakes
groundwater: water stored naturally in underground aquifers
hydrology
field of water science
- aquifer- a layer or section of earth or rock that contains freshwater, known as groundwater
the hydrological cylce
evaporation, accumulation, precipitation
- precipitation that falls over land forms glaciers, groundwater, and flows back to the oceans as river run-off
freshwater resources
- majority of freshwater is unavailable for human use
- comes from lakes, rivers, and shallow underground aquifers
- 9,000 cubic meters for each person on earth is available for use by the human population
water scarcity
- a country faces water scarcity when its annual supply of renewable freshwater is less than 1000 cubic meters per person
treatment of water for residential consumption
water in the US must undergo water treatment and meet quality standards set by the EPA
Water treatment in most plants are:
- coagulation- removes suspended material
- sedimentation - causes heavy particles to settle to bottom of tanks for collection
- filtration- removes smaller particles
- disinfection- destroys pathogens
water treatment
- untreated water first goes through coagulation. Aluminum sulfate is used as the coagulating agent
- this mixture is then transferred to sedimentation tanks. it is filtered to remove small impurities through filters of sand and activated charcoal
- lastly, the water is treated with a disinfectant to destroy pathogens
fluoridation of water
- Dr. Frederick McKay noticed water with naturally high levels of fluoride helped protect against tooth decay
- the US adds fluoride to public drinking water to prevent tooth decay
treatment of water from aquifers
- sometimes water form aquifers is free from microorganisms but still undesirable for human consumption because of impurities and coloration
- minimal aeration, filtration, and disinfection are necessary
- uses ultrafine filters
anthropogenic sources of drinking water contamination
- almost all water in its natural state is impure due to pollution
- urban water supply can be contaminated by man-made pollutants such as; chemicals and nutrients, rubber, heavy metal, sodium, petroleum by-products, heavy metals, and microbial pathogens
waterborne diseases
health conditions that are transmitted through the ingestion of contaminated water and water acts as the passive carrier of the infectious agent
waterborne diseases and pathogens
- bacterial, viral, protozoan, and some other agents are responsible for waterborne infections
cryptosporidiosis
agent- protozoal organism
source and exposure route-
- c. parvum oocysts are excreted in the stools of infected persons
- water used for recreation and drinking may be contaminated with infected sewage
- c. parvum oocytes can survive water chlorination
- following ingestion by the human host, the oocysts reproduce in the body
oocyst
- a hard, thick-walled structure formed by certain parasitic protozoa
- stage in the life cycle of parasites, helping them survive outside a host organism
- contain infectious forms of the parasite and are often transmitted through ingestion of contaminated food/water
- once inside a new host, oocysts release sporozoites, which invade the cells and multiply causing protozoal parasites-induced waterborne diseases
amebiasis
caused by protozoal parasite
source and exposure route
- e. histolytica produces cysts that are carried in human feces
- transmission occurs via the ingestion of cysts that are contained in food and water that have been contaminated
giardiasis
- agent is a protozoal organism
sources and exposure route - g. lamblia produces cysts that transmit the condition via contaminated food and water
- the cysts have the ability to survive for long periods in cold water
cyclosporiasis
caused by a protozoal organism
source and exposure route
- cyclosporiasis is transmitted via ingestion of food and water that have been contaminated
typhoid fever
salmonella bacteria cause typhoid fever
- salmonella is transmitted by contaminated food and water
e. coli
- bacterial infection
- primary source of e. coli is the intestines of people and animals, particularly cattle
- e. coli infections are transmitted through contact with contaminated lakes and swimming pools and via the ingestion of contaminated food and water
cholera
caused by a bacterial agent
- inadequate infrastructure for processing water causing food or water to be contaminated with the cholera bacteria
- cholera is a continuing pandemic lasting four decades in Asia, Africa, and Latin America
waterborne diseases caused by viral pathogens
- viruses are more resistant to environmental conditions and sewage treatment processes, including chlorination and UV radiation, than bacteria
norovirus
- transmission routes include ingestion of contaminated food or water and close contact with those who are infected
viral hepatitis
- viral hep A can be spread via person-to-person contact and by contaminated food, water, and ice. countries with poor sanitation can be settings for the spread of hep a
- viral hep B is transmitted via the fecal-oral route and is found in developing countries with inadequate sanitation of drinking water. most frequent mode of transmission is via polluted drinking water
guinea worm
- caused by a nematode - a kind of roundworm
- worm forms larva that enter the water supply. infect small crustaceans in the water which are then ingested through drinking unfiltered water
- in the abdomen of the human host the larvae mature into worms
- mature worms migrate to the surface of the skin of the feet where they produce painful blister
legionellosis
- waterborne bacterial infection
- two forms are legionnaries’ disease and pontiac fever
- legionnaires’ disease produces fever, cough, and pneumonia
- L. pneumophila can grow in domestic water systems, cooling systems, and whirlpool spas
- transmission of bacterium can occur when water that is rich in the bacteria becomes aerosolized and inhaled into the human resp. system
chemicals in the water supply
chemicals that have been identified
- Cr6, As, Pb, fluoride, pesticides, disinfectant by-products, etc.
- pharmaceutical and personal care products
- sewage epidemiology- field of monitoring excreted drugs in the sewer system to assess the level of illicit drug use in the community
water disinfectant by-products
- chemicals used to disinfect water include chlorine, chloramines, chlorine dioxide, and ozone.
- chlorine is associated with trihalomethanes, most common DBP
beach and coastal pollution
- during heavy rains, urban runoff into the oceans degrades the quality of ocean water by adding microbial agents, nutrients, and chemical toxins
- excessive nutrient levels entering the ocean can lead to harmful algal blooms, which deplete oxygen levels in the water
- urban runoff and sewage contamination can expose swimmers to waterborne diseases
clean air act of 1990
substantially reduced the mortality of adults and infants from particle pollution and ozone
causes of poor air quality
combustion of fossil fuels
smog
a mixture of pollutants, principally ground-level ozone, produced by photochemical reactions in the air involving smog-forming chemicals
smog complex
eye irritation, irritation of the respiratory tract, chest pains, cough, shortness of breath, nausea, and headache
effects of air pollution
adverse human health effects;
- respiratory and eye irritations
- impairment of lung function, lung damage, and lung cancer
adverse environmental effects
- acid rain
- reduced visibility
- global warming
air pollution episodes in history
- Meuse Valley, Belgium
- Donora, Pennsylvania
- London, England
sources of air pollution
natural sources - mainly particulate matter
- wind-blown dust, breaking waves, mold spores, pollen, forest fires, volcanic eruptions
anthropogenic sources
- stationary sources- electric generating plants, factories and manufacturing complexes, oil refineries, chemical plants, incinerators
- mobile sources- cars, trucks, buses, airplanes, ships, and trains
mobile sources and air pollution
- automobiles produce approx. half of two major causes of smog- VOCs and NOx, most carbon monoxide, and about half of emissions of other toxic air pollutants
- buses and trucks cause more pollution than automobiles
- off-road vehicles contribute to air pollution in the areas where they are used
- large commercial jets are the third largest contributor of greenhouse gases
criteria of air pollutants
air pollution is composed of particles, gases, and vapors;
- ozone, nitrogen oxides, carbon monoxide, particulate matter, sulfur oxides, lead - these are the 6 moist common outdoor air pollutants that the EPA regulates
- greenhouse gases
- hydrocarbons
- other heavy metals
ozone
- O3 is a main component of smog
- ground-level ozone stems from a series of photochemical reactions among the products of combustion and fossil fuels
- major ozone episodes are often linked to heavy motor vehicle traffic, sunshine, high temp, and temp inversion
- health effects- resp. difficulties, increased allergies, local irritation of the eyes, reduced ability to fight colds, increased resp. infections
- environmental impact- damage to forests and plants
nitrogen oxides
- NOx refers to gases made up of a single molecule of nitrogen combined with varying numbers of molecules of oxygen
- approximately 25 percent is produced from the combustion of fossil fuels
- ground level ozone formation is attributed to the production of NOx
- health effects- potentially harmful to the respiratory system
- environmental impacts- NOx are major components of acid rain.
carbon monoxide
- produced by the incomplete burning of solid, liquid, and gaseous fuels
- appliances fueled with gases and oils may produce CO as well as burning coal, wood, and charcoal
- care exhaust also contains CO
- health effects- aggravates coronary heart disease, reduced oxygen-carrying capacity of the blood and increased demand on the heart and lungs
particulate matter
- also known as aerosol particles; includes dust, soot, and other find solid and liquid materials that are suspended in and move with the air
- sources include diesel exhaust, smoke, burning wastes, industrial activities, and effluents form wood-burning fire places
- health effects- eye and resp. irritation, lung damage, bronchitis, and early mortality
- environmental impacts- degradation through the deposition of soot
health effects of PM2.5
- bypasses the body’s normal defenses and can enter deep in the lungs. If the particle doesn’t dissolve the body’s natural clearance mechanisms are unable to remove them efficiently
sulfur oxides
- SO2 is a gas produced by burning sulfur contaminants in fuel
- power plants that use high-sulfur coal or do not have effective emission controls are a source of SO2
- health effects- bronchoconstriction and production of excess mucus
- environmental impacts- can form sulfuric acid playing a role in the production of acid rain
lead
- used to be a universal component of gasoline but has been banned as in additive in the US
volatile organic compounds
- class of chemicals that contain carbon. these evaporate and escape into the air easily
- NOT classified as criteria air pollutants, they are the product of fuel combustion
- most significant source is automobiles
- health effects- various types of cancers
- environmental impacts- harmful to plants
diesel exhaust
- complex mixture of particles and gases, including carbon, condensed hydrocarbons, gases, and polycyclic aromatic hydrocarbons
- particles are very fine and easily inhaled deeply into the lungs
- health effects- airway inflammation, allergies, asthma, increased risk of lung cancer
- children who ride school buses are exposed to a greater amount of diesel exhaust
acid rain
- when SO2 and NOx are emitted into the atmosphere, and reacted with water, oxygen, and other chemicals they will form sulfuric and nitric acids that eventually fall to the ground with rain
- acid rain settles on the earth creating abnormally high levels of acidity that are damaging to the environment, wild life, and human health
temperature inversion
- reverse of the usual situation- the warm layer of air stalls above a layer of cool air that is closer to the surface of the earth
- there is no upward air convection and pollutants are trapped and building up close to the earth’s surface
- contributes to the creation of smog in the LA Basin
- during temp inversion episodes smog is trapped creating higher levels of pollution
The Air Quality Index
- AQI is used to provide an indication of air quality in specific areas
- calculated for 5 major air pollutants regulated by the clean air act- O3, PM, CO, SO2, NOx
- AQI less than 50- good
- AQI 51-100- moderate
- AQI 101-150- unhealthy for sensitive groups
- AQI 151-200- unhealthy
- AQI 201-300- very unhealthy
- AQI greater than 300- hazardous
National Ambient Air Quality Standards
- EPA standards for air pollution
- primary standards provide public health protection
- secondary standards provide public welfare protection
health effects of air pollution
- 3 major effects- asthma, lung cancer, and heart attacks
- heavy episodes of air pollution have been correlated with increased mortality rates
- common short-term effects- irritation of eyes, nose and throat, aching lungs, bronchitis, pneumonia, wheezing, coughing, nausea, headaches
- general long-term effects- heart disease, chronic obstructive pulmonary disease, lung cancer
effects of air pollution on coronary heart disease
- indirect association between exposure to CO in ambient air and acute myocardial infarction through smokings, which is associated with elevated blood CO levels
- people with pre-existing heart problems may be at increased risk of aggravation to their condition when exposed to high levels of ambient CO in the urban environment
effects of air pollution on asthma
- asthma is a major public health problem in the US
- indoor/outdoor air quality and genetic factors influence the occurrence of asthma
- potential triggers include- environmental tobacco smoke, cold air, exercise, stress, and asprin
effects of air pollution and lung cancer
- correlation between geographic distribution of lung cancer cases and general location of emission sources for hydrocarbons
-exposure to fine PM over extended periods of time is a risk factor for lung cancer - risk of lung cnacer increased among heavy smokers who had extensive exposure to air pollution
Indoor Air Quality
- many people spend 90 percent of their time indoors
- health outcomes related to indoor air quality; Legionnaires’ disease, sick building syndrome, hypersensitivity pneumonitis, multiple chemical sensitivity
indoor use of biomass fuels
- Frequent cause of indoor air pollution in developing countries in unventilated indoor cooking stoves that burn biomass fuels; house fills with smoke
- exposed to pollutants like PM, CO, NO, SO, and PAHs
- elderly exposed to biomass fuels have higher prevalence of asthma compared to their counterparts
Sick Building Syndrome
- building occupants experience acute health effects that are linked to time spent in a building, but no specific illness or cause can be identified
- temporary phenomenon that is relieved by leaving the building
- symptoms include headache, respiratory irritation, dry skin, and fatigue
- possible cause is inadequate ventilation, chemical contaminants, and bio contaminants
Building Related Illness
- symptoms of a diagnosable illness are identified and can be attributed directly to specific airborne building contaminants
- examples are Legionnaires’ disease and hypersensitivity pneumonitis
secondhand smoking
- exposure to environmental tobacco smoke
- human lung carcinogen responsible for approx. 3,000 death annually among non smokers
- passive smoking is associated with bronchitis, pneumonia, asthma
Global Warming
- increase in the near surface temperature of the Earth
- burning of fossil fuels causes the release of greenhouse gases. Greenhouse causes can trap heat and cause the earth’s temperature to rise
- Earth’s surface has warmed about 1 F in the past 140 years.
Natural Temp Cycle or Greenhouse effect
- analyses of global temp changes over the past millennium are done by using data from tree rings and ice cores
- recent large temp increases during the late 20th century are likely due to anthropogenic activities
Global Warming Contributors; Deforestation
- decreases the capacity of trees and the forest ecosystem to reduce the amount of CO2 in the atmosphere
- often causes by the burning of large areas of land, further contributing to greenhouse gas
Potential Impacts of Global Warming
- disturbances in the native habitats of plant and animal species
- create environments that are beneficial to the growth of vector-borne diseases
- sea level rising
- increased impacts of air pollution
- disruption of the food supply chain and resources
- increase in heat-related illness and deaths
- increase in vector- and rodent-borne diseases
Potential Impacts of Global Warming; Distribution of Endemic Diseases Shift
- global temp increases favor the growth of some disease causing agents and disease-carrying vectors
Potential Impacts of Global Warming; Retreating Glaciers and Rising Oceans
- evidence of climate change is the retreat of glaciers
- as water stored in frozen sources melts, the average height of the world’s oceans rises gradually
- increases the risk of flooding in low-lying countries
- if oceans rise by 16 inches in the year 2080, as many as 200 million people would be affected by surges in the ocean level
Potential Impacts of Global Warming; extreme climatic conditions
- global warming is associated with extreme climate conditions including heat waves and severe rainstorms
the status of greenhouse gas emissions
- at the start of the 21st century the US was the leading producer of greenhouse gases
- The US is second leading source of CO2 emissions, China is the leading source
controlling global warming; The Kyoto Protocol 1997
- international treaty addressing climate change. purpose was to reduce emissions of greenhouse gases
- protocol required participating countries to reduce their emissions by a specific amount
Controlling Global Warming; Copenhagen Accord, 2009
- articulated a political intention for controlling carbon emissions and reacting to climate change
- not a legally binding document but overall goal to keep future global temperature increases below 2 degrees celsius
Controlling Global Warming; Paris Climate Agreement
- 195 countries signed the legally binding agreement
- efforts to limit the temp rise to 1.5 C
- periodic meetings to discuss progress on meeting climate targets; meet every 5 years
- came into effect Nov 4, 2016
- on June 1, 2017 US withdrew from the paris agreement, but joined again Jan 2021
COP29
conference where countries discuss and negotiate progress towards achieving the goals set out in the paris climate agreement
energy conservation steps to reduce greenhouse gases
- increase efficiency of older power plants
- develop more renewable and alternative energy sources
- use energy-efficient designs in home construction and electrical appliances
- increase the fuel efficiency of motor vehicles as in the use of fully electric, hybrid gas-electric, and other designs
- increase the use of public transport and bicycles
waste
materials that are perceived to be of negative value. a major concern for waste disposal is the pollution that can result from the process of disposal
problems caused by the growing volume of waste
- space reserved for dump sites is being rapidly depleted
- endangerment of safe drinking water supplies and viability of aquatic environments
hazardous waste
the by-products that can pose substantial or potential hazard to human health or the environment when improperly managed
possess at least one of four characteristics;
- ignitability
- corrosivity
- reactivity
- toxicity
sources of hazardous waste
hazardous materials used in the home
- pesticides, cleaning products, automotive products, painting supplies, etc
Medical waste
- chemicals, infectious agents, radioactive materials
Industrial hazardous waste
- heavy metals from plating operations, toxic chemicals, solvents, and residues from the manufacturing of pesticides
Radioactive waste
- spent nuclear fuel and tailings from uranium processing
Mining wastes and extraction wastes
- Toxic chemicals left over from mining operations include acids and heavy metals
problems with hazardous waste
- industrialized countries ship hazardous waste materials to developing countries who will take them for cash payments
- many developing nations do not have adequate facilities for safe disposal of hazardous wastes which endangers the health of the local population
-Basal convention of the control of… hazardous wastes and their materials is sponsored by the united nations. the goal is to regulate international transport of hazardous wastes and promote the disposal of such wastes in a safe manner
uncontrolled hazardous waste sites in the US
- toxic materials contained in uncontrolled hazardous waste sites raise major concerns for public health and environment
- at least 40,000 uncontrolled sites had been reported as of march 2010
- superfund legislation mandates the clean up of hazardous waste sites in the US
- release of hazardous waste from these sites into the environment may cause; potential adverse human health effects, high costs of cleanup, reduction in property values, potential ecological damage
Environmental migration of hazardous waste
- toxic chemicals may enter the water supply and through biomagnification could enter the food chain
- solid wastes deposited in terrestrial environments are subject to leaching by surface and ground waters
- leachates interact with natural organic matter, clays, and microogranisms in soils and sediments
- food chain transport results in movement of hazardous chemicals from lower to higher positions in the food web
medical waste
- hazardous wastes generated in healthcare facilities
- risks of medical waste are far greater to medical workers than to the general public
- medical waste can be deposited in land fills as long as it has been treated first
safe disposal of hazardous wastes
- use of land disposal units is the most used method for disposing hazardous waste
- hazardous waste landfills must be designed with heavy liners and collection systems in order to protect groundwater
- liquid hazardous wastes are placed in hazardous waste injection wells - deep underground at high pressures
- liquid wastes in injection wells are also regulated by the safe drinking water act because they may impact groundwater
municipal solid waste
variety of solid waste materials generate by households, businesses, institutions within an urban area
- finding new sites for the disposal of MSW is becoming a challenging problem for several areas of the US
components of MSW
components of MSW stream include packaging, food waste, paper, electronics, appliances, and organic materials such as yard trimmings
wastes from construction sites, sewage sludge from wastewater, and industrial wastes that are not hazardous are usually NOT termed MSW
Solid waste management
municipal solid waste disposal is an industrial enterprise that has 4 main dimensions;
- recycling
- composting
- combustion
- landfills
when MSW is disposed in landfills, methane is sometimes generated as a byproduct
EPA hierarchy for management of MSW
- the US EPA has a heirarchy for management of MSW
- procedures at the top of the heirarchy are favored over those at the bottom
order is as follows - source reduction and reuse
- recycling/composting
- energy recovery
- treatment and disposal
source reduction
reducing waste at the source, which is the most environmentally preferred strategy. through source reduction, the volume of solid waste that is put in landfills is reduced
two important components; waste reduction, waste reuse
examples of source reduction methods
- financial incentives to homeowners
- improved packaging designs that reduce the amount of materials that must be reduced
- design products that can be reused
- design products with longer service life so they don’t need disposed of as frequently
recycling
a process of collecting and reprocessing a resource so it can be used
advantages of recycling
- prevents pollution generated by the use of new materials
- saves energy
- reduces emissions of greenhouse gases
- decreases the amount of materials shipped to landfills
- preservers natural resources
- opens up new manufacturing employment opportunities
composting
the aerobic decomposition of organic materials to produce a stable product
- biodegradation is a natural, ongoing biological process. breaks down organic materials through physical and chemical processes
- composting produces a useful material that resembles soil
- composting has the potential for reducing greatly the amount of materials that must be disposed of in landfills because 1/4 of household wastes consists of yard trimmings and food wastes
combustion
- reduces the volume and weight of waste, while at the same time generating energy
- this form of disposal occurs via incinerators
- do not need to seperate waste before incineration and ash can be disposed of in land fills
- major concern is generation of air pollution
landfills
a landfill is composed of four major parts; bottom liner, system for collecting leachates, cover, and appropriate location
- landfill steps; 1- flexible membrane liners at bottom to stop toxic chemicals; 2- garbage is piled up in rows to be compacted; 3- after the garbage is covered, anaerobic bacteria aid in the decomposition of organic materials materials and produce methane gas
water and air pollution produced from landfills
water pollution - leachate refers to water that collects contaminants as it trickles through wastes, pesticides or fertilizers
air pollution- MSW landfills generate methane, VOCs and other gases
- methane vented from landfills poses a fire hazard
- VOC emissions from landfills can lead to odor complaints from nearby residents and may be linked to respiratory irritation symptoms. some VOCs may have carcinogenic properties
federal landfill standards and megafills
- EPA established federal standards for the landfill construction in 1988 to increase safety
- to follow the safety standards, the small existing 10,000 landfills were combined into 3,500 megafills
- megafills take in 5-10,000 tons of trash per day
- larger landfills tend to be more cost effective than incinerators; landfills now are used for the disposal of most of the solid waste produced in the us
sewage
the wastewater and human waste produced by residential and commercial sources discharged into sewers
- in the middle ages human waste from street gutters seeped into drinking water wells causing typhoid fever and cholera to spread rapidly
- pipe sewage treatment plants process sewage to prevent the spread of water borne diseases
modern sewage treatment
- modern treatment produces wastewater that can be returned safely to waterways or in some cases reused/recycled
typical treatment involves - preliminary phase; screening- remove large objects
- primary phase; sedimentation- remove small particles
- secondary phase- filtration and disinfection- addition of chemicals
primary and secondary stages of sewage treatment
- primary stage aims to remove suspended small materials, which can be composted or shipped to landfills
- secondary processing promotes microbial digestion of organic material that remain in the sewage; microorganisms that are present naturally in sewage
- following these stages the treated sewage water is sometimes discharged into waterways
tertiary stage of sewage treatment
- tertiary processing is directed at removal of remaining solids and microorganisms from the liquid portion of the sewage
- filtration through sand and charcoal filters, and decativation of microorganisms through chlorine/UV radiation
- finished wastewater can be recycled
reuse of treated wastewater
- most places in the US require wastewater receive at least secondary treatment
- water that has received only primary treatment is not recommended for any use
septic system
a septic system includes a septic tank and subsurface fluid distribution system
- anaerobic action treats waste material as it sits in the septic tank; solids collect at the bottom of the tank
- objects disposed of in a septic system should be limited to biodegradable items
hazards posed by animal wastes
- nutrients- buildup of nutrients on the land, surface contamination, and water pollution due to runoff that later may infiltrate the water supply
- microorganisms- salmonella, escherichia coli, protozoa, and zoonotic agents
- residues of animal medicines- when antimicrobials from animals enter the water supply they can foster the production of antibiotic resistant organisms
- potentially toxic gases- methane from cattle
occupational health
a field focused on the health and safety of the workers; closely related to
- industrial hygiene
- occupational safety
- occupational medicine
bernardino ramazzini
- father of occupational medicine
- created detailed descriptions of the manifestations of occupational diseases among different workers
- pioneer in the field of ergonomics pointing out the dangers of different postures assumed in various occupations
- authored De Morbis Artificum Diatriba - diseases of workers- highlighting the risks posed by hazardous chemicals, dusts, and metals used in the workplace
alice hamilton
- mother of occupational safety and health
- first identifiable industrial hygienist in the united states
- author of exploring the dangerous trades
- first women faculty at harvard
- supported the settlement house movement in the us
- peace worker in world war 1
phossy jaw
- described by dr. alice hamilton - phosphorus necrosis of the jaw
- occured in match factory workers in the late 1800s, many were children
- affected the jawbone, causing severe pain and abcesses that drained, eventually led to disfigured jaws. removing the jawbone was the only treatment
- caused by exposure to white phosphorus
mad hatters disease
- hat workers were exposed to mercury fumes causing them to develop mercurial erethism - neuropsychiatric syndrome
- characterized by symptoms including irritability, personality change, loss of self confidence, depression, memory loss, and reduced ability to concentrate
gauley bridge disaster
- workers creating tunneling in the gauley bridge were exposed to high levels of silica dust
- 1500 workers contracted silicosis and 1000 workers died from it
workers memorial day
- april 28
- established in 1971
- under the occupational health and safety act of 1970 employers are responsible for providing safe and healthful workplaces for their workers
occupational injury and illness
- 2.9 million nonfatal work place injuries or illnesses reported in 2015
agents of occupational disease
physical
- noise
- ionizing radiation
chemical
- dusts
- toxic heavy metals and fumes
- carbon monoxide
- chemicals
biological
- microbial agents
psychological
- work-related stress
argonomics
- lifting heavy weights
- repetitive motion
safety
- accidents
noise
- unwanted sound
- noise induced hearing loss is cumulative
- annoying and can disrupt performance
- can be linked with psychological disturbances and mental disorders
ototoxicants
- certain pesticides, solvents, and metals that can negatively effect how the ear functions causing hearing loss
- have a synergistic effect on hearing loss with noise exposure
dusts
- black lung disease- found in coal mining industry
- brown ling disease is caused by cotton and textile dusts in workplace
- exposure to dusts in workplace are associated with many other occupation pneumonoconiosis, lung cancer, and other pulmonary conditions
toxic heavy metals and their fumes
- during the processing and milling of heavy metals, employees are at risk of breathing fumes and dust of toxic heavy metals
- lead poisoning is called plumbism
carbon monoxide
- CO is odorless
- product formed by CO and hemoglobin and carboxyhemoglobinemia
- workers who have preexisting lung and heart diseases, or anemia are at increased risk of the effects of CO poisoning
- many small gasoline-powered engines used in occupational settings are the source of CO in workplaces. Care should be taken to provide adequate ventilation
chemicals
- agricultural workers are exposed routinely to potentially toxic pesticides
- workplace chemical exposures have been associated with dermatoses, liver disease, and many other conditions
biological agents
- hospital employees, sewage workers, and agricultural workers are exposed to biological agents
- microbial agents originate from a number of sources including human and animal blood and bodily fluids, feces from humans and animals
- bloodborne pathogens- type b hep and type c hep
- aerosol transmissible pathogens- tb, anthrax, influenza
work-related stresses
- chronic stress has been implicated in a range of somatic conditions and mental disorders include depression
occupationally associated diseases and conditions
respiratory diseases, allergic and irritant dermatitis, fertility and pregnancy abnormalities, hearing loss, infectious diseases, musculoskeletal disorders, traumatic injuries and fatalities, conditions associated with job stress
occupational respiratory diseases
- primary route workplace hazards enter workers’ bodies is through inhalation
- many work-related respiratory diseases are chronic conditions with long latency periods
- frequency of respiratory conditions contributing to morbidity and mortality is likely underestimated
chronic obstructive pulmonary disease and asthma
- COPD causes significant reduction in work time, economic losses, morbidity, and an increase in the risk of mortality
- 15 to 19 percent of cases of COPD and asthma can be linked to occupational exposures to aerosol
- asthma is the most frequently diagnosed occupational respiratory disease
- occupational exposure may exacerbate preexisting asthma
pneumoconiosis
- accumulation of dust in the lungs and the tissue reaction to its presence
- can result of fibrosis in the lungs and lung nodules
- workplace aerosols that can cause it include; asbestos, cotton dust, silica dust, coal dust
asbestosis
- asbestos has been used for fireproofing, insulation, and motor vehicle brakes
- asbestosis refers to a type of pulmonary fibrosis associated with inhalation of large amounts of asbestos fibers over long periods of time
- related to decline in pulmonary function and increased risk of lung cancer
- in 1973 the EPA banned the spraying of materials that contained asbestos on buildings
- in 1989 the EPA issued a regulation that prohibited most other uses of asbestors
black lung disease
- coal workers pneumoconiosis is a potentially fatal lung disease that is associated with breathing coal dust which gets deposited in the lungs
- over time lungs afflicted with CWP lose their elasticity causing respiration to become difficult
- after the federal coal mine and safety act of 1969 average dust levels in coal mines declined sharply
silicosis
- condition caused by inhaling respirable crystalline silica dust
- invisible fine silica particles can be drawn deep into the lung
- chronic silicosis can take years to develop and may result in pulmonary fibrosis, loss of lung function, and connective tissue death
allergic and irritant dematitis
- dermal contact is the second most common route for workplace chemicals to enter the workers body
- workers at highest risk are employed in manufacturing, construction, food production, and activities such as metal plating and engine service
fertility and pregnancy abnormalities
- workers exposure to teratogens such as lead, solvents, ionizing radiation, and anti-cancer drugs are known to cause developmental abnormalities
noise in the workplace
- noise in the workplace may interfere workers alertness and communication and induce stress over time
- recommended exposure limit for noise is 85 dB
- workers most effected; construction industry and healthcare industry
adverse health effects caused by noise
- reactions to noise are annoyance, sleep disturbance, and reduction in cognitive performance
- effects of prolonged exposure to noise are possible psych reactions that aversely impact the immune system and physical well-being
- hearing loss is the major health problem resulting from workplace noise exposure
- hearing loss is caused by permanent damage to the hair cells in the inner ear
infectious diseases-
- healthcare workers are at increased risk of exposure to hepatitis and hiv
- public utility workers may be exposed to hazards of disease carried in raw sewage
- agricultural workers are at increased risk of exposure to zoonotic diseases through contact with animals and disease agents contained in the soil
- social service workers and corrections personnel may be exposed to tuberculosis and other infectious disease
- clinical lab specialists may be exposed to infectious agents from specimens including bloodborne pathogens, viruses, and bacterial agents
musculoskeletal disorder
- MSD refers to an injury or disorder of the muscles, nerves, tendons, joints, cartilage, or spinal discs, which occurs widely in the work environment and account for 31 percent of all nonfatal occupational injury
- the branch of occupational health that studies MSD is known as ergonomics
carpal tunnel syndrome
- type of msd condition that is associated with compression or squeezing of the median nerve
- may produce symptoms of numbness or pain in the wrist and hand
- related to repetitive work activities with the hand and wrist - one industry with high occurrence is the meat packing industry
back injuries
- 17% of all occupational injuries and illnesses
- factors that contribute are performing repetitive movements that affect the back, remaining sedentary for long periods of time, or putting too much strain on the back
- nurses is one of the highest risk occupations due to lifting patients
traumatic injuries and fatalities
- injuries are the result of energy applied to the human body in such a manner that the energy exceeds the body’s physical tolerance
- most fatalities are transport incidents and highway deaths, next is falls, slips, and trips
job stress and associated conditions
- job stress is the harmful physical and emotional responses that occur when the requirements of the job do not make the capabilities, resources, or needs of the worker
- can cause impaired mental health and adverse physical health- coronary hear disease and dizziness during the workday
- adverse physical and mental health outcomes are highest among millenials and lowest for baby boomers
preventing occupational disease; occupational health control
- elimination- changing or altering a process to eliminate worker exposure
- substitution- substituting less toxic for more toxic materials to minimize exposure
- engineering control- incorporate proper exposure control engineering to reduce contact
- administrative control- provide employees with health and safety training or rotating job assignments to achieve exposure control
- PPE- ensure employees use personal protective equipment
