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78 Cards in this Set
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problems with air pollution
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a person inhales approximately 35 pounds of air per day (roughly 6 times more than food and drink consumed)
breathing is continuous and involuntary air may be polluted both outdoors and indoors lung disease is the 3rd leading cause of death in the US (~335,000 deaths/yr) |
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chronic obstructive pulmonary disease (COPD)
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a major cause of disability
4th leading cause of death in the US more than 12 million people are currently diagnosed with COPD asthma is the most common chronic illness in children (leading cause of hospital admissions of children) |
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lungs are used to exchange gasses
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inhaling oxygen
exhaling carbon dioxide |
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the asthma epidemic exists particularly in...
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urban areas
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examples of catastrophic air pollution
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London (1911) - 1150 died form the effects of coal smoke (first time the mix of smoke and fog over london was called smog)
London (1952) - 4000 died from smog Donora, PA (1948) - 20 died and 6000 were ill from smog from the community's steel mill, zinc smelter, and sulfuric acid plant NYC (1963) - 300 people died from air pollution |
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cost of air pollution (annual 1999 EPA report to congress)
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total cost - 71 billion
health - 68 billion (morbidity/mortality) worker productivity - 460 million agriculture - 45 million (many food products are more expensive to compensate for the cost of the crops lost due to air pollution) |
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types of air pollutants
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natural (volcanic ash, pollen dust, smoke from fires)
man made 1. gaseous - derived from combustion processes, hydrocarbons, oxides of sulfur and nitrogen compounds 2. particulate matter - solid or aqueous particles |
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particulate matter
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smallest (aerosols) can remain suspended
below ~2.5 micrometers are capable of penetrating all sites of the respiratory tract (carbonaceous, metallic oxides, salt or acids also have a porosity such that they absorb other gasses and liquids) |
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the clean air act classified 2 broad classes of air pollutants
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"criteria" air pollutants and hazardous air pollutants
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criteria pollutants (CAPs)
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ubiquitous (wide spread)
not very toxic (not carcinogenic) emitted from many large, diverse sources (including mobile and stationary sources) omnipresent (therefore posing the greatest overall threat to human health) presupposition - the adverse health effects are not cancerous and their dose response exhibits a threshhold particulate matter (PM) sulfur dioxide nitrogen dioxide ozone carbon monoxide lead (put into the environment when once used in gasoline) |
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hazardous air pollutants (HAPs)
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sources may be limited and industry specific
considered more toxic and even carcinogenic ~188 chemicals (benzene, formaldehyde, cadmium, vinyl chlorine) separate strategies exist for regulating the criteria and hazardous pollutants |
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sources of primary air pollutans
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transportation 46%
fuel combustion (stationary sources) 29% industrial processes 16% miscellaneous 7% solid waste disposal 2% |
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emissions of primary air pollutants
(percentages) |
CO 48%
SO2 16% NO2 16% VOCs 15% particulates 5% |
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transformation and long-range transport of air pollutants
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sources - mobile, stationary, and natural
--> primary pollutants - SO2, NO2, CO, PM --> chemical transformation in atmosphere secondarily formed pollutants (ozone, acid aerosols) |
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transformation of air pollutants (secondary pollutants)
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hydrocarbons (VOCs) + NO2 -(sunlight)-> ozone
SO2 (gas) -(atmospheric oxidization)-> H2SO4 particle (droplet aerosols) |
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concentration of gases in photo-chemical smog as a function of time
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cyclic
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coal mines in ohio pollute...
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the ohio river
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winds and geography play a role in the spread of air pollutants
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move across the US from west to east
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normal patterns of layers of air
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solar radiation
cooler air cool air warm air (on the ground) |
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temperature inversion
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solar radiation
cool air warm inversion layer (which traps pollution) cool air (on the ground) |
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areas in the us with the most unhealthy days due to pollution
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souther california is the worst
urban settings (wind blows upward on the east coast giving them more good days) |
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how do we communicate with the public
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color hazard chart
orange represents unhealthy for sensitive groups (e.g. children and people with lung disease) |
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common symptoms of irritation from air pollution
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eye irritation
coughing sore throat shortness of breath lung damage airway constriction nasal discharge headaches/dizziness (in nasal passages you have a lot of nerves that go to your brain causing headaches) |
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pulmonary responses to toxicants
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local irritation, which results in bronchial constriction and edema; secondary infection (bronchitis) frequently compounds the damage
damage to the cells of the airway which results in necrosis (cells die, leading to more types of damage) fibrosis (stiffening of the lungs) and emphysema (destruction of airways) airway constriction through allergic responses (asthma) lung cancer (ozone may be a tumor promoter) |
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health effects of particulate matter
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premature deaths of elderly
increased hospital use (emergency room visits and admissions) aggravated asthma (many people end up in the OR) acute symptoms including aggravated coughing and difficulties in breathing decreased lung function (shortness of breath) work and school absences |
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the smaller the particulate ______
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the deeper in the lung it can go
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summary of ozone effects on acute exposure
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irritative symptoms
functional changes (including broncho-constriction) temporary decrease in lung capacity and mild inflammation of the peripheral lung in moderately exercising subjects (breathe harder when you exercise) increased risk of asthma attacks |
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EPA health effects research laboratory (HERL) ozone clinical study protocol
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lab settings with ozone in the room and subject on the treadmill
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summary of ozone effects (long-term, related exposures)
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there is no definitive answer to this critical issue; possible to probable effects include:
impaired growth and development of the young lung (animal toxicology) accelerated lung aging contributes to the progression of underlying lung disease |
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ozone
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sources - product of NO2 emissions from motor vehicles, power utilities, and industries burning fossil fuels, combined with hydrocarbons and sunlight in the atmosphere
health effects - causes difficulty breathing, irritation to mucous membranes, and increases risk to respiratory infections welfare effects - corrodes rubber, paint, weakens fabric, produces leaf damage and retardation of plant growth |
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carbon monoxide
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sources - incomplete combustion of fossil fuels as in vehicles, kerosene heaters, boilers, and furnaces
health effects - interferes with oxygen transport in blood by binding to hemoglobin, causes headaches, fatigue, and cardiovascular disease welfare effects - effects on plants or material are not evident |
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nitrogen dioxide
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sources - emitted from the combustion of fossil fuels in vehicles, industrial boilers, and electric generating utilities
health effects - increased risk of respiratory infections and aggravates symptoms in persons with asthma and chronic bronchitis welfare effects - produces a reddish brown hue over cities which reduces horizon visibility, causes leaves to yellow, and is a precursor to acid deposition and tropospheric ozone |
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sulfur dioxide
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sources - fossil fuel combustion especially in coal-burning electric power utilities, metal smelters, oil refineries and industrial boilers
health effects - causes irritation of the throat and lungs and aggravates symptoms in persons with asthma and chronic bronchitis welfare effects - causes corrosion and deterioration of metals, brittleness of paper, point discoloration, damages textiles and leaves of plants, and is a precursor to acid disposition |
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lead
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sources- histoirclaly emitted from vehicles burning leaded gasoline (emissions have been reduced by 98% since 1974, most exposures in the U.S. are not airborne)
health effects - damage to the CNS, blood forming tissues, kidneys, evidence of neurobehavioral disorders including learning disabilities and antisocial behavior welfare effects - no known effect on vegetation materials |
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clean air act (CAA)
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everybody should have the same degree of protection (establish UNIFORM national standards)
most susceptible subgroups of individuals (i.e. asthmatics, children) are to be protected |
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regulation of criteria pollutants
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national ambient air quality standards (NAAQS)
level of protection - "adequate margin of safety" |
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legislative background for NAAQS
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CAA directs EPA to identify air pollutants that may reasonably be anticipated to endanger public health
criteria are to reflect the latest scientific information used in indicating the kind and extent of all identifiable effects the standard, in the judgement of the EPA administrator, allows for "an adequate margin of safety" CAA requires periodic review and, if appropriate, revision of existing crieria and standards CAA does not permit the EPA to consider costs in setting the NAAQS |
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issues central to standard setting
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"all identifiable effects" are to be reviewed (the EPA is not free to define as adverse only those effects that are clearly harmful and about which there is medical consensus)
"adequate margin of safety" (the protect against effects that have not yet been uncovered by research, and effects whose medical significance is a matter of controversy and to be set low enough to protect the health of all susceptible groups within the population) concept of threshold (assumption that a safe population dose exists) |
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health bases for current NAAQ standards
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ozone - acute symptoms such as pain in breathing, irritative cough, and reduced vital capacity and FEV, etc.
NOx and VOCs - regulated largely on basis on controlling ozone formation via state and regional effects PM - human mortality studies CO - acute risk to people with cardiovascular disease sulfur dioxide - control of acid rain is the major driver lead - neurotoxicity to children |
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how EPA standards are done
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scientific literature is the key to identification of adverse health effects
EPA must assess the potential that symptomatic effects are indicators of their more serious health effects at the margin where effects are often subtle and reasonable scientists disagree about their importance, the EPA administrator must ultimately judge which effects should be regarded as "adverse" for standard-setting purposes |
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hypersusceptibility
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an exaggerated response to a specific dose
pollutant specific |
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criteria pollutants and their susceptible sub-populations
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SO2 - persons with increased airway reactivity (asthmatics)
CO - persons with arteriosclerotic disease affecting coronary vessels (angina patients) Pb - fetus and children PM10 - mortality (the elderly with cardiovascular and pulmonary disease), morbidity (children) NO2 - children (respiratory illness) O3 - active people, persons with pulmonary disease |
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how were carbon monoxide settings created?
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doctor who used his patients with angina. put them on treadmills and drove them around los angeles.
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NAAQS ozone discussions
who benefits? how many? |
who benefits?
construction workers, outdoor exercisers, those with impaired resistance to ozone how many? numbers based on risk analysis; will be hard to confirm epidemiologically |
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the EPAs justification for proposed change (0.12 to 0.08 ppm)
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new scientific data show that ozone at levels below the previous standard causes significant adverse health effects
extend new health protection to 35 million, bringing to 113 million americans protected |
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strategies for implementing standards
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technology driven control - best available technology on smokestacks, catalytic converters on cars
modify products - fuel additives (oxygenates - improve combustion) restrict use - asbestos ban - cholorofluorocarbons disclose risk - california proposition 65 (seller must disclose risk of any known carcinogen or reproductive toxin contained in the product) economic incentives - trade/sell pollutant emissions |
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what else can be done (beyond standards)
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increased control of industrial activities and household activities that are known to contribute to air pollution
strategies to discourage automobile use and reduce the number of cars stricter emission controls for automobiles requirement for a certain number of zero-pollutant automobiles (electric cars) improved public transportation and incentives for people to use it mandatory car pooling |
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copsa mica, romania
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67,000 tons of SO2, 500 tons of lead, 400 tons of zinc and 4 tins of cadmium released annually from two smelters
1989 - was one of the most polluted places in europe highest infant mortality rate in europe 10% of population suffered "neuro-behavioral" problems smelters shut down in 1993 |
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air pollution __(verb)__s
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travels
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hazardous pollutants (HAPs)
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1990 CAA amendment specified 188 pollutants or chemical groups
HAPs are more toxic than criteria pollutants examples - heavy metals (chromium, mercury) and organics (benzene, perchloroethylene) |
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air toxics sources
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point sources - 61%
(chemical plants, oil refineries, steel mills, aerospace manufacturers, marine tank vessel loading) mobile sources - 21% (gasoline has benzene in it --> amount increased when lead was removed form gasoline) area sources - 18% (dry cleaning operations, solvent cleaning, secondary lead smelters and chrome plating, commercial sterilizers) |
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air toxics ambient air quality data
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release - 1993 ~8.1 million tons (national toxics release inventory)
no reliable network to measure ambient levels of air toxics |
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health effects of air toxics
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little information available (most derived from experimental animal studies)
potential health effects (Cancer, neurological, cardiovascular, and respiratory effects; effects on liver, kidney, immune system, and reproductive system, and effects of fetal and child development) about half of the HAPs have been classified as "known," "probable," or "possible" carcinogens |
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method of control for air toxics
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because they may exhibit no threshold, and air quality standards would be inappropriate, site-specific emission standards are established instead (national toxic release inventory)
the emission standards must provide an ample (not simply adequate - as with the criteria pollutants) margin of safety HAPs lack a monitoring system but the EPA does manage these inventories |
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clean air act
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NAAQS - criteria pollutants
HAPs - old (now repealed approach) was health-based, the new approach is technology based with a "risk kicker" that applies to sources under technology standards |
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HAPs technology based standards
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standards set according to what is available using available technology
"residual risks" are determined after the fact and perhaps more control applied at that point |
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reasons for concern about indoor air pollution
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~75-90% of time is spent indoors
many air pollutants known to be hazardous to health are emitted indoors indoor environments trap pollutants (levels may be 2 to 5 times higher than outside) |
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air inside can be polluted as a result of...
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energy conservation measures (e.g. "air tightening" of buildings and lower ventilations standards)
building occupancy human activities inside the structure gas-off from synthetic building materials forced air ventilation systems biogenic pollutants (from biological organisms, e.g. fungi, aeropathogens, aeroallergens) inflitration from outdoors poor housing conditions (vermin and pets) |
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air exchange rate
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rate at which air is replaced in the structure by external air - average from the american home is .7 to 1.0 changes per hour, tightly sealed homes without provisions for and exchange have ~0.2 air changes/hr
make-up air (from outside) - before 1973 - 15 CFM/person, after 1973 - 5.0 CFM/person |
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health effects of indoor air pollutants
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irritation (eyes, nose, throat, upper airways, skin)
respiratory symptoms (wheezing couching, chest tightness, shortness of breath) neurological symptoms (nausea, dizziness, headache, loss of coordination, tiredness, loss of concentration) immunological reactions (inflammation, allergic reactions, delayed hypersensitivity) asthma aggravation increased susceptibility to respiratory infections cancer |
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major indoor air pollutants of concern
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combustion products
volatile chemicals and chemical mixtures respirable particulates biological pollutants radon odors |
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sources of indoor air pollutants
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soil and groundwater - radon and radioactive progeny
building materials and furnishings - formaldehyde, asbestos, vinyl chloride, organic fumes personal activities and hobbies - cigarette smoking, fireplace smoke (more examples in slides) |
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combustion products (scope of the problem)
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more than 1/2 of the world's population relies on dung, wood, crop waste, or coal to meet their most basic energy needs
cooking and heating with such solid fuels on open fired or stoves without chimneys leads to indoor air pollution this indoor smoke contains a range of health-damaging pollutants including small soot or dust particles that are able to penetrate deep into the lungs exposure is particularly high among women and children who spend most of their time near their domestic hearth air pollution is responsible for one death every 20 seconds |
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indoor smoke contains a variety of health-damaging pollutants
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particles (complex mixtures of chemicals in solid form droplets)
carbon monoxide nitrous oxide sulfur oxides (mainly from coal) formaldehyde carcinogens (chemical substances known to increase the risk of cancer) |
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determinants of exposure to indoor air pollution
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the concentrations of pollutants in the indoor environment (mainly determined by the type of fuel and stove used, and the kitchen location)
the time that individuals spend in polluted environments |
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disease issues
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pneumonia and other acute lower respiratory infections - globally they represent the single most important cause of death in children under 5 years (exposure to indoor air pollution more than doubles one's risk)
COPD - women exposed to indoor smoke are three times more likely to have COPD, the risk for men is doubled lung cancer - exposure to smoke from coal fires doubles the risk for lung cancer |
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wood burning emits high levels of
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particulate matter and CO
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role of biofuels in cooking and heating (developed vs. developing countries)
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developed - 3%
developing - 33% |
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VOCs are taking in through what route?
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inhalation (volatile = gas)
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sources of VOCs in indoor air
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construction materials - foam insulation, carpet, glue, paint (emissions - methyl chloroform, formaldehyde, etc.)
structural components - vinyl tile, sheetrock (emissions - formaldehyde, benzene, etc.) cleaners and solvent - liquid detergent, chlorine bleach, furniture wax (emissions - xylene, chloroform, benzene) more examples on slides |
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environmental tobacco smoke (ETS)
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non smokers will be exposed to smoke in the environment where there are other smokers
side stream - chemicals may be higher in concentration in the smoke coming off the tip of the cigarette than what the smoker is taking into their body |
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ETS and children
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lower birth weights for infants of non-smoking mothers exposed to ETS during pregnancy
ETS exposure in pregnant women linked to growth retardation and congenital malformations in their babies significant association - up to 40% increased risk of SIDS in infants exposed to ETS extensive epidemiological evidence links ETS to an increased risk of lower respiratory tract illness such as bronchitis and pneumonia in children of parents who smoke U.S. surgeon general report concluded that exposure to ETS can reduce lung infection in children may contribute significantly to childhood asthma |
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special environments
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airplanes (temperature, humidity, CO, ETS, infectious agents, pesticides on international fights)
others - xerox machine rooms, space heaters, public gathering places |
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occupational environments
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with the onset of the energy crisis in the 1970s, buildigns in advanced countries were constructed to be energy efficient with less air exchange between the indoor air and the outdoor air. with this energy-efficient mindset, among the problems that arose in building were:
retention of higher temperatures higher humidity levels decreased ventilation increased odor retention |
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building related illness
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discrete, identifiable disease or illness
can be traced to a specific pollutant or sources within a building cough, chest tightness, fever chills, muscle aches or more serious outcomes legionaries disease, hypersensitivity pneumonitis, humidifier fever |
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sick building syndrome (SBS)
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set of symptoms associated with time spent in building (respiratory tract irritation, skin irritation, headache, dizziness, nausea, fatigue, concentration problems)
symptoms diminish or cease when occupants leave the building >20% of occupants report SBS cannot be traced to specific pollutants or sources within the building |
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regulatory jurisdictions
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outdoor air - EPA, clean air act
occupational air - OSHA indoor air (apart from occupational air) - no specific federal laws, state and local jurisdictions regulate air quality in PUBLIC BUILDINGS (limit use of products that effect air quality, ventilation and air exchange standard rates, controlling activities) private residence - must rely on education |
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strategies to control indoor air pollution
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ventilation
source removal source modification air cleaning (pollutant removal) education |