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Emission factors
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Health effects[edit source | editbeta]
See also: Neuroplastic effects of pollution
Air pollution is a significant risk factor for multiple health conditions including respiratory infections, heart disease, and lung cancer, according to the WHO. The health effects caused by air pollution may include difficulty in breathing, wheezing, coughing, asthma and aggravation of existing respiratory and cardiac conditions. These effects can result in increased medication use, increased doctor or emergency room visits, more hospital admissions and premature death. The human health effects of poor air quality are far reaching, but principally affect the body's respiratory system and the cardiovascular system. Individual reactions to air pollutants depend on the type of pollutant a person is exposed to, the degree of exposure, the individual's health status and genetics.[citation needed]
The most common sources of air pollution include particulates, ozone, nitrogen dioxide, and sulfur dioxide. Both indoor and outdoor air pollution have caused approximately 3.3 million deaths worldwide. Children aged less than five years that live in developing countries are the most vulnerable population in terms of total deaths attributable to indoor and outdoor air pollution.[14]
The World Health Organization states that 2.4 million people die each year from causes directly attributable to air pollution, with 1.5 million of these deaths attributable to indoor air pollution.[15] "Epidemiological studies suggest that more than 500,000 Americans die each year from cardiopulmonary disease linked to breathing fine particle air pollution. . ."[16] A study by the University of Birmingham has shown a strong correlation between pneumonia related deaths and air pollution from motor vehicles.[17] Worldwide more deaths per year are linked to air pollution than to automobile accidents.[18] A 2005 study by the European Commission calculated that air pollution reduces life expectancy by an average of almost nine months across the European Union.[19] Causes of deaths include aggravated asthma, emphysema, lung and heart diseases, and respiratory allergies.[20] The US EPA estimates that a proposed set of changes in diesel enginetechnology (Tier 2) could result in 12,000 fewer premature mortalities, 15,000 fewer heart attacks, 6,000 fewer emergency room visits by children with asthma, and 8,900 fewer respiratory-related hospital admissions each year in the United States.[citation needed]
The US EPA estimates allowing a ground-level ozone concentration of 65 parts per billion, would avert 1,700 to 5,100 premature deaths nationwide in 2020 compared with the current 75-ppb standard. The agency projects the stricter standard would also prevent an additional 26,000 cases of aggravated asthma, and more than a million cases of missed work or school.[21][22]
The worst short term civilian pollution crisis in India was the 1984 Bhopal Disaster.[23] Leaked industrial vapours from the Union Carbide factory, belonging to Union Carbide, Inc., U.S.A., killed more than 25,000 people outright and injured anywhere from 150,000 to 600,000. The United Kingdom suffered its worst air pollution event when the December 4 Great Smog of 1952 formed over London. In six days more than 4,000 died, and 8,000 more died within the following months.[citation needed] An accidental leak of anthrax spores from a biological warfare laboratory in the former USSR in 1979 near Sverdlovsk is believed to have been the cause of hundreds of civilian deaths.[citation needed] The worst single incident of air pollution to occur in the US occurred in Donora, Pennsylvania in late October, 1948, when 20 people died and over 7,000 were injured.[24]
A new economic study of the health impacts and associated costs of air pollution in the Los Angeles Basin and San Joaquin Valley of Southern California shows that more than 3800 people die prematurely (approximately 14 years earlier than normal) each year because air pollution levels violate federal standards. The number of annual premature deaths is considerably higher than the fatalities related to auto collisions in the same area, which average fewer than 2,000 per year.[25][26][27]
Diesel exhaust (DE) is a major contributor to combustion derived particulate matter air pollution. In several human experimental studies, using a well validated exposure chamber setup, DE has been linked to acute vascular dysfunction and increased thrombus formation.[28][29] This serves as a plausible mechanistic link between the previously described association between particulates air pollution and increased cardiovascular morbidity and mortality.
What are toxic air pollutants?
Toxic air pollutants, also known as hazardous air pollutants, are those pollutants that are known or suspected to cause cancer or other serious health effects, such as reproductive effects or birth defects, or adverse environmental effects. EPA is working with state, local, and tribal governments to reduce air toxics releases of 187 pollutants to the environment. Examples of toxic air pollutants include benzene, which is found in gasoline; perchloroethylene, which is emitted from some dry cleaning facilities; and methylene chloride, which is used as a solvent and paint stripper by a number of industries. Examples of other listed air toxics include dioxin, asbestos, toluene, and metals such as cadmium, mercury, chromium, and lead compounds.
What are the health and environmental effects of toxic air pollutants?
People exposed to toxic air pollutants at sufficient concentrations and durations may have an increased chance of getting cancer or experiencing other serious health effects. These health effects can include damage to the immune system, as well as neurological, reproductive (e.g., reduced fertility), developmental, respiratory and other health problems. In addition to exposure from breathing air toxics, some toxic air pollutants such as mercury can deposit onto soils or surface waters, where they are taken up by plants and ingested by animals and are eventually magnified up through the food chain. Like humans, animals may experience health problems if exposed to sufficient quantities of air toxics over time.
Where do toxic air pollutants come from?
Most air toxics originate from human-made sources, including mobile sources (e.g., cars, trucks, buses) and stationary sources (e.g., factories, refineries, power plants), as well as indoor sources (e.g., some building materials and cleaning solvents). Some air toxics are also released from natural sources such as volcanic eruptions and forest fires.
How are people exposed to air toxics?
People are exposed to toxic air pollutants in many ways that can pose health risks, such as by:
• Breathing contaminated air.
• Eating contaminated food products, such as fish from contaminated waters; meat, milk, or eggs from animals that fed on contaminated plants; and fruits and vegetables grown in contaminated soil on which air toxics have been deposited.
• Drinking water contaminated by toxic air pollutants.
• Ingesting contaminated soil. Young children are especially vulnerable because they often ingest soil from their hands or from objects they place in their mouths.
• Touching (making skin contact with) contaminated soil, dust, or water (for example, during recreational use of contaminated water bodies).
Once toxic air pollutants enter the body, some persistent toxic air pollutants accumulate in body tissues. Predators typically accumulate even greater pollutant concentrations than their contaminated prey. As a result, people and other animals at the top of the food chain who eat contaminated fish or meat are exposed to concentrations that are much higher than the concentrations in the water, air, or soil.
Can I find out about the toxics in my community?
• National Air Toxics Assessment -- This site provides emissions and health risk information on 33 air toxics that present the greatest threat to public health in the largest number of urban areas. Maps and lists are available and can be requested by state or county level.
• Toxics Release Inventory -- This database includes information for the public about releases of toxic chemicals from manufacturing facilities into the environment through the air, water, and land. You can access the data by typing in your zip code.
Pollutants and Sources
The Pollutants
Hazardous air pollutants, also known as toxic air pollutants or air toxics, are those pollutants that cause or may cause cancer or other serious health effects, such as reproductive effects or birth defects, or adverse environmental and ecological effects. EPA is required to control 187 hazardous air pollutants. Examples of toxic air pollutants include benzene, which is found in gasoline; perchlorethlyene, which is emitted from some dry cleaning facilities; and methylene chloride, which is used as a solvent and paint stripper by a number of industries. Through appropriate rulemaking, the Clean Air Act list can be modified. A current list of modifications is available. Some clarification on certain pollutant aggregation is also available.
The Sources
Most air toxics originate from human-made sources, including mobile sources (e.g., cars, trucks, buses) and stationary sources (e.g., factories, refineries, power plants), as well asindoor sources (e.g., building materials and activities such as cleaning). There are two types of stationary sources that generate routine emissions of air toxics:
• "Major" sources are defined as sources that emit 10 tons per year of any of the listed toxic air pollutants, or 25 tons per year of a mixture of air toxics. These sources may release air toxics from equipment leaks, when materials are transferred from one location to another, or during discharge through emission stacks or vents
• "Area" sources consist of smaller-size facilities that release lesser quantities of toxic pollutants into the air. Area sources are defined as sources that emit less than 10 tons per year of a single air toxic, or less than 25 tons per year of a combination of air toxics. Though emissions from individual area sources are often relatively small, collectively their emissions can be of concern - particularly where large numbers of sources are located in heavily populated areas.
EPA published the initial list of "source categories" in 1992 (57FR31576 , July 16, 1992) and since that time has issued several revisions and updates to the list and promulgation schedule. For each listed source category, EPA indicates whether the sources are considered to be "major" sources or "area" sources. The 1990 Clean Air Act Amendments direct EPA to set standards for all major sources of air toxics (and some area sources that are of particular concern
Air Pollution and Human Health
Scientific experts now believe the nation faces an epidemic of illnesses that are exacerbated by air pollution. These illnesses include cardiovascular disease, asthma, chronic obstructive pulmonary disease, lung cancer, and diabetes.
Children at Special Risk
The American Academy of Pediatrics has concluded that levels of ozone and particulate matter are high enough in many parts of the U.S. to threaten children’s health. (1) Eleven million U.S. children live in areas that exceed one or more federal air quality standards; 9 million children live in areas where ozone standards are exceeded; 3.5 million children live in areas where the particulate standards are exceeded, and 2.8 million children live in counties where the carbon monoxide standard is exceeded. (2)
Elderly at Special Risk
Cardiovascular disease, hypertension, diabetes and cancer are all ill-nesses disproportionately borne by the elderly. Nearly one-half million Connecticut residents are over 65 years of age.
Asthma
Chemicals in vehicle exhaust are harmful to asthmatics. Exhaust can adversely affect lung function (3,4,5,6) and may promote allergic reactions and airway constriction. (7) All vehicles, especially diesel engines, emit very fine particles that deeply penetrate lungs and inflame the circulatory system, damaging cells and causing respiratory problems. (8) Even short-term exposure to vehicle exhaust may harm asthmatics. (9,10,11,12) Asthmatic children are particularly sensitive to air pollution. New England states have some of the highest asthma rates in the country. About 9 percent of Connecticut’s youth have the disease. (13) Inhalation of vehicle emissions, even for short periods, may be harmful to asthmatics. One study found that children are 40 percent more likely to have an attack on high outdoor pollution days. (14)
Chronic Obstructive Pulmonary Disease
Vehicle emissions are particularly harmful to people afflicted with chronic obstructive pulmonary disease (COPD), such as chronic bronchitis. Significant and replicated associations have been found between increased ozone levels and a range of adverse effects on the lungs, (15) and several studies have shown increased risk of hospital admission from COPD associated with high ozone levels. (16) There is also a relationship between the levels of PM10 and morbidity (17) in patients with COPD. These associations were noted in Philadelphia, where the major source of these particles is motor vehicles. (18) Fine particle matter is especially harmful to people with COPD (19, 20) and has been found to increase their hospital admission rates. (21) High levels of PM10 are also associated with increased morbidity among those with the illness.
Cardiovascular Disease
Mortality and hospital admissions for myocardial infarction, congestive cardiac failure and cardiac arrhythmia increase with a rise in the concentrations of particulate and gaseous pollutants. (22) As concentrations of airborne particles increase, those with cardiovascular disease may experience increasing severity of symptoms, rates of hospitalization, and mortality. (23) The risk of having a heart attack is greater for people exposed to pollution from heavy traffic, as well as for those living near air-polluted roadways. (24)
Cancer
Vehicles emit numerous carcinogenic chemicals. Diesel contains benzene, formaldehyde, and 1,3-butadiene—all three are well recognized carcinogens. EPA estimates that vehicle emissions account for as many as half of all cancers attributed to outdoor air pollution. (25)
Diabetes
Increasing levels of air pollution are associated with rising mortality rates among diabetics. Because of the overlap between diabetes and cardiovascular disease, the nature of this association is not yet clear. (26)
Air Pollution Increases Mortality Among Susceptible Groups
Air pollution kills more Americans than breast and prostate cancers combined, (27) and the premature deaths associated with particulate matter pollution alone are comparable to deaths from traffic accidents. (28) Air pollution is a serious and growing threat to the health of Connecticut residents. We estimate that nearly one million of Connecticut’s 3.5 million residents experience one or more of these illnesses, some without knowing it.
Vehicle Emissions
Mobile emissions that are believed to present the greatest health risk to Connecticut residents include ozone, particulate matter, acetaldehyde, acrolein, benzene, 1,3-butadiene, formaldehyde, and diesel exhaust.
Ozone and Motor Vehicles
Motor vehicles emit millions of pounds of hazardous pollutants into the air each year in the U.S., including volatile organic compounds and oxides of nitrogen (NOx). These chemicals form ozone in the presence of sunlight.
Fine Particulate Matter
Fine particulate matter is a serious threat to human health. Fine particles can aggravate both heart and lung diseases. Those with diabetes, older adults, and children are especially sensitive. Fine particulate matter is responsible for several tens of thousands of premature deaths annually in the U.S. (29) and is measured at levels above federal air quality standards in Connecticut. (30)
Diesel Exhaust
Diesel exhaust is especially dangerous, containing nearly 40 hazardous pollutants. The mixture contains carbon particles that are exceptionally small in size, less than one micron. These fine particles may be deeply inhaled into the lung and carry with them a collection of attached hazardous compounds. Diesel emissions increase the severity and duration of asthma attacks.
Diesel Emissions
The California Air Resources Board concluded that diesel emissions account for the majority of cancer risk created by all outdoor air pollution sources in the state. The American Academy of Pediatrics recommends that children’s exposure to diesel exhaust particles should be decreased and that idling of diesel vehicles in places where children live and congregate should be minimized to protect their health. (31) School bus particulate emissions sometimes exceed the federal PM2.5 standards by as much as ten-fold.
Averaging Air Pollution
The government is allowed to average some pollutants across long periods of time. For example, PM2.5 is permitted to be averaged over 24 hour intervals, and the 24-hour averages are then averaged over three years, before compliance with federal standards is determined. The results mask serious high pollution episodes. Medical scientists have determined that much shorter-term exposures, measured in hours or minutes, are potentially dangerous to susceptible populations, such as those with cardiovascular, respiratory, and other illnesses.
Air Quality Monitoring Deficiencies
Government understanding of the severity of air pollution depends upon what is being monitored and where the monitoring occurs. Air quality varies across space and time, and is dependent upon climatic conditions. It is poorest, but may not be monitored, where traffic is most intense, normally where highways slow near urban areas, near construction sites, and where trucks, buses, and cars tend to concentrate and idle: schools, hospitals, shopping centers, truck stops, warehouses, ports and shipping facilities, oil tank farms, rail stations, bus terminals, and where gas and diesel powered vehicles are used within warehouses or ships.
Diesel Fuel Consumption
Use of diesel fuel doubled in the U.S. between 1982 and 1998. The demand for transportation fuel continues to rise throughout the nation, particularly for diesel fuel.
Fuel Economy Stagnation
In the last 15 years, there has been little improvement in the miles per gallon (MPG) rating of cars and light trucks. The average MPG achieved by trucks has remained the same for the last 30 years at approximately 5.5 miles per gallon.
Highways as Air Pollution Corridors
Highways are recognized by scientific experts to act as three-dimensional corridors of air pollution containing many hazardous chemicals.
Fuel Oil Consumption
Home heating fuel is essentially the same as diesel fuel, although the sulfur content is higher. Connecticut is exceptionally dependent on No. 2 fuel oil for heating purposes, and last year ranked fourth in the nation in raw consumption at more than 660 million gallons. By contrast, 230 million gallons of diesel fuel were used for transport purposes. Connecticut ranks first in the nation in fuel oil consumption per square mile of state area. This means that diesel pollution will be most severe where residential and traffic density are highest. It also explains the high particulate counts routinely measured in areas where population density is high and where multiple traffic lanes funnel into single lanes. Chronic traffic congestion leads to chronic human exposure to known hazardous air pollutants.
PM2.5 Non-Compliance
Fine particulate matter in Connecticut exceeds federal air quality standards. (32) During the first six months of 2005, levels of fine particulates, or PM2.5, in New Haven, Connecticut, exceeded the federal standard for 70 days, roughly 40 percent of the time.
Ozone Non-Compliance
The entire state of Connecticut exceeds the eight-hour ozone standard. (33)
Connecticut’s Dependence on Motor Vehicles
Fewer than three percent of Connecticut residents walk to work, (34) and 45 percent of all Connecticut trips under a half-mile are made in a vehicle. (35) Connecticut residents spend on average 70 minutes a day in their cars, often breathing this polluted air. (36)
Connecticut Citizens’ Proximity to Highways
One in three Connecticut citizens live within a mile of an interstate highway. As many as 70,000 of those residents are under the age of five. (37) In addition, 37 percent of the state’s schools are located within a mile of an interstate highway. (38)
Vehicle Miles Traveled (VMT)
Connecticut residents own nearly three million vehicles, and travel nearly 31 billion miles each year. Each year residents put more miles on their vehicles in a year than ever before. The number of vehicles driven in the state is also growing. Between 1995 and and 2000, state residents increased the miles driven by 10 percent (39) and this trend is expected to continue. The number of Vehicle miles traveled (VMT) in the state is projected to rise by another 12 percent by 2010 and by 27 percent by 2025. (40) The increase in VMT in recent years has overwhelmed the technological advances made with respect to vehicle emissions reductions. (41)
Idling and Wasted Fuel
The U.S. Argonne National Laboratory estimates that about 20 million barrels of diesel fuel are consumed each year by idling long-haul trucks. Estimated truck emissions total about 10 million tons of CO2, 50,000 tons of nitrogen oxides, and 2,000 tons of particulates. (42)
Natural Resources
Canada estimates that idling a light duty vehicle for 10 minutes a day uses an average of 26.4 gallons (100 liters) of gas a year. Assuming Connecticut has approximately 2.2 million light duty vehicles, if idling time were reduced by 10 minutes per day for each, nearly 58 million gallons of gas would be saved per year, along with $145 million in fuel costs per year if one assumes that gas costs $2.50 per gallon.
Vehicle Emissions and Climate Change
Vehicle emissions contribute to air pollution generated from the combustion of fossil fuels from many other sources, including the burning of coal and oil in power plants, incinerators, home heating oil, and construction equipment. The combustion of gas and diesel fuels produce greenhouse gases that are contributing to local, regional and global climatic changes. A recent study published in Science analyzed more than 900 scientific articles listed with the keywords “global climate change.” Not one disagreed with the consensus view that humans are contributing to global warming. (43) Little initiative is expected on this issue at the national and international levels of government. Connecticut has the potential to become a leader among states in reducing these gases.
Carbon Dioxide
Carbon dioxide (CO2), considered the largest contributor to greenhouse climate change, accounts for more than 80 percent of U.S. greenhouse gas emissions. One-third of these emissions come from the transportation sector. (44) Carbon dioxide emissions originate almost entirely from fossil fuel consumption, and two-thirds of U.S. fuel consumption is used for transportation.