Abstract
Millions of Americans live in areas where air pollution levels are high enough to cause both acute and chronic health effects. Those Americans most exposed to air pollution are often low-income families and people of color living in close proximity to industrial air pollution sources and freeways. APHA believes that breathing clean air is a basic right of all people and that more robust funding and enforcement of air quality programs under the Clean Air Act are needed to ensure that improvements to the nation’s air quality continue. The U.S. Environmental Protection Agency (EPA) should aggressively address localized exposures to hazardous air pollutants and provide leadership in implementing innovative miniaturized monitoring technologies that promise to change the paradigm for air quality exposure assessment in the United States. State and local agencies and health departments should collaborate with the EPA to address disproportionate exposures to air pollution in communities, improve communication with industry and the public on steps to reduce exposures, and incorporate air quality information into professional training, university degree programs, and K–12 science curricula. Health professionals should help government officials and the public recognize how the health benefits associated with clean air, including reduced hospital visits and fewer missed days at school and work due to illness, far outweigh the costs of air pollution control. Finally, APHA calls upon the public and government agencies and health departments to forcefully defend policies aimed at fighting climate change because of the air quality benefits associated with reduced global warming and greater reliance on renewable energy sources.
Relationship to Existing APHA Policy Statements
This policy statement builds upon and replaces APHA Policy Statement 200017 (Confirming Need for Protective National Health Based Air Quality Standards). It is also consistent with the following policy statements that reference or are related to air pollution:
This new policy statement is also consistent with a number of older statements, many of which have been archived. Included among these older policy statements are 8912 (Public Health Control of Hazardous Air Pollutants) and 8530 (Ambient Air Quality Standards for Short-term Exposure to Sulfur Dioxide).
Problem Statement
Under the Clean Air Act, the United States has made substantial progress in reducing air pollutants that threaten public health and damage crops and materials. Despite this progress, poor air quality and localized exposures to hazardous air pollutants remain problems in many urban areas, representing significant health risks for millions of Americans. Children and older adults are particularly at risk, and low-income and minority populations often suffer disproportionately from air pollution. More progress in implementing the Clean Air Act is needed for everyone to enjoy their right to clean air.
Emissions of the six common pollutants for which there are national ambient air quality standards—carbon monoxide, lead, nitrogen dioxide, ozone, particulate matter, and sulfur dioxide—have decreased by 65% since 1980.[1,2] This is an impressive accomplishment, particularly given that factors tending to increase pollution (e.g., population growth, national energy consumption, vehicle miles driven, and gross domestic product) have steadily risen at the same time. Nevertheless, in 2015 about 121 million Americans still lived in counties having air pollution levels exceeding one or more of the national ambient air quality standards.[1,2] These Americans, in addition to many others who are sensitive to air pollution (especially children, pregnant women, older adults, and people with compromised immune systems), are at increased risk for lung and heart disease, asthma, chronic cough, throat irritation, shortness of breath, and other adverse health conditions.[3–12]
Many Americans are also exposed to unacceptable levels of hazardous air pollutants (also known as toxic air pollutants or, simply, air toxics).[13–17] Air toxics are known or suspected to cause cancer and other serious health conditions, including neurological effects, reproductive problems, and birth defects. There are many types of air toxics (the Clean Air Act lists 188 of them), but the ones contributing most to national cancer risks are believed to be acetaldehyde, benzene, diesel emissions, and formaldehyde, while those contributing most to non-cancer risks are believed to be acrolein, chlorine, and diesel particulate matter.[14,16] Air toxics are not as widespread as the six ambient pollutants discussed above, and they tend to represent more of a localized problem for people living in close proximity to certain industrial air pollution sources and freeways. In its latest national air toxics assessment (released in December 2015), the U.S. Environmental Protection Agency (EPA) found an elevated cancer risk from exposure to air toxics, particularly in urban areas, with the risk greater than 100 in 1 million in about 130 census tracts.[14] Both industrial operations and mobile sources contribute to this risk.
While everyone is at increased risk of health effects from air pollution exposures, children, pregnant women, and older adults are especially vulnerable.[8–10] Children breathe more than adults on a body-weight basis (e.g., a 3-month-old infant breathes 35 times more air per body weight than an adult), and substantial lung development occurs through adolescence. Children are also more likely to spend time outdoors breathing polluted air, and, through oral exploration, infants and toddlers may be exposed to dirt and other objects contaminated by air pollution. In addition, air pollutants can interfere with development of the nervous, reproductive, and metabolic systems during childhood.[18–22] In the case of pregnant women, compensatory cardiopulmonary system changes that occur during pregnancy are essential to maintaining the pregnancy but may also render women exposed to air pollution vulnerable to cardiopulmonary effects. These effects can contribute to poor health outcomes during pregnancy and beyond for both mother and baby.[8–10] Finally, the bodies of older adults are less able to compensate for exposure to air pollution, often due to existing conditions such as chronic obstructive pulmonary disease, asthma, and diabetes.[5,23–25] Air pollution exposure also increases the risk for cardiovascular events.[23] The result is that older adults living in polluted environments may increase medication use and spend more time in the doctor’s office and emergency room. In addition to children and older adults, people who work or exercise outdoors, who are obese, or who have lung diseases such as asthma are more susceptible to polluted air.[5,10,11]
Exposure to the highest levels of air pollution generally occurs in urban areas, where air pollution concentrations can reach unacceptable levels due to the proximity and density of industrial, commercial, and mobile sources. The EPA is particularly concerned about elevated concentrations of ground-level ozone and fine particulate matter (i.e., particles with a diameter of less than 2.5 micrometers), which are implicated in a number of adverse health outcomes.[26,27] For example, ozone can inflame the airways, causing chest pain, coughing, wheezing, and shortness of breath, and these conditions can be worse in people with existing lung disease, including asthma. Fine particles can harm the cardiovascular system and cause respiratory disease, sometimes resulting in premature death. Ozone and fine particles also contribute to climate change, which in turn can create more ground-level ozone. (Climate change contributes to heat waves as well, which increase power demand for air conditioning, resulting in more air pollution.) More than 45 million Americans in urban areas live, work, or attend school within 300 feet of a major roadway, airport, or railroad, each of which is a major source of polluted air.[27] With the EPA’s latest mobile source rules, mobile sources are becoming much cleaner, but more work needs to be done to ensure that the standards are vigorously enforced, especially in vulnerable communities.[28]
There is increasing awareness that air toxics also constitute a significant health risk in urban environments, particularly for low-income families and people of color who often live closest to freeways and sources of industrial air toxics.[29–31] This represents a serious environmental equity problem for millions of Americans residing in urban areas, who are disproportionately exposed to high levels of air pollution because of where they live. Often these low-income families and people of color are underrepresented in pollution abatement programs, and they may face economic constraints that prevent them from moving to cleaner environments and create barriers to receiving medical care. The result is that polluted air represents an impediment to economic opportunity and security. Many health professionals consider clean air a basic right for all people, and for a number of years the EPA has called for greater attention to environmental justice, defined by the agency as “the fair treatment and meaningful involvement of all people regardless of race, color, national origin, or income, with respect to the development, implementation, and enforcement of environmental laws, regulations, and policies.”[29] However, there is still much work to be done to address disparities in air pollution exposure.
Unfortunately, very limited federal research funding has been allocated to studying environmental justice, and it is difficult to estimate the extent of the problem, particularly with respect to the long-term effects of exposure to air toxics. Nevertheless, we know that among the 24 million Americans suffering from asthma, minority communities are disproportionately affected. For example, African American children are four times more likely than White children to be hospitalized for asthma, and they are seven times more likely to die from an asthma attack. Similarly, Hispanics are 60% more likely than non-Hispanic Whites to visit a hospital for severe asthma symptoms.[29]
One of the most egregious sources of air pollution is electric power generation with fossil fuels.[8–10,17] There are about 1,400 coal- and oil-fired electric power plants in the United States, and many still do not have advanced pollution control equipment. In addition to being the largest domestic source of carbon dioxide (the most widespread global warming gas in the United States), these electric power plants are responsible for 62% of the nation’s arsenic air pollution, 60% of sulfur dioxide, 50% of mercury, 22% of chromium, and 13% of nitrogen oxides. The EPA has a number of rules limiting emissions from electric power plants using fossil fuels, including rules for mercury, sulfur dioxide, nitrogen oxides, and particulates. To comply with these rules, some plants have installed expensive emission controls while others have shut down, in some cases to be replaced by cleaner renewable energy (e.g., solar, wind, and geothermal power). Also, state and local agencies are promoting power plant emission reductions by developing green building standards and implementing energy-efficiency and renewable energy policies.
In addition to regulating ambient air pollutants and air toxics, the Clean Air Act requires a reduction in pollutants that deplete the Earth’s stratospheric ozone layer, which is located between 10 and 25 miles above the Earth’s surface. The stratospheric ozone layer plays a crucial role in reducing the amount of ultraviolet (UV) radiation that reaches the Earth’s surface and in preventing skin cancer. Skin cancer is the most common form of cancer diagnosed in the United States, and the majority of skin cancer cases are caused by exposure to UV radiation from the sun. The surgeon general reports that nearly 5 million people in the United States are treated for skin cancer each year, at an annual cost of about $8 billion, and nearly 9,000 people die annually from melanoma, the most dangerous form of skin cancer.[32] The EPA, in collaboration with the National Weather Service, has developed a UV index to forecast the risk of overexposure to ultraviolet radiation according to local weather conditions and other factors.[33]
Air pollution does not recognize international boundaries. Thus, air pollutants originating in the more industrialized regions of the world, including the United States, Europe, and China, routinely drift to other regions, worsening existing air quality problems. For example, a recent study showed that the transport of ozone and its precursors from China can offset U.S. air quality gains, and other studies have documented the presence of ozone, ozone precursors, and particulate matter originating along the U.S. East Coast at remote Atlantic and European ground stations.[34–36] The international community has taken steps to address the cross-boundary transport of air pollution through the United Nations Convention on Long-range Transboundary Air Pollution.
Of course, public health concerns about air pollution are not limited to the United States. According to the World Health Organization (WHO), 92% of the world’s population in 2014 was living in areas where WHO air quality guidelines were not met; in addition, outdoor air pollution caused 3 million premature deaths in 2012, mostly in low- and middle-income countries in the Western Pacific and Southeast Asia.[37] About 72% of these premature deaths were caused by ischemic heart disease and strokes, 14% by chronic obstructive pulmonary disease or acute lower respiratory infections, and 14% by lung cancer. Some deaths were attributed to more than one risk factor occurring at the same time, for example air pollution and smoking, which are both associated with lung cancer. (WHO also estimates that about 4.3 million premature deaths in 2012 were caused by indoor air pollution associated with use of biomass and coal for cooking and heating.) WHO’s International Agency for Research on Cancer has determined that outdoor air pollution as a broad category is carcinogenic, especially the particulate matter component.[38]
A problem in regulating air pollution is that generally we cannot see it. For example, gaseous pollution is usually invisible, and fine particulate air pollution is much too small to see with the unaided eye. This highlights the challenge and also the importance of communicating air pollution risks to the public. The EPA has made great strides in communicating air pollution health risks, for example by providing daily air quality reports through its AirNow Air Quality Index; this index is routinely included in local and national weather reports, particularly during air pollution episodes.[39,40] (The index translates air pollution data into numbers and colors that help people know when to modify their activities, such as limiting outdoor exercise or remaining indoors.) State and local agencies need to make better use of the Air Quality Index to trigger certain events, such as providing reduced-fare or free public transportation or banning fireplace and woodstove use when air quality is poor.
Indoor air quality refers to the quality of the air we breathe inside buildings, such as offices, factories, homes, schools, and hospitals. Because Americans spend about 90% of their time indoors, poor indoor air quality can be an even greater concern for some people than outdoor air pollution.[41–44] For example, the EPA estimates that indoor air pollution levels can be two to five times higher than outdoor levels and, occasionally, more than 100 times higher. Reducing indoor air pollution in schools is especially important because children are more sensitive to air pollutants and spend much of their day inside school buildings, which tend to be more densely occupied than homes and offices. The EPA does not regulate indoor air quality, but it does issue guidelines to reduce exposures and offer grants for research and training. Unfortunately, this program has been curtailed in recent years, despite mounting evidence of the adverse health effects of poor indoor air quality.[45–49] Irritation of the eyes, nose, and throat is an increasingly common complaint inside buildings. Other concerns range from headaches, dizziness, and fatigue to more serious, long-term issues such as respiratory and heart disease and cancer. Researchers also fear that climate change may worsen existing indoor air quality problems and introduce new problems.[50,51]
A growing concern of APHA is preserving the strength, integrity, and independence of the EPA. Many Americans have recently witnessed on TV news broadcasts the horrendous air pollution episodes routinely occurring in Beijing, where strong evidence has emerged of an association between fine particulate pollution, emergency room admissions, and respiratory disease morbidity, particularly among women and older adults.[52] Without the protections of the Clean Air Act and a strong and independent EPA, it is not inconceivable that we would return to the days when dense smog darkened the daylight hours in our large cities, filling our emergency rooms with the individuals most sensitive to air pollution, especially children, pregnant women, and older adults. Furthermore, a strong and independent EPA is needed to protect the public from new chemicals in the environment, many of which are known or suspected carcinogens. Low-income and minority communities are particularly vulnerable to these toxic air emissions.
Evidence-Based Strategies to Address the Problem
Recommended strategies are centered around increasing EPA funding for ambient and community-scale air toxics programs, focusing more resources on environmental justice issues, developing and validating advanced monitoring and data analysis technologies, and promoting clean power (greenhouse gas reduction) programs because of the air quality co-benefits. The rationale for these strategies is presented below.
There is a critical need for Congress and the White House to increase funding to the EPA, making up for recent budget cuts and providing additional funding for innovation and research. During the period 2010 to 2016, when the EPA’s budget dropped 21% and positions were reduced by 11%, the nation’s air quality programs experienced commensurate reductions in key initiatives aimed at implementing and enforcing the Clean Air Act. Budget increases are needed across the board, but particularly for the national ambient air quality program, the maximum achievable control technology program for air toxics, and various area source and urban pollution initiatives. These and other key provisions of the Clean Air Act are behind schedule or not even being addressed due to budget shortfalls.
One important air quality initiative that has not received sufficient funding concerns community-scale air toxics. There is an impressive knowledge base on air toxics nationwide, particularly those toxic pollutants listed in the Clean Air Act, but little is known about air toxics exposures on a local scale in many communities throughout the United States. Although there are thousands of air quality monitors for ambient air quality pollutants, surprisingly only 29 air monitoring stations exist nationwide for air toxics under the EPA’s National Air Toxics Assessment program.[14] This results in a paucity of air toxics exposure data for people living close to industrial and commercial air toxics sources and virtually no data for rural areas. Another shortcoming of the air toxics monitoring program is that most monitoring involves only the 188 toxic air pollutants listed in the 1990 Clean Air Act amendments, with little or no monitoring taking place for any new toxic chemicals developed since then. Most community-scale air toxics funding at the federal level is limited to an EPA $10 million competitive grant program for state and local agencies, and there is no assurance that this program will be continued.[26]
The deficit in air toxics monitoring is all the more serious because many low-income families and people of color live in inner-city and industrial areas where air toxics concentrations would be expected to be highest and where little monitoring currently takes place. This is a serious environmental equity issue that needs to be addressed. Because many air toxics chemicals are suspected or confirmed carcinogens, it is incumbent upon the federal government, under the EPA’s leadership, to allocate resources toward understanding air toxics exposures at the community scale, thereby ensuring that air toxics rules target sources associated with the greatest risk to public health while addressing environmental equity concerns in our cities.
Another critical air quality need that is not being adequately addressed involves the development and validation of advanced monitoring technologies and associated data analyses. The development of miniaturized, low-cost air quality monitors represents an important step forward in assessing air pollution exposure and public health risk. Several organizations are involved with the miniaturization of air quality monitors, and we are quickly approaching a time when tens of thousands of environmentally conscious citizens will pin these miniature monitors to their clothing while shopping or going to and from work. (Other monitors may be placed on auto rooftops, providing real-time air quality data, similar to the way today’s GPS systems amass data on traffic conditions and recommend alternate routes.) This will create vast amounts of data, potentially collected and transmitted through smart phones or smart watches, that must be managed and analyzed. And for the first time, the federal government may find itself having little control over the collection and analysis of air quality data and interpretation of exposure levels (including spatial and temporal factors) for potential health consequences.
Because different manufacturers are involved in developing and marketing these miniature monitoring devices, an urgent need is evolving for validating the accuracy and precision of the monitored data, possibly by third-party organizations subject to EPA standards and oversight. In addition, computer systems and software must be developed to collect, analyze, and interpret potentially tens of millions of data points collected daily from across the United States. Also, educational material will be needed to help the public understand what the data mean and what actions are required to minimize exposures (e.g., understanding why there may be a high particulate pollution reading at a bus stop but not in the park a block away and what this mean for one’s health). Once these issues are addressed, the miniaturization of air quality monitoring devices will revolutionize the way we collect environmental data and protect the public from high levels of exposure.
Finally, the public health community must do all it can to preserve the goals of the EPA’s Clean Power Plan (CPP), even if the plan itself does not survive at the federal level. (The CPP is currently under review by the Trump administration.) Although the CPP is designed to reduce greenhouse gas emissions from the power sector, there are also substantial public health benefits to be realized by concomitant reductions in other pollutants, including sulfur dioxide, nitrogen oxides, and particulates that contribute to dangerous urban soot and smog.[45,46,53,54] Through reductions in these pollutants, the EPA estimates that 3,600 premature deaths, 1,700 heart attacks, 90,000 asthma attacks, and 300,000 missed work and school days could be avoided every year under the CPP. The dollar value of these benefits is estimated at between $14 and $34 billion annually. Regardless of whether there is a federal CPP requirement, the states need to implement the provisions of the CPP or similar provisions, along with energy-efficiency and renewable energy requirements, to realize the maximum health and dollar benefits for their states.
If clean air strategies, including public outreach programs, are to be successful, collaboration with a range of public and private organizations (e.g., industry trade associations, nonprofit groups, and environmental organizations) will be essential. Equally important is the involvement of local community groups having firsthand experience with air pollution and environmental justice issues in their neighborhoods. Tribal organizations are often overlooked and also need to be involved in environmental assessment actions involving their territories, including air pollution originating outside of territorial boundaries. Ultimately, the primary objective must be to build a strong constituency for the Clean Air Act so that when Congress debates the merits of the act and funding for the EPA, a wide spectrum of Americans and American businesses will defend clean air programs.
One strategy not recommended is amending the Clean Air Act. While there is more work to be done to fully implement the provisions of this landmark clean air legislation, the act already provides the tools and regulatory mechanisms necessary to continue making progress on the nation’s most serious air quality challenges.[24] There has been some discussion in Congress over the years about whether the act should be revised to take costs into consideration when setting national ambient air quality standards. (Currently, the EPA performs a cost-benefit analysis as part of its regulatory impact analysis, but costs are not used to set the levels of the standards.) However, most air quality managers and many legislators believe that these standards should be based solely on the exposure levels needed to protect public health without regard to costs, and this policy statement is in agreement. (Costs are considered later when states decide on the most practicable and cost-effective approaches to comply with the standards.) More work is needed to fully implement the act, but there is little to be gained at this time from changing the legislation itself.
Opposing Arguments/Evidence
Air pollution regulation is under greater scrutiny now than at perhaps any time since the Clean Air Act legislation was enacted in 1970. Most of the arguments against air pollution regulation focus on the costs of pollution control relative to the health benefits, on damage to the competitiveness of American industry and loss of jobs, and on the importance of decentralizing regulatory actions (i.e., giving states and communities more autonomy in setting regulations because, it is argued, they better understand local issues and circumstances). Other arguments are driven by the desire of some state and industry leaders to expand fossil fuel production, particularly coal mining.
It is true that air pollution controls at electric power facilities and in other industries can be quite expensive, sometimes costing billions of dollars on a nationwide basis. However, studies have consistently demonstrated that the costs of air pollution control are far outweighed by the benefits to society: improved public health, fewer sick days for students and workers, and reduced health care expenses. For example, the Obama administration’s climate change rules for power plants, which also reduce urban soot and smog, would achieve up to four dollars in health benefits for every dollar invested in complying with the rules.[46] (These rules are currently under review by the Trump administration.) Also, the EPA’s Second Prospective Study estimates that the benefits of air pollution control under the Clean Air Act substantially exceed costs, ranging from a factor of 3 to 90 depending on assumptions.[47] Finally, according to the Office of Management and Budget’s 2015 Report to Congress on the Benefits and Costs of Federal Regulations and Agency Compliance With the Unfunded Mandates Reform Act, costs for 22 rules issued by the EPA air program office ranged from $36.6 to $44.1 billion, whereas benefits ranged from $157.4 to $777.9 billion (in 2010 dollars).[48] Thus, a strong argument can be made for air pollution regulation when considering benefits to American society as a whole. Furthermore, there is no evidence that air pollution controls make American industry less competitive.[49] Quite to the contrary, industries with state-of-the-art environmental controls tend to be more energy efficient, resource conscious, and innovative, and they are valued as good corporate citizens in their communities.
Interest in decentralizing pollution regulations away from Washington, D.C., is a manifestation of a broader political argument about the role of government that has been around since the founding of our country. While this argument was present when Congress first drafted the Clean Air Act, there was a stronger interest in establishing a “level playing field” among the states.[55] Without federal regulation applying uniformly to all states, each state would be free to develop regulations as stringent or lenient as it wished, without regard to regulations developed by other states. This scenario would present two problems. First, if one state’s regulations are tougher than another state’s, industries may tend to move to the state with the least stringent (and, thus, least costly) regulations. Second, because air pollution crosses boundaries between states, air pollution from states with lenient regulations may drift toward states with stringent regulations, worsening air quality in those states and negating the benefits of their tougher regulations. Congress judged that air pollution regulations set at the federal level (while still giving states some flexibility to set more stringent regulations) would largely avoid these problems. Thus, the Clean Air Act was born. The argument about decentralizing federal power will always be present, but other issues aside, public health benefits more from national ambient air quality regulations set and enforced by the federal government, which is in the best position to conduct research, assess health risks, and apply rules uniformly across the nation.
A particularly contentious issue concerns the potential loss of coal mining jobs due to air pollution controls that discourage the use of coal, especially in electric utility power plants (e.g., limits on mercury, sulfur, and particulate emissions). However, coal mining has been in decline for a number of years largely as a result of other economic factors, including the availability of less expensive natural gas, the retirement of many older coal-burning power plants, and the proliferation of renewable energy sources (e.g., solar panels and wind turbines). In 2016, only 55% of electric power generation and fuel technology workers were employed at traditional coal, oil, and gas facilities, while in that same year the solar energy workforce increased by 25% and wind energy employment increased by 32%.[56] Regardless of whether tough environmental regulations are in place, it is just a matter of time before renewable energy and low-emission natural gas facilities come to dominate the U.S. energy sector.
Action Steps
Therefore, APHA:
