Air Pollution: Unregulated Contaminants And Health Risks

The US Environmental Protection Agency (EPA) regulates air pollutants through the Clean Air Act (CAA), which requires the EPA to set National Ambient Air Quality Standards (NAAQS) for six common air pollutants, also known as criteria air pollutants. These pollutants, which include carbon monoxide, ground-level ozone, lead, nitrogen oxides, particulate matter, and sulfur dioxide, are harmful to both public health and the environment. While the EPA provides information and assistance on indoor air quality issues like mold and radon, it does not regulate indoor air. The EPA also works with state, local, and tribal governments to reduce emissions of toxic or hazardous air pollutants, such as benzene and perchloroethylene, which are known or suspected to cause cancer and other adverse health and environmental effects.

The Clean Air Act

One of the initial goals of the Clean Air Act was to achieve NAAQS in every state by 1975, recognising the risks posed by widespread air pollutants. To achieve these standards, states were directed to develop state implementation plans (SIPs) applicable to industrial sources. The Act has been amended several times to set new deadlines for achieving NAAQS, as many areas struggled to meet the initial targets.

Criteria Air Pollutants

The Clean Air Act (CAA) requires the US Environmental Protection Agency (EPA) to set National Ambient Air Quality Standards (NAAQS) for six commonly found air pollutants known as criteria air pollutants. These pollutants are carbon monoxide, ground-level ozone, lead, nitrogen oxides, particulate matter, and sulfur dioxide.

When the EPA establishes or revises a NAAQS, it sets in motion actions to ensure that air quality throughout the country meets those standards. The EPA designates areas as meeting (attainment) or not meeting (nonattainment) the standard. States must develop general and specific plans, known as state implementation plans (SIPs), to attain and maintain the standards, particularly for areas designated as nonattainment.

For example, New Hampshire was previously designated as nonattainment for the 1971 carbon monoxide standard, the 1979 1-hour and 1997 8-hour ozone standards, and the 2010 sulfur dioxide standard. However, New Hampshire's air quality currently meets all federal standards. Certain Northeast states, including New Hampshire, are part of the Ozone Transport Region (OTR) and must submit SIPs for ozone-forming pollutants regardless of attainment status.

The EPA's Clean Air Markets Division (CAMD) runs programs to reduce air pollution from power plants, addressing issues such as acid rain, ozone, and particulate pollution, as well as the interstate transport of air pollution. The EPA also provides information on greenhouse gas emissions, climate change impacts, and indoor air quality issues, although it does not regulate indoor air.

Toxic Air Pollutants

The Clean Air Act (CAA) requires the US Environmental Protection Agency (EPA) to regulate hazardous air pollutants, also known as air toxics, from categories of industrial facilities. These hazardous air pollutants are substances that are known to cause cancer and other serious health issues, including birth defects. The EPA has classified 188 pollutants as hazardous, including gases like hydrogen chloride, benzene, and toluene, and compounds and metals such as asbestos, cadmium, mercury, and chromium.

Major sources of outdoor toxic air pollutants include emissions from coal-fired power plants, industries, refineries, and vehicles like cars, trucks, and buses. Certain industries produce specific air toxins, such as ethylene oxide leaks from medical equipment sterilization facilities and other industrial sources. Chemical releases during accidents at industrial facilities or during the transport of hazardous materials can also release air toxics.

The Clean Air Act has led to the cleanup of many of these sources, but more work is needed. The EPA's Clean Air Markets Division (CAMD) runs programs to reduce air pollution from power plants, addressing issues like acid rain, ozone depletion, and particle pollution. The EPA establishes emission standards, known as "maximum achievable control technology" or "MACT" standards, for major sources that emit hazardous air pollutants. These standards are reviewed and revised as necessary to address any residual risks.

Indoor air can also contain hazardous air pollutants from tobacco smoke, building materials like asbestos, and consumer products like cleaning supplies and air fresheners. While the EPA does not regulate indoor air, they do offer assistance and information to help improve indoor air quality, including resources for issues like mold, radon, and formaldehyde.

Greenhouse Gas Emissions

The Clean Air Act (CAA) is a federal law that regulates air emissions from stationary and mobile sources. The Act requires the Environmental Protection Agency (EPA) to establish National Ambient Air Quality Standards (NAAQS) to protect public health and welfare and to regulate hazardous air pollutant emissions. The EPA is also responsible for creating a list of important categories of stationary sources of air pollution and establishing Federal standards of performance for new sources within these categories. These New Source Performance Standards (NSPS) include equipment specifications and operation and measurement requirements.

The EPA provides information about greenhouse gas emissions levels, sources of GHGs, partnerships, and options for cutting emissions. Greenhouse gas emissions come from various sectors, including transportation, electricity production, industry, commercial and residential, agriculture, and land use and forestry. The transportation sector is the largest source of direct greenhouse gas emissions due to the burning of fossil fuels for cars, trucks, ships, trains, and planes. Electricity production emissions come from electricity used by other end-use sectors, such as the industry. Industrial emissions are the third-largest source, resulting from burning fossil fuels for energy and specific chemical reactions to produce goods from raw materials.

Commercial and residential sector emissions are also significant, arising from burning fossil fuels for heat and using gases for refrigeration and cooling in buildings. Additionally, non-building-specific emissions, such as waste handling, contribute to this sector's emissions. Agriculture sector emissions are associated with livestock, agricultural soils, rice production, and powering buildings and equipment. Land areas can act as a sink, absorbing CO2 from the atmosphere, or a source of emissions, depending on land use and forestry practices.

To address these emissions, the EPA offers voluntary programs and provides information on climate change impacts and research. The EPA also develops regulations and policies to control air pollution through its Clean Air Markets Division (CAMD), which runs programs to reduce air pollution from power plants and address issues like acid rain and ozone depletion. While the EPA does not regulate indoor air, it offers assistance and information on improving indoor air quality by addressing mold, radon, formaldehyde, and other indoor air pollutants.

Wireless Technology Devices

The Clean Air Act (CAA) requires the EPA to set National Ambient Air Quality Standards (NAAQS) for six common air pollutants: carbon monoxide, ground-level ozone, lead, nitrogen oxides, particulate matter, and sulfur dioxide. However, the EPA does not regulate all aspects of air quality. For example, it does not regulate indoor air quality, though it does offer resources and information on improving indoor air quality and reducing mould and other contaminants.

While not directly regulated by the EPA, wireless technology devices have been proposed as a potential solution to the challenge of monitoring air pollution, particularly in urban areas. The development and installation of low-cost, wireless air quality sensors have been identified as a way to overcome the high costs associated with traditional air monitoring networks. These sensors can be mounted on public transportation or placed in static locations, providing real-time data on air pollution levels.

Wireless Sensor Networks (WSNs) have been specifically identified as a promising technology for air pollution monitoring. WSNs can incorporate low-cost electrochemical gas sensors that measure the concentrations of pollutant gases with relatively good accuracy. However, the reliability of these sensors over time has been questioned due to factors such as exposure to high levels of gases, temperature fluctuations, and moisture, which can lead to sensor aging and inaccurate readings.

Despite the challenges, the use of wireless technologies in air pollution monitoring is seen as an opportunity to reduce environmental impacts. By utilizing the mobility of public transportation and the advancements in sensing technologies, researchers have achieved significant breakthroughs in developing the Next Generation Air Pollution Monitoring System (TNGAPMS). This system aims to address the limitations of conventional air pollution monitoring systems by providing real-time data with high spatio-temporal resolution.

In conclusion, while wireless technology devices themselves are not regulated by the EPA, they have the potential to play a crucial role in monitoring and addressing air pollution, which is a key focus area for the EPA and other regulatory bodies.

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