Other results include:

• a 66% reduction in benzene;

• a nearly 60% reduction in mercury from man-made sources such as coal-fired power plants;

• an 84% decrease of lead in outdoor air;

• the removal of an estimated 1.5 million tons per year of air toxics such as arsenic, benzene, lead and nickel from stationary sources; and

• approximately 3 million tons per year of criteria pollutants, such as particulate matter and sulfur dioxide, have been reduced as co-benefits of air toxics reductions.

HAPs are known or suspected of causing cancer and can damage the immune, respiratory, neurological, reproductive and developmental systems.

Amendments to the Clean Air Act in 1990 required EPA to take specific actions to reduce emissions and risks from air toxics. Air toxics (also known as hazardous air pollutants or HAPs) are pollutants known to cause or suspected of causing cancer as well as respiratory, neurological, reproductive and other serious health effects.

The Clean Air Act identifies 187 HAPs that EPA is required to control to protect public health. More specifically, to address HAPs in urban areas, section 112(k) of the Clean Air Act directs EPA to:

• Identify a subset of 30 HAPs that present the greatest threat to public health in the largest number of urban areas. These 30 HAPs are known as the 30 urban air toxics.

• Identify area sources that represent 90% of the combined emissions of the 30 urban air toxics, and subject these sources to regulation. The EPA identified 68 area source categories of urban air toxics.

In 1999, EPA developed the Integrated Urban Air Toxics Strategy for reducing cumulative public health risks in urban areas posed by the aggregated exposures of air toxics emitted from major stationary sources, smaller area stationary sources and mobile sources. It consists of four key components:

• Source-specific and sector-based standards
• National, regional and community-based initiatives
• National-level air toxics assessments
• Education and outreach

Between 1990 and 2012 the EPA issued 97 technology-based standards covering 174 major source categories—including gasoline distribution facilities, chemical plants, petroleum refineries and utilities—that have resulted in significant improvements in air quality across the nation.

EPA also issued rules for 68 area source categories—such as dry cleaners, electric arc furnaces and small PVC manufacturers—addressing 90% of the worst urban HAPs.

For mobile sources, the EPA issued a rule in 2007 to reduce air toxics from gasoline-fueled passenger vehicles, gasoline fuel and portable fuel containers. In addition, the EPA has issued many rules to reduce volatile organic compounds, including gaseous air toxics, and diesel particulate matter (PM) from a range of on- and off-road gasoline and diesel vehicles and equipment. Exhaust from diesel engines contains many urban air toxics, such as acetaldehyde, acrolein, benzene, 1,3-butadiene, formaldehyde and polycyclic aromatic hydrocarbons.

In addition, national initiatives like the National Clean Diesel Campaign, Burn Wise, the Collision Repair Campaign and SmartWay have further reduced air toxics through voluntary partnerships with industry.

The CAA also required EPA to submit two reports to Congress describing the agency’s actions to reduce public health risks from urban air toxics. The EPA issued the first Urban Air Toxics Report to Congress in 2000. This latest report fulfills the requirement for the second report to Congress.

The report identifies six challenges to the current air toxics program where continued effort is needed:

• Improved emissions data;

• Ambient data in more areas for more pollutants;

• New monitoring technologies that are accessible, transparent and cost effective;

• More research into the cumulative impacts of exposure to air toxics on human health;

• Better integration of air toxics, pollution prevention and voluntary programs in regulatory and non-regulatory efforts; and

• Regulatory tools to direct national regulatory efforts at source categories where emissions pose significant risks.

Resources

• National Air Toxics Program: The Second Integrated Urban Air Toxics Report to Congress