The Air Toxics Health Effects Database (ATHED).

Area of Science:

• Environmental Science
• Toxicology
• Public Health

Background:

• The U.S. Environmental Protection Agency (EPA) utilizes the Air Toxics Health Effects Database (ATHED) for risk assessments.
• ATHED supports the Residual Risk Program, which evaluates risks post-Maximum Achievable Control Technologies (MACT) standards.
• This program aims to ensure acceptable residual risk and implement additional regulations if necessary.

Purpose of the Study:

• To describe the Air Toxics Health Effects Database (ATHED) and its role in supporting EPA risk assessments.
• To highlight ATHED's function in evaluating residual risks from hazardous air pollutants (HAPs).
• To explain how ATHED provides benchmark values for acceptable exposure levels.

Main Methods:

• ATHED compiles reference values for HAPs from Section 112 of the Clean Air Act.
• The database includes values across all exposure durations: acute, short-term, subchronic, and chronic.
• ATHED provides background information on uncertainty factors, points of departure, and critical studies for each reference value.

Main Results:

• ATHED serves as a critical resource for the EPA's Office of Air Quality Planning and Standards (OAQPS).
• The database contains comprehensive data on health effects and exposure benchmarks for HAPs.
• Graphical presentation of ATHED data facilitates comparisons of values across different exposure durations for specific chemicals.

Conclusions:

• ATHED is essential for determining acceptable exposure levels to HAPs.
• The database supports regulatory decisions within the Residual Risk Program.
• ATHED's comprehensive data and presentation features aid in understanding and managing air toxics risks.