Integrated Science Assessment (ISA) for Particulate Matter
Particulate matter (PM) is a complex mixture of extremely small particles and liquid droplets in the air. Particulate matter causes concern because it is associated with serious health effects such as aggravated asthma, difficulty breathing, chronic bronchitis, decreased lung function, and premature death. PM contributes to haze and can harm the environment by changing the natural nutrient and chemical balance of the soil.
EPA scientists are conducting research to better understand which attributes of particulate matter cause ill health effects, who may be most susceptible to these effects, how particles form in the atmosphere, and what the contributions are from various sources in different regions of the country.
The Clean Air Act requires EPA to periodically review the science for six major air pollutants, including PM. EPA's National Center for Environmental Assessment develops Integrated Science Assessments (ISAs) that summarize the science related to the health and ecological effects caused by these pollutants. ISAs provide a comprehensive review of the policy-relevant scientific literature published since the last National Ambient Air Quality (NAAQS) review and are a critical part of the scientific basis for establishing the NAAQS. EPA released the latest Integrated Science Assessment for Particulate Matter Final Report in Dec 2009.
- Learn about the 2009 Final Report: Integrated Science Assessment for Particulate Matter
- Learn about the Particulate Matter Air Quality Standards
History of the Particulate Matter Assessments
Peer Reviewed Literature
While working on the assessment of particulate matter (2009), EPA used the Health and Environmental Research Online (HERO) database to augment the underlining literature that supported the final assessment.
Update in 2012: PM Provisional Assessment