SPECIATE Database Provides Important Resource for Air Quality Management
Published April 6, 2021
Every day, thousands of chemical pollutants are emitted into the air from a variety of sources such as motor vehicles, oil and gas operations, industrial processes, household product use, and smoke from fires, including wildfires and prescribed burning. However, the specific atmospheric chemicals in each source of emissions is not always known. Understanding the chemical composition of emissions from air pollution sources and developing detailed profiles of them is important to supporting air quality management.
To provide source characterization of air pollutants, EPA developed SPECIATE. SPECIATE is an archive of speciation profiles of air pollution sources that provides the chemical species makeup or composition of organic gas, particulate matter (PM), and other pollutants emitted from these sources. The profiles provide a chemical description of an air pollution source, in some ways like a profile of an individual’s characteristics, such as gender, race, and color of hair and eyes.
Thousands of these profiles for different sources of pollution have been added to the database over the years and are used by air quality regulators, managers, and researchers. SPECIATE has multiple air quality managment applications, including regulatory model applications, research model development, and use in integrated science assessments and health studies (e.g., the National Air Toxics Assessment). States have used SPECIATE data in air quality models to develop strategies to meet the National Ambient Air Quality Standards. SPECIATE is also a key input to EPA’s state-of-the-art Community Multiscale Air Quality (CMAQ) model, which is used by the states to develop and assess air quality management decisions to meet the nation’s air quality standards.
With the newest update released in July 2020, SPECIATE 5.1 currently contains 6,746 chemical profiles. The new version provides many improvements, including those to make it a more user-friendly research experience. The SPECIATE website provides the database, browser, documentation, and a data developer’s guide.
EPA created SPECIATE for Agency use in 1988 and released the first version to the public user community in 1993. In the years since, more than one thousand domestic and international research and policy planning institutes have used SPECIATE and cited it in their publications.
EPA researcher Marc Menetrez, who has led the SPECIATE workgroup since 2017, says active participation in the workgroup by researchers across the globe is a measure of the success of the database. The workgroup was created in 2005 to update SPECIATE while keeping up with new data and technological advances after rigorous review.
“The SPECIATE Workgroup continues to assess the needs for air quality modeling and strives to develop profiles to fulfill those needs. Keeping the research community informed is key,” says Madeleine Strum, an engineer in the SPECIATE workgroup.
The SPECIATE database is updated routinely with new speciated air quality profile data, made available from EPA, state agencies, peer-reviewed literature, and other sources. Continued updates are important because the chemical characteristics of emissions sources change due to new technologies, emissions control equipment, and product formulations.
SPECIATE has been an essential tool for air quality modelers and air quality management since its inception and will continue to be for many years to come with the continued efforts by the SPECIATE workgroup and the contributions of the broader research community.
Bray CD, Strum M, Simon H, Riddick L, Kosusko M, Menetrez M, Hays MD, Rao V. An assessment of important SPECIATE profiles in the EPA emissions modeling platform and current data gaps. Atmospheric Environment. 2019 Jun 15; 207:93-104.