Next Generation Emission Measurements Help Understand Air Pollutants in Rubbertown Industrial Area of Louisville, Kentucky

Published February 9, 2021

A passive sample deployed at the Louisville Air Pollution Control District shelter.

Volatile organic compounds (VOCs) include a wide range of chemical gases emitted into the air from various products or industrial processes. Some VOCs are identified as hazardous air pollutants and may be harmful to human health. In addition, VOCs can react in the atmosphere to produce secondary pollutants such as ozone. Over the last several years, many areas across the U.S. have seen reductions in criteria air pollutants (including ozone) as well as hazardous air pollutants. However, there remain areas of concern such as those where VOCs and other air pollutants continue to be emitted near communities. People who are exposed to enough of certain toxic air pollutants for a long enough period of time could have increased chances of getting cancer or developing immune system, neurological, reproductive, developmental, respiratory or other health problems. Work must continue to ensure clean air for all communities.

The Rubbertown industrial area of Louisville, Kentucky, is home to over ten industrial sources of air pollutants and is adjacent to residential areas. The area is characterized as an environmental justice community, with a large number of people of color and lower income individuals living, working, playing, and attending school in and around the vicinity of the industrial facilities. EPA’s National Air Toxics Assessment has shown that the Rubbertown area has an increased risk of cancer and other health problems.

To help understand how the emissions from these sources may impact residential areas, EPA collaborated with the City of Louisville Metro Air Pollution Control District on a study from 2017 to 2018. They used novel Next Generation Emissions Measurement (NGEM) systems to measure hazardous air pollutants, including select VOCs, in the vicinity of Rubbertown’s industrial facilities. Among the advantages of NGEM systems are that they can be either stationary or mobile and can provide emissions and meteorological data to help inform air quality models used to characterize air pollutants at different spatial and temporal scales.

To collect data for the study, the researchers deployed passive samplers for two weeks at ten sites in and around the Rubbertown area. Those sites were combined into three groups at different distances from the Rubbertown industrial facilities.

The researchers were able to use the passive sampler measurements to characterize VOC emissions over the study period, suggesting that these EPA methods can be useful in future community studies to assess gradients of VOC emissions from chemical facilities. The study showed that overall VOC concentrations were higher at sites near Rubbertown industrial sources than they were at community sites and other distant sites. They also found that VOC concentrations were lower than had been reported in a previous study that collected data from the same area from 2001 to 2005, suggesting an overall reduction in VOC emissions.

This research is important because NGEM systems can improve the understanding of air emissions from sources and their potential impacts on nearby communities. Expanding knowledge about the spatial differences in air pollutant concentrations across a study area, combined with information about activity patterns of populations in and near the chemical industry, could help improve the estimates of the population’s exposure to potentially harmful VOCs.

“Emerging NGEM technologies can help regulators and industry identify and control fugitive emissions of VOCs and hazardous air pollutants. leading to lower air quality impacts for nearby communities,” said Eben Thoma, one of the lead EPA researchers for this study.

Several follow-on projects in the Rubbertown area have focused on continuing community concerns regarding odors that come from the surrounding industrial facilities and other sources in the area. To help address odor complaints, the researchers developed a VOC sensor system called the Odor VOC Emissions Tracker (oVet) which includes complementary NGEM systems to detect and measure odorous VOCs. Another project involves the development of a mobile phone app called ‘Odor Explore’ that allows the public to report odors in their community and view odor reports submitted by others. As part of the app, researchers are investigating the use of NGEM systems to provide a measurement that corresponds to odor reports submitted in the app. The Odor Explore app will be pilot tested in Rubbertown and other parts of Louisville in Winter 2021.

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Next Generation Emission Measurements Help Understand Air Pollutants in Rubbertown Industrial Area of Louisville, Kentucky

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