Solving Air Quality Injustice and Creating Cleaner Cities with Passive Samplers

Our scientists support studies to monitor human exposure to environmental pollutants and address environmental justice, sustainability, and human health concerns.

Negative health effects from air pollution

Air pollution is caused by several sources, including various forms of transportation, fuels for cooking, agriculture, waste burning, and coal-fired power plants. Exposure to air pollution has been associated with negative short and long-term health effects. Fine particles formed from gaseous pollutants such as nitrogen oxides can impact air quality and ultimately human health.

Long-term air pollution exposure leads to a decline in overall health. It can cause respiratory complications like lung cancer and heart disease. According to the American Lung Association, living with poor air quality can cause “frequent asthma attacks, heart attacks and strokes, lung cancer, reproductive harm, premature birth and low-birth weight, and even early death.” Children exposed to air pollutants over time are more likely to develop asthma, and those with asthma often experience more severe symptoms.

Short-term exposure to air pollution can lead to respiratory infections, headaches, nausea, and dizziness. While these short-term problems are usually temporary, they can lead to unwanted consequences like decreased productivity.

Air pollution effects those who are already ill at a greater rate; however, certain groups are more susceptible to these negative effects. According to the World Health Organization, children and the elderly have a higher risk of experiencing health complications from air pollutions, with premature death being the most extreme consequence.  

Using passive samplers to solve environmental inequities and create substainability

The Clean Air Act, which went into effect in 1990, has improved air quality in the United States over the past 30 years. While some areas have made significant progress in their air quality, many densely populated metropolitan areas still do not meet clean air standards. Poor air quality must be addressed in urban areas that are home to disproportionate populations of individuals from racial and ethnic minorities. A recent study showed that people of color are 1.5 times more likely to be exposed to fine particle air pollution, making it important to develop equitable solutions to the problem of air pollution.

An individual’s environment and exposure sources are dependent on their mobility, which can be directly related to wealth. Moving away from areas with high fossil fuel emissions is not feasible for underserved populations, so many cities across the United States are seeking to address this environmental inequity by developing sustainable approaches for creating cleaner environments.

For example, those living closer to a roadway might be exposed to a higher concentration of nitrogen dioxide (NO₂) emitted from vehicles. Pollutants, including NO₂, agitate respiratory systems, especially for individuals who have asthma. Those exposed to higher rates of NO₂ are more likely to develop respiratory health complications and cardiovascular harm later in life. Switching the roadway to a walking path can drastically decrease NO₂ emissions in the area. Creating sustainable cities and clean air environments can provide safe living spaces for the most vulnerable populations.  

What are passive samplers? 

How can cities measure air pollution over time and across different geographic areas? This is where passive samplers come in. The National Library of Medicine defines passive samplers as devices that “allow the quantification of cumulative air pollutant exposures, as total or average pollutant concentrations, over a sampling duration.” 

Passive sampler devices are usually comprised of small polypropylene vessels that hold collection pads. They can be attached to clothing to measure personal exposure or deployed under shelters to monitor indoor and outdoor air quality. They can be deployed anywhere from one day to two weeks depending upon the anticipated pollutant concentrations. The sampler is activated when a user removes it from its sealed packaging, and it absorbs chemicals from the environment like a sponge. Specific chemicals in the air are bound inside the sampler, so they can be analyzed and provide information about the environments where humans and animals live and to what chemicals they are exposed.

Passive samplers are well-suited to understanding air quality in underserved communities and industrial areas. Unlike traditional air quality monitors, passive samplers require no power or maintenance. Passive samplers also are less expensive than continuous air quality monitoring. Since the users must remove the device from their package to begin monitoring, they are easily used by untrained individuals for community-based studies.

RTI's experience with passive samplers

RTI International supports studies to determine how economically disadvantaged areas are affected by environmental hazards. We have provided passive sampler analysis and expertise to collaborators from diverse sectors for over three decades. We partner with Ogawa USA to provide technical expertise and analysis services for global researchers investigating the health impacts of air pollution and their treatment. Ogawa passive monitors measure NO₂, nitric oxide (NO), sulfur dioxide (SO₂), and ozone (O₃) in ambient air. We also partner with federal and private entities interested in creating sustainable cities and addressing clean air inequities.

Providing analysis to New York Community Air Survey program

In New York City, researchers at the Barry Commoner Center for Health and the Environment use Ogawa passive samplers to conduct an ongoing air quality study. This study is part of the New York City Community Air Survey (NYCCAS) program and is a joint effort between the center and the New York Department of Health and Mental Hygiene. Center researchers monitored 95 locations in New York City to model their air quality and gain an understanding of the distribution of these pollutants across the city.           

RTI’s Analytical Science Division analyzes the passive samplers for New York City. After collecting data for 13 years, analytical trends demonstrate that these pollutants are continuing to decline; however, areas with high traffic, industry and building density still have some of the highest emission patterns in the city.  

“The information gathered from these trends is essential to continue efforts that help to achieve the goals and objectives of New York City’s sustainability plan,” said Holger Eisl, PhD, environmental scientist and NYCCAS project director. “It not only reduces emissions of pollutants, but also helps reduce the carbon footprint of the largest city in the United States.”  

RTI’s support for New York City’s clean air initiatives serves as a model for efforts in other places. Cities like Philadelphia are partnering with us to analyze passive samplers in their own urban areas. These efforts not only help to address air quality in each city, but they also will address sustainability goals and improve quality of life for underserved populations where pollutants are increasingly prevalent.