Air pollution. 

When most people hear those words they imagine a big city skyline covered with smog. Carbon released from industrial smokestacks. Smoke produced by coal-fired power plants darkening the sky. 

But consider household dust, which can contain high concentrations of bacteria, lead and other heavy metals, pet allergens, dust mites, and pesticides and is continuously recirculated throughout a house. 

"Researchers interested in monitoring air quality and its exposure and impact on human health have historically focused on measuring and tracking down the sources of outdoor air pollution," says Andrea Ferro, professor of civil & environmental engineering. "But it is actually indoor air quality that results in high pollutant exposure and potential health effects. In fact, people spend most of their time indoors, so they are breathing primarily indoor air. Indoor air includes pollutants from both outdoor air and indoor air; however, on average, the fraction of material released that actually enters someone's breathing zone is 1,000 times higher for a pollutant released indoors than for a pollutant released outdoors."

Researchers like Ferro are changing the way people think about pollution by looking at the pollution that lives inside our buildings. For the past 12 years, Ferro has studied indoor air quality and how it affects humans, but the subject's importance is now just coming to the public's attention thanks to the "green building" movement.

Ferro's research focuses on the effects of resuspended dust particles on human exposure and the length of time pollutants remain in the indoor environment. "Certain particles deposit on surfaces quickly, others remain in the air for longer periods of time," Ferro explains. "Once deposited, the particles can be resuspended into the air with human activities that stir up dust such as walking around.

"Particles also have different residence times, that is, some remain present in the indoor air environment longer before settling and being removed by cleaning or floating out an open window," she adds. "The fate of an indoor air particle depends on its size and composition and the human activity indoors."

Ferro assesses human exposure to air contaminants through direct (measurement) and indirect (modeling) methods in order to find the links between human exposure and human health. For example, there has been a sharp rise in childhood asthma which has been linked to air pollution, but its causes are still not completely understood. Ferro has been working with colleagues on research related to asthma and resuspended particles in indoor environments. "We do know that the resuspension of indoor aeroallergens is directly implicated in lung inflammation in asthmatic children."

Working with Philip K. Hopke, director of Clarkson's Institute for a Sustainable Environment and the Clarkson Center for Air Resources Engineering & Science (CARES), and Air Innovations Inc., a Syracuse-based company led by Clarkson alumnus Michael Wetzel '88 and his father, Lawrence Wetzel, Ferro is helping to develop an air purifier and ventilator to improve air quality in the bedrooms of people with asthma. Already, the team has proved the HEPAiRx® to improve children's asthma symptoms.

"The overall goal of my work is to improve human health by improving the quality of the air we breathe through source control, ventilation and purification strategies, education and regulatory policy," she says.

To further research into resuspended particles in indoor air environments, the University recently received a state-of-the-art air quality chamber donated to CARES by Air Innovations Inc. Categorized by the International Organization for Standardization as an ISO Class 3 cleanroom, the new space will further the research efforts of Professors Andrea Ferro and Philip Hopke to develop an air purifier and ventilation system to improve air quality for asthma sufferers.