Prof Linsey Marr Discusses Air Quality and Disease Transmission

SelectScience interviewed Professor Linsey Marr, from the Civil and Environmental Engineering Department at Virginia Tech, USA, about her research into the release of pollutants to the atmosphere, their fate and transport in the atmosphere, and their impacts on the environment and human health.

What problems are associated with pollutant particles in the air?

LM: Particulate pollutants cause adverse health effects such as heart disease and cancer. They can also impair visibility, and they contribute to global climate change.

How does your research help to develop strategies to clean the air?

LM: My research helps to improve the understanding of what the largest sources of pollutant emissions are, and which sources contribute the most to air pollution problems, so that we can target reductions to these sources.

Is it possible to avoid producing particulates?

LM: It is very difficult to avoid producing particulates from processes such as fuel combustion. But in some cases, emissions can be captured by pollution control devices such as filters and electrostatic precipitators. Some particulates are naturally generated, such as by windblown dust and wildfires, and it is impossible to control these.

How does your research help to understand the long-term impact of human activities on the environment?

LM: My research contributes to knowledge about the fate of air pollutant emissions from human activities. If a certain activity leads to persistent, high levels of a certain pollutant that is not easily removed from the atmosphere, then we should not be surprised to find long-term effects from that pollutant. Some pollutants can be transformed to less harmful products, while others can be transformed to more harmful products. It is important to understand these transformations to predict long-term impacts of the activities that cause the emissions.

How does your research help to prevent the spread of diseases?

LM: We are applying the same tools we use for particulates to airborne pathogens that cause infectious disease. We are trying to understand how atmospheric conditions, such as humidity, affect the viability of the pathogens. If we can identify certain conditions that are less favorable to the pathogen, we could then design our indoor spaces to take advantage of this relationship and reduce the spread of certain diseases.

What instruments do you use to detect/quantify the particles in the air?

LM: We use various types of instruments to quantify particles in the air. We can estimate the mass concentration of particles through light scattering and we can count them using optical methods. Then we can size them by putting a charge on them and passing them through an electric field. We use tracer methods in the laboratory, where we generate particles of specific size and chemical composition and assess their behavior, and there are certain tracer methods that can be used outdoors safely. The modeling we use can predict the transport, reactions, and deposition of gases and particles in the atmosphere.

What is the future of your research?

LM: My group is currently focused on the environmental impacts of engineered nanomaterials and airborne transmission of infectious disease. We are actually bringing the two fields together in developing nanotechnology-based sensors to detect airborne pathogens. Watch this video to learn more about Professor Marr’s work with nanomaterials.