Linsey Marr Bridges Engineering and Public Health

Air pollution is responsible for seven million premature deaths per year. Linsey Marr, professor of environmental and water resources engineering, is seeking to change that trend.

Her research focuses on emissions, transformation, fate, and effects of air pollutants such as ozone and airborne particles to provide the scientific basis for improving air quality and health. Marr is also addressing concerns about engineered nanomaterials in the atmosphere.

So what are nanoparticles? Nanoparticles are materials smaller than 100 nanometers (about 1000 times smaller than the width of a human hair), and nanotechnology is the application of these materials for the development of new products such as drug delivery devices, thin solar cells, and sensors for environmental toxins.

These nanoparticles can be released into the air during manufacturing, use, or disposal of products and can be transported vast distances in the atmosphere. However, the health and environmental impacts of engineered nanomaterials are still somewhat unknown and inhalation exposure can be concerning.

Marr hopes to find out more about the release, transformation, fate, and toxicity of nanomaterials in the atmosphere. One challenge is finding a way to study the behavior of nanomaterials under realistic conditions in the environment, in terms of the chemical composition of air, water, and soil.

Marr’s research also dives into the airborne transmission of infectious disease such as the flu because the virus that causes it behaves like nanoparticles in air. Her interest in this topic grew out of frustration with the high frequency that her young children were catching infectious diseases from their peers at daycare.

The same tools and concepts she used to study engineered nanomaterials in the atmosphere also apply to viruses.
Marr has been especially interested in the seasonality of the flu, why it happens during the wintertime. She has studied it in a lab and in a daycare setting.

Initial results showed that the flu virus survived best when the relative humidity was either close to 100 percent, like when it’s rainy outside, or below 50 percent, like when we heat indoor air in the wintertime, but results in more realistic droplets show that the virus survives well across a wide range of humidities.

She is looking into different ways that humidity the flu virus, and the story is continuing to unfold. Marr spent the last year in Taiwan on a Fulbright fellowship to examine whether the flu can be transmitted through the atmosphere over distances of hundreds of kilometers or more. She worked with colleagues from National Taiwan University to estimate the amount of flu virus released from neighboring countries, such as China, and then to use an atmospheric transport model to predict how much would reach Taiwan.

Her ultimate goal is to bridge public health and engineering to produce new insight into how the flu spreads.
Marr bridges engineering and public health