Air Pollution Health Impacts in a Warming World

Expected start date：July-2023

Rising global temperatures and air pollution may be a dangerous combination that can lead to severe human health problems. One major form of air pollution is airborne particulate matter (PM)— microscopic solid or liquid particles suspended in the air that come from a variety of sources including burning and dust-generating activities. Breathing in fine PM can lead to heart and lung problems, and even premature death. Ever-more frequent heat waves may exacerbate these negative health impacts, yet we are still not sure why. Only by understanding how temperature and PM interact can we devise mitigating strategies.

Populations already vulnerable to air pollution, including the elderly and those already suffering from lung diseases e.g. asthma, could become even more disadvantaged in a warmer world. Lung injury might allow fine PM to more readily enter the blood stream from the lungs, across what is called the “blood-air barrier”. This is the cellular barrier between the alveoli (air sacs) and blood vessels, comprising “epithelial” and “endothelial cells”, respectively. This is the route by which oxygen ordinarily enters the bloodstream, and also fine PM. Inhaled PM small enough to enter the bloodstream could reach heart cells, which could underlie cardiovascular effects. Yet, we are not sure how increasing temperatures might exacerbate this.

Dr. Lareb Dean will address these urgent questions during her AXA Fellowship at the University of Southampton. Dr. Dean will use cell cultures to methodologically investigate how the detrimental effects of PM on lung and heart cells will be influenced by rising temperatures.

To examine the interaction between heat and PM concentration in the lungs, Dr. Dean will conduct laboratory experiments with the complex network of three interacting cell types in the  alveoli: the blood-air barrier’s epithelial cells and endothelial cells, and “macrophages”, which are specialized cells involved in the body’s immune response and which detect harmful substances in the body. Dr. Dean will inspect how these cells respond to different temperatures and PM concentrations, as well as exposure-related changes in the lung barrier and the changing ability for PM to cross this. Ultimately, this will allow her to define the impact of increasing temperature on cellular responses to PM.

To examine the cardiac impacts of heat and PM concentration in the heart, Dr. Dean will collaborate with experts at the University of Edinburgh. She will investigate how human heart cells respond to various PM and temperature exposure conditions. Specifically, Dr. Dean will look at how healthy cells are, their ability to contract, and their spontaneous beating rate. These factors can give an idea about heart health at the cellular level.

Dr. Dean's research will provide insights into the potential health outcomes of climate change, particularly with regard to rising temperatures and worsening air pollution. These insights will assist policy makers in the development of interventions to reduce exposure and improve treatment for vulnerable populations.

April 2023