Susceptibility to particulate air pollution linked to genetic factors

According to researchers at the Johns Hopkins Schools of Public Health and Medicine, genetic risk factors may help explain the increasing incidence of pollution-related disease and mortality in urban areas.

The researchers located two genes that control susceptibility to toxic effects of particle exposure. The existence of these genes suggests that some people may be more susceptible to pollution-associated viral and bacterial respiratory infections. The discovery of the genes may also lead to methods for identifying and treating people who are at risk from such infections.

Human exposure to particulate air pollution has been linked to respiratory illness, such as chronic cough, bronchitis, and pneumonia, but the precise toxicological or physiological reasons for this link are not known. Although children, the elderly, and patients with pre-existing chronic diseases seem to be particularly at risk, scientists believe that not all particle-associated illness and mortality can be attributed solely to age or pre-existing disease.

According to senior author Steven R. Kleeberger, Ph.D., associate professor, Department of Environmental Health Sciences, Johns Hopkins School of Public Health, “Identification of these susceptibility genes will lead to a better understanding of the effects of air pollution on respiratory health. Individuals with a genetic predisposition to an impaired immune response may be more susceptible to pollution-associated viral and bacterial respiratory infections that lead to hospitalisation.”

The researchers surveyed the entire genome of a genetically standardised mouse in search of correlations between immune response and genetic markers. The mice were then exposed to acid-coated particles for four hours.

The researchers discovered regions on two chromosomes that accounted for much of the variance in susceptibility to the acid-coated particles. The same two regions had also been identified in a previous study on ozone pollution.