Exposure to local environmental factors, such as air pollution, has a larger impact than genetic ancestry on modulating gene expression and health reports an analysis involving a cohort of about 1,000 individuals from Quebec, Canada, published this week in Nature Communications.

Industrialization and increased use of fossil-fuel energies have led to air pollution and hazardous air quality in many parts of the world. It is thought that individuals with varying genetic backgrounds respond differently to environmental factors, leading to variance in heritability and risk of certain diseases. However, disease risk owing to environmental exposures and their interactions with the genome remain poorly understood.

Philip Awadalla and colleagues assessed data encompassing a range of environmental exposures, health, gene expression levels, and whole genome genetic variation information from 1,007 individuals across different regions of Quebec. The authors found that the impact of the environment on gene expression profiles in blood samples overrides that of genetic ancestry. Furthermore, local ambient air pollution, such as fine particulate matter (PM2.5), nitrogen dioxide and sulphur dioxide modulates gene expression affecting cardio-metabolic and respiratory traits, which may lead to lung disease and arterial stiffness.

The authors conclude that their findings demonstrate how the local environment directly affects disease risk and that genetic variation can modulate an individual’s response to environmental challenges.