Is Air Pollution Changing Our Genes?

By: Mary Beazley

Air pollution is ​composed of ​multiple gases. It’s largest components are mainly carbon monoxide, lead, nitrogen oxides, ozone, sulfur dioxides, and particulate matter. Of all these components, particulate matter is especially dangerous and poses the greatest threat to our overall health.. These microscopic ​particles​ are the reason for reduced visibility on days where air quality is particularly low. When we inhale them they enter deep into our lungs and may enter into our bloodstream as well.

In adults ​long-term air pollution​ exposure has a highly negative impact on lung function. Specifically, nitrogen dioxide exposure has shown to correspond to DNA methylation, leading to these negative impacts on lung function. ​DNA methylation is the addition of methyl groups to the DNA molecule. When DNA methylation occurs at specific regions in our DNA, it contributes to the regulation of our gene expression. Depending on where exactly the methylation occurs, methylation can either activate or reduce gene expression.
Newer research studies are bringing up data that the effects may not only contribute to the development of existing diseases but may lead to development and risks for presentation of these diseases in the first place. ​DNA methylation in adults​ was shown to be more prevalent in adults with longer periods of exposure to air pollution, this shows that DNA changes may accumulate from exposure over time.

In a​ recently published study​, the effects of air pollutants on both children’s cardiovascular and immune systems were observed over the course of a year. The results of this study found that air pollutants, mainly particulate matter, lead to an overall increase in monocytes. Monocytes are a type of white blood cell important for regulating immunity against foreign substances. However, monocytes can also be involved in plaque buildup in arteries, which can greatly increase the risk of heart attacks and strokes. Increased blood pressure was also shown to have a correlation of increased levels of monocytes and with particulate matter. The most significant findings from this study were that the particle matter exposure also led to increased methylation in genes associated with immune response. This is significant as the alterations to these genes may not only affect children in their adult lives, but may be passed onto their children as well. In a nutshell, these findings show how early exposure to pollutants may increase risk for cardiovascular diseases later on. Going forward, we need to focus on what preventative measures need to be taken in order to prevent disease in adulthood.

All of these findings are only one step in resolving the bigger issue, but how can people now protect themselves and their children? Especially important for those living in larger urban centers and regions with lower or poor air quality. Face masks are one possible way to reduce risks of inhaling particulate matter on days with especially harmful air quality. Due to the pandemic of COVID-19, face masks have become more common and readily available. The ​CDC ​however, warns that although some cloth facemasks may be suitable in preventing the spread of the coronavirus, they are not suitable when it comes to preventing inhalation of harmful pollutants. The N95 mask is more effective in this regard but less available due to supply shortages as a result of the COVID-19 pandemic. One promising ​preventative measure​ is the use of B vitamins. People who supplemented vitamins including B6 and B12 up to four times a week were able to limit particulate matter effects by significant amounts at multiple gene locations. Although the easiest preventative measure to take is staying up to date with local air quality reports, and avoiding outdoor activities on days when the air quality index is most hazardous.

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References: 

Air Quality - Air Pollutants | CDC. (2021). ​https://www.cdc.gov/air/pollutants.htm 

Particulate Matter (PM) Basics | US EPA. (2021). https://www.epa.gov/pm-pollution/particulate-matter-pm-basics
Wildfire Smoke and COVID-19 | CDC. (2021). Retrieved 8 March 2021, from https://www.cdc.gov/disasters/covid-19/wildfire_smoke_covid-19.html
Rider, C.F., Carlsten, C. Air pollution and DNA methylation: effects of exposure in humans. ​Clin Epigenet​ 11, 131 (2019).​ ​https://doi.org/10.1186/s13148-019-0713-2
Prunicki, M., Cauwenberghs, N., Lee, J. ​et al.​ Air pollution exposure is linked with methylation of immunoregulatory genes, altered immune cell profiles, and increased blood pressure in children. ​Sci Rep​ 11, 4067 (2021).https://doi.org/10.1038/s41598-021-83577-3
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