By Michael Brenneis
More and more people are recognizing the costs associated with driving, and that driving less opens space for alternatives and makes us healthier. Now new research adds one more tick to the human health costs column: particulates from transportation cause cancer.
Transportation is not the only source of particulates, of course. Other sources include the burning of fossil fuels for heating and power generation, some industrial processes, agriculture, and wildfires. But, as Lloyd Alter points out in Treehugger, of the total particulate emissions, transportation generates about half. The particles in question here measure 2.5 microns or smaller (PM2.5) and are produced from vehicle exhaust, tire and brake wear, and the churning up of other particulates from the road surface.
Particulates, as we know, are detrimental to human health. The World Health Organization links exposure to particulates and other air pollution with heightened risk of asthma, heart disease, adverse birth outcomes, diabetes, and stroke.
But now we know for certain. PM2.5 causes cancer by triggering inflammation in the lungs that causes cells with particular mutations to start growing a tumor—mutations present in 1 in 600,000 cells, researchers estimate, a number that increases with age—even in the lungs of people who have never smoked.
Exposure is also inequitable. Communities living in proximity to high-volume roads—often people of color and low-income groups—can have elevated exposure.
Sadly, as important as electrifying our vehicles will be for cutting carbon emissions, that may not reduce the problem of PM2.5 as much as many have hoped. With automakers developing electric vehicles that are as heavy or heavier than their gas-powered equivalents, the problems—especially tire wear—likely will continue. As Alter puts it, “No matter how they are powered, we need fewer, lighter, and smaller cars, particularly in our cities.”