Benzene, Formaldehyde Used In Cars May Increase Cancer Risks: Study

A typical commute to work may place a driver at risk of exposure to two highly carcinogenic chemicals found in automobiles, including benzene and formaldehyde, according to the findings of a new study.

The average American spends nearly one hour commuting to work each day, and researchers from University of California, Riverside indicate that commute may be exposing riders to levels of benzene and formaldehyde, which could increase their risk of cancer, according to a report published online January 29 by the medical journal Environment International.

Chemicals used to manufacture new cars can slowly seep into the air due to off-gassing, or seep into the dust. Materials used to make cars include hard and soft plastics, adhesives, textiles and foam, all which have chemical components.

California’s Prop 65 lists potentially harmful chemicals which may cause cancer, birth defects or other reproductive harm. Some of these chemicals are often detected within interior vehicle dust and air. For example, benzene is found in rubber and dyes and formaldehyde is used in carpets and paints.

Researchers examined the potential risk associated with five California Prop 65-listed chemicals detected within vehicle interiors during daily commutes to work: benzene, formaldehyde, di (2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP), and tris(1,3-dichloro-2-propyl)phosphate (TDCIPP).

The study used census data, estimated commuter times, and prior studies which measured chemicals detected in the cars of people who spent more than 20 minutes in their car during their commute.

Benzene and formaldehyde were detected in vehicle interior air and DEHP, DBP and TDCIPP were detected in vehicle interior dust samples. Overall, one in 10 people had a greater chance of exceeding the cancer risk exposure thresholds for benzene and formaldehyde due to their daily drive to and from work.

The data indicated benzene and formaldehyde levels would exceed levels considered safe or allowable by California health authorities after 20 minutes in the vehicle. The risk increased along with the length of the commute.

The percent reference dose (RfD) was greater than 100% across any of the commute times for both benzene and formaldehyde. The likelihood of exceeding 100% RfD was highest in regard to cancer risks linked with the two chemicals, and the risk of reproductive and developmental toxicity associated with benzene.

The research indicates a high proportion of the commuter population in California may exceed 100% RfD for benzene and formaldehyde on a daily basis.

“Overall, our study raises concerns about the potential risk associated with inhalation of benzene and formaldehyde for people who spend a significant amount of time in their vehicles, an issue that is especially pertinent to traffic-congested areas where people have longer commutes,” researchers wrote.

The researchers warn chemicals used in car manufacturing may pose a serious health risk for commuters who spend a significant time in their car going to and from work every day. While the study did not focus on the overall poor health outcomes of commuters in general such as higher rates of cancer from factors like inactivity, obesity, and shorter sleep duration, the researchers say the findings highlight an important aspect of commuter safety which should be considered more seriously.