The average American spends nearly an hour commuting every day, a number that adds up quickly.
Now, research has shown that California auto commuters can be exposed to above tolerable levels of unhealthy chemicals in their daily work trips.
By estimating travel times based on census data and using measurements of chemicals detected in previous studies, the new study found that commute times of more than 20 minutes put people at risk for unacceptably high levels of two carcinogens used in the production of cars.
At first glance, it may seem troubling news to people who spend a lot of time behind the wheel on their daily commute. But many factors come into play, so let’s unpack it a bit.
The distinctive smell of a new car gives you a hint of what is happening here. The materials used to equip cars, from hard and soft plastics to adhesives, textiles and foams, contain chemicals that can slowly seep into the air (the technical term is ‘off-gas’) or run on dust.
“These chemicals are highly volatile and move easily from plastics and textiles to the air you breathe,” said environmental toxicologist David Volz of the University of California Riverside, who co-authored the study.
Volatile compounds can build up in small spaces, such as in a car (unless you open a window for fresh air).
While much research has been done so far on outdoor air pollution and its impact on health and the indoor environment, such as workplaces or homes where people spend most of their days, this study suggests that chemicals that build up in vehicles can also cause concern give birth – for some drivers.
The study aimed to estimate when a person’s exposure to known carcinogens was likely to exceed safe thresholds based on the time commuters spent in their vehicles and based on the levels of five chemicals found in cars in previous studies. detected.
The researchers predicted that commuter daily exposure to two of the five chemicals studied – benzene and formaldehyde – would likely exceed levels considered safe or tolerable by California health authorities after 20 minutes. The likelihood continued to increase as the commute lengthened.
The two chemicals of concern are not great unknowns, but they certainly deserve attention. Benzene is found in rubber and dyes, and formaldehyde is used in carpets and paint, both of which are on the long list of carcinogens in California’s Proposition 65. What’s new here is looking at the risk that these chemicals can pose specifically to motorists.
“Our study raises concerns about the potential risk associated with benzene and formaldehyde inhalation to people who spend a significant amount of time in their vehicles, a problem especially relevant to high-traffic areas where people have to commute longer”, said the study authors. wrote.
Perhaps unsurprisingly, a higher proportion of people were at an increased risk (more than 1 in 10) of exceeding benzene and formaldehyde risk thresholds on their daily commute to work in areas around San Francisco and notoriously busy Los Angeles.
“Of course there is an exposure range that depends on how long you are in the car and how much of the compounds your car emits,” which can depend on the age of the vehicle and the ambient temperatures, graduate student and study lead author Aalekhya Reddam also said of the University of California Riverside.
In other words, just because something is listed as a carcinogen doesn’t mean it’s guaranteed to cause health problems – it depends on the dose people are exposed to and how often.
Even known carcinogens are unlikely to cause cancer below certain thresholds, and by limiting your exposure to harmful substances, all associated risks are significantly reduced.
In addition, the poor health outcomes seen in commuters – including higher cancer rates – may be the result of a combination of inactivity, obesity, and reduced sleep often associated with lengthy commuting. These factors have not been taken into account in this study.
However, some people have no choice but to travel by car – or maybe it’s taxi drivers whose job is to drive. To reduce their risk of exposure, more could be done during the car manufacturing process to replace chemicals such as benzene and formaldehyde with less harmful alternatives, the researchers said.
“Because long commuters are already a vulnerable underpopulation, additional measures may need to be taken to reduce the potential cancer risks associated with benzene and formaldehyde exposure,” the duo wrote in their paper.
“There should be alternatives to these chemicals to achieve the same goals in car production,” added Volz. “If so, these should be used.”
By improving access to public transportation and cycling networks, people can also get more options for getting to work, while at the same time adding some occasional exercise to their commute and helping reduce traffic congestion clogging city roads.
The research is published in Environment International.