The average American spends nearly an hour each day commuting to work, a number that adds up quickly.
Now, research has found that California car commuters can be exposed to above-acceptable levels of harmful chemicals during their daily business trips.
By estimating commute times from census data and using measurements of chemicals detected in previous studies, the new study found that commutes of more than 20 minutes put people at risk for unacceptably high levels of two carcinogens used in automobile manufacturing.
At first glance, it may seem like worrying news to people who spend a lot of time behind the wheel on their daily commutes. But there are many factors at play, so let’s analyze a little.
The distinctive smell of a new car gives you an idea of what is happening here. Materials used to equip cars – from hard and soft plastics to adhesives, textiles and foams – contain some chemicals that can slowly seep into the air (the technical term is ‘exhaust gas’) or trap dust.
“These chemicals are very volatile, they move easily from plastics and textiles into the air you breathe,” said environmental toxicologist David Volz of the University of California at Riverside, a co-author of the study.
Volatile compounds can accumulate in small spaces, such as the interior of a car (unless you open a window to let in fresh air).
While much of the research to date has focused on outdoor air pollution and its impact on health, and indoor environments such as workplaces or homes where people spend most of their day, this The study suggests that chemicals that build up inside vehicles could also be a concern, for some drivers.
The study aimed to estimate when a person’s exposure to known carcinogens likely leaned above safety thresholds based on the time travelers spent in their vehicles and on the levels of five chemicals detected inside cars. in previous studies.
The researchers predicted that the daily exposure of travelers to two of the five chemicals studied, benzene and formaldehyde, would likely exceed levels considered safe or permitted by California health authorities after 20 minutes. The probability kept increasing the longer a person traveled.
The two chemicals of interest are not huge unknowns, but they certainly deserve attention. Benzene is found in rubber and dyes, and formaldehyde is used in carpets and paints, both of which are included on California’s extensive Proposition 65 list of carcinogens. What’s new here is looking at the risk that these chemicals can pose to drivers specifically.
“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, a problem that is especially pertinent for traffic congested areas where people have longer trips. “, the study authors wrote.
Perhaps unsurprisingly, a larger fraction of people had a high probability (above 1 in 10) of exceeding cancer risk thresholds for benzene and formaldehyde on their daily commute in areas around San Francisco and the Notoriously congested Los Angeles.
“Of course, there is a range of exposure that depends on how long you are in the car and the amount of compounds your car emits,” which can depend on the age of the vehicle and the surrounding temperatures, said a graduate student and study. lead author Aalekhya Reddam, also from the University of California Riverside.
In other words, just because something is listed as a carcinogen does not mean that it is guaranteed to cause health problems; It depends on how much people are exposed to and how often.
Even known carcinogens are unlikely to cause cancer below certain thresholds, and limiting your exposure to harmful substances goes a long way toward reducing any associated risks.
Additionally, the poor health outcomes seen among travelers, including higher rates of cancer, may be due to a combination of inactivity, obesity, and fewer hours of sleep that often come with long trips. These factors were not considered in this study.
Some people, however, have no choice but to travel by car, or perhaps they are taxi drivers, whose job is lead. To reduce your risk of exposure, more could be done during the car manufacturing process to substitute chemicals such as benzene and formaldehyde with less harmful alternatives, the researchers said.
“As people with long commutes are an already vulnerable subpopulation, additional measures may be necessary to mitigate the potential cancer risks associated with exposure to benzene and formaldehyde,” the duo wrote in their article.
“There should be alternatives to these chemicals to achieve the same goals during vehicle manufacturing,” Volz added. “If so, these should be used.”
Improving access to public transportation and bike networks could also give people more options to get to work while adding some extra exercise to their commute and helping to ease traffic congestion that clogs the roads of the city.
The research was published in Environment International.