We’ve known for some time that the chemical benzene is toxic to humans and can cause cancer. But we’re only beginning to learn the extent of the health impacts of BTEX, the stew of hydrocarbons that include benzene and which constitute a key additive for gasoline.
BTEX stands for benzene, toluene, ethyl-benzene and xylene. The four chemicals are pulled up as part of the oil-drilling process, and often they’re infused into gasoline at the refinery level because they elevate the octane rating of gas. BTEX also is present in cigarette smoke, as well as a wide variety of household products, including detergents, cleaners, nail polish and even children’s toys.
Last month a trio of researchers with The Endocrine Disruption Exchange (TEDX), based in tiny Paonia, Colorado, published a study in the journal Environmental Science & Technology showing that even low-level exposure to BTEX can elevate the risk of reproductive disorders, respiratory illnesses like asthma, and cardiovascular disease.
“These chemicals are in the air, most of us are exposed to them on a regular basis, and they’re probably making us sick,” said Carol Kwiatkowski, one of the three researchers on the study, said on Dec. 14, 2015, when the group’s findings were presented during a discussion hosted by the Environmental and Energy Study Institute in Washington, D.C.
The paper’s co-authors were Theo Colborn and Ashley Bolden. Colborn, who founded TEDX in 2003, died Dec. 14, 2014, exactly a year before the EESI presentation. She was 87.
“We’ve been working on this paper for years,” Kwiatkowski, the executive director of TEDX, told the Daily Sentinel of Grand Junction, Colorado. “She would say many times, if we could just get the BTEX paper out before she died, she’d be happy. We didn’t exactly pull it off but she knew we were close.”
Ninety percent of outdoor exposure to BTEX comes from tailpipe emissions of vehicles, Kwiatkowski said. And since many Americans live near major roadways or other areas where air pollution is prevalent, the risk could be much higher than anyone imagined. According to the American Lung Association’s 2016 “State of the Air” report, more than half of Americans — 166 million — “live in counties that have unhealthful levels of either ozone or particle pollution.”
“We actually need to do a lot more research,” Jessie Stolark, a policy associate at EESI who introduced Kwiatkowski at the December event, told me. “Because a lot of times these compounds are studied alone, so that’s why a lot of research was done on benzene. And that’s why I think there’s been so much focus on benzene, but nobody’s really been looking at these compounds in concert.”
BTEX, also known as aromatics, are only the latest in a long line of additives for blending into gasoline, to bring an otherwise inferior product up to minimum octane standards. For decades lead was the additive of choice, until a relatively small group of government workers got the neurotoxin eliminated. MTBE was next, but concerns about groundwater contamination brought a crackdown. There have been misgivings among health advocates about BTEX for years, and its use has dropped, but it’s still relied on at the refinery level.
Many experts say ethanol, a cleaner, cheaper additive that also is a natural octane booster, is the wisest choice. During the upcoming Midterm Evaluation of the federal fuel-economy standards (known as CAFE), the issue of whether to infuse more high-octane ethanol into the nation’s gasoline supply is likely to come up.
“I see it as two sides of the same coin,” said Stolark, who authored an authoritative history of octane and gasoline additives. “You’re really, by having a clean source of octane, solving all these issues with health. But then you’re also addressing CAFE; it’s a potential CAFE game-changer … another potential pathway to reduce petroleum consumption, and to reduce the carbon intensity in the transportation sector.”