Benzene research conducted by the World Health Organization’s (WHO) cancer research agency is significantly inadequate and flawed, but the agency refuses to take any action to correct its deficiencies, an investigative report by Reuters has found.
WHO’s International Agency for Research on Cancer (IARC), widely considered to be the world’s top authority on the toxicity of benzene and other chemicals to human health, underplayed human exposures to the carcinogenic chemical in assessing its dangers, Melvyn Kopstein, a Doctor of Chemical Engineering, found. The studies are flawed, Dr. Kopstein said, because they limited assessments to products containing small amounts of benzene, which doesn’t accurately account for its pervasive presence in the real world.
“So, while IARC was correctly gauging the danger of benzene itself, he concluded, the agency was giving unrealistically low estimates of how much of the carcinogen workers are exposed to in everyday jobs,” according to Reuters.
Dr. Kopstein contacted the IARC in 2015 and pointed out the problem with its benzene research. Kurt Straif, head of the IARC’s Monograph unit that seeks to determine how carcinogenic substances are to humans, initially replied to Dr. Kopstein’s concerns. He acknowledged that the agency’s study of benzene had limitations, was “condensed,” and wasn’t intended to be an “exhaustive” study.
But now, three years after Dr. Kopstein first contacted the IARC, one of its senior scientists emailed Dr. Kopstein to say, “We do not plan to amend (the benzene determinations) or take any further action.”
Dr. Kopstein told Reuters the response blindsided him. “After all, they – IARC – are supposed to be the go-to source around the world of unbiased scientific information on the carcinogenicity of products and chemicals,” he told Reuters.
Measuring the Danger
The crux of Dr. Kopstein’s argument with the IARC’s benzene determinations focuses on the agency’s Monograph 100F report, in which it classifies benzene as a human carcinogen but boldly claims that workers’ exposures to the chemical have been lower than the recommended daily limits for exposure since the 1980s.
According to Dr. Kopstein, his peer-reviewed scientific research has found that occupational exposure to benzene is often substantially higher than the IARC’s assessment suggests. But he is not alone in his findings. A multitude of studies that the IARC did not take into consideration shows that workers in the U.S. and around the world continue to be exposed to dangerously high benzene levels on the job.
An American Public Health Association report released in 2005 found that 3 million workers in the U.S., 1.4 million workers in the European Union, and an undetermined number of others in developing countries are exposed to benzene in industries such as adhesives, auto repair, chemicals, gas stations, paint, petroleum, rubber, shoe/leather, and shipping, among many others.
The U.S. produces more than 16 billion pounds of benzene per year, making it the 17th most widely produced chemical in the U.S. and one of the most commonly used. Since 1992 U.S. benzene production has grown substantially year to year, and with that growth comes more opportunity for exposure.
The U.S. Occupational Safety and Health Administration (OSHA) sets a maximum level of benzene exposure for workers at 1 part per million parts of air over an 8-hour workday and 40-hour work week. The short-term occupational exposure limit is 5 parts of benzene per million parts of air in a 15-minute period.
Long-term benzene exposures, even in the lowest concentrations, are particularly dangerous for workers. Over several months or years, exposure can lead to anemia and other blood disorders. Exposure to benzene causes anemia and acute myeloid leukemia (AML) and evidence also points to the chemical as a trigger for chronic lymphocytic leukemia, non-Hodgkin’s lymphoma, and multiple myeloma.
Such cancers are higher than normal among workers in certain industries, such as chemical manufacturing, shoemaking, ship-building, oil refining, and coal distillation.
Why No Update?
Yet despite the deadly risks that benzene exposure poses to workers around the world, the IARC isn’t in a hurry to update its understanding of those risks. In fact, three decades have passed since the last time the IARC assessed the chemical’s risks in 1987. In that time, major studies of benzene’s toxicity and other research have been published.
Martyn Smith, one of the IARC’s members who assessed benzene’s risks, told Dr. Kopstein in an email that the working group “tried to cover too much … so I’m not surprised it has left out key findings or focused on the wrong studies.”
The IARC’s research on benzene and other toxins informs governments around the world, and government officials use the information to set safety rules and regulations. The IARC’s work also influences policies and standards set by companies and entire industries, not to mention countless toxic tort cases involving personal injury and wrongful death claims.
In the long-run, the IARC’s reluctance to take any further action on the matter puts countless millions at risk of developing life-threatening cancers. It could also weaken the agency’s credibility as an authority on carcinogenic substances in the future.
American Public Health Association
World Health Organization
American Cancer Society