One chemical in the air causes far more cancer than any other, elevating everyone’s risk throughout the United States no matter where they live. Formaldehyde has long been in the crosshairs of the Environmental Protection Agency, which was first alerted to the chemical’s carcinogenicity more than 40 years ago. Studies also show it causes respiratory problems and miscarriages. But because the chemical is used by many major sectors of the economy, companies that rely on formaldehyde have rallied to its defense. As a result, it has proven incredibly difficult to regulate.
ProPublica reporters knew last year was the right time for a deep dive. The EPA was preparing to release a report on formaldehyde’s toxicity that had been decades in the making and to take the first step to regulate the chemical under the Toxic Substances Control Act. Sharon Lerner, Al Shaw and Topher Sanders set about quantifying the grave danger the chemical poses and exploring why environmental regulators have failed to protect people from it. The reporting took eight months, but it was worth it.
ProPublica’s groundbreaking analysis of air pollution data from each of the nation’s 5.8 million populated census blocks showed that almost everyone in the U.S. has an elevated cancer risk from formaldehyde in outdoor air; some 320 million people live in parts of the country where the lifetime cancer risk from outdoor exposure to formaldehyde is at least 10 times higher than the agency’s ideal. Shaw used that data to create a powerful tool that allows readers to look up the precise risk that formaldehyde poses at any address in the country.
The reporters also found that the EPA used several novel techniques to downplay that risk. In one example, in a draft report, the agency had determined whether concentrations of formaldehyde in outdoor air posed an “unreasonable risk” — a level that requires the agency to address it — not by measuring them against its own health-based standard, but rather by comparing them to the highest level of the chemical measured outdoors in a six-year period. ProPublica tracked down the source of that measurement and found that the local air monitoring body had determined it was a fluke and did not meet its quality control standards. After we reported on the EPA’s unfortunate choice of benchmark, the agency removed that argument from a final version of the report, which was released in January.
Perhaps the most disturbing of ProPublica’s findings is that the EPA knowingly underestimated the cancer risk of formaldehyde by failing to include the risk of myeloid leukemia, the most common cancer it causes. The agency acknowledged to ProPublica that if it had included that risk in its recently published toxicity report, the nationwide average cancer risk of formaldehyde in outdoor air would be approximately 77 times the agency’s goal.
