How ‘Safe’ Chemicals Could Team Up to Cause Cancer
July 29, 2015
Chemicals that are benign on their own may turn malignant in combination with others circulating in the environment, researchers warn.
Even as scientists and the chemical industry are playing catch-up on studying the health impacts of thousands of chemicals, researchers are talking about a new concern: the effect of apparently “safe” chemicals mixing in dangerous combinations.
Even if certain chemicals are generally considered innocuous on their own, the cumulative effect of so many in our environment may cause or advance cancer by affecting multiple organs, systems, tissues, and pathways at once, according to a recent study published in the journal Carcinogenesis. The researchers selected 85 common chemicals—including bisphenol-A (BPA), cadmium, polybrominated diphenyl ethers (PBDEs) and phthalates—and studied whether they might impact any one mechanism that has been tied to cancer development.
Though none are considered carcinogenic when acting alone, 50 of these chemicals were found to support at least one key carcinogenic mechanism at current low levels of exposure. These mechanisms include sustained cell proliferation, genome instability, inhibited immune response, and changes to tumor micro-environments.
Can cancer result if you combine the effects of multiple chemicals? The experts don’t know. But given that 7%–19% of cancers are attributable to environmental exposures, according to the International Agency for Research on Cancer, chemical safety testing should start accounting for likely interactions, they argue.
“Every day, we are exposed to an environmental chemical soup, and we need testing to evaluate the effects of our ongoing exposure to the mixtures in this soup,” says lead author William Goodson III, M.D., a senior scientist at the California Pacific Medical Center in San Francisco.