Billions of dollars are spent each year to research and develop new cancer treatments. Yet when it comes to preventing this deadly disease, the focus may not be on target, putting too little emphasis on the role of cancer-causing chemicals in the environment, according to a recent report in Reviews on Environmental Health.“A lot of the research right now is about treatment and the genetics of cancer,” says lead study author Richard Clapp, MPH, DSc, professor at the Boston University School of Public Health and adjunct professor at the University of Massachusetts Lowell – Lowell Center for Sustainable Production. “It’s true that the survival rate is much better than it was 20 years ago. But I think there’s been an imbalance in the funding of research…we need to think more about toxic use reduction or alternatives assessment.”
Cancer development involves a complicated interplay of genetic and environmental influences, but exposure to certain chemicals released through manufacturing and industrial processes is a significant contributor, according to the report. The International Agency for Research on Cancer has linked more than 400 different chemicals to an increased cancer risk.
Clapp and his colleagues reviewed studies on many of these chemicals, and found several strong links to cancer, among them:
– Dioxin (created during manufacture and combustion processes)—Leukemia, non-Hodgkin’s lymphoma.
– Hair dyes—Brain cancer, colon cancer, leukemia
– Metals (arsenic, lead, mercury)—Bladder cancer, brain and central nervous system cancers, lung cancer, skin cancer, kidney cancer, liver cancer
– Mineral oils—Bladder cancer, laryngeal cancer, prostate cancer, skin cancer
– Non-ionizing radiation (microwaves and cell phones)—Brain and central nervous system cancers, breast cancer, childhood leukemia
– Pesticides—Brain cancer, breast cancer, colon cancer, leukemia, lung cancer, multiple myeloma, non-Hodgkin’s lymphoma, prostate cancer, rectal cancer, skin cancer
– Polycyclic aromatic hydrocarbons (PAHs — from burning fuels)—Bladder cancer, breast cancer, prostate cancer
– Solvents—Bladder cancer, kidney cancer, leukemia, lung cancer, multiple myeloma, non-Hodgkin’s lymphoma, prostate cancer
The risk is greatest among people who work in the industries that use these chemicals, Clapp says. However, anyone who lives near manufacturing plants or uses these chemicals at home (such as from dry cleaning or pesticides) is also at risk.
If so many chemicals have the potential to cause cancer, why aren’t manufacturers doing more to reduce the use of these substances? “That’s the big question,” Clapp says. “When you declare something to be carcinogenic to humans, that means the industry has to find some alternative or stop using it. So they fight against having things called carcinogens.”
“I think most companies would rather not have something that was carcinogenic in their production process, but once they find out that it is, they’re typically reluctant to move very fast to phase it out,” he adds. And even when a handful of chemicals are phased out—like DDT and the herbicide 2,4,5-T—more toxins are introduced.
Clapp and his colleagues cite the need for a new cancer prevention paradigm, which aims to reduce exposure to environmental carcinogens. This approach relies on the efforts of government and industry, but it starts with consumers. “People can be aware—be judicious about what they’re buying and putting in their houses,” Clapp says. “As we either choose safer products or demand safer products, that demands the industry to make changes.”
Clapp ultimately believes the solution lies in green chemistry—producing chemicals in a way that is safe to both workers and consumers. As the cancer burden continues to grow, the need for greener solutions becomes ever more pressing.
Clapp RW, Jacobs MM, Loechler EL. Environmental and occupational causes of cancer: new evidence 2005-2007. Rev Environ Health. 2008;23:1-37.