Environmental Causes Contribute to Lung Cancer More Than Previously Thought

The presence of environmental toxins, such as carcinogens, creates a higher risk for cancer than previously thought, according to a recent report from a presidential cancer panel.

In an unrelated 2009 review performed by the American Cancer Society, it was reported that environmental pollutants cause no more than five percent of all cases of cancer. However, in a review of 450 research papers and supporting documents, the presidential panel suggests that the actual percentage is much higher.

According to the panel, the cause for this underestimation is threefold:

  • The original study fails to account for compounding interactions due to the exposure of several contaminants

  • The amount of harmful pollutants is increasing

  • All cancer causes are as of yet still unknown

The findings come as a surprise to even those involved with the study – which was initiated because the researchers had concerns that previous reports linking environmental exposures to cancer were over-exaggerated.

While a more accurate estimation of cancer cases caused by environmental exposures is not cited by the report (due in large part to the lack of previous studies performed on the issue), the team is confident that an increased focus on investigating the linkage between carcinogens and cancer is necessary.

According to the co-authors of the 240-page report – Dr. LaSalle D. Leffall, Jr. and Margaret L. Kripke – there are “nearly 80,000 chemicals on the market in the United States, many of which…are un- or understudied and largely unregulated.” As a result of this fact, the panel recommends initiating additional safety evaluations at the early stages of product development. They also suggest greater regulatory actions against chemical manufacturers who fail to take measures to test the safety of their products.

While increased funds for studying the link between carcinogens and cancer would certainly be insightful, some cancer experts suggest the focus on research should be elsewhere. For example, Dr. Graham Colditz of Washington University School of Medicine in St. Louis believes the greater focus should be placed on more tangible and widespread causes of cancer. As Colditz states, “The lack of physical activity, weight gain, obesity clearly account for 20 percent or more of cancer in the United States today.”

Even at high estimates, the number of cancer cases caused by environmental factors can’t match these other, easier to manage concerns.

Still, despite this opposition, most researchers agree that additional research is necessary into the dangers of new and current chemicals on the market. Clearly, there is a linkage there that needs to be addressed more clearly.