Does Pollution Increase the Risk of Cancer?
Cancer remains the No. 2 killer of Americans after heart disease, claiming nearly 600,000 lives each year. But 39 in every 100,000 of those deaths could be prevented by cleaning up some of the country’s worst environmental hazards, according to a study published last month in the journal Cancer.
Researchers led by Jyotsna Jagai of the University of Illinois began with data from the U.S. EPA Environmental Quality Index, which details cumulative environmental exposures on a county-by-county basis. To reach their conclusion, the team culled EQI data from 2000 through 2005 and compared it to cancer incidence rates for the following five years.
The results showed higher incidence of cancer in counties with lower environmental quality. But not everyone is sold on the findings.
In a Forbes op-ed, Geoffrey Kabat questioned the broad scope of the study and argued that county-level data is not enough to link a region’s environment with cancer diagnoses among residents.
“While exposure to pollutants could be important in some locations, it is unevenly distributed within counties, and its effects are likely to be dwarfed by the effects of personal behaviors,” wrote Kabat, a cancer epidemiologist at the Albert Einstein College of Medicine.
Scarlett Lin Gomez, a research scientist with the Cancer Prevention Institute of California, noted this distinction in an accompanying editorial. “There is a tension in the field as to whether to focus on individual or cumulative environmental exposures,” she wrote, as quoted by New Scientist. Even Jagai herself told Science Daily that researchers must “look at geographic areas smaller than counties" to further refine the data.
The truth is that risk factors such as genetics, behavior, environment and socioeconomic status often overlap, meaning scientists may never know for sure what causes cancer.
“It’s like looking at strands of a spider web and deciding which one is important,” Ted Schettler, director of the Science and Environmental Health Network, told Scientific American in response to a 2010 study that also sought to establish a firmer link between environmental exposure and cancer rates.
But as we hope to create a world without cancer, most researchers agree that focusing solely on either behavior or environment is a losing approach, as in recently introduced legislation that seeks to limit collection of environmental quality data that is crucial to future research.