Scientists have long wondered what triggers a cancer "cluster" or "hot spot" -- a geographic area where higher than normal rates of cancer prevail over a limited time period. There are many likely reasons this happens. A new study might offer an important clue about one big cause.
The University of Missouri-Columbia and the University of Florida jointly studied adult cancer rates in Florida between 1986 to 2010. They selected Florida because it holds two dubious honors. Florida was projected in 2016 to have the second largest number of new cancer cases in the United States.
Florida is also home to the sixth highest number of hazardous waste Superfund cleanup sites -- 77 of them in 22 counties, to be exact. Could there be a link? Researchers wanted to find out.
What's a Superfund Site?
First, it's important to understand what we're talking about. Superfund sites are places that have been contaminated by hazardous waste and identified by the Environmental Protection Agency (EPA) as needing cleanup because they pose a serious risk to human health and/or the environment. They are generally the nation's worst hazardous waste sites, often becoming national news because of their significance.
If you want to search to see if there are Superfund sites near you, EPA has a web page that allows you to do that. Click here to take a look.
What the Study Considered
The research team excluded consideration of air pollution, since much work in that area is already available. Instead, the study took a close look at drinking water contamination and soil contamination. Those are what the study called "common avenues of exposure for hazardous wastes."
Using cancer incidence data from the Florida Department of Health, the study looked only at adults. It excluded pediatric cancer because it is often genetic, not environmental in nature. Additionally, cancer often needs a long latency period to take hold -- between 2 years for chronic lymphocytic leukemia to 56.8 years for ascending colon cancer.
Focusing on the instance of all forms of adult cancer, what the study found is interesting, to say the least.
"Our goal was to determine if there were differences or associations regarding cancer incidence in counties that contain Superfund sites compared to counties that do not," said Dr. Emily Leary, study co-author, in a press release. "We found the rate of cancer incidence increased by more than 6 percent in counties with Superfund sites."
That's a concerning statistic, but it isn't yet clear exactly what it means. The research team views its conclusions as a staring point for more study, not as a definitive pronouncement that they've figured something out.
The study's findings show spatial and gender differences across Florida in adult cancer incidents. In other words, the results change, depending on where you are and whether you're male or female. Ultimately, the study's "[r]esults indicated potential association with environmental exposures related to Superfund sites and cancer incidence rates for Florida."
"This work is novel because it is another piece of evidence to support an environmental cause of cancer," Leary said. "While it would be premature to say these differences are attributed to Superfund sites, there does appear to be an association. More research is needed to determine what this relationship is and why it exists, but identifying that a difference exists is a necessary first step."
Worrying About Past Misdeeds
We need to worry about whether our past environmental misdeeds still affect our health and environment even today. This is the legacy left behind by decades of often uncontrolled pollution.
Environmental contamination is sometimes intentional and sometimes the result of a mistake – but it so often causes real harm to innocent bystanders. People, animals and ecosystems suffer. Consequences can be devastating.
I'm left wondering whether the Trump Administration's desired rollbacks of environmental laws will exacerbate this kind of problem. Supporting business interests at the expense of the environment is foolhardy. If we no longer have the tools to regulate pollution, we're in for so many more of these problems in the years and decades to come.
Continue to raise your voice on these issues. Don't become complacent. Don't believe you aren't making headway, because you are. There's probably a March for Science sister march in your area on April 22. Show up for it and bring friends.
These are crazy times. Keep pushing for sanity and responsible action.