Researchers Concede: Latest Findings ‘Do Not Provide Enough Evidence’ for Health Effects
In an opinion piece published by the Denver Post this morning, a team of researchers favored by anti-fracking activists concedes that its latest findings “do not provide enough evidence to say that living near oil and gas wells causes leukemia or does not cause non-Hodgkin lymphoma.” The concession followed weeks of public criticism from state health regulators, who publicly disavowed and debunked the researchers’ latest attempt to scare the public about oil and natural gas development in Colorado.
Last month, a team led by Lisa McKenzie, an assistant research professor at the University of Colorado, released a new study that tries to link oil and natural gas development to childhood leukemia. The study quickly became a talking point for “ban fracking” activists, who took it out for a spin when making their case for a ban on oil and natural gas development before the Boulder County Commissioners last week.
McKenzie’s new study, however, was quickly disavowed and discredited by state health officials. “[T]his study’s conclusions are misleading in that the study questions a possible association between oil and gas operations and childhood leukemia; it does not prove or establish such a connection,” Dr. Larry Wolk, Chief Medical Officer and Executive Director of the Colorado Department of Public Health and Environment (CDPHE) wrote in a statement.
“The lack of a conclusive association is as a result of many limitations,” he continued, including the paper’s reliance on “administrative data” instead of actual environmental exposures, and the fact that the conclusions “are driven by only 16 cases, which significantly limits the strength of the finding.”
In an interview with The Colorado Independent, Dr. Wolk’s colleague, CDPHE’s head of environmental epidemiology, occupational health, and toxicology Dr. Mike Van Dyke, clarified that the study was “not research that definitely links oil and gas exposure to cancers in this age group” due to “significant limitations,” and “there are a lot of alternative explanations that could be proposed to explain this same relationship”:
“…I think what it really is, is there are a lot of alternative explanations that could be proposed to explain this same relationship. …
“It could also be due to living near a road, there could also be unmeasured factors in terms of things like agricultural exposures, there could be family exposures like people smoking indoors. None of those things were really accounted for in the design of the study, nor should they have been. That kind of research requires a much more detailed and expensive study. I don’t want this to come across as if I’m bashing this study, but I do want to come across as saying that this study has significant limitations.”
McKenzie and her team admitted as much in their opinion piece published today:
“Because we did not have access to evidence about other factors that contribute to these cancers, like genetics, these scientifically valid findings do not provide enough evidence to say that living near oil and gas wells causes leukemia or does not cause non-Hodgkin lymphoma.”
These findings, however, were “published in a highly reputable open-access scientific journal,” they added, referring to an open-access journal that that publishes roughly 30,000 articles every year, accepts around 70 percent of all submissions, and features a correction rate three times higher than the average for academic journals.
In short, these researchers are experiencing yet another case of déjà vu: Their 2014 paper that attempted to link oil and natural gas development to birth defects was promptly disavowed by the CDPHE, and their 2012 paper that attempted to connect proximity to natural gas wells to increased cancer risks forced concessions and qualifications from McKenzie on the findings. Of course, these flaws did not stop activists from using the studies to provide false legitimacy to their “ban fracking” campaigns.
One week after the release of McKenzie’s latest study, CDPHE unveiled a new health assessment that found that “the risk of harmful health effects is low for residents living [near] oil and gas operations,” and that “results from exposure and health effect studies do not indicate the need for immediate public health action.”
Commenting on the substances emitted into the air from oil and natural gas operations, Dr. Van Dyke told the media, “What I can say, from a science perspective, is that science doesn’t support the supposition that all exposure is harmful. Science supports that there is a safe level of exposure for most of these things.”
For more from CDPHE on potential health impacts of oil and natural gas development, see here, here, here, here and here.