Oil and gas-leukemia link deserves further study
As educators, researchers and Colorado citizens, we feel that Colorado families deserve a safe and healthy environment no matter where they live. As authors of a recent study on childhood leukemia and proximity to oil and gas wells, we feel it important to clarify recent misinterpretations of our study.
Our study compared the frequency of leukemia and nonHodgkin lymphoma between children living and not living near oil and gas wells. We used a rigorous design called a registrybased case-control study and included 740 children living in rural Colorado. Eighty-seven of these children had leukemia and 50 had non-Hodgkin lymphoma. We observed that the children with leukemia, but not nonHodgkin lymphoma, were more likely to live closest to the oil and gas wells. 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.
Our study has several strengths. It was conducted using data in the Colorado Central Cancer Registry housed at the Colorado Department of Public Health and Environment (CDPHE). This registry identifies cancer cases and has a “gold” certification from the North American Association of Central Cancer Registries. It is accessible to researchers conducting ethical research that protects the privacy of study participants. Our study design was reviewed by the CDPHE and approved by the Colorado Multiple Institutional Internal Review Board. The results underwent a rigorous peer-review process and were published in a highly reputable open-access scientific journal. Open access means that a subscription to the journal is not required for public access to research. Our study was funded with a $30,000 pilot grant from the University of Colorado Cancer Center, one of only 69 cancer centers in the U.S. recognized by the National Cancer Institute.
All scientific studies have limitations, and our study is no exception. We are planning a more definitive study with researchers from other states to address these limitations. We appreciate comments from Dr. Mike Van Dyke, chief of environmental epidemiology at CDPHE, acknowledging that our study is important and crediting us for explaining our study’s limitations and reasons why more study is needed. Like Dr. Larry Wolk, CDPHE director, we think it is very important that more studies be done to better understand the health risks and benefits that are associated with oil and gas production. This is because hundreds of thousands of Coloradans are either living near oil and gas production or are facing this prospect.
Our critics have made several misinterpretations of our study that lead us to think they did not really understand our rigorous study design. We did not use administrative hospital data, compare leukemia in oil and gas counties to the statewide expected averages, or test variables until a statistically significant association was found.
Our critics are entitled to their opinions. To some, our observed four-fold increase in leukemia risk for Colorado’s children may seem “minuscule.” However, our critics’ opinions cannot change the reality that Colorado kids who live closest to oil and gas wells are more likely to have leukemia. It is our opinion that the public deserves to know about our findings and have further scientifically valid studies conducted that can provide a body of evidence essential to making public health-based decisions regarding oil and gas production.
We thank the CDPHE and University of Colorado Cancer Center for recognizing the importance of asking questions about risks to people who live near oil and gas production. This forward-thinking approach could save lives, prevent illness and avoid countless dollars in health care spending.