Back in April, I blogged about a report released by a professor at the University of Texas suggesting that there was a “cancer cluster” in the Town of Flower Mound, Texas — and that a prior State study suggesting otherwise was flawed. In particular, the professor criticized the State’s use of a 99% confidence interval as too stringent and argued that using a 95% confidence interval suggested that the incidences of cancer were not random. Of note, Flower Mound is located about 20 miles northwest of Dallas — an area with active “fracking” of the Barnett Shale. Area residents raised concerns that these fracking operations were to blame for the increased cancer rates. In light of these concerns, and the University of Texas report, the Texas Department of State Health Services agreed to reexamine the earlier data it had collected and issue a report. The State released its updated report this week, and is available here.
As reported in the Texas Department of State Health Service’ press release, its reanalysis using a 95% confidence interval (in addition to the 99% level that Texas cancer cluster investigations typically use) yielded the same results as the prior investigation. Specifically, the report notes that:
- With the exception of breast cancer, cancer numbers in the city’s two primary zip codes are not higher than what was expected for 2002 to 2011.
- Consistent with previous analyses, female breast cancer had a higher than expected number of cases in the area.
- The analysis also found the expected number of leukemia, brain/central nervous system and liver cancers in children; the expected number of breast cancer in males; and the expected number of leukemia and non-Hodgkin’s lymphoma in males and females.
- DSHS broadened its analysis from previous years to include more cancer types, updated cancer and population data, two confidence intervals rather than one, and the most recent range of available years. DSHS added childhood liver cancers to this analysis due to community concerns about the cancer type.
The findings with respect to female breast cancer rates have continued to raise concerns among Town residents, some of whom continue to believe that the higher rates may be attributable to fracking operations. Recent media reports quote the Mayor of Flower Mound that cases were about 22 percent higher than the average which is “very concerning for our community.”
That said, the State’s report notes that risk factors for breast cancer include family history, lifestyle choices and other factors such as gender and age. Furthermore, populations screened for cancer more frequently can yield more cases — possibly explaining the above-normal rates. Regardless, the DSHS has agreed to continue monitoring cancer incidence in the area. And, for its part, the Town issued a press release, noting that “the Town remains steadfast in its dedication to continue its stringent air quality tests and monitoring” and that “Flower Mound continues to be a leader in air quality monitoring as well as municipal oil and gas drilling regulations.”
Fracking operations are under the microscope from all angles. It should go without saying that any supposed link between fracking operations and cancer (or any allegedy injury) should be based on sound science, not guesswork or bias. As always, we’ll keep a close eye on these developments.