UPDATE (2/15/17, 5:35 EST) Dr. Larry Wolk, Chief Medical Officer and Executive Director of the Colorado Department of Public Health and Environment (CDPHE), has just weighed in on the latest study by Lisa McKenzie. Here’s what he had to say:
We support studies that evaluate the potential impact of environmental contaminants on public health, and certainly, Benzene exposure has been proven to increase risk of certain types of cancers, including leukemia. However, this 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. The lack of a conclusive association is as a result of many limitations:
1) The study design relies on administrative data and does not take individual exposures to other potential cancer-causing substances into account.
2) The study compared leukemia cases to other cancer cases, rather than comparison to healthy people which makes findings more difficult to interpret.
3) The findings are driven by only 16 cases which significantly limits the strength of the finding.
4) The study did not adequately address additional or alternate explanations for findings, specifically differences in population demographics, smoking history and exposure to other environmental factors such as agricultural chemicals and traffic emissions.
5) The study did not account for resident mobility or full-address history during exposure time period – which could be as high as 66 percent based on previous studies.
As with all chemicals the critical factors are the exposure concentration and the length of time exposed. This is one of the main reasons CDPHE has been studying air quality in oil and gas basins for many years. CDPHE’s analysis of air quality data in high oil and gas areas of Colorado spanning the last six years and encompassing more than 10,000 individual samples indicate benzene exposures are within EPA’s generally acceptable cancer risk range and are similar to those of Denver. Exposure to benzene is among the reasons oil and gas emissions regulations were strengthened in 2014 making Colorado’s the most stringent regulations in the country. (emphasis added)
— Original Post, February 15, 2017 —
A controversial research team, led by assistant research professor Lisa McKenzie, published a new paper today that tries to link oil and natural gas development with childhood leukemia. McKenzie has doggedly tried to link energy development to cancer and birth defects in Colorado for years, and has been rebuked by state public health officials for making assertions that simply aren’t supported by the data.
Based on a quick review of McKenzie’s new paper, the experts at the Colorado Department of Public Health and Environment (CDPHE) are probably outraged all over again. Because the paper presents evidence of nothing, except a desire to alarm the public, generate headlines and grab the attention of potential donors for future research grants. Even worse, this transparent sales pitch exploits the suffering of children with leukemia and their families.
Here are a few of the paper’s biggest problems:
Disavowed by health experts who know the data better than anyone
The paper uses CDPHE health data to claim that “acute lymphocytic leukemia” are more likely to live within 16.1 kilometers – that’s 10 miles – of an oil and gas well.
But buried near the end of the paper is a huge concession: “The CDPHE disclaims responsibility for any analyses, interpretations, or conclusions it has not provided.”
Three years ago, CDPHE officials insisted on a similar disclaimer in one of McKenzie’s papers. In that paper, she tried to link oil and gas development to birth defects. In addition to the disclaimer, the CDPHE issued a statement warning the public not to be misled.
Dr. Larry Wolk, the CDPHE’s Chief Medical Officer and Executive Director, said the researchers used “miniscule” statistical differences to claim some kind of connection – a connection which public health officials rejected. “[W]e disagree with many of the specific associations … [and] a reader of the study could easily be misled to become overly concerned,” Wolk said in a January 2014 statement.
In their 2014 paper, McKenzie and her research team zeroed in on oil and gas development and ignored a host of other risk factors, including smoking during pregnancy, access to pre-natal care and genetic history. “Many factors known to contribute to birth defects were ignored in this study,” Wolk said.
In the wake of this rebuke, one of McKenzie’s co-authors admitted the paper’s shortcomings, telling Rocky Mountain PBS: “It’s certainly not a conclusive study, and it doesn’t demonstrate that pollutants related to shale development have caused birth defects.”
But three years later, it would appear that McKenzie’s research team is up to the same old tricks.
Major risk factors are ignored – again
Just as McKenzie’s 2014 paper targeted oil and gas from the beginning, so does her new paper. Buried inside the paper are concessions about all the other factors that were ignored, such as:
“Our inability to adjust for early common infections, nutrition, family history of neoplasms, water source, proximity to other pollutants, and daycare attendance, as well as individual income, may have resulted in residual confounding. …
Our inability to adjust for maternal smoking during pregnancy also may have resulted in residual confounding.”
This is a huge problem with the paper’s analysis, but the authors just shrug it off. According to the Mayo Clinic, major risk factors for ALL include family history, genetic disorders, exposure to very high levels of radiation and previous cancer treatment involving chemotherapy or radiation. But McKenzie and her team of researchers only seem interested in oil and gas.
This is exactly the same problem that earned the researchers a rebuke from Colorado health officials three years ago – focusing on oil and natural gas to the exclusion of everything else without scientific justification.
So how did they justify the focus on oil and gas this time around? The introduction contains the following sentence:
“The existing literature indicates that populations living in areas with oil and gas development may be at an increased risk for health effects, including cancers such as ALL and NHL, resulting from these exposures.”
But McKenzie and her team cite only one source for the “existing literature” – their own work. It’s a 2012 paper, based on a project commissioned by Garfield County, Colo., which claimed higher health risks for people living within half a mile of oil and gas wells. But what’s missing from the citation is an important detail – the research team was fired by the county almost a year before the paper was published.
In other words, McKenzie and her research team believe oil and gas development is responsible for health impacts because they believe oil and gas development is responsible for health impacts. They are free to believe what they want, of course, but science isn’t based on beliefs – it’s based on facts.
For the record, Wolk – a practicing physician once named Colorado Pediatrician of the Year – has weighed in a number of times about the data on health and energy development, in response to fearmongering by anti-fracking activists.
In Weld County, for example, Wolk says the data show no connection between health impacts and oil and gas development. That’s especially significant because Weld County has more than 23,000 active oil and gas wells – almost half the state’s total of 54,000.
“[T]here’s no reason to believe that there is a causal relationship between oil and gas operations and chronic diseases or cancers,” Wolk told the Greeley Tribune last year. “That plays out in the end numbers.”
In the same news article, Wolk explained why the state health department spoke out against McKenzie’s earlier research: “We wanted to make sure the public wasn’t unnecessarily misled.”
As for McKenzie, she conceded to the Tribune her past research has major limitations and is “not enough to show that oil and gas development causes” the health impacts she claims. The researcher also explained her strategy for securing bigger research grants in the future.
“[Y]ou do the less expensive, simpler studies first, and if those are indicating there might be potential for health defects, that provides justification for the larger studies,” McKenzie said.
No wonder she keeps grasping for connections that state public health professionals – who know the data better than anyone else – just don’t see.
Published in a “joke” of a journal
Given how many times their credibility has been called into question, it’s no surprise to learn that McKenzie and her colleagues turned to a questionable journal to publish their latest findings.
The journal – PLOS One – is an open-access journal that publishes roughly 30,000 articles every year, according to Retraction Watch, and its correction rate is more than three times higher than the average for academic journals.
To publish so many articles – more than 80 every day – PLOS One accepts roughly 70 percent of all submissions, according to Nature magazine. Beyond that, the journal outsources the editorial and review process to more than 6,100 different editors across the globe. And authors who submit papers must pay to have their papers published – between $1,495 and $2,900 based on the journal’s fee schedule.
This approach has prompted significant concern within scientific publishing circles. Last year, the Society for Scholarly Publishing posted a column from David Crotty, the editorial director of journals policy for the Oxford University Press, dealing with PLOS One and similar open-access journals. He listed a range of concerns, including:
“There is no consistent level of quality control because there are 6,100 different sets of standards being used and no central point where they come together. …
“Crowdsourced editorial management is a deliberate strategy — it cuts costs and likely speeds the review process. … The question that must be asked then, is whether these decentralized approaches are “good enough” for the research literature? …
“What other timebombs are lurking in the enormous archives of these publications? …
“All journals make mistakes and have to issue corrections and retractions, to be sure, but are we willing to accept mistakes that are due to a fundamental lack of oversight, with no one really checking to see that the article was indeed properly reviewed (or reviewed at all)? …
“Editors have a solemn responsibility to strive for quality in all efforts, and a journal’s reputation is based on someone setting standards and consistently enforcing them. Turn that over to a crowd of editors and the resulting articles are likely going to be all over the place. Does reputation still matter? Is this “good enough” for the scholarly literature?”
But Prof. James McInerney, Chair in Evolutionary Biology at The University of Manchester and a fellow of the American Academy of Microbiology, had a more blunt assessment after reading a paper that PLOS One was later forced to retract. It’s “an absolute joke of a journal,” he said.
The favorite research team for anti-fracking groups
McKenzie’s research team is famous for supplying talking points to anti-fracking groups. For example, Food & Water Watch, one of the nation’s leading anti-oil and gas groups, cites two of McKenzie’s research papers in a report titled “The Urgent Case for a Ban on Fracking.” The same group used her work was used in a cringe-worthy celebrity video targeting Colorado Gov. John Hickenlooper (D) and in a campaign against California Gov. Jerry Brown (D).
McKenzie is most well known for her 2012 study that claimed people who live within a half-mile of a natural gas wells may have an increased lifetime cancer risk. That 2012 study – which didn’t actually show any meaningful increase in cancer rates – has morphed into one of the anti-fracking campaign’s most frequently used talking points. It was even cited in a celebrity “ban fracking” video last November that targeted Gov. John Hickenlooper.
According to FracTracker Alliance, an environmental group funded by the anti-fracking Park Foundation, McKenzie’s work was also used in a failed ballot-measure campaign against Colorado’s oil and gas sector last year.
One of the measures would have imposed a 2,500-foot setback between drilling locations, occupied buildings and other areas of “special concern.” Public officials warned the measure would have blocked drilling across 90 percent of Colorado’s land mass – an effective statewide ban.
And how did the activists arrive at 2,500 feet? “This setback distance is based on a Colorado health study, concluding that people living with a half-mile of wells had an increased risk of illness than those further away,” according to FracTracker.
The CDPHE’s disavowal of these researchers – not once but twice – is a big deal. It should raise red flags for the media, for policymakers and for the public about the credibility of the claims made in today’s newly released paper.
CDPHE professionals are the stewards of the State of Colorado’s database of health records. They know the data better than anyone else. And when they have serious concerns about how a particular team of researchers is using that data, so should everyone else.