Not content to let its lawyers comments about Appalachian inbreeding just fade away quietly, the National Mining Association this morning launched another attack on West Virginia University researcher Michael Hendryx and his colleagues for their recent study linking mountaintop removal to increased rates of birth defects in the coalfields.
It seems that the NMA (or perhaps its law firm) hired a firm called Exponent to produce this eight-page critique of the birth defects paper, and in a news release this morning, the lobby group’s vice president, Bruce Watzman, said:
A recent critique of the analysis completed by Dr. Michael Hendryx, as well as data from the state of West Virginia’s Birth Defects Surveillance System, raises doubts about the conclusions reached by Dr. Hendryx and his colleagues.
Does it really raise doubts?
Well, many of the things outlined by Exponent were already discussed — in a fair amount of detail — in the birth defects paper itself, in the second called, “Limitations of the Study.”
For example, Exponent opines that Dr. Hendryx and his co-authors did not adequately take into account other potential influences on birth defect rates, such as smoking, alcohol consumption, and other socioeconomic factors.
But the paper did attempt to take these other factors into account, and discussed some of the weaknesses in the way the authors were able to do this. For example, the paper says:
Self-reported data … on behaviors such as smoking and drinking during pregnancy are likely to contain error … reporting regarding birth defects is incomplete on birth certificates and is dependent on how easily anomalies are detected after birth and before data are compiled for the birth defects registration.
Also, the Exponent critique makes the point that, without direct exposure data, it’s impossible to say for sure what’s going on regarding any mining exposure and birth defects.
But the study itself discusses such matters:
In this exploratory study, we do not have the data to examine biological mechanisms by which mountaintop mining pollution may lead to brith defects. Investigating these potential mechanisms remains an important future research step.
And, the authors also were pretty clear that they’re not sure their paper has all the answers:
Elevated birth defect rates are partly a function of socioeconomic disadvantage, but remain elevated after controlling for those risks. Both socioeconomic and environmental influences in mountaintop mining areas may be contributing factors.
UPDATED: Michael Hendryx has provided this response to the Exponent critique of his study.
It’s also worth considering the source of this critique of the birth defects study … just exactly who is Exponent and should we believe what they’re telling us?
Well, any simple Internet search shows up some interesting stuff about this Menlo Park, Calif., firm. For example, there’s this L.A. Times story headlined, Toyota calls in Exponent Inc. as hired gun. It reports:
When some of the world’s best-known companies faced disputes over secondhand smoke, toxic waste in the jungle and asbestos, they all turned to the same source for a staunch defense: Exponent Inc.
Now that same engineering and consulting firm has been hired by Toyota Motor Corp. as it seeks to fend off claims that sudden acceleration in its vehicles could be caused by problems in its electronic throttle systems.
The Times story continued:
But Exponent’s research has come under fire from critics, including engineers, attorneys and academics who say the company tends to deliver to clients the reports they need to mount a public defense.
“If I were Toyota, I wouldn’t have picked somebody like Exponent to do analysis,” said Stanton Glantz, a cardiologist at UC San Francisco who runs a database on the tobacco industry that contains thousands of pages of Exponent research arguing, among other things, that secondhand smoke does not cause cancer. “I would have picked a firm with more of a reputation of neutrality.”
And, it added:
Mike Gaulke, executive chairman of Exponent and an employee of the company since 1992, called critiques that it produced only favorable research a “cheap shot.”
“Do we tell our clients a lot of what they don’t want to hear? Absolutely,” Gaulke said.
He said the firm often comes up with results that don’t favor clients, although he couldn’t provide specific examples.
Another L.A. Times story had this to say about Exponent, regarding a House investigation of Toyota’s safety problems:
The committee investigation found e-mails from Benenson Strategy Group, a public relations firm hired by Toyota, that did polling test messages to be used in ads and public statements to improve the company’s image after the recalls.
Among the messages were attacks on the findings by David Gilbert, a professor at Southern Illinois University, who testified to the committee in February that he had triggered sudden acceleration in a Toyota vehicle without setting off an error code in the vehicle’s computer.
Toyota hired a testing firm, Exponent Inc., to review Gilbert’s findings. Exponent disputed the findings as part of a public presentation held by Toyota in March at the company’s Torrance operations center aimed at debunking Gilbert’s research.
Stupak called Exponent’s report “a hit job, not solid science.” He said Exponent had withheld documents from the committee’s investigation and had modified some documents before producing them, “in direct violation of the committee’s instructions.”
Waxman questioned Toyota’s statement that Exponent was conducting a comprehensive and independent review. The only document provided to the committee about their relationship, he said, was “a contract between Toyota’s litigation defense counsel and Exponent for ‘engineering consulting services related to class actions filed against Toyota.’ “
Perhaps less noticed by the public were efforts by Exponent to stop the U.S. Occupational Safety and Health Administration from regulating the toxic chemical hexavalent chromium. Interestingly, as reported in the journal Environmental Health:
The industry paid for services provided by ChemRisk and Exponent, Inc. through its trade association’s attorneys. This arrangement was selected to “…preserve the confidentiality of information, opinion, and data to the extent provided for under the attorney-client privilege and attorney work product privilege,” ensuring that material developed through the process could be sequestered from public view.
That paper mentioning Exponent was written by David Michaels, who is now head of OSHA, and by Celeste Monforton, a public health researcher who also follows efforts by industry to misuse science.
Dr. Michaels wrote extensively about Exponent in his book, Doubt is Their Product: How Industry’s Assault on Science Threatens Your Health. Among other things, he explains how Exponent has “flooded the literature” with allegations that exposure to asbestos brake shoes was not a danger to auto mechanics. Dr. Michaels observed:
Exponent’s scientists are prolific writers of scientific reports and papers. While some may exist, I have yet to see an Exponent study that does not support the conclusion needed by the corporation or trade association that is paying the bill.
I asked Dr. Monforton to take a quick look at the Hendryx birth defects study and the Exponent criticism of it. She told me via email:
The Hendryx paper explains fully that it is an ecological design. By its nature, an ecological design is hypothesis generating and is not used to find associations. The authors explain fully the limitations of the data they used for their analysis but to the extent possible control for the factors associated with birth defects. They also say their findings “suggest an effect” of mountaintop removal mining.
It’s clear that NMA was concerned about how this analysis would be reported in the press and interpreted by the public. Thus, they hired one of the most notorious product-defense firms to critique the study.
As I mentioned to you in the past, it is easy for individuals with training in epidemiology to critique other people’s work and find flaws in their methods. There is no such thing as a perfect study so all of them will have flaws.
For example, Exponent criticizes the analysis for not including the “mother’s residence during pregnancy”—an easy criticism—-but don’t say where in the world the researchers would get that information or how much it would cost to obtain it. Unlike other economically-developed countries, we don’t have a national health system where such information would be contained in a dataset. Similarly the criticize them for not having the mother’s education level. The analysis is an ecological study—it is not a cohort study where researchers have specific information on each subject.
Hendryx and company are examining a legitmate scientific/public health question using the best data available. Other than paying companies like Exponent to critique other people’s analysis, I don’t see NMA offering funds to Hendryx to help him fill the data gaps that NMA claims make his analysis unreliable. They don’t want to have the public health question answered, they’d rather just throw stones at researchers who are trying to answer this legitimate question.