Two Harvard scientists are bucking congressional and EPA requests to fully disclose the data used to support a key set of studies on the health effects that stem from particulate matter exposure, countering that they are already taking steps to share relevant information with an independent review panel.
Some scientists lament that the position taken by the Harvard researchers is disappointing because their work serves as a linchpin for EPA's move to strengthen the national PM standard even though their critical supporting data has never been completely disclosed to the public.
In 1994, EPA began paying close attention to a set of PM studies that were conducted by Harvard researchers Joel Schwartz and Douglas Dockery. EPA has given great credence to the researchers' "six cities" study, which suggests that there is a strong link between elevated exposure to fine particles and premature mortality. EPA officials have acknowledged that the study played a key role in the agency's decision to propose a stringent new fine particle standard to protect public health.
A number of scientists, however, are leery of the study, charging that it is difficult to test its accuracy because Schwartz and Dockery have never fully disclosed some key data sets that were relied upon. In particular, various scientists have raised concerns that the individual health histories used in the study have never been fully disclosed. A number of scientists, including a handful who serve on EPA's Clean Air Scientific Advisory Committee believe that this is an important issue because a thorough re-analysis of the data could suggest that the causal link between exposure and mortality is not as strong as the Harvard researchers have suggested.
House Commerce Committee Chairman Thomas Bliley (R-VA) earlier this month called on EPA to use its authority to obtain the data. In a Feb. 5 memo to the agency, Bliley writes that EPA should "exercise its authority, pursuant to the regulations governing cooperative agreements, to obtain all of the data and supplementary materials and make such underlying data .. available for the public record." EPA's air chief Mary Nichols had asked the researchers on Jan. 31 to "make data associated with your published studies available to interested parties as soon as possible."
Dockery and Schwartz responded Feb. 10 by saying that they are already accommodating these concerns under a project that is being undertaken with the Boston-based Health Effects Institute. The letter points out that efforts have previously been made to share certain data sets with HEI and last year an agreement was reached to continue this relationship. However, in their response, Schwartz and Dockery stop short of agreeing to disseminate their data throughout the scientific community at large.
EPA sources warn that there is not much more the agency can do because much of the data in question is proprietary and protected under various agreements that the researchers have made. EPA staff do point out, however, that much of the information used in the "six city" study has or will be shared with the public and the agency remains confident that the study in question remains highly credible.
Nonetheless, various scientists remain disappointed that this continues to be an issue. One source points out that EPA should have taken aggressive action on this front two years ago and said that agency consideration of the study was contingent on full disclosure. Had EPA pursued such a move, this source says various scientists could have evaluated the data in time to affect the debate over whether a new PM standard is needed.
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