The Environmental Protection Agency’s (EPA’s) Science Advisory Board has scheduled a public teleconference on November 22, 2010, to conduct a quality review of a draft board report that analyzes EPA’s February 2010 toxicological review of inorganic arsenic.

The board forwarded its review comments to EPA Administrator Lisa Jackson on October 25. Among other matters, the draft comments note that EPA has only partially responded to its 2007 suggestions about factoring background dietary intake of inorganic arsenic into its “assessment of lung and bladder cancer risk associated with exposures to arsenic in drinking water.” In this regard, the board recommends that EPA make “more transparent the scientific basis of the exposure assumptions used” and enhance “the rigor and transparency of the sensitivity analysis.”

EPA’s review, which apparently proposes a 17-fold increase in cancer potency from oral exposure to inorganic arsenic, has been developed under the Integrated Risk Information System (IRIS), and the agency is accordingly considering making the federal arsenic standards for drinking water more stringent. A number of congressional representatives and industry interests have written to the administrator to express their concerns. Republican lawmakers have, in fact, called on the agency to “suspend further work on the IRIS assessment of inorganic arsenic,” contending that the agency must consider ongoing research and thoroughly evaluate all existing scientific data. They assert that small drinking water systems are still struggling to comply with standards developed under the Clinton administration.

Industry interests claim that “many aberrations from generally accepted public processes and procedures” have marked the development of the IRIS assessment. They contend that opportunity for public participation has been limited and that the Science Advisory Board work group participating in the project has not been provided whatever public comment was submitted. They also believe that comments by outside scientists have been ignored. Of most concern is that the agency appears to be rushing to judgment given the costs that apparently will be involved to reducing arsenic concentrations in drinking water and soil. See, October 27, 2010.