Arsenic, Inorganic

EPA is currently revising its Integrated Risk Information System (IRIS) assessment of inorganic arsenic. This assessment addresses both noncancer and cancer human health effects that may result from chronic inhalation exposure to this chemical. To facilitate discussion of several scientific issues pertinent to the assessment, EPA hosted a state-of-the-science workshop. This workshop was open to the public, broadcast by webinar/teleconference, and took place in Arlington, VA on January 8-9, 2013.

Background

EPA is developing a plan for drafting a new IRIS Toxicological Review of Inorganic Arsenic. The first planning step is determining the scope of the Toxicological Review. The scope transparently communicates why the Toxicological Review is being performed and what it will include or exclude. The meeting consisted of 5 sessions of panel discussions focused on a series of charge questions. Lead discussants briefly summarized the available data to address the questions and facilitate discussion with other panelists. Once the panel discussion is over, participants attending the meeting in person or remotely via webinar/teleconference were given the opportunity to ask questions or provide comments within the time constraints of the meeting. In addition to discussions after the panel sessions, time was allotted for participants attending the meeting in person or remotely via webinar/teleconference to provide additional comments.

Meeting Objective

This workshop is designed to inform the development of EPA’s draft Toxicological Review of inorganic arsenic (iAs) (cancer and non-cancer effects), which EPA intends to post to the Integrated Risk Information System (IRIS) database. Workshop participants will be asked to highlight significant new and emerging research that could inform the development of the draft Toxicological Review, discuss methods for identifying the relevant literature, identify major areas of scientific controversy, identify data gaps, and discuss potential approaches for characterizing dose-response.

Workshop Goals:

• Ensure that EPA provides the public an opportunity to inform the Toxicological Review.
• Transparently communicate how EPA will produce a Toxicological Review that meets the needs of the Agency and the public.

Workshop participants are encouraged to think broadly about the body of iAs scientific evidence and how it can best be used in a draft Toxicological Review. Attendees are invited to participate in an open dialogue regarding ways in which the data would most effectively be used in the Toxicological Review that will serve as part of the scientific and technical foundations for the Agency’s decisions on iAs. Specifically, workshop discussions will provide important input as EPA considers the design, scope, and methods used to develop the draft Toxicological Review. The Toxicological Review, in turn, will inform risk management decisions by Agency stakeholders and partners. Panelists participating in the workshop represent a range of scientific expertise (e.g., epidemiology, human and animal toxicology, systematic review, risk assessment, dose-response, and mode of action).

Outcome

The outcome of the workshop will inform EPA’s planning for the Toxicological Review and an upcoming National Academy of Sciences (NAS) public workshop on iAs. Development of the draft Toxicological Review will be informed by the key issues and recommendations from the public NAS and EPA meetings. In addition to conducting a workshop, the NAS will also conduct a review of the draft Toxicological Review. Throughout the process, the public is encouraged to take advantage of the opportunities to review and comment on the draft Toxicological Review. The draft Toxicological Review will be revised in response to the NAS and public review comments. The Toxicological Review will be finalized as expeditiously as possible after the NAS review.

Final Reports: EPA produced a planning and scoping summary document at the end of this public workshop. This planning and scoping summary document aims to communicate how EPA will produce the assessment while meeting the needs of the Agency and the American people.