Arsenic, Inorganic
CASRN 7440-38-2 | DTXSID4023886
- Toxicological Review (PDF) (318 pp, 17.0 MB)
- IRIS Summary (PDF) (6 pp, 422.9 KB)
- Workshop & meeting details from the development of the draft IRIS Assessment for inorganic arsenic
Inorganic Arsenic Meetings & Webinars (Sep 2012 - Jul 2019)
Notice
Meeting Agenda
Background
EPA’s Integrated Risk Information System (IRIS) Program is developing an updated assessment of inorganic arsenic. See the chemical information page tab for the most up-to-date information about the status of this assessment.
Assessment History
EPA published an IRIS summary of inorganic arsenic in 1988 and began updating the assessment in 2003. The update implemented recommendations from two National Academies of Science (NAS) reports (1999 and 2001) that evaluated EPA’s drinking water standards for inorganic arsenic. In 2005, the IRIS Program released a draft arsenic assessment (focused on cancer health effects following oral exposure to inorganic arsenic) for public comment and review by EPA’s Science Advisory Board (SAB). The SAB provided recommendations in 2007, and in 2010, EPA released a revised draft inorganic arsenic assessment (focused on cancer health effects following oral exposure to inorganic arsenic) for public comment and review by the SAB. In 2011, the SAB provided comments and recommendations on the 2010 draft.
EPA is now working to develop an updated IRIS assessment of inorganic arsenic (focused on both cancer and noncancer health effects). When a draft assessment has been developed, EPA will submit it for peer review by the NAS.
IRIS Assessment Development
Below is a list of milestones and associated products that have been released while developing the updated IRIS assessment of inorganic arsenic.
Step 1: Draft Development
- Sep 2012: EPA internal meeting on planning and scoping for the development of the inorganic arsenic IRIS assessment.
- Jan 2013: EPA hosted an inorganic arsenic workshop (see related links) to discuss the planning and scoping for the development of the inorganic arsenic IRIS assessment.
- Mar-Aug 2013: EPA Arsenic Webinar Series (see below)
- Jun 2014: EPA hosted a June IRIS public science meeting on preliminary materials that were prepared for the inorganic arsenic (iAs) assessment.
- May-July 2019: EPA released an Updated Problem Formulation and Systematic Review Protocol for the Inorganic Arsenic (iAs) IRIS Assessment for public comment. The National Academies of Sciences, Engineering, and Medicine (NAS) hosted a public meeting on July 16, 2019 to discuss recent progress and updates on the IRIS assessment.
Providing Comments
If you would like to provide additional comments please use the Docket, ID #EPA-HQ-ORD-2012-0830, at Regulations.gov.
Meetings
EPA-Led Meetings & Workshops
- Jun 25-27, 2014: EPA hosted an IRIS public science meeting (June 2014) to provide an opportunity for the public to give input and participate in an open discussion regarding preliminary materials that were prepared for the IRIS chemicals, hexavalent chromium (Cr(VI)) and inorganic arsenic (iAs), prior to the development of the draft assessment.
- Jan 8-9, 2013: EPA held an Inorganic Arsenic Workshop for the planning and scoping of the IRIS Toxicological Review of Inorganic Arsenic.
National Academies of Sciences (NAS)-Led Meetings & Workshops
The list below includes events hosted by the National Academies of Sciences for the review of the IRIS Toxicological Assessment of Inorganic Arsenic:
2019
- July 16, 2019: The National Academies of Sciences, Engineering, and Medicine (NAS) will be hosting a public meeting to evaluate the Updated Problem Formulation and Systematic Review Protocol for the Inorganic Arsenic (iAs) IRIS Assessment document released in May 2019.
In July 2019, an NAS ad hoc committee will conduct a peer review of the revised scope of the assessment and determine whether the proposed methods are appropriate to synthesize the scientific evidence and develop conclusions. Given the size and complexity of the evidence base for this chemical, input on the scope of this assessment has been sought from the National Academy of Sciences, Engineering, and Medicine (NAS), EPA Program and Regional Offices, other federal agencies, and public stakeholders to help focus the objectives of the assessment and ensure it is transparently conducted. The Updated Problem Formulation and Protocol summarizes the Agency's need for the assessment and presents the refined focus based on problem formulation activities conducted since the last assessment plan released to the NAS in 2015.
Materials provided to the NAS include presentations on the topics noted above and the updated problem formulation and systematic review protocol.
- Updated Problem Formulation and Systematic Review Protocol for the Inorganic Arsenic (iAs) IRIS Assessment
- EPA Presentations from the National Research Council Meeting:
- Introduction and Role of the Protocol in the IRIS Systematic Review Process (PDF)
- U.S.EPA Updated Problem Formulation and Scoping (for the IRIS Assessment of Inorganic Arsenic) (PDF)
- U.S.EPA Systematic Review Methods Used to Prioritize Health Outcome (PDF)
- U.S.EPA Inorganic Arsenic IRIS Dose-Response Analyses (PDF)
- <Summary Table for Comments Received on iAs Protocol for Transmittal to the NAS Committee (PDF)
- EPA Posters from the National Research Council Meeting:
- Poster 1: Systematic Review Methods and Hazard Characterization for the Updated Problem Formulation and Protocol for the Inorganic Arsenic (iAs) IRIS Assessment
- Poster 2: Building an Adverse Outcome Pathway Network for Arsenic-Induced Bladder Cancer
- Poster 3: Evaluation of a Physiologically-based Pharmacokinetic (PBPK) Model for Inorganic Arsenic (iAs) Exposure Using Data from Two Diverse Human Populations
- Poster 4: Analyzing Study-Specific Estimates of Exposures Associated with a Defined Relative Risk vs U.S. Background Exposure (RRBs) for Inorganic Arsenic (iAs) Health Outcome
- Poster 5: The Application of Model Averaging Methods to Assess the Suitability of Taiwanese Studies for Predicting U.S. Bladder and Lung Cancer Risk from Inorganic Arsenic (iAs) Intake
- Poster 6: Bayesian Hierarchical Meta-Regression of Epidemiologic Studies: Dose and Response Pre-Analysis
- Poster 7: Bayesian Hierarchical Meta-Regression of Epidemiologic Studies: Dose-Response Modeling and Target Population Predictions
2015
- Dec 2-3, 2015: Meeting Information - Guidance for and Review of EPA's Toxicological Assessment of Inorganic Arsenic
In December 2015, the National Academies of Sciences (NAS) hosted an introductory meeting of the committee formed to peer review the draft IRIS assessment of inorganic arsenic. EPA provided background and overview information during the public session on December 2nd. The information covered the systematic review methods, approaches for mode of action analyses and hazard identification, toxicokinetics, and approaches for dose-response that are under development in the assessment.
Materials provided to the NAS include presentations on the topics noted above and the Assessment Development Plan (ADP). The ADP characterizes the scoping, problem formulation, and overarching approach for the IRIS assessment. The ADP was previously released in April 2014 and discussed at an IRIS public science meeting in June 2014. The ADP has been revised based on comments from the previous NAS committee, stakeholders, and the public.
- Assessment Development Plan for the Integrated Risk Information System (IRIS) Toxicological Review of Inorganic Arsenic
- EPA Presentations for the National Research Council Meeting:
- Introduction to the IRIS Toxicological Review of Inorganic Arsenic
- Approach to Systematic Review for the IRIS Toxicological Review of Inorganic Arsenic
- Hazard Identification for the IRIS Toxicological Review of Inorganic Arsenic
- Conceptual Mechanistic Models for the IRIS Toxicological Review of Inorganic Arsenic
- Toxicokinetics for the IRIS Toxicological Review of Inorganic Arsenic
- Dose-Response Methods for the IRIS Toxicological Review of Inorganic Arsenic
The assessment will examine the cancer and noncancer effects from oral, inhalation, and dermal exposure to inorganic arsenic. The committee will review the draft assessment to determine whether the scientific literature on inorganic arsenic was adequately evaluated, whether appropriate methods were used to derive cancer risk estimates and noncancer reference values, and whether dose-response relationships between inorganic arsenic and cancer and noncancer effects were appropriately estimated and characterized.
2013
- Jan - May 2013: The NAS held three public meetings on inorganic arsenic (see links below) resulting in a release of an interim report on November 7, 2013 titled Critical Aspects of EPA's IRIS Assessment of Inorganic Arsenic . This report describes the committee’s recommendations to the IRIS Program for developing an updated assessment of inorganic arsenic. The report contains findings and recommendations related to six critical areas, including: hazard identification; systematic review assessment of causality; mode of action; susceptibility; and dose-response analysis.
See the report in brief. Additional details are available from the NAS iAs Project Information page.
Webinars
The IRIS Program has been utilizing webinars in the development of the IRIS assessment for inorganic arsenic to foster public engagement and enhance transparency in the assessment development process. Webinars associated with the inorganic arsenic assessment can be found below:
- 7/31/2013: Investigations Into its Mode of Action
- 6/26/2013: Environmental Justice
- 5/22/2013: Arsenic and Children’s Neurodevelopment: What is the Literature Telling Us?
- 5/08/2013: Mode of Action of Arsenical Carcinogenesis
- 4/24/2013: Recent Developments in Adverse Outcome Pathway/Mode of Action Analysis
- 4/11/2013: Inorganic Arsenic Exposure and Hypertension: A Focus on Blood Pressure Reactivity
- 3/27/2013: Transplacental Arsenic Carcinogenesis and Stem Cells
- 3/20/2013: Considerations in Assessing Low-Level Exposure to Arsenic in Drinking Water
Note: Contact the chemical manager to request a copy of any of the 2013 webinar series presentations.
Jul 31, 2013: Is Arsenic a Mutagenic Carcinogen? Investigations Into its Mode of Action
Invited Speaker: Dr. Andrew Kligerman
June 26, 2013: Environmental Justice
Invited Speaker: Michele Roberts
May 22, 2013: Arsenic and Children’s Neurodevelopment: What is the Literature Telling Us?
Invited Speaker: Dr. David Bellinger
May 8, 2013: Mode of Action of Arsenical Carcinogenesis
Invited Speaker: Dr. Samuel Cohen
April 24, 2013: Recent Developments in Adverse Outcome Pathway/Mode of Action Analysis
Invited Speaker: Dr. Bette Meek
April 11, 2013: Inorganic Arsenic Exposure and Hypertension: A Focus on Blood Pressure Reactivity
Invited Speakers: Drs. Catherine W. Yeckel and Kathleen McCarty
March 27, 2013: Transplacental Arsenic Carcinogenesis and Stem Cells
Invited Speaker: Dr. Erik Tokar
March 20, 2013: Considerations in Assessing Low-Level Exposure to Arsenic in Drinking Water
Invited Speaker: Dr. Jaymie Meliker
Meeting Materials
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