Arsenic, Inorganic

CASRN 7440-38-2 | DTXSID4023886

Inorganic Arsenic Meetings & Webinars (Sep 2012 - Jul 2019)


This page provides information on public meetings and webinars for the Integrated Risk Information System (IRIS) assessment of inorganic arsenic. EPA's IRIS Program is committed to proactively engaging stakeholders, increasing transparency, and using the best available science to develop IRIS assessments. These public meetings and webinars are designed to inform the development of EPA’s toxicological review of chronic exposure to inorganic arsenic (cancer and non-cancer effects), and facilitate dialogue with interested parties and stakeholders.

Meeting Agenda


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

Providing Comments

If you would like to provide additional comments please use the Docket, ID #EPA-HQ-ORD-2012-0830, at


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:


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.


  • 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.

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.


  • 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.


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:

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

Biography: Dr. Andrew Kligerman is currently a research biologist in the Integrated Systems Toxicology Division at the U.S. EPA in Research Triangle Park, NC. He has been a cytogeneticist and genetic toxicologist at the EPA for over 24 years. His research interest focuses on studying the genotoxicity of important environmental and commodity chemicals. For the previous 10 years his research has concentrated on investigating the mode of action of arsenicals in inducing genetic damage and cancer. He is currently doing a rotation with the National Center for Computational Toxicology at the EPA, where he is investigating the sensitivity and specificity of high-throughput tests for determining the genetic toxicology of chemicals.

June 26, 2013: Environmental Justice

Invited Speaker: Michele Roberts

Biography: Michele Roberts is currently co-director of the Environmental Justice and Health Alliance for Chemical Policy Reform. Since 1990, Ms. Roberts has provided technical assistance and advocacy support to communities regarding the impacts of toxins on human health and the environment. She also is a spoken word artist, who created Arts Slam @ SsAMS, a community-based arts program. She received a master of art degree (2000) from the University of Delaware and a bachelor of science degree in biology (1983) from Morgan State University. Ms. Roberts has co-authored reports on environmental justice issues. Her advocacy work has been featured in television, print news, and magazines. Prior to being an advocate, Michele worked for 20 years as an environmental scientist for the government.

May 22, 2013: Arsenic and Children’s Neurodevelopment: What is the Literature Telling Us?

Invited Speaker: Dr. David Bellinger

Biography: Dr. Bellinger is a Senior Research Associate in Neurology and Professor of Neurology at Boston Children’s Hospital. He holds a secondary appointment as Professor in the Department of Environmental Health at the Harvard School of Public Health. Dr. Bellinger is currently President of the International Society for Children’s Health and the Environment. Dr. Bellinger's research focuses on two types of early insults to the developing nervous system—chemical exposures (e.g., lead, elemental mercury, methylmercury, arsenic, manganese, pesticides and anesthetic agents) and insults related to serious medical conditions (e.g., congenital heart lesions, schistosomiasis and congenital diaphragmatic hernia).

May 8, 2013: Mode of Action of Arsenical Carcinogenesis

Invited Speaker: Dr. Samuel Cohen

Biography: Dr. Cohen is currently a Professor in the Department of Pathology and Microbiology at the University of Nebraska Medical Center. Dr. Cohen’s research has focused on mechanisms of carcinogenesis, with a focus on the role of cell proliferation in the carcinogenic process, primarily utilizing the urinary bladder as a model system. Most recently this has involved investigations into the mechanisms of bladder carcinogenesis produced by arsenicals and PPAR agonists. In addition, his research has involved clinical investigations of various aspects of urologic pathology and extrapolation between animals and humans.

April 24, 2013: Recent Developments in Adverse Outcome Pathway/Mode of Action Analysis

Invited Speaker: Dr. Bette Meek

Biography: Dr. Meek is currently the Associate Director of Chemical Risk Assessment at the McLaughlin Centre for Population Health Risk Assessment, University of Ottawa. She has extensive experience in the conduct and management of chemical risk assessments within the Government of Canada. Specific areas of experience include the development of frameworks for weight of evidence analysis including mode of action, chemical specific adjustment factors, physiologically-based pharmacokinetic modeling, combined exposures and predictive modeling.

April 11, 2013: Inorganic Arsenic Exposure and Hypertension: A Focus on Blood Pressure Reactivity

Invited Speakers: Drs. Catherine W. Yeckel and Kathleen McCarty

Biography: Dr. Yeckel is an associate research scientist and lecturer in epidemiology at the Yale School of Public Health. Dr. Yeckel’s research focuses on physiological mechanisms of human metabolism in health and disease. Her research interests include obesity, insulin resistance, and exercise training.
Dr. McCarty is currently an assistant director in epidemiology at Biogen Idec in Cambridge and an adjunct faculty at Yale School of Medicine. Prior to joining Biogen, Dr. McCarty was an assistant professor at the Yale School of Public Health where her main research projects involve environmental co-factors, genetic susceptibility, arsenic exposure and health outcomes, gene-environment interactions and breast cancer risk, and biomarker development.

March 27, 2013: Transplacental Arsenic Carcinogenesis and Stem Cells

Invited Speaker: Dr. Erik Tokar

Biography: Dr. Tokar is a biologist in the Inorganic Toxicology Group at NIEHS. His major research interests involve the role of stem cells in inorganic carcinogenesis, with an emphasis on arsenic and cadmium. His research also focuses on the role of stem cells in the developmental basis of adult diseases, such as cancer.

March 20, 2013: Considerations in Assessing Low-Level Exposure to Arsenic in Drinking Water

Invited Speaker: Dr. Jaymie Meliker

Biography: Dr. Meliker is an associate professor of Preventive Medicine in the Division of Evaluative Sciences at Stony Brook University Medical Center. Dr. Meliker’s research contributes to the fields of exposure science, health geography, and environmental epidemiology. He is interested in identifying environmental factors that play important roles in disease morbidity and developing space-time methods that improve our ability to investigate exposure-disease relationships.

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Meeting Materials

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Quick Check

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