Systematic Review Protocol for the Methylmercury (MeHg) IRIS Assessment (Preliminary Assessment Materials)

IRIS

Methylmercury (MeHg)

CASRN 22967-92-6 | DTXSID9024198

IRIS Summary (PDF) (44 pp, 252.0 KB)
Status: methylmercury (mehg) is in step 1 at this time.

On this page:

Overview
Background
Downloads

Notice

EPA announces the availability of the Systematic Review Protocol for the Methylmercury IRIS Assessment (Preliminary Assessment Materials) for a 45-day public comment period as announced in the Federal Register. The deadline for comments is July 13, 2020.

Overview

In May 2020, EPA released the Systematic Review Protocol for the Methylmercury IRIS Assessment (Preliminary Assessment Materials). As part of developing a draft IRIS assessment, EPA presents a methods document, referred to as the protocol, for conducting a chemical-specific systematic review of the available scientific literature. Protocols communicate the rationale for conducting the assessment of methylmercury, describe screening criteria to identify relevant literature, outline the approach for evaluating study quality, and describe the dose-response methods.

Citation

U.S. EPA. Systematic Review Protocol for the Methylmercury (MeHg) IRIS Assessment (Preliminary Assessment Materials). U.S. Environmental Protection Agency, Washington, DC, EPA/635/R-19/243, 2020.

Top of Page

Background

Gaseous elemental mercury is released into the atmosphere from natural (e.g., volcanoes) and manmade (e.g., fossil-fuel combustion) sources. Elemental mercury can be converted to inorganic mercury, which then can be transported and deposited to land or water. Methylmercury is formed from methylation of inorganic mercury by biota in water and soil. Once converted, methylmercury bioaccumulates in fish tissue and increases in concentration at successively higher levels of the food chain.

The general population is predominantly exposed to methylmercury through consumption of contaminated fish and other seafood. Subsistence fishing communities and other populations with high dietary intakes of predatory fish species could be exposed to higher-than-average levels of methylmercury. Contaminated rice and rice-based food products, such as infant cereals, also can be a source of methylmercury exposure.

Methylmercury readily crosses the placenta and concentrates in cord blood. It is also transferred from mothers to children via breastmilk. The developing nervous system is particularly sensitive to methylmercury, so gestational, lactational, and other postnatal exposures are of concern.

History/Chronology

Date	Description
09- May 2020	EPA released the Systematic Review Protocol for the Methylmercury IRIS Assessment (Preliminary Assessment Materials) for a 45-day public review and comment period. [Federal Register Notice May 28, 2020]
08- May 2019	EPA hosted a public science meeting to discuss preliminary meeting materials for methylmercury.
07- Apr 2019	EPA released the IRIS Assessment Plan (IAP) for Methylmercury for public comment and review. [Federal Register Notice Apr 4, 2019]
05- Apr 2010	EPA released an update, referred to as the Methylmercury Implementation Guidance (Updated Apr 2010).
04- Jan 2009	EPA released the Methylmercury Implementation Guidance.
03- Jan 2001	EPA released the IRIS Summary for Methylmercury on the IRIS website and released the water quality criteria guidelines for states and authorized tribes.
02- Oct 2000	EPA released a draft document titled, Reference Dose for Methylmercury (NCEA-S-0930)" for a 30-day public review and comment period. Following the review an external peer-review workshop was held to review the document.
01- Dec 1997	EPA released the Mercury Study Report to Congress.

Status

The IRIS Program will use the methods for conducting the systematic review as described in the protocol to develop the draft assessment.

Top of Page

Download(s)

This download(s) is distributed solely for the purpose of pre-dissemination peer review under applicable information quality guidelines. It has not been formally disseminated by EPA. It does not represent and should not be construed to represent any Agency determination or policy.

Systematic Review Protocol for the Methylmercury IRIS Assessment (Preliminary Assessment Materials) (PDF) (83 pp, 1.2 MB, about PDF)

If you have a disability and the format of any material on our web pages interferes with your ability to access the information, please reach out to us using the Contact Us about IRIS form for assistance. To enable us to respond in a manner most helpful to you, please indicate the nature of the accessibility problem, the web address of the requested material, your preferred format in which you want to receive the material (electronic format (ASCII, etc.), standard print, large print, etc.), and your contact information.

Document Related Link(s)

HERO Project

Literature Search References Sorted by Author (Methylmercury)

Federal Register Notices

FR Notice: May 28, 2020

Docket

Comments on the assessment may be submitted and reviewed using the Docket ID EPA-HQ-ORD-2018-0655

Top of Page

US EPA

IRIS

Methylmercury (MeHg)

CASRN 22967-92-6 | DTXSID9024198