X hits on this document

PDF document

Local telephone number 907-269-8000 - page 33 / 44

112 views

0 shares

0 downloads

0 comments

33 / 44

Fish consumption guidelines for women who are or can become pregnant, nursing mothers and young children are warranted for a small number of Alaska fish species due to elevated mercury levels in these fish (see Fish Consumption Guidance below). However, the EPA reference dose for mercury is unnecessarily restrictive for application in Alaska, where the risk/benefit balance is influenced strongly by local factors.

The U.S. Agency for Toxic Substances and Disease Registry (ATSDR) struck the most appropriate balance in risk interpretation of mercury intake for public health purposes in developing its No Observed Adverse Effect Level of 0.0013 mg/kg body weight/day, which was based upon an analysis of the Seychelles Islands epidemiologic study.

68

The Seychelles Islands study provides the most appropriate data for determining the human health risks posed by mercury exposure via fish consumption in Alaska. The Seychelles Islander and Alaskan exposure scenarios are comparable, as both populations eat large quantities of ocean fish that have minimal influence from local mercury sources, and the two locations have similar mercury levels in most fish species. Therefore, the Seychelles Islands study provides the most appropriate data to develop an Alaska-specific Acceptable Daily Intake for methylmercury for use in consumption guideline calculations.

For Alaska’s purposes, it is appropriate to remove the 1.5-fold modifying factor that ATSDR originally used in its Minimal Risk Level calculation to account for domain-specific findings in the Faroe Island study. The domain-specific tests have since been performed in the Seychelles cohort, and no negative associations with mercury exposure were observed.56 When the 1.5-fold modifying factor is removed, a 3-fold uncertainty factor remains.

The 3-fold uncertainty factor applied to ATSDR’s No Observed Adverse Effect Level provides sufficient protection against any subtle neurodevelopmental effects from mercury exposure. Additional uncertainty factors are not warranted and would result in fish consumption restrictions that would likely be more harmful than beneficial to the health of Alaskans.

Therefore, the Alaska-specific chronic oral Acceptable Daily Intake for methylmercury for women who are or can become pregnant, nursing mothers, and young children is 0.0004 mg/kg body weight/day. This value was derived using the ATSDR No Observed Adverse Effect Level of 0.0013 mg/kg body weight/day52 divided by a 3-fold uncertainty factor for human pharmacokinetic and pharmacodynamic variability.

Alaska demographic groups other than women who are or can become pregnant, nursing mothers, and young children should continue to enjoy unlimited consumption of all fish from Alaska waters.

Fish consumption advice must be tailored and targeted for specific demographic groups and actual fish species consumed. DPH will develop separate, specific health education materials for the general public eating store-bought fish, subsistence consumers, recreational fishermen, and health care providers.

Persons limiting consumption of a particular fish due to mercury concerns should substitute it with an Alaskan fish lower in mercury (such as salmon), or with another food of comparable nutritional quality.

Monitoring of both fish and humans should be expanded to fill important data gaps. The process of data evaluation and development of consumption guidance will be an ongoing effort, with updated guidance provided as needed.

Fish Consumption Advice for Alaskans

Acceptable Daily Intakes for Contaminants Vary According to their Purpose: Public Health Practice vs. Regulation

Some confusion may result from varying safety guidelines developed by numerous government agencies. In this case, the chronic oral Acceptable Daily Intake for methylmercury for women who are or can become pregnant, nursing mothers, and young children adopted by the State of Alaska for fish consumption advice is 0.0004 mg/kg body weight/day. This is four times higher than the EPA’s Reference Dose of 0.0001 mg/kg body weight/day.

29

Document info
Document views112
Page views112
Page last viewedSun Dec 11 08:29:51 UTC 2016
Pages44
Paragraphs1112
Words20920

Comments