Some people are eating so much of the commercial, high-mercury fish that they are over the mark for tolerable allowances set by the Environmental Protection Agency, the FDA, the Agency for Toxic Substances and Disease Registry and the World Health Organization.
Jane Hightower, M.D.
The link is to a 2007 article that Dr. Hightower wrote that is very well worth reading. She ends the article with the following:
As for fish consumption in adults, both men and women, the current advice is that two three-ounce servings or one six-ounce serving per week is where the benefits outweigh the risk, but up to twelve ounces is acceptable if the fish are low in contaminants (Mozaffarian 2006).
The article, however, also discusses children, both born and unborn, and other vulnerable populations, such as Pacific islanders and Native Americans. As I said, the entire article is worth reading.
The initial quote above is in an email I received from John McDougall, MD. I am on his email mailing list.