Federal regulators seek to change guidelines on fish consumption for pregnant women and young children.

For quite some time, the Food and Drug Administration has maintained that fish consumption on this category of people should be limited in order to avoid exposure to potentially harmful amounts of mercury.

But now the agency sent a draft report to the White House Office of Management and Budget in which it asserts that pregnant women should eat at least 12 ounces of fish per week, a complete reversal of the current guidelines. The FDA says that nutrients in fish, including omega-3 fatty acids, selenium and other minerals could boost a child’s IQ by three points.

The report, however, is not backed by the Environmental Working Group and other scientists and advocates. They sustain the report is “scientifically flawed and inadequate” and an “oversimplification” lacking analytical rigor.

“The FDA was once a fearsome protector of the public health. Now it’s nothing more than a patsy for polluters,” Richard Wiles, executive director of the Environmental Working Group, said in a statement.

Humans risk ingesting dangerous levels of mercury when they eat contaminated fish. Since the poison is odorless, invisible and accumulates in the meat of the fish, it is not easy to detect and can't be avoided by trimming off the skin or other parts.

Once in the human body, mercury acts as a neurotoxin, interfering with the brain and nervous system.

Exposure to mercury can be particularly hazardous for pregnant women and small children. During the first several years of life, a child's brain is still developing and rapidly absorbing nutrients. Prenatal and infant mercury exposure can cause mental retardation, cerebral palsy, deafness and blindness. Even in low doses, mercury may affect a child's development, delaying walking and talking, shortening attention span and causing learning disabilities.

In adults, mercury poisoning can adversely affect fertility and blood pressure regulation and can cause memory loss, tremors, vision loss and numbness of the fingers and toes. A growing body of evidence suggests that exposure to mercury may also lead to heart disease.