Pregnant women who eat fish don’t just risk their own health—they also jeopardize the health of their unborn baby.
PCBs, mercury, and other toxins found in fish can be passed on to nursing babies through a mother’s breast milk. Researchers from Wayne State University found that “women who regularly ate fish, even many years before becoming pregnant, were more likely to have babies who were sluggish at birth, had small head circumferences, and had developmental problems.”
The EPA estimates that 600,000 children born in 2000 are at risk for lower intelligence and learning difficulties each year because of mercury exposure because their pregnant or nursing mothers ate fish.40 Even low levels of mercury in a mother’s blood can cause her child to have developmental problems. Mercury poisoning is particularly dangerous to fetuses because the level of mercury in a fetus’s blood is potentially 70 percent higher than in the mother’s. This may be because the fetus’s blood concentrates mercury with other important molecules that the fetus needs to grow.
Mothers who eat fish during pregnancy may also seriously damage their baby’s brain and nervous system. Studies have shown that children born to mothers who ate a lot of fish were slower to talk, walk, and develop fine motor skills and have weaker memories and attention spans.
The EPA estimates that 600,000 children born in 2000 are at risk for lower intelligence and learning difficulties each year because of mercury exposure because their pregnant or nursing mothers ate fish.
“It might reduce IQ by a few points,” says Dr. Michael Gochfeld, chair of New Jersey’s mercury task force. “It might reduce motor coordination, so that this child is someone we think of as a klutz.”
Dr. Roberta F. White, chair of the Department of Environmental Health at Boston University and director of the Boston Environmental Hazards Research Center, says children exposed to mercury before birth do much poorer on tests measuring nerve function.
The brain damage caused by a fish-eating mother is apparently permanent. “If something happens in the brain at development, you don’t get a second chance,” says lead researcher Philippe Grandjean.
According to the Natural Resources Defense Council, as many as one in six U.S. women of reproductive age might have mercury levels that could put their babies at risk. The Public Interest Research Group and the Environmental Working Group (EWG) warn that women who eat more than one can of tuna a month during pregnancy could ingest enough mercury to damage the developing brain of a fetus.
Scientists at the Harvard School of Public Health have found that mercury contamination of seafood can cause heart damage and irreversible impairment to brain function in children, both in the womb and as they grow. Even mild exposure can result in impaired immune function, developmental delays, and physical deformities.
Mercury-rich ocean fish aren’t the only source of dangerous contamination—fish from our lakes and rivers also threaten the health of expecting mothers and their children. Even the notoriously conservative EPA has determined that more than half of all the freshwater fish it sampled from America’s lakes could be unsafe for women of childbearing age to eat twice a week, and more than three-quarters had mercury levels that may be unhealthy for children younger than 3.51 Massachusetts has warned pregnant women not to eat any freshwater fish caught in the state because of mercury contamination. As of 2002, 43 states had issued warnings about freshwater fish, restrictions that encompass 30 percent of the nation’s lakes and 13 percent of its rivers.
In response to this growing threat, the Food and Drug Administration and the EPA have both advised women of childbearing age and young children not to eat certain fish that are known to contain alarmingly high levels of mercury. But all fish contain some mercury, and since mercury is a poison, should any of us needlessly ingest a substance that is known to cause such an array of horrible conditions?
The Public Interest Research Group and the Environmental Working Group (EWG) warn that women who eat more than one can of tuna a month during pregnancy could ingest enough mercury to damage the developing brain of a fetus.
Fish consumption has also been linked to decreased fertility and increased rates of breast cancer. Even women who eat small amounts of contaminated fish have a more difficult time becoming pregnant. Scientists at the University of Wisconsin-Madison found that women who consume freshwater fish suffer from unusually high breast cancer rates. A similar study conducted by Danish researchers has confirmed the link between fish consumption and increased breast cancer risk.
Sick moms and sick kids: Fish consumption poses serious health risks to women and children, and we all gamble every time we sit down to a meal of fish sticks or flounder. The only way to protect our families and ourselves is leave fish in the oceans and off our plates.