Despite reductions in mercury, pesticides and other pollutants being deposited in U.S. lakes and rivers, the number of fish becoming contaminated only continues to grow.
More than 3,000 water bodies nationwide were under fish consumption advisories in 2003 – an increase of almost 10 percent over the previous year, according to an annual Environmental Protection Agency report released Tuesday.
In Maine, 19 rivers and lakes are protected by advisories, most of which have been in place for about a decade.
“There’s little change in New England – our states have been on the leading edge of taking this issue seriously,” regional EPA spokesman Dave Deegan said from his Boston office Tuesday.
But nationally, 280 new water bodies were placed under advisory in 2003, bringing the total contaminated waters to one-third of the nation’s lake acreage and nearly one quarter of its river miles, scattered through 48 states. Only Alaska and Wyoming report no advisories.
While strict regulations over the past 14 years have helped to cut mercury pollution in the atmosphere by half, the number of contaminated lakes and streams continues to increase because many states are only now quantifying long-established problems, Deegan said.
“We’re looking for [mercury] in more places, and we’re finding it,” he said.
Most of these advisories are a response to high levels of mercury in fish.
Mercury is released into the environment through the burning of fossil fuels or through the incineration of trash containing mercury, such as batteries. Once in lakes and rivers, it undergoes a process called methylation, which gives the pollutant the ability to be stored in muscle tissues of fish. When people eat the contaminated fish, they can accumulate large amounts of mercury in their bodies, which some studies suggest can cause neurological problems.
However, federal environmental officials argue that the health benefits of eating fish, which is low in fat and high in heart-friendly omega-3 oils, outweigh the contaminant risks for most people.
“For the vast majority of the population, eating fish is not a concern – it’s a healthy food,” Deegan said.
But environmentalist Matt Prindiville of the Natural Resources Council of Maine argues that the risks to women of childbearing age are substantial. One in six of these potential mothers has high enough mercury levels in her body to put a child at risk for developmental problems, he said, quoting EPA data.
And unless the federal government establishes stronger controls on mercury pollution, the problem will only continue to grow, he said, citing predictions that new air quality rules will turn around more than a decade of progress and increase mercury pollution.
“We’ve had fish consumption advisories in Maine for 10 years now. … A pamphlet doesn’t clean up mercury pollution,” Prindiville said.
Fish consumption advisories in Maine
Maine’s current fish consumption advisories warn the general public not to eat more than one meal per week of brook trout or landlocked salmon, and not more than two meals per month of other types of wild freshwater fish.
Pregnant and nursing women, women who are trying to become pregnant, and children under the age of 8 are warned not to eat more than one meal per month of brook trout or landlocked salmon, and to avoid all other freshwater fish.