Report: Mercury levels mostly down in Great Lakes

JOHN FLESHER

AP Envi­ron­men­tal Writer

DETROIT — Mer­cury lev­els have dropped about 20 per­cent in the Great Lakes in recent decades but remain dan­ger­ously high and are get­ting worse in some places, sci­en­tists said in a report released Tuesday.

Con­cen­tra­tions of mer­cury exceed the risk thresh­old for peo­ple and wildlife at many spots across the region and are par­tic­u­larly high in inland water­ways, said the report issued by the Great Lakes Com­mis­sion, an agency that rep­re­sents the eight states and two Cana­dian provinces sur­round­ing the lakes. The report said sci­en­tists had found mer­cury is toxic to fish and wildlife at sur­pris­ingly low levels.

The report was issued the day after 25 states asked a fed­eral court to block lim­its on mer­cury and other air pol­lu­tion from power plants that the Envi­ron­men­tal Pro­tec­tion Agency plans to set next month. Michi­gan Attor­ney Gen­eral Bill Schuette, who led the effort, said the reg­u­la­tions would hurt the econ­omy and cause elec­tric rates to jump. The Republican-controlled U.S. House last week voted to delay rules to cut emis­sions from cement plants, solid waste incin­er­a­tors and indus­trial boilers.

Authors of the Great Lakes report said lower emis­sions from incin­er­a­tors were largely respon­si­ble for the mer­cury drop-off.

“Logic would sug­gest if we con­trolled them fur­ther, we would be even more suc­cess­ful,” said Charles Driscoll, a Syra­cuse Uni­ver­sity envi­ron­men­tal engineer.

The report was based on what Tim Eder, the Great Lakes Commission’s exec­u­tive direc­tor, said was the most thor­ough eval­u­a­tion of mer­cury pol­lu­tion trends ever con­ducted in the region. It involved 170 researchers who pro­duced 35 peer-reviewed papers after tak­ing more than 300,000 mea­sure­ments, includ­ing sam­ples from birds, fish and sediment.

The over­all decline in mer­cury con­t­a­m­i­na­tion is “very wel­come news,” said study co-author James Wiener of the Uni­ver­sity of Wis­con­sin at La Crosse.

But rea­sons for con­cern remain, he said. Six com­monly eaten game fish had aver­age mer­cury con­cen­tra­tions above the EPA’s des­ig­nated safe level in more than 60 per­cent of the area stud­ied. An uptick in con­cen­tra­tions of some fish and wildlife such as loons in Wis­con­sin, eagles in Min­nesota and wall­eye in Ontario lakes is wor­ri­some — largely because sci­en­tists don’t know why it’s hap­pen­ing, Wiener said.

“The more we look, the more sam­ples that are taken, the more evi­dence of mer­cury we find,” Eder said.

A study led by David Evers, exec­u­tive direc­tor of the Bio­di­ver­sity Research Insti­tute in Maine, found the Adiron­dack moun­tain range in New York is a hot spot because heavy for­est cover and plen­ti­ful wet­lands pro­mote the chem­i­cal reac­tion that causes mer­cury to con­cen­trate as it moves up the food chain. The sit­u­a­tion is sim­i­lar else­where in the north­ern Great Lakes region, such as Michigan’s Upper Peninsula.

Mer­cury is a pow­er­ful toxin that can dam­age the human ner­vous sys­tem, par­tic­u­larly in young chil­dren. Fetuses exposed to mer­cury can develop brain dam­age, blind­ness and seizures.

Humans with high lev­els of mer­cury usu­ally get them by eat­ing con­t­a­m­i­nated fish. Most states issue advi­sories warn­ing peo­ple to limit con­sump­tion of fish species with high lev­els of mer­cury and other contaminants.

Mer­cury pol­lu­tion in the Great Lakes began ris­ing in the mid-1800s from sources such as burn­ing coal, incin­er­at­ing waste, min­ing and metal smelt­ing. Lev­els peaked in the 1980s before drop­ping as pol­lu­tion con­trols kicked in. Despite a 60 per­cent decline in emis­sions from human activ­i­ties between 1990 and 2005, about 100 tons are gen­er­ated from human activ­i­ties each year, the report said.

Even as the U.S. has cracked down on emis­sions, they’ve risen else­where, par­tic­u­larly in fast-growing nations such as China and India. But the research found the drop in mer­cury lev­els in soils around the Great Lakes region came as emis­sions from sources in the region fell by nearly half.

“U.S. sources are the dom­i­nant influ­ence on mer­cury in the Great Lakes region,” said Kathy Fal­lon Lam­bert of Har­vard Uni­ver­sity, who also con­tributed to the report. Coal-fired power plants are “the sin­gle largest remain­ing uncon­trolled source in the U.S.,” she said.

Schuette and the other states that filed a brief with the U.S. Dis­trict Court in Wash­ing­ton, D.C., want the effec­tive date of EPA’s power plant rules to be delayed one year.

“We are very glad to hear mer­cury lev­els are down in the Great Lakes and in this sit­u­a­tion sim­ply ask for time to prop­erly study the com­plex reg­u­la­tory pro­pos­als to ensure we pro­tect the envi­ron­ment and jobs,” spokesman John Sellek said.

Posted by AP News on Oct 12 2011. You can follow any responses to this entry through the RSS Feed. Comments can be made below.