BILLINGS, Mont. — Pesticides, heavy metals and other airborne contaminants are raining down on national parks across the West and Alaska, including Rocky Mountain National Park, turning up at sometimes dangerously high levels in lakes, plants and fish.
A sweeping, six-year federal study released Tuesday found evidence of 70 contaminants in 20 national parks and monuments — from Denali in Alaska and Glacier in Montana to Big Bend in Texas and Yosemite in California.
The findings revealed that some of Earth’s most pristine wilderness is still within reach of the toxic byproducts of the industrial age.
“Contaminants are everywhere. You can’t get more remote than these northern parts of Alaska and the high Rockies,” said Michael Kent, a fish researcher with Oregon State University who co-authored the study.
The substances detected ranged from mercury produced by power plants and industrial chemicals such as PCBs to the banned insecticides dieldrin and DDT. Those can cause health problems in humans, including nervous-system damage, reduced immune-system responses and lowered reproductive success.
Contaminants that accumulated in fish exceeded human-consumption thresholds at the eight parks that researchers focused on most: Sequoia and Kings Canyon, Mt. Rainier, Olympic, Glacier, Rocky Mountain, Gates of the Arctic and Denali national parks, and Alaska’s Noatak National Preserve.
Also, mercury levels at the eight parks and DDT levels at Glacier and Sequoia and Kings Canyon exceeded health thresholds for fish-eating wildlife. Kent said he found airborne contaminants are causing male fish to develop female organs in some parks.
Much of the contamination is thought to have come from overseas — traveling global air currents from Europe and Asia.
But researchers said they were surprised to find substantial contamination from the local use of legal pesticides, particularly in agricultural areas around Glacier, Rocky Mountain and Sequoia and Kings Canyon parks.
The National Parks Conservation Association called the federal report “a wake-up call” that should mobilize Congress to take a tougher stance on air pollution.
