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Sierra Magazine
Lay of the Land

What's Wrong With the Frogs | Battle of the Bigs | Rocky Mountain Hothouse Flowers | Mythbuster

What's Wrong With the Frogs?

Scientists are narrowing in on pesticides as the cause of deformities

At first it seemed like a bad dream or an oddball freak of nature. In August 1995, a class of Minnesota middle-school students on a field trip to a farm wetland found a frog with a missing leg. Then another and another. By the end of their trip, the students had caught 22 frogs, half of which had missing or deformed legs.

The students reported their observations to the Minnesota Pollution Control Agency. Within weeks of their widely publicized discovery, more reports of deformed frogs poured in from other areas. Now the Great Lakes region, New England, the Pacific Northwest, and the St. Lawrence River valley in Quebec are North American hot spots for deformed frogs. Whodunit? A final verdict has yet to be reached, but the leading suspects are pond-dwelling parasites called trematodes and chemical contamination from pesticides and other sources.

Scientists have linked parasites to frog deformities in the Pacific Northwest and the Northeast but exonerated them elsewhere. In the case of the Minnesota frog deformities, a research group led by National Institute of Environmental Health Sciences biochemist James Burkhart points to a still unidentified chemical or combination of chemicals as the most likely culprits. The group's report, published in last December's Environmental Health Perspectives, adds to the work of other scientists who suspect pesticides or other chemicals that disrupt endocrine systems.

Meanwhile, Canadian research has identified agricultural pesticides as a main cause of frog deformations in a farm-rich area outside Montreal. Seven years ago, veterinarian Martin Ouellet began tracking the overall abundance and health of frogs in the St. Lawrence River valley, particularly in ponds on farms that use pesticides. "I was expecting to find a lot of tumors and cancers," Ouellet says, since fish in polluted waters often develop such symptoms. Instead, he found a variety of deformities, including missing and malformed legs.

Since then, Ouellet has examined 30,000 frogs in 100 ponds. In ponds exposed to pesticides through spraying drift, runoff, or careless disposal of pesticide containers, 15 to 20 percent of the frogs were deformed. In unexposed control ponds, misshapen frogs amounted to 2 percent or less-a level that conforms to what scientists believe is a natural rate of deformity. "It's very clear that there are many things that can cause deformities," Ouellet concludes. "In my area, there is a clear association with pesticides."

Together with a team of scientists from McGill University and the Canadian Wildlife Service, Ouellet examined the genetic condition of St. Lawrence River valley frogs. Abnormal DNA profiles, the researchers found, were significantly more common in frogs from pesticide-laden ponds, whether or not the frogs had obvious deformities. The ponds Ouellet studied were tainted with carbofuran, used on corn crops, and azinophos-methyl, used on potato fields. He notes that specifying exactly which ingredient in the "cocktail of pesticides" is hurting the frogs will require more research.

Another Canadian study found that pesticides may cause wild frogs problems beyond DNA changes and deformities. Exposure to the pesticide endosulfan at very low levels (similar to those at which it might drift over a pond from aerial spraying) can cause lethargy and twitching in tadpoles, making them easier for predators to catch.

Scientists are notoriously cautious about drawing broad conclusions from their data. Still, one biologist studying the Minnesota deformities confided that his research has changed his shopping habits: he now buys only pesticide-free produce.—Kathryn Phillips


Battle of the Bigs:
Oil companies and Detroit pass the buck

Proponents of new clean-air standards have found an unlikely ally: Detroit. Auto manufacturers are supporting a requirement that gasoline contain less pollution-causing sulfur. Carmakers are backing the measure because sulfur damages catalytic converters, which are critical to efforts to reduce tailpipe pollution. To no one's surprise, the oil companies are fighting the proposal. They say that retooling refineries will be costly, causing the price of gasoline-at its lowest level in decades-to increase up to six cents a gallon.

But Detroit has hardly turned green. It is nowhere near as excited about another clean-air proposal, one that would prohibit sport utility vehicles, minivans, and pickup trucks (collectively known as "light trucks") from polluting more than cars.

Clean-air activists are urging the Environmental Protection Agency to be firm with the Big Three and Big Oil. "If we want our kids to breathe clean air," says Ann Mesnikoff, director of the Sierra Club's Clean Car campaign, "we need both cleaner cars and cleaner gas."

According to the EPA, 107 million Americans breathe dirty air, and autos create a large-and easily targeted-part of the problem. The agency's proposed clean-air regulations would address the light-truck loophole, sulfur levels in gasoline, and particulate pollution created by diesel engines. The most comprehensive attempt to tackle air pollution since passage of the Clean Air Act amendments in 1990, the rules should be finalized by the end of the year.

The Sierra Club and state pollution-control officials want a nationwide sulfur standard modeled after the one already in effect in California: 30 parts per million, compared to the current national average of 300 parts per million. According to the State and Territorial Air Pollution Administration, an association of government air-pollution-control officials, reducing sulfur levels nationwide would be the equivalent of taking 54 million cars off the road. The oil industry wants to exempt western states from the new rules, because they have low populations and fewer Clean Air Act violations than the rest of the country.

"Their message," says Mesnikoff, "is 'let western states stay dirty.' " She points out a serious problem with inconsistent regulations: if drivers from clean-gas states buy fuel in dirty states, they could damage their emission-control systems and pollute the air when they return home.

Closing the light-truck loophole will contribute to clean air just as dramatically. These vehicles, which don't have to meet the same fuel-efficiency standards as cars, are also allowed to spew more pollutants per mile. Both loopholes are holdovers from the early 1970s, when "light trucks" were treated less stringently than passenger cars because they were a small part of the market, used primarily as farm and work vehicles. Today, these light trucks are more often substitutes for cars, and they now outsell passenger cars in the United States.

California has already done away with the discrepancy in emission standards between cars and light trucks, effective in 2004. And since Ford already produces several sport-utility behemoths whose tailpipe emissions are no worse than their cars', the handwriting is on the wall for other manufacturers. Predictably, the industry is whining about the cost of the proposed regulation. But their bottom lines will hardly be affected, because every large sport utility vehicle sold can generate $10,000 or more in profit. The California Air Resources Board says that light trucks can meet the new standards for under $250. Because so many people drive these vehicles, benefits to the environment will add up quickly.

But the problem won't truly be solved until enough drivers ignore Detroit's ad blitz, take a deep breath, and exercise restraint in the showroom. While the 5,600-pound Lincoln Navigator is one of a few sport utes that meet the EPA's low-emission standard, it still gets only 12 miles per gallon as it lumbers along to the supermarket or soccer practice. Over its lifetime, it will spew more than 70 tons of carbon dioxide, the primary global-warming pollutant. If that doesn't make you choke, Ford is readying its next loophole vehicle: the 19-foot-long Excursion. This "sport" ute is so heavy that fully-loaded versions may be able to ignore the so-called light-truck emissions standards entirely. Finding themselves staring into the tailpipe of this global-warmer while stuck at a stoplight, some drivers may decide it ignores standards of decency, too. —Reed McManus


Rocky Mountain Hothouse Flowers

At the same time Rocky Mountain National Park is trying to ban commercial helicopter flights into backcountry areas, it is approving chopper transport for tenderfoot government workers.

For the past three years, government soil scientists working in the park's Mummy Range and Paradise Park wilderness areas have hiked in, but now they're tired and want to fly, according to Public Employees for Environmental Responsibility. In a memo approving the request, park officials noted that the "agency culture and individual backgrounds" of the scientists "do not lend themselves towards days of hiking and camping without the normal accoutrements." The head scientist explained that he wanted a shower at the end of the day. A dip in a mountain lake won't do?—Paul Rauber


MYTHBUSTER: Not Clean Enough

In December, the Better Business Bureau called on the Washington, D.C.-based Nuclear Energy Institute to stop running advertisements claiming that nuclear power is "environmentally clean." By neglecting to mention the nuclear waste and air pollution caused by producing nuclear fuel, the bureau said, the nuclear industry's ads went too far in trumpeting the safety and cleanliness of nuclear power.

What motivated the longtime champion of complaining consumers everywhere to take on the nuclear industry? Utility deregulation. In the past, the nuclear industry might have gotten away with image ads touting whatever environmental virtues they could conjure up. But now that they're players in the consumer marketplace, the bureau reasons, it's time to tell the truth.

"We felt it is very important that, as this market opens up, claims about the environment be very clear and very specific," said Andrea Levine, director of the national advertising division at the Council of Better Business Bureaus in New York. "You can sort of think of it as a warning shot to the industry."

Environmental groups applauded the bureau's move, and the institute promised to consider the nonbinding decision in future advertisements.

(C) 2000 Sierra Club. Reproduction of this article is not permitted without permission. Contact sierra.magazine@sierraclub.org for more information.


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