ANCHORAGE (AP) -- A pesticide banned in the United States in the 1980s has turned up in the wastewater of three cruise ships operating in Alaska.
The pesticide is heptachlor, used to kill termites and other insects.
The Alaska Department of Environmental Conservation says tests revealed it was 100 times higher than the allowable limit on two ships and about 15 times higher on the third ship.
Regulators are withholding the names of the four ships.
''We have no idea where the heck the heptachlor is coming from,'' David Rogers, a DEC water quality manager, told the Anchorage Daily News.
In the wastewater of four cruise ships, levels of copper and zinc also violated state law governing the protection of marine life, according to the results, released Thursday.
In addition, excessive amounts of lead and silver were found in three ships' waste.
The U.S. Environmental Protection Agency appointed a team of experts in Seattle to analyze the results. The agency won't comment until the review is complete.
Alaska environmental officials consider the results preliminary but cause for concern and more review, Rogers said.
Gov. Tony Knowles on Thursday called on Congress to start regulating cruise ship discharges.
DEC officials speculate the heptachlor may have been used on wooden crates that store fruits and vegetables grown overseas. If the produce touched the pesticide-treated wood, or if it was sprayed with heptachlor and then washed, the galley water may have become contaminated.
Some countries still use heptachlor to eradicate bugs from cotton fields. The sheets and towels used on the ships may be leaching the toxic substance, said John Hansen, executive director of the North West CruiseShip Association.
''We don't like to see any kind of chemical like that'' in the wastewater, Hansen said.
The cruise lines involved are already trying to trace the source of the contamination.
The metals could be coming from the fresh water the vessels take on in Vancouver before they set sail, or in Alaska ports along the way, Hansen and DEC officials said.
While the levels exceeded Alaska standards for marine waters, they were within acceptable limits for public drinking water. That's because humans can tolerate higher amounts of heavy metals than fish can, said Deena Henkins, DEC chief of water quality.
Though the average cruise ship releases about 200,000 gallons of wastewater into Alaska waters daily during the tourist season, no law requires the cruise lines to test or monitor wastewater.
The industry this summer agreed to subject its entire fleet of some 21 cruise ships to a voluntary inspection. A Juneau lab took samples from each ship and screened for pollutants.
None of the tests so far have detected PCBs or other priority pollutants, though excess levels of a plastics compound were also detected Thursday on three ships.
''The industry has repeatedly told us that their gray water is nothing more than soap suds. These results show it's an industrial effluent that needs to be regulated,'' said Gershon Cohen, a Haines clean-water advocate.
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