Scientists studying PCB pollution of the sediment underlying Los Angeles Harbor are attempting to use a new type of chemical analysis to track down the sources of the contamination.
Chemists with the Southern California Coastal Water Research Project are centering their efforts on harbor sediment near a giant Terminal Island metal-shredding facility, site of the worst PCB pollution found so far.
The study employs a method of analysis that can identify different types of PCBs, or polychlorinated biphenyls. PCBs are toxic chemicals that were used in products ranging from lubricants to electric transformers until their manufacture was banned in 1979. They are suspected of causing cancer in humans.
Now nearing completion, the study was commissioned in 1988 by the state Regional Water Quality Control Board. Board staffers say that although PCB pollution in the harbor has been known since the early 1970s, the new technique may for the first time allow them to pinpoint those who should be made responsible for cleaning it up.
"There are a number of formulations of (PCBs)," said Robert Ghirelli, the board's staff director. "Without this fingerprinting technique, it is very difficult and in some cases impossible to show that the chemical in the water originated from a particular onshore location."
Environmentalists applaud the effort. They admit that PCB pollution should be expected in water bodies like Los Angeles Harbor, for decades the site of intense waterfront industrial activity. But they point out that PCBs threaten to contaminate marine life there, some of which serves as a local food source.
"Like it or not, there are subsistence fishermen who fish the harbor," said biologist Mark Gold of Save the Bay, a Santa Monica environmental group. "And fish don't stay in one place. They move around."
The new technique of PCB analysis was developed by Robert Eganhouse, a chemist with the Coastal Water Research Project, a public marine research agency. It allows scientists to distinguish among PCBs, complex mixtures of 40 to 70 distinct compounds, by identifying and measuring their chemical components.
The research project is using the technique to analyze samples from more than a dozen harbor locations in hopes of determining whether pollution of the underlying sediment can be linked to contamination from facilities on the shore.
But chemists are focusing most of their attention on the Hugo Neu-Proler Co., on the north side of Terminal Island, which shreds discarded metal products ranging from cars to refrigerators and loads the scrap onto ships for export.
Although most of the harbor's PCB contamination is believed to stem from pollution that occurred more than a decade ago, officials fear that PCBs could be entering the harbor today as discarded goods containing them are processed at Neu-Proler.
In operation since 1962, the company says it grinds up more than 700 automobiles and 3,000 household appliances daily to help fuel scrap exports amounting to more than 1 million tons a year.
Harbor sediment near the scrap yard registered by far the highest PCB levels found in the study, in which samples were gathered at more than a dozen harbor locations.
A sample of sediment taken near a conveyor that loads the scrap onto ships registered concentrations of 11.5 parts per million, well above the next highest level, 1.87 parts per million, detected near the former Todd Shipyards.
"We knew there were high concentrations in the harbor, but we didn't know about Neu-Proler," said Richard Gossett, the chemist in charge of the study. "These levels (near) the conveyor area are about five times higher than what I've seen elsewhere in the harbor."
The levels also outstrip those in an area of known PCB contamination outside the harbor: the ocean bottom near the Los Angeles County Sanitation Districts' sewage outfalls off the Palos Verdes Peninsula. According to Gossett, the highest concentrations measured there recently were 1.5 million parts per million.
Gossett says his analysis shows that the PCBs found off Neu-Proler are "very dissimilar" to samples his agency took from the other harbor sampling sites. But they exhibit strong similarities to the PCBs in debris collected on land directly under the loading conveyor, he said.
"I would say (the connection) looks very strong," Gossett said last week. "They were very similar." In an interview, Eganhouse said he agrees with Gossett's appraisal.
Shirley Birosik, a water board staff member monitoring the harbor study, takes a more conservative view, saying that a final test Gossett is conducting must be completed before her agency can begin to reach conclusions.
The test will determine whether tiny particles on the water's surface near Neu-Proler carry the same type of PCBs found on the shore and in the underlying sediment. After that test, Gossett will submit a final report to the regional water board's staff, officials say.
"Our staff will evaluate their report," Ghirelli said. "If in fact the evidence does point to a linkage between what was found in the sediment and the material on shore, then the board would have evidence to go ahead and order a cleanup."
Hugo Neu-Proler General Manager John Prudent said his company will not comment in detail on the PCB investigation until the study is finished. But he indicated that the company would be willing to take cleanup action if it is found to be causing the pollution.
"We would be ready to cooperate," he said.
Officials say it is unclear whether funding will be available for tracing other possible sources of PCB contamination in the harbor once the Hugo Neu-Proler survey is complete. Even if such projects are funded, they would face serious challenges.
For instance, PCBs at many locations in the harbor are intermingled in a confusing jumble or are too degraded chemically to identify with precision. Still, officials are hopeful that further PCB sleuthing could establish links between underwater pollution and onshore sources.
One possibility, for instance, would be to trace the origin of contamination that has apparently emanated from the Dominguez Channel. That would involve analyzing PCBs found in channel sediment and at polluted sites along the banks to see whether there is a connection.
Ghirelli said that even if a suspected polluter is no longer in business, solid evidence of a link between sediment contamination and an onshore facility would give the water board grounds to take regulatory action against the former operator.
Said Ghirelli: "We'd have the smoking gun."
PCB LEVELS IN LOS ANGELES HARBOR
A study of PCB pollution levels in the sediment underlying Los Angeles Harbor turned up extremely high concentrations of the chemical off the Hugo Neu-Proler metal shredding facility on Terminal Island. High PCB levels were also detected in sediment near the former Todd Shipyards and in the Consolidated Slip/East Basin area.