Pollution at Pearl Harbor does not pose a public health threat at current levels of use, as long as residents don't eat fish or crabs caught in the basin, according to the federal agency that evaluates public health threats at Superfund contamination sites.

On Dec. 28, the Agency for Toxic Substances and Disease Registry issued its public health assessment for the Pearl Harbor Naval Complex. It noted that public exposure to contaminated sites is comparatively low, which in turn contributes to the lack of direct threats to public health.

"There are a number of areas that are contaminated," said Sue Neurath, an environmental health scientist with the agency.

The Navy has evaluated thousands of sites at Pearl Harbor with known contaminants, and the agency said it found that "749 sites are undergoing some type of response action or require further evaluation." The agency said the contamination cleanup process involves the Environmental Protection Agency and the Navy, and is beyond the scope of its jurisdiction.

"Our goal is to take a look at the community that surrounds the site. We didn't find (public exposure to contaminants) at the levels that could cause health effects," Neurath said.

Pearl Harbor has been a naval base for more than a century, and a range of contamination can be expected, she said.

Perhaps the most significant threat is in eating fished products. The agency reviewed tests on tilapia, goatfish, mullet and blue-clawed stone crabs caught at Pearl Harbor. The testing for 276 different chemicals assumed that a person ate 2.5 meals of fish weekly and three crab meals monthly from Pearl Harbor. It found that levels of polychlorinated biphenyls, or PCBs, were high enough to be of concern.

"For most chemicals identified in the fish tissues sampled, this amount of local fish consumption has not been associated with health concerns. However, the estimated exposure for PCBs approached levels in which harmful health effects were observed in animals," the report said.

The state Department of Health has had a pollution advisory in place since 1998 on the eating of fish products from Pearl Harbor, and also warns against eating fished products from the Ala Wai Canal and several urban streams. In its Dec. 28 report, the toxic substances agency said it supports the state advisory.

In two places, the 'Ewa Junction Drumming Facility and the Red Hill Oily Waste Disposal Facility, spilled or dumped contaminants have gotten into shallow groundwater. This is not considered a public health hazard only because the public doesn't use the aquifers under those sites for drinking water.

"The contaminants have not reached and are unlikely to reach the deeper aquifer used to supply drinking water," the report said.

The agency found that several toxic sites are fenced or access is sufficiently limited to ensure no health threat. These include the Pearl City Peninsula landfill, the Waipahu ash landfill, a former pesticide mixing area and a transformer leakage site on the Waipi'o Peninsula. The agency said it "concludes that incidental, short-duration exposures to the contaminants found at those sites did not in the past and does not now pose a human health threat."

The agency said it has reviewed tests performed from 1996 to the present on indoor air quality at St. Elizabeth Church and School and at 'Aiea Elementary School, following concerns that fumes from dry-cleaning solvent from the 'Aiea Laundry were a potential threat. The agency said that volatile compounds were measurable in the buildings but that they are so low, they "do not pose a past, current or potential future health hazard for the church staff, students and members."

Reach Jan TenBruggencate at jant@honoluluadvertiser.com.