DDT, Chlordane, Toxaphene and PCB Residues in Newport Bay and Watershed: Assessment of Hazard to Wildlife and Human Health - Reviews of Environmental Contamination and Toxicology - page 134

were likely not at a steady state in the 1975 data from Anderson et al. The Great
Lakes study estimated a sevenfold lower egg residue than found by Anderson et al.
( 1975 ), if brown pelicans took 2 years to reach steady state with the DDTs in north-
ern anchovy. Two years is a reasonable estimate based on the very slow excretion of
the DDTs and the 10-15 year lifespan of the brown pelican, compared to the
1-2 year lifespan of northern anchovy. Consideration of these facts supports
the 150 ppb level in fi sh as a NOEL, when a steady-state is reached. The use of the
BTAG fi sh guidance provides an extra threefold level of protection beyond that
provided by the National criterion.

3.2.6 California EPA Sport Fish Guidance for DDT

to Protect Human Health

The SARWQCB ( 2006 ) has concurred with U.S. EPA Region IX ( 2002 ) to use 100 ppb
total DDT in fi sh fi llets as a TMDL target to protect human health. The 100 ppb target
was adopted from guidance issued by the Offi ce of Environmental Health Hazard
Assessment (OEHHA) of the California EPA. The guidance was developed to protect
sport fi shermen. The guidance is explained in a report published by OEHHA scientists
in 1991 (Pollock et al. 1991 ) and a later update (Brodberg and Pollock 1999 ). The fol-
lowing is a review of the sport fi sh guidance developed by OEHHA.
The guidance was based on fi sh caught in Southern California in 1987. The focus
was the high concentrations of total DDT in fi sh in the area of the Palos Verdes
Shelf. Fish there were contaminated from DDT wastes from the Montrose Chemical
Company that were released by way of the Los Angeles County Sanitation District's
wastewater outfall at White's Point. The intent was to limit the potential cancer risks
of ingestion of a variety of fi sh species at the more highly contaminated sites.
A trigger level, set at a lifetime cancer risk of 1/100,000, was developed for each
chemical based on cancer potency in rodents and assuming a linear dose-response.
The OEHHA report stated that:
The trigger levels for total DDTs and chlordanes are based on excess cancer risks of about
1 in 100,000 (1 x 10 -5 ).

and that:
Recommendations are provided for species and sites which exceeded 100 ppb of either total
DDTs or PCBs or 23 ppb of total chlordane.

The trigger levels were not intended to be used as standards as stated in the report
as follows.
The trigger levels were developed specifi c to this study, therefore, and should not be used
in deriving standards.

Although the trigger levels were developed for each species and chemical, the
overall objective was to achieve a potential cancer risk of less than 1/10,000 as
stated in the report as follows:
The specifi c recommendations for each site and species attempt to reduce exposures to
levels that result in overall risks of less than 1 x 10 -4 (risk for PCBs at the MDL) or lower
depending on the site.