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 90

The recommendation of 1,000 ppb in fresh water fi sh appears to be based on
laboratory studies in ducks and chickens, which are less sensitive species. The dose
levels in these studies were intentionally high to assure inducing eggshell thinning
and reproductive failure. The studies did not establish a chronic threshold for these
effects. The panel admitted that their recommendation may not protect all species.
The recommendation of 1,000 ppb in fresh water fi sh to protect wildlife appears not
to be protective of reproduction in sensitive avian species.
The panel for marine fi sh guidance had one member, Robert Risebrough, who
was an active investigator of the effects of DDT on eggshell thinning and reproduc-
tion in birds. At the time of this recommendation, Robert Risebrough had just
published an article with Helen Hays on DDT in terns and fi sh scraps on Great
Gull Island, 6 miles off the Connecticut coast in Long Island Sound. The 1970 fi sh
data in this study (Table 7 ) appear to have become the basis for the 50 ppb recom-
mendation. The data are reproduced below from the original publication by Hays
and Risebrough ( 1972 ).
Table 7 DDT in fi sh from Great Gull Island. Table 2 in Hays and Risebrough ( 1972 ) reproduced
with permission