Chlorinated hydrocarbons and eggshell changes in raptorial and fish-eating birds.

Catastrophic declines of three raptorial species in the United States have been accompanied by decreases in eggshell thickness that began in 1947, have amounted to 19 percent or more, and were identical to phenomena reported in Britain. In 1967, shell thickness in herring gull eggs from five states decreased with increases in chlorinated hydrocarbon residues.

Pesticide pollution control. Suggestions are made for improving the quality of water subject to pollution by pesticides.

The suggested methods for evaluating water quality with respect to its content of selected groups of pesticides are based on interpretation of generally available information. They are intended to provide a base for discussion leading to the development of public policy for the inclusion of such values in water quality standards.