In Pursuit of Safety: One-Hundred Years of Toxicological Risk Assessment

ABSTRACT

The publication in 1962 of Rachel Carson's Silent Spring marks the mid-point in a century that saw, in its first half, the emergence of public health concerns related to human exposures to chemicals, and, in its second half, the emergence of public policies to deal with those concerns. Those policies made it imperative that the scientific community come to grips with the problem of identifying exposure levels not likely to cause harm. This problem was not significantly discussed within the scientific community until the 1950s, and well-described methods for practical solutions to it did not appear until the 1970s. An important report from the National Academy of Sciences, published in 1983 (Risk Assessment in the Federal Government), provided an analysis of these emerging methods, and recommended a useful framework for the assessment and management of risk. This framework remains central to public health and regulatory decision-making. A high-level perspective is offered on events leading to and following the 1983 report. The article describes early thinking about chemical toxicity and the scientific path that thinking followed through the 20th century, and to the present.

Key Words:

• risk assessment
• decision-making
• toxicity
• regulation
• history
• Silent Spring

ACKNOWLEDGMENTS

The author expresses appreciation for the invitation and travel support from the Royal Society of Chemistry, and for helpful comments from two ENVIRON colleagues, Sue Bullock and Miranda Henning.

Prepared in Commemoration of the Fiftieth Anniversary of the Publication of Rachel Carson's Silent Spring, and presented at The Royal Society of Chemistry, Burlington House, London, October 2, 2012.

Notes

The giants are: Edward Frankland (1825–99) at Manchester, Justus von Liebig (1803–73) at Geissen, Joens J. F. von Berzelius (1779–1848) at Stockholm, Friederick Wohler (1800–82) at Gottingen, Marcellin Bertholet (1827–1907) at Paris. (Leicester 1956).

Questions relating to harm to nonhuman forms of life are of equal importance but will not be significantly discussed.

Occupational Safety and Health Administration (OSHA); Consumer Product Safety Commission (CPSC); U.S. Department of Agriculture/Food Safety Inspection Service (USDA/FSIS).

Except in trivial cases. If, for example, a hazardous chemical is banned or no longer in use, human exposure to it cannot occur. In this case we can be certain it poses no risk (assuming that, during its period of manufacture and use, it did not significantly contaminate the environment).

Food ingredients directly added to food and regulated under The Delaney Clause remain strictly prohibited, irrespective of risk.

REACH: Registration, Evaluation, Authorization and Restriction of Chemicals.