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Sources for which regulation is not proposed
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Gur suggested cutoff for aggregate population risk is
based on the following observation: where the annual cancer
incidence at current emission levels is Jess than one cancer
per year, any additional regulatory requirements would
likely impose costs of several million dollars per year while
only negligible public health gains would be achieved. Our
suggested cutoff for individual risk is based on our argu-
ment (outlined below) that annual risks te the most exposed
individual that are smaller than other risks generally encountered in the course of daily life need not be considered
independently of aggregate population risk.
3. The Measure of Individual Risk
In its preamble discussion, EPA outlines its concern for
the individual risks to the most exposed members of the
population and requests comments on the best way to consider individual risk in its decision process." We believe that
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"48 FR 33116.
1-13-84
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annual individual risk is a better measure than EPA’s
measure of ‘maximum individual lifetime” risk. “Maximum
individual lifetime” risk incorporates several important assumptions that overstate actual individual risks.”
First, maximum lifetime estimates of individual risk assumethat the individual receives the maximum exposure to
the substance--in effect, at the fenceline of the “worst”
facility-continuously for the full 70 years. The population in
the United States is highly mobile, however, and it is extremely unlikely that any individual would remain in a
single location for a lifetime. In addition, many of these
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facilities have a limited life and are unlikely to operate for _%
an additional 70 years. Second, a maximum individual life
time risk estimate incorrectly assumes that the last year of =~)
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*This conservalism in the risk estimate is independent of the é
extent to which EPA has adopted conservative assumptions in its)
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risk assessment.
Published by THE BUREAU OF NATIONAL AFFAIRS, INC., Washington, D.C. 20037
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