Assessment of Exposure-Response Functions for Rocket-Emission Toxicants (1998) / Chapter Skim
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Description of the Launch Area Toxic Risk Analysis (LATRA) Model
Description of the Launch Area Toxic Risk Analysis (LATRA) Model
Pages 14-23
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From page 14... ...
The ERFs included in LATRA at present are lognormal for noncarcinogenic substances and linear, passing through the origin, for carcinogenic substances. When sufficient data are available to support a nonlinear ERF for a carcinogen, the Air Force should consider modeling such data.
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From page 15... ...
_~__~_ id, -, ~ TOXICITY OF ROCKET EMISSIONS The toxicity reference values originally used by the Air Force In the LATRA-ERF mode! to represent a 1 %-effect level for HCI, NO2, and HNO3, hac!
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From page 16... ...
Although this approach requires quantifying separate ERFs for each population subgroup, the Air Force pointed out that it allows them to apply the ERF for healthy adults to all locations where sensitive subgroups are not found. The more conservative ERFs for sensitive individuals need be applied only to those locations where Me census data indicate that there are sensitive subgroups and only to the proportion of the population considered sensitive at those locations.
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From page 17... ...
Also, because the Air Force stated that a category reflecting moderate effects would assist in making launch decisions, the subcommittee evaluated how to define three levels of effect severity mild, moderate, and severe-in a way that is both scientifically sound and meaningful to an Air Force commander. The subcommittee's evaluation, conclusions, and recommendations concerning the approach and definition of severing categories are presented in Chapter 4.
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From page 18... ...
] is the cumulative lognormal distribution function with mean natural logarithm of concentration, In(C)
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From page 19... ...
does analyze exposures down to 5-m~n increments. The documentation supplied to the subcommittee did not specify, however, how maximum peak or TWA exposure concentrations are derived from the REEDM output for comparison with the toxicity values.
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From page 20... ...
The Air Force considered SPEGEs and other established exposure concentrations considered safe for the general public when seding the % effect levels for sensitive populations. Similarly, the Air Force considered established exposure concentrations considered safe for workers In sewing the 1% effect levels for normal populations.
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From page 21... ...
ox 111 I a)
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From page 22... ...
when the probability of effect per individual is PE(S,C,73. In the current LATRA model, all of those binomial distributions are combined by adding their means and variances to obtain the mean and variance of the total number of people suffering effects of a given severity at ah receptor locahons.
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From page 23... ...
Depending on the toxicity criteria used, as well as the quantity of propellants onboard, meteorological conditions, proximity of population centers, and so forth, far greater health risks generally are expected for catastrophic aborts than for normal launches. As a consequence, the total risk estimate produced by LATRA generally reflects the risks estimated for a catastrophic abort because the risks estimated for a normal launch usually are much lower.
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