Assessment of Exposure-Response Functions for Rocket-Emission Toxicants (1998) / Chapter Skim
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Subpopulations Sensitive to Air Contamination
Subpopulations Sensitive to Air Contamination
Pages 24-36
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From page 24... ...
In the fourth section, the subcommittee describes common practices for accounting for sensitive subpopulations in human heady risk assessments when data on sensitivity are lacking. In the fifth section, the subcommittee evaluates the Air Force criteria for defining sensitive subpopulations.
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From page 25... ...
Non-neoplastic and neoplastic pulmonary diseases were discussed. The analysis was limited, however, to the effects of comparatively low-concentration, long-term exposures to common air pollutants and did not provide substantial guidance relevant to short-term exposures or to the specific compounds-HC1, NO2, and HNO3- examined in this report.
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From page 26... ...
. On balance, thorough evaluation of available epidemiolog~cal and controRed-chamber studies did not provide much evidence that adverse health effects caused by exposure to common air pollutants would be substantially more serious in potentially sensitive subpopulations (i.e., asthmatic individuals, children, and the elderly)
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From page 27... ...
On the basis of general occupational experiences, industrial hygienists suggest that slight symptoms might occur at exposure concentrations around 5 ppm (see Appendix D)
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From page 28... ...
Mohsenin (1987) found heightened airway reactivity in asthmatic subjects exposed to NO2 at 0.5 ppm for ~ hr.
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From page 29... ...
1987) , healthy and atopic subjects showed practically no changes In pulmonary function when exposed to SO2 at 0.6 ppm, whereas some moderately to severely asthmatic subjects responder!
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From page 30... ...
At higher exposure concentrations, such as those that might occur during a catastrophic abort of a rocket launch, young children or elderly people with compromised pulmonary and cardiovascular hearth might tee disproportionately more affected than healthy individuals and show more severe responses. Finally, experimental studies on humans measure only a few aspects of the effects of air pollution: pulmonary-function-test changes and, on occasion, minor signs of inflammatory events in airways and lung parenchyma.
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From page 31... ...
Although the subcommittee found the information discussed in the symposium to be useful In general, it did not find any specific data relevant to the three rocket-em~ssion compounds under consideration or to acute inhalation exposures. In developing guidelines for setting community emergency exposure levels (CEELs)
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From page 32... ...
Air Force Space Command, personal commun., May 6,1996~. The subcommittee finds the phrase "physiological stress" to be too vague to be useful, is not aware of data supporting the particular age cutoffs specified, and does not support the use of age cutoffs in general for identifying sensitive subgroups.
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From page 33... ...
Conditions identifiecI In questions about the cardiovascular-system include rheumatic fever, rheumatic heart disease, arteriosclerosis, congenital heart disease, coronary heart disease, hypertension, stroke or cardiovascular accident, brain hemorrhage, angina pectoris, myocardial infarction, other heart attacks, damaged heart valves, tachycardia, heart murmur, other heart trouble, and aneurysm. The subcommittee considers any of the cardiovascular and pulmonary conditions listed above as likely to render an individual more sensitive to the effects of rocket-enussion toxicants than members of the population without those conditions.
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From page 34... ...
The ERFs included In LATRA assume that case 3 applies; in over words, sensitive subgroups begin to respond at lower concentrations than the normal population, and the slope of the exposure-versus-incidence curve is steeper for the sensitive subgroup than for the normal population. Although a lower threshold and steeper slope of the exposureversus-incidence curve for the sensitive subgroup seems reasonable, as described above, data that would allow quantifying a difference in both Intercept (threshold)
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From page 35... ...
35 ~n ~ 2 Q ~ ^ ~ ~o ^ c ~n cn ._ ._ c ._ o c c > ._ ._ tn c a)
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From page 36... ...
Data for ad the inhalation toxicants discussed above, however, are for comparatively low exposure concentrations. Conceivably, et higher exposure concentrations, young children or individuals with comprom~sed pulmonary or cardiovascular health might be more severely affected than healthy individuals.
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