Nonoccupant risk

Robertson appears to have found strong evidence that the safety standards did not increase nonoccupant risk and even made nonoccupants safer. One... 

Although most nickel sensitization results from nonoccupational exposures, nickel dermatitis was historically a problem in workplaces where there was a high risk of continuous contact with soluble nickel, eg, in electroplating (qv) shops. Improved personal and industrial hygiene has largely eliminated this problem. However, there are a few occupations involving wet nickel work, particularly where detergents faciUtate the penetration of skin by nickel, where hand eczema may occur (126). 

A retrospective case-control study conducted in humans compared spontaneous abortion rates among women who had been exposed occupationally or nonoccupationally to trichloroethylene and other solvents to rates among women without solvent exposure (Windham et al. 1991). The authors observed approximately three times the risk of spontaneous abortion with exposure to trichloroethylene. This risk increased further when women with less than a half hour of exposure to trichloroethylene each week were excluded from the analysis. However, a consistent dose-response relationship was not observed, and most of the women were exposed to a variety of solvents, not just trichloroethylene. 

Breslow, L. (1984). Nonoccupational health risks of asbestiform fibers. Committee on Nonoccupational Health Risks of Asbestiform Fibers, Board of Toxicology and Environmental Health Hazards, Commission on Life Sciences, National Research Council, Washington, DC. 

In 1971 the National Academy of Science published a 40-page report, Asbestos The Need for and Feasibility of Air Pollution Controls, (Cooper, 1971) summarizing the illnesses associated with occupational exposure to asbestos and the risks of developing asbestosis, pleural calcifications, and cancers of the pulmonary and gastrointestinal tracts and thoracic cavity. Based on the evidence, the committee recommended control and reduction of dust containing fibrous inorganic materials in the workplace it also discussed nonoccupational exposure to asbestos. 

Camus M, Siematycki J, Meek B. 1998. Nonoccupational exposure to chrysotile asbestos and the risk of lung cancer. N Engl J Med 338 1565-1571. 

NRC. 1984. National Research Council. Asbestiform fibers Nonoccupational health risks. Washington, DC National Academy Press. 

This chapter consists of two primary sections. The first section presents a framework or methodology for reconstructing exposures of interest, which can then be used to produce exposure estimates appropriate for conducting cancer risk assessments. The second section discusses the application of reconstructed exposures to the determination of dose estimates and cancer potency. Although the methods discussed here can be used in both occupational and nonoccupational exposure scenarios, the focus of this chapter is primarily on occupational exposure reconstruction methods. 

Polycyclic aromatic hydrocarbons are capable of forming adducts with DNA in cells. Exposure to PAHs from creosote were measured in the personal work areas of coke oven workers in the Czech Republic (Lewtas et al. 1997). Measured levels of DNA adducts in white blood cells of a nonoccupationally exposed population were well correlated with the low to moderate environmental exposures. The DNA adducts of the coke oven workers who were exposed to carcinogenic PAHs at levels of <5->200,000 ng/m3 (<0.005->200 pg/m3) did not correlate well with the exposure levels. These authors concluded that various mechanisms were responsible for the lower DNA-binding potency at the higher exposure levels, precluding the use of a linear model for dose-response extrapolation in risk assessment. 

The U.S. Environmental Protection Agency (EPA) presently has no limits on dioxin contamination levels in soil. After studying the risks, however, the Centers for Disease Control (CDC) of the U.S. Department of Health and Human Services in Atlanta, GA, has concluded that residual soil contamination levels at or above 1 ppb of 2,3,7,8-TCDD in residential areas cannot be considered safe and represent a level of concern ( 5). Uniform contamination levels are assumed. CDC also recommends low levels for pasture lands because of food chain accumulation. However, CDC concludes that, in certain commercial areas, higher levels in soils may represent an acceptable risk to nonoccupationally exposed individuals, but that level has not been defined. 

Thus, cumulative risk" is defined a.s the risk that may result from dietaiy, residential, or other nonoccupational exposure to multiple chemicals that have a common mechanism of toxicity (i.e., cumulative risk). Cumulative risk as.sessments include multiple pathways and multiple chcmicaLs. EPA-OPP has developed a guidance document for developing cumulative risks assessments under FQPA (EPA, 2002b). 

Cardiovascular effects of Pb in humans are the subject of Chapter 13, particularly with respect to effect potency in older exposure subjects but with inclusion of other risk groups. Cardiovascular effects, while inconsistently quantified across human populations, have been identified in multiple epidemiological studies, supported by a number of experimental data sets appearing in the global literature. Chapter 14 on human reproductive and developmental impacts of lead exposures presents the more useful data across several risk groups within human populations. Chapter 15 discusses adverse effects of lead on the renal system as nephrotoxicity is considered to occur across both occupational and nonoccupational subsets of human populations and subsets within nonoccupational categories. Discussions in Chapter 15, much like those in Chapter 18 on immunotoxicity, have benefited from quite recent findings. 

The assumption of traveler passivity biases conventional benefit-cost studies towards positive net benefits. The reason for the bias in favor of safety equipment is that reasonable substitutions (risk compensation) can lead to more accidents and more violent accidents. The consequences are that the decrease in occupant fatalities will be less than expected based on technological effectiveness and that there will be an increase in nonoccupant injuries. 

Unintended side effects, or derived externalities, are another nonmarket failure found in traffic safety poUcy. The most striking example comes from the review of the evidence on the safety effects of vehicle safety standards. In Chapter 3 we concluded that while overall highway travel is safer, nonoccupants such as pedestrians, bicyclists and motorcycUsts are in greater danger. Because the policy approach ignored risk compensation this occupant-nonoccupant tradeoff was unexpected by policy makers. 

Vulnerable nonoccupants such as pedestrians, bicyclists and motorcyclists are in greater danger due to risk compensation. 

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