response activities. The final section of this chapter describes the committee score and rationale for program impact.
Ideally, a review of the HHE Program would yield quantitative evidence of the reduction of illness or death (earlier defined as “end outcomes”) at specific investigated worksites or similar workplaces throughout the country. Such quantitative evidence of impact is generally unavailable. In the field of occupational health, however, there is solid evidence that exposure to certain chemical or physical agents causes illness, injury, or death. In general, a reduction in the level or frequency of exposures is expected to reduce the number of workers who develop disease. Elimination of exposures can reduce the number of cases of disease in those already exposed, prevent disease in new hires, or both. Based on this cause-and-effect relationship, attempts are made to reduce disease risk by reducing or eliminating exposures to various agents. Sometimes, based on reduced exposure, it is possible to make estimates of disease or deaths avoided.
Reductions in exposure at one workplace as a result of HHE Program recommendations can lead NIOSH or other agencies to take action to reduce exposures in similar workplaces nationwide. Information regarding exposure reduction measures can be provided to employees at a site where an HHE was conducted, and then to occupational health professionals, public health practitioners, and state and federal regulators elsewhere through reports, hazard alerts, and other publications. It is conceivable that NIOSH would have the data to estimate the number of lives saved and the reductions in diseases that can be direct or indirect results of HHEs conducted. For example, HHE recommendations describe the actions needed to reduce exposures of elevated chemical or physical hazards identified during an investigation. Follow-up with employers, and especially employees, could yield information about actions taken to reduce exposures. With sufficient evidence that harmful exposures have been reduced or eliminated (for example, by substitution of one chemical or process for another), it may be possible to develop quantitative estimates of occupational illness or death avoided.
Existing occupational health and safety data are insufficient to support robust analyses of impacts of the HHE Program. This is not to say that the HHE Program does not have impact, but that there are inadequacies in the reporting system. Because occupational disease and death statistics in particular are limited in the U.S. health data systems, other evidence is examined by the committee to estimate HHE impacts. The committee began this process by looking at the HHE Program’s strategic goals and determining the number of HHEs conducted relevant to each strategic goal and by hazard type (Table 4-1). Starting with a table provided by the HHE Program (NIOSH, 2007b:Table 3-1), the committee used the program’s online HHE search engine to identify related reports.1 This simple exercise yields
See http://www.cdc.gov/niosh/hhe/ (accessed July 9, 2008).