Despite the known health hazards associated with exposure to lead, occupational lead poisoning remains a health problem. Although a variety of public health programs have been implemented to control this exposure, knowledge of which occupational groups are at greatest risk is incomplete. This research developed and applied a lead risk model that generated estimates of lead-using industries and numbers of employees potentially exposed to lead, and then, validated the model through a lead exposure prevalence survey among construction workers. The lead risk model was developed using data from the National Occupational Exposure Survey, state lead registries, lead inspection results from the Occupational Safety and Health Administration, and other sources. The model was applied to Massachusetts County Business Patterns and Department of Employment and Training databases to produce state and county estimates of numbers of employees potentially exposed to lead, and lead-using companies, ranked by exposure risk. The sensitivity of the state lead registry was evaluated using estimates from this model. To validate the model, a prevalence survey of lead exposure was conducted among a sample of 127 western Massachusetts plumbers. Based on the model, an estimated 1% (20,825) of Massachusetts employees are potentially exposed to lead, 53% are at moderate or high risk of lead exposure, and 74% work within a 5 contiguous-county area in eastern Massachusetts. There are 3,448 lead-using facilities, representing 2% of total companies. The model also showed a high sensitivity (70%) for state regulated construction groups within the lead registry, but low sensitivities for all other construction industries. The geometric mean for blood lead and zinc protoporphyrin among plumbers in the prevalence survey were 7.0 $\mu$g/dl and 30.9 $\mu$g/dl, respectively, indicating relatively low levels of lead exposure. Current smokers, smoking at the workplace, and hand scraping metal were associated with higher lead levels, while wearing protective equipment at work was associated with lower levels. The model identified non-traditional lead-using industries, thus, potentially allowing the state to better target educational and medical intervention activities to reduce the risk of occupational lead exposure. Similar lead-reduction activities can be applied to other states that adopt the model.

Injury epidemiology, a relatively new sub-discipline of epidemiology, has continued to evolve since the ground-breaking work by Dr. William Haddon during the 1960s. The case-crossover design is a relatively new epidemiological methodology developed specifically for investigating the transient effects of a brief exposure on the onset of an acute outcome. This dissertation work provides some initial empirical data illustrating the strengths and limitations of the case-crossover design as applied within the field of occupational injury epidemiology. The review of the literature details the utility of the case-crossover study design, the currently known strengths and limitations, and confirms the under-utilization of this design to date. Examples from an on-going multi-center, interview-based, case-crossover study of acute traumatic occupational hand injuries are utilized to highlight some of the strengths and weaknesses of this new method, as applied to injury research. The application demonstrates the importance of temporal factors in determining the etiology of occupational acute traumatic hand injury. The findings point out the need to know more about the timing of high risk work tasks and transient exposures throughout the work day. These factors should be taken into consideration when developing intervention strategies for the prevention of hand injuries in the workplace. To evaluate the potential impact of information bias on the results of this study, a reliability study was also conducted. The findings from this test-retest study suggest that the frequency and duration of unusual transient workplace exposures, occurring proximal to the time of an injury, can be reliably recalled using a telephone interview.