A recent cohort mortality study of male, hourly wage employees of a large Michigan chemical production and research facility had found a greater than expected number of deaths coded to liver and biliary tract cancer. In response, an additional investigation was then undertaken of the 44 liver and biliary tract cancer deaths observed between 1940 and 1982. A random sample (N = 1,888) of subjects was selected from the total cohort (N = 21,437) to serve as referents. Company work history records were used to classify cases and referents by work area assignment and potential for exposure to 11 selected chemical agents which have been shown to produce cancer of the liver or biliary passages in experimental animals. Statistically significant associations in both positive and negative directions were found for several work areas within the facility. A suggestive association was found for vinyl chloride monomer, based on five cases with presumed exposure.

Andersen air samplers were used to determine the particle size distribution of Serratia marcescens aerosols created during several common laboratory procedures and simulated laboratory accidents. Over 1,600 viable particles per cubic foot of air sampled were aerosolized during blending operations. More than 98% of these particles were less than 5 ,u in size. In contrast, 80% of the viable particles aerosolized by handling lyophilized cultures were larger than 5 ,u. Harvesting infected eggs, sonic treatment, centrifugation, mixing cultures, and dropping infectious material produced aerosols composed primarily of particles in the 1.0to 7.5-,u size range. Considerable information has been compiled in recent years concerning the aerosol spread of microorganisms during routine bacteriological and virological procedures. Operations involving withdrawal of material from vaccine bottles (2, 6, 12), inoculation of mice and the inoculation and harvesting of eggs (6, 12), handling of lyophilized cultures (14, 15, 18), pipetting (2, 10, 16), use of the inoculating loop (2, 11), blending (2,

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High concentrations of influenza virus and T3 coliphage were inoculated into mouse tissue blocks. Exposure of the inoculated tissue blocks to 5% alkaline glutaraldehyde resulted in rapid inactivation of both viral agents.

Engineering and microbiological tests indicated that a typical, commercial laminar airflow cabinet was not effective in providing either product protection or agent containment. The cabinet was modified and tested through a series of alternate configurations to establish a set of design criteria. A mock-up cabinet was developed from these design criteria. The mock-up unit was evaluated for efficiency in providing both product protection and agent containment. In these evaluations, challenge methods were developed to simulate normal, in-use laboratory operations. Controlled bacterial or viral aerosol challenges were used at higher than normal levels to provide stringent test conditions. Test results indicated that the mock-up unit was considerably better in preventing agent penetration (0.1 to 0.2 particles per 100 ft 3 of air) than the commercial cabinet (5 to 6 particles per 100 ft 3 of air) during product protection tests. Similarly, agent containment was considerably better in the new cabinet (particle escape of 2 to 3 per 100 ft 3 of air at only one of the five test sites) than in the commercial cabinet (particle escape of 2 to 14 per 100 ft 3 of air at three of the five test sites).