The U.S. EPA Conference on Preventable Causes of Cancer in Children: a research agenda.

On 15-16 September 1997, the U.S. Environmental Protection Agency sponsored the Conference on Preventable Causes of Cancer in Children. The conference was convened to examine rising trends in reported incidence of childhood cancer and the association of these trends with environmental exposures. This paper summarizes recommendations for future research offered by participants. These recommendations included more collaborative research integrating epidemiology, molecular biology, toxicology, and risk assessment; the development of better protocols for toxicologic testing including carcinogenicity using young animals; and research focused on specific periods of development during which susceptibility to environmental agents may be enhanced. Also recommended was enhanced use and development of molecular biomarkers for identification of susceptible populations, and documentation of exposures and effects in epidemiologic and toxicologic studies. Although toxicologic testing is considered essential to determine the effects of potential carcinogens on biological organisms, participants emphasized the need to link these findings with epidemiologic and exposure assessment research.

Occupational risk of Mycobacterium tuberculosis infection in hospital workers.

We conducted a 4-year (1/89-12/92) retrospective cohort study among employees at a large metropolitan hospital where a nosocomial outbreak of multidrug-resistant tuberculosis (TB) had occurred. We compared the risk of tuberculin skin test (TST) conversion among employees who worked on wards where patients with culture-confirmed TB were cared for ("exposed") with the risk among employees who worked on wards with no such patients ("unexposed"). Exposed employees had a higher 4-year risk of TST conversion (14.5%) than unexposed employees (1.4%) (adjusted relative risk 13.4; 95 percent confidence interval 5.1-35.2). Exposed employees had significantly higher risks of conversion than unexposed employees during 1989-91, but not for 1992. Among the exposed, ward clerks had a risk of conversion (15.6%) only slightly lower than nurses (18.2%). We conclude that employees who worked in areas where patients with active M. tuberculosis infection were cared for, including workers who did not provide direct patient care, had a higher risk of TST conversion than employees who did not work in these areas. Reasons for the decline in risk over time include outbreak termination, fewer admissions of patients with TB, implementation of effective infection control measures, and possible resistance to infection in some members of the study population.

Immunochemical quantification and particle size distribution of airborne papain in a meat portioning facility.

The use of enzymes in industry continues to expand. With this increased use comes a concerted need to better understand potential respiratory health hazards to exposed workers and to quantify exposure levels that cause impaired health. To this end, projects were undertaken by the National Institute for Occupational Safety and Health (NIOSH) Health Hazard Evaluations Program and Cole Associates whereby this information was collected. Data concerning medical evaluation and aspects of industrial hygiene are the subjects of two separate reports from these respective groups. This method/results report includes a description of (1) a sensitive immunoradiometric assay for the quantification of airborne papain and its particle size distribution, (2) measurement of papain from both general area and personal breathing zone air samples obtained from a meat processing plant that used this immunochemical analysis, (3) a sampling strategy, and (4) an improved air sample processing technique. Airborne papain was measured at levels ranging from low nanogram to microgram per cubic meter concentrations. Approximately half of the papain activity was associated with particles having an aerodynamic diameter of less than 9.4 microns. These data point to a need for containment and controls in the manufacture and use of such compounds. This approach can be considered by the hygienist as an effective tool to be used in conjunction with epidemiologic studies to help set standards that are practical, safe, and maintained.