Work in Brief
INFECTION RISKS AMONG SEWAGE WORKERS
The treatment of sewage is an important public health measure, but some recent research suggests that workers exposed to sewage may be at increased risk for occupationally-acquired infection, notably with hepatitis viruses and Helicobacter pylori, a cause of peptic ulcer and stomach cancer. Tschopp et al1 address this concern with findings from a follow-up of Zurich municipal workers with and without exposure to sewage who participated in a previous cross-sectional study.2 The authors found no difference between exposed and unexposed workers in rates of seroconversion for Hepatitis E virus or H pylori, or in the incidence of clinical endpoints associated with H pylori. The findings are reassuring, but the authors caution that they might not apply in areas of endemic infection.
CHROMOSOME ABERRATIONS AND FLYING
Cosmic radiation is the major source of population exposure to ionizing radiation and is particularly important for aviation flight crews, who some studies suggest have increased risks for some cancers. In this issue, Yong et al3 report on a study of chromosome translocations among airline pilots and non-flying referent subjects. The overall frequency of translocations was similar for pilots and the comparison group. Among pilots only, however, the frequency of translocations increased about 6% for each year of flying experience. When pilots with over 23 years of flying experience were compared to pilots with 13 or fewer years experience, the adjusted translocation rate ratio was approximately 2.6. The authors interpret their results as an indication that pilots may receive biologically-significant ionizing radiation doses over the course of a career.
DO SICK LEAVE BENEFITS PREDICT TIME AWAY FROM WORK?
One of the more controversial questions about sickness absence has been whether more generous benefits lead to more frequent or longer sick leaves. Benavides et al4 studied this question using data from the Spanish social security system, which provides higher benefit levels for sick leave classified as work-related than for non-work related leave. The authors hypothesized that higher benefits would be associated with longer time off work, but this hypothesis was supported only for episodes shorter than 16 days, and then the effect was modest. With longer leave periods, workers receiving more generous benefits returned to work in about half the time. Data on diagnoses were not available, but the authors suggest that the length of absence might vary with illness severity.
