Cancer of the uterine cervix,

a site repeatedly appearing in excess in previous studies of PER-exposed workers (IARC 1995b), is now understood as a disease of infectious origin (Schiffman et al. 2007) rather than associated with chemical exposures in working populations. Hence, previous observations of increased rates of cervical cancer in dry-cleaning and laundry workers are best interpreted in terms of socio-economic or lifestyle-related determinants of risk, as discussed buy C59 wnt earlier. Slightly increased point estimates of cervical cancer were observed in PER-exposed as well as laundry workers included in the present study, corroborating a concept of equal risks. As for oesophageal cancer, another tumour site showing excess in PER-exposed groups (IARC 1995b), alcohol and smoking are well recognised and synergistic determinants, notably for squamous cell carcinoma (Lagergren et al. 2000; Morita et al. 2010). In this study, the power to evaluate the epidemiology of oesophageal cancer was low, but there was a notable gender difference. Inversely to the general check details background with a clear male dominance (Chandanos and Lagergren 2009), we observed

a non-significant increase in female workers (both in the PER and laundry groups, respectively), whereas in male workers, no cases were observed versus 3.7 expected. These findings would suggest a VX-680 differential risk panorama between the genders, but due to the low numbers involved, no conclusions can be drawn triclocarban in this respect. Non-Hodgkin’s lymphoma

is a complex conglomerate of disease subtypes (Swerdlow et al. 2008), in contemporary pathology thinking including also Hodgkin’s disease (Taylor 2005) and thus creating a considerable challenge for the epidemiologist. The histological characteristics of the non-Hodgkin’s lymphomas in workers from companies using a high proportion of PER in this study (Table 5) also showed a wide variation and included both B- and T-cell lymphomas where a common aetiology is difficult to comprehend. Moreover, incident cases in this study were evenly distributed in both male and female PER-exposed and laundry workers, respectively, suggesting equal risk patterns between the groups. Dry-cleaning with PER might well prove to represent an obsolete technology which may be replaced by a variety of environmentally “green” alternatives (so-called wet cleaning, carbon dioxide-based dry-cleaning and other methods), but the present study has not provided evidence to suggest that PER is hazardous as a human carcinogen. In conclusion, this historically prospective cohort study of dry-cleaners and laundry workers showed no clear association between occupational exposure to PER and the subsequent incidence of cancer, adding weight to the part of the available epidemiological evidence that suggests absence of such an association. Acknowledgments Ing-Liss Bryngelsson provided substantial technical assistance.