Night shift work characteristics and occupational co-exposures in industrial plants in Łódź, Poland

Abstract

Objectives: Night shift work involving circadian rhythm disruption has been classified by IARC as a probably carcinogenic to humans (Group 2A). Little is known about co-exposures of the night shift work in occupational settings. The aim of our study was to characterize night shift work systems and industrial exposures occurring in the manufacturing plants in Łódź, Poland, where night shift work system operates, with particular focus on potential carcinogens. Material and Methods: Data on the night shift work systems and hazardous agents were collected through survey performed in 44 enterprises. The identified hazardous agents were checked using the IARC carcinogen list, and the harmonized EU classification of chemical substances. We also examined databases of the Central Register of Data on exposure to substances, preparations, agents and technological processes showing carcinogenic or mutagenic properties in Poland. Results: The most common system of work among studied enterprises employed 3 (8-hour) shifts within a 5-day cycle. We identified as many as 153 hazards occurring in the environment of the plants, with noise, carbon monoxide and formaldehyde recorded as the most common ones. Out of these hazards, 11 agents have been classified by IARC to group 1 -carcinogenic to humans, whereas 10 agents have been classified as carcinogens by the regulation of European Classification of carcinogens. Analysis of the data from the Central Register revealed that 6 plants reported presence of carcinogens in the environment of work. Conclusions: In our study we observed that in none of the workplaces the night shift work was a single exposure. Further epidemiological studies focusing on investigation of health effects of the night shift work should identify occupational co-exposures and examine them as potential confounders.

Rotating night shift work and physical activity of nurses and midwives in the cross-sectional study inŁódź, Poland

“…Of importance here is that nurses in Poland work rotating system, mostly with 12 h long two shifts, while at industry the most prevalent system that includes three shifts, with five consecutive shifts (Peplonska et al, 2013), and thus consequences to lifestyle may differ. Given cross-national social and lifestyle differences, the limitation may also apply to generalization of the results to nurses in other countries, in particular, if their system of work is different.…”

Circadian Disruption and Prostate Cancer Risk: An Updated Review of Epidemiological Evidences

“…Indeed, the meta-analysis provided a meta-OR for eight studies that provide very different definitions and assessments of night shift work across studies. Moreover, only three studies of eight were of high quality according to the Newcastle- Ottawa Scale criteria (45). Out of those eight studies, four were included in Sigurdardottir's review (27)(28)(29)(30) and four are part of ours (31)(32)(33)(34).…”

“…Among the five more recent studies included in our review, two were suggestive of an association between night shift work and prostate cancer (31,32) while three studies did not (33)(34)(35). Even though those five studies presented several positive features that should be emphasized: high quality exposure information with detailed lifetime job histories, large population size studies, information on sleep patterns, and chronotype in two studies of five, several limitations to an overall interpretation should also be highlighted: lack of standardization in both definition of night shift work and exposure assessment; different potential confounding factors taken into account; different prostate cancer outcomes either incidence or mortality; differences in populations studied some of them being population-based while others focused on specific occupational groups; few studies with information on prostate cancer aggressiveness, and few studies taking into account other occupational exposures that may also play a role in prostate cancer (45).…”

Variations in exposure to carcinogens among shift workers and non‐shift workers

“…Similarly, a study in France found that night‐shift workers were more frequently exposed to at least one carcinogen, or mutagenic and reprotoxic chemical and had a higher exposure intensity compared to occupations without night‐shift work . A study in industrial plants in Poland where a night shift work system operates found co‐exposure to other occupational hazards among workers including carcinogens to be relatively common …”