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

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 carcino - gens 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

Night shift work and modifiable lifestyle factors

Objectives: Night shift work has been linked to some chronic diseases. Modification of lifestyle by night work may partially contribute to the development of these diseases, nevertheless, so far epidemiological evidence is limited. The aim of the study was to explore association between night shift work and lifestyle factors using data from a cross-sectional study among blue-collar workers employed in industrial plants in Łódź, Poland. Material and Methods: The anonymous questionnaire was self-administered among 605 employees (236 women and 369 men, aged 35 or more) - 434 individuals currently wor­king night shifts. Distribution of the selected lifestyle related factors such as smoking, alcohol drinking, physical activity, body mass index (BMI), number of main meals and the hour of the last meal was compared between current, former, and never night shift workers. Adjusted ORs or predicted means were calculated, as a measure of the associations between night shift work and lifestyle factors, with age, marital status and education included in the models as covariates. Results: Recreational inactivity (defined here as less than one hour per week of recreational physical activity) was associated with current night shift work when compared to never night shift workers (OR = 2.43, 95% CI: 1.13-5.22) among men. Alcohol abstinence and later time of the last meal was associated with night shift work among women. Statistically significant positive relationship between night shift work duration and BMI was observed among men (p = 0.029). Conclusions: This study confirms previous studies reporting lower exercising among night shift workers and tendency to increase body weight. This finding provides important public health implication for the prevention of chronic diseases among night shift workers. Initiatives promoting physical activity addressed in particular to the night shift workers are recommended