The cardiologist in the Third World.

Abstract

<h3>Objectives</h3> In 2007, shift work involving circadian disruption was classified as probably carcinogenic to humans (Group 2A) by the International Agency for Research on Cancer. In most instances, the exposure in the occupational settings is complex and rarely only one hazardous occupational factor is present. Little is known so far about industrial exposures occurring in the manufacturing plants where night shift work system operates. <h3>Methods</h3> We collected data on the night shift work systems and hazardous agents present in 44 enterprises, based on a short survey filled in by the inspectors of safety and hygiene employed at the manufacturing plants. All identified hazardous factors were classified according to the IARC list of carcinogens and the European classification of carcinogens. <h3>Results</h3> The most common system of work employs 3 (8-hour) shifts within a 5-day cycle. Altogether, as many as 153 occupational exposures occurring in the environment of the plants were identified, with noise, carbon oxide, and formaldehyde recorded among the most common exposures. Night shift work was not noted as the sole hazardous occupational factor present at the work environment in the plants. We identified 20 factors that have been evaluated by IARC, 11 of them classified to Group 1 - carcinogenic to humans. 10 factors have been classified as carcinogens according to the regulation of the European classification of carcinogens. <h3>Conclusions</h3> Our study shows that in most instances, real life exposure circumstances at work places are complex and involve a variety of factors that may affect human response to night shift work involving circadian rhythm disruption. The project is funded from a grant of the Polish National Research Fund, Grant No: PB5169/B/P01/2010/38.