Occupational effects on the health of workers and laboratory technicians in petrochemical plants

A study was conducted over a 3-year period on the morbidity in petrochemical plants producing xylene, benzene, phenol and acetone, and in the related service laboratory. The incidence rate of system and target organ disorders due to the adverse effects of benzene, toluene, xylene, phenol, acetone, etc., was calculated. The exposure to chemical hazards (except benzene) of plant workers was not high--the concentrations were below the maximum allowable concentrations (MACs) and the duration of contact was not longer than 270 min per 8-h shift. The duration of exposure for laboratory technicians (all female) comprised an entire 8-h working shift, but concentrations of the chemical substances did not exceed MACs. The incidence rate of system and target organ disorders as a total of all production plants was 6% on average over the 3-year period, and for laboratory workers it was 10.3%. The average total incidence rate (comprising all diseases) was 42% in the production plants and comparatively greater in the laboratory--56% as an average for the period. Since laboratory technician posts are well mainly by women in Bulgaria, recommendations are to minimize contact with chemical hazards for women of child-bearing age, as was the case for benzene.