A Michailova1, T Kuneva, T Popov. 1. National Centre of Hygiene, Medical Ecology and Nutrition, Sofia, Bulgaria. popov@mgu.bg
Abstract
OBJECTIVES: The group studied included 666 workers from the benzene (n = 30), xylenes (n = 144), ethylene oxide (n = 91), 1,3-butadiene (n = 110) and transport and mechanisation (n = 82) departments of a petrochemical plant in Bulgaria. The leading hazards for the particular departments are as follows: Benzene: benzene (up to ten times the threshold limit value; TLV): xylenes: benzene (up to nine times TLV) and xylenes (up to 1.6 times TLV); ethylene oxide: ethylene oxide (up to 20 times TLV) and ethylene (up to 30 times TLV); divinyl: 1,3-butadiene (five times TLV) and acetonitrile (six times TLV); transport and mechanisation: benzene, xylenes and pentane (0.7-10 times TLV). METHODS: The functional status of the liver was assessed by clinical (medical check-up), echographic and biochemical (ASAT, ALAT, APh, gamma-GT, lipid fractions, reduced glutathione and SH groups) investigations. Biochemical analyses were performed with POINTE 190 (USA). The results obtained were compared with those of a control group (n = 150), consisting of subjects with no occupational exposure to chemical hazards. RESULTS: Comparisons showed that the metabolic disturbances determined were most significant in workers from the ethylene oxide department. Significant decreases in the serum levels of reduced glutathione (up to 48%) and of thiol groups (with 23%), increased enyzme activity (up to 18%) and lipid fractions (up to 24%) were observed. In the benzene and xylenes departments, deviations in the indices studied were equally manifest. In workers exposed to 1,3-butadiene, the changes in lipid indices were prevalent (registered in 25% of the studied persons). The staff in transport and mechanisation showed deviations in enzyme indices at a slight increase of the lipid fractions. The changes determined in serum biochemical characteristics corresponded to the clinical findings--hepatomegaly, confirmed echographically in 10%-20% in the different departments. CONCLUSIONS: The results obtained followed the exposure-response relationship. The deviations registered in workers with a length of service of more than 10 years were the most significant. The occupational genesis of the determined disturbances was confirmed in 11 subjects.
OBJECTIVES: The group studied included 666 workers from the benzene (n = 30), xylenes (n = 144), ethylene oxide (n = 91), 1,3-butadiene (n = 110) and transport and mechanisation (n = 82) departments of a petrochemical plant in Bulgaria. The leading hazards for the particular departments are as follows: Benzene: benzene (up to ten times the threshold limit value; TLV): xylenes: benzene (up to nine times TLV) and xylenes (up to 1.6 times TLV); ethylene oxide: ethylene oxide (up to 20 times TLV) and ethylene (up to 30 times TLV); divinyl: 1,3-butadiene (five times TLV) and acetonitrile (six times TLV); transport and mechanisation: benzene, xylenes and pentane (0.7-10 times TLV). METHODS: The functional status of the liver was assessed by clinical (medical check-up), echographic and biochemical (ASAT, ALAT, APh, gamma-GT, lipid fractions, reduced glutathione and SH groups) investigations. Biochemical analyses were performed with POINTE 190 (USA). The results obtained were compared with those of a control group (n = 150), consisting of subjects with no occupational exposure to chemical hazards. RESULTS: Comparisons showed that the metabolic disturbances determined were most significant in workers from the ethylene oxide department. Significant decreases in the serum levels of reduced glutathione (up to 48%) and of thiol groups (with 23%), increased enyzme activity (up to 18%) and lipid fractions (up to 24%) were observed. In the benzene and xylenes departments, deviations in the indices studied were equally manifest. In workers exposed to 1,3-butadiene, the changes in lipid indices were prevalent (registered in 25% of the studied persons). The staff in transport and mechanisation showed deviations in enzyme indices at a slight increase of the lipid fractions. The changes determined in serum biochemical characteristics corresponded to the clinical findings--hepatomegaly, confirmed echographically in 10%-20% in the different departments. CONCLUSIONS: The results obtained followed the exposure-response relationship. The deviations registered in workers with a length of service of more than 10 years were the most significant. The occupational genesis of the determined disturbances was confirmed in 11 subjects.