A retrospective cohort study on abnormal blood lead levels in lead-exposed workers in a storage battery factory / 中国职业医学

ABSTRACT

OBJECTIVE: To analyze the influencing factors of high blood lead levels in lead-exposed workers of a storage battery factory. METHODS: By the typical sampling method,lead-exposed workers were chosen as study subjects for a three-year retrospective cohort study starting from September of 2011 and ending in September of 2014. The starting blood lead level was < 400. 0 μg / L and ending blood lead level was ≥400. 0 μg / L( abnormal level). The influencing factors of abnormal blood lead level were analyzed by the COX regression analysis method. RESULTS: There were 244 lead-exposed workers included in this study. The median( M) working years of baseline lead exposure was 6. 3( 0. 7-35. 9) years,the M of baseline blood lead level was 321. 5( 215. 7-398. 7) μg / L by September of 2011. During the 3 years,there were 78 workers found to have abnormal blood lead levels,with an abnormality rate of 32. 0%. The multivariable COX regression analysis indicated that the workers with following situations had relative higher incidences of abnormal blood lead levelworking without masks,baseline blood lead level over 300. 0 μg / L,the air concentration of lead in workplace beyond the standard and the workers exposed to lead for over 5. 0 years,their relative risk ratios were 6. 89,4. 00,9. 02 and 2. 93 times of those workers with the opposite situations,respectively( P < 0. 01). CONCLUSION: Measures should be taken to prevent and control the occupational chronic lead poisoning especially in those lead-exposed workers who don't wear masks during work,whose baseline blood lead level was over 300. 0 μg / L,whose air concentrations of lead in workplace were beyond the standard and whose lead exposure year was over 5. 0 years.