Blood lead level and liver function status of occupationally lead-exposed workers and their influence factors

Objective To understand blood lead level(BLL)and liver function status of occupationally lead-exposed workers and to analyze their influence factors so as to provide orientation for protecting workers' health.

Methods Totally 1 179 workers in a lead-acid battery company were studied, including 801 workers exposed to lead and 378 non-exposed workers(administrative and logistic workers). They were surveyed with questionnaire and occupational health examination.

Results The levels of blood lead ranged from 89 to 463 μg/L and the M(P₂₅, P₇₅) was 152.2(65.4, 356.7)μg/L among these workers, and 10.2% workers had higher BLL than biological exposure limit (400 μg/L). The abnormal rate of blood lead in exposure group was significant higher than that in non-exposure group with the risk of 7.321-fold (P < 0.01). Logistic regression analysis showed that the risk of abnormal liver function among workers with LLB of 200-300 μg/L, 301-400 μg/L and more than 400 μg/L was 1.775, 2.659 and 3.114 (P < 0.05), respectively, compared with workers with LLB of lower than 100 μg/L. The risks of abnormal liver function among workers with employed time of 10-13 years and 5-9 years was 1.454 and 1.122 (P < 0.05), respectively, compared with workers with employed time of less than 5 years. The risk of abnormal ultrasonic B examination among workers with LLB of 200-300 μg/L, 301-400 μg/L and more than 400 μg/L was 1.650, 2.219 and 2.658 (P < 0.05), respectively, compared with workers with LLB of lower than 100 μg/L. The risk of abnormal B-mode ultrasonography among lead-exposed workers was 2.235 times higher than non-exposed workers (P < 0.05).

Conclusion Occupational lead exposure induced the blood lead level increase, and BLL was an independent risk factor for abnormality of liver function and ultrasonic B examination. Health surveillance should be strengthened in routine occupational health work.