Investigation on health condition of 749 cadmium-exposed workers

Objective To investigate the adverse effects of cadmium exposure on the health condition of workers in nickel-cadmium battery plants and to analyze the influencing factors of urinary cadmium.

Methods Totally 749 workers in Xinxiang nickle-cadmium battery enterprises in 2011 were studied with health examination and questionnaire. Their urinary cadmium was measured. Among these workers 270 workers were followed up in 2014. The effects of cadmium exposure on the health condition, such as blood routine indices, lung function, urine routine indices, blood pressure, and liver function were evaluated.

Results The average level of urinary cadmium of 749 workers was (8.89±4.00) μg/g creatinine, and 64% workers' urinary cadmium levels were higher than national standard (5 μg/g creatinine). The urinary cadmium level of female workers was significantly higher than that of male workers(9.35±4.00)μg/g vs.(8.36±3.94)μg/g, P < 0.01). With the increase of cadmium level in urine, the abnormal rate of lung function, blood pressure, liver function, B-mode ultrasound and chest X-ray examination also increased (P < 0.05). The multivariable linear regression model analysis showed that the sex (β_{female vs. male}=0.680, P < 0.01), age(β=0.048, P < 0.05), employment time within enterprises(β=0.114, P < 0.01), exposure level (β_{medium vs. lower}=3.030, β_{higher vs. lower}=4.661, P < 0.01)were factors affecting the urinary cadmium level(F=47.519, P < 0.01), and the coefficient of determination was 0.242 (P < 0.01). The follow-up results in 2014 among 270 workers showed that the abnormal rate of blood routine indices was 70.0%, and the abnormal rates of urine routine indices, blood pressure and chest X-ray examination were higher than those in 2011(P < 0.05).

Conclusion The health effects of long-term occupational exposure to cadmium, such as liver function, blood pressure and lung function, should be noted.