Blood lead level of workers occupationally exposed to lead in Nanjing 2016

Objective To understand the lead exposure level of workers in lead-used or produced industries in Nanjing.

Methods The data of occupational surveillance of lead-exposed workers in Nanjing, including employment history and their blood levels in the year of 2016 were collected and analyzed according to the types of enterprises, such as the location, scale of economies, and industrial characteristic.

Results The lead-exposed workers' age ranged from 17.0 to 60.0 (32.8±9.3) years old, and their employment time varied from 0.6 to 40.0(10.3±9.0) years. Their blood lead level, as median, was 33.0μg/L, while P₂₅ and P₇₅ was 18.0 and 50.0μg/L, respectively. It was found that 1.82% workers had higher blood lead level than the reference value but no chronic lead poisoning cases was diagnosed, and 9% workers had a higher blood lead level than 100μg/L and the blood lead level had a weak positive correlation with workers' age (r=0.25, P < 0.05)or employment time(r=0.12, P < 0.05). Male workers had a higher blood lead level than female workers and the difference was statistically significant (P < 0.01). It seemed that the workers in the special equipment manufacturing, chemical raw materials and chemical manufacturing industries had significantly higher blood level than the workers in the other 8 sectors(P < 0.05), and the workers of Liuhe District had significantly higher blood level than the workers in the other 4 districts(P < 0.05). The blood lead levels of workers seemed to be decreased in turn, in the micro-, small-, medium-and/or large-enterprises, or in the private, foreign and state-owned enterprises(P < 0.05).

Conclusion The occupationally lead-exposed workers' blood lead level in Nanjing was higher than that in the general population. Particular attention should be paid to the prevention and control of lead hazards among lead-exposed workers in chemical raw materials and chemical manufacturing, special equipment manufacturing sectors, as well as in micro and small enterprises and private enterprises.