[Investigation on occupational hazards in 20 automobile manufacturing enterprises in Shandong Province]

Objective: To investigate the current situation of occupational hazards in automobile manufacturing enterprises in Shandong Province. Methods: From February to May 2019, the convenience sampling method was adopted to conduct on-site occupational health surveys with 20 automobile manufacturing enterprises in Shandong Province as the survey subjects, to detect the occupational hazard factors in the workplaces and individual exposure levels, and to analyze the occupational health check results of operators. Results: There were 13 small-sized, 4 medium-sized and 3 large-sized enterprises among the 20 automobile manufacturing enterprises. The detection results of benzene and toluene in the workplaces met the occupational exposure limits, and the detection results of welding fumes, manganese and its compounds, and xylene exceed the occupational exposure limits. The maximum short-term exposure concentration (C(STE)) of welding fume in the air of workplaces was 24.23 mg/m(3), and the over-standard rate was 11.0% (16/146) . The maximum time-weighted average concentration (C(TWA)) of welding fume of operators is 10.60 mg/m(3), and the over-standard rate was 11.0% (8/73) . The maximum C(STE) of manganese and its compounds in the air of workplaces was 0.879 mg/m(3), and the of manganese and its compounds of operators was 0.175 mg/m(3), and the over-standard rate was 5.7% (4/70) . The maximum xylene C(STE) in the air of workplaces was 230.00 mg/m(3), and the over-standard rate was 3.9% (2/51) . The maximum xylene C(TWA) of operators was 70.40 mg/m(3), the over-standard rate was 3.6% (1/28) . Among the 4775 workers exposed to occupational hazards, 38 (0.80%) were suspected of electric welder's pneumoconiosis, 27 (0.57%) were suspected of manganese poisoning and 31 (0.65%) were suspected of chronic low-concentration benzene and benzene series poisoning. The detection rates of suspected occupational diseases among workers in small and medium-sized enterprises were relatively high, 2.86% (30/1048) and 4.51% (51/1132) respectively. There was a statistically significant difference in the detection rates of suspected occupational diseases among the operators of different scale automobile manufacturers (P<0.05) . Conclusion: The exposure levels of electric welding fumes, manganese and its compounds in welding jobs and xylene exposure levels in spray painting jobsin Shandong Province's automobile manufacturing enterprises are more serious. The supervision and management of occupational hygiene should be strengthened, the working environment should be improved, and the health of welding and painting workers should be protected.

[An investigation of occupational exposure to welding fume, manganese, and manganese compounds in a large container manufacturing enterprise]

Objective: To investigate the current status of the occupational hazards of welding fume, manganese, and manganese compounds in the welding environment of a large container manufacturing enterprise, as well as the status of occupational health examination of workers, and to provide a basis for improving the welding environment of this enterprise. Methods: In August 2016, July 2017, and August 2018, convenience sampling was used to perform an on-site occupational hygiene survey of the welding workshop for three consecutive years, and welding fume, manganese and, manganese compounds (counted as manganese dioxide) were measured for their workplace exposure concentrations and exposure levels in workers. A comprehensive analysis was performed for the results of occupational health examination. Results: Welding fume, manganese, and manganese compounds in the welding environment gradually increased from 2016 to 2018 (χ(2)(trend)=5.14 and 5.54, P<0.05). The maximum over-standard rate of concentration-short term exposure limit was 43.3% (13/30) for welding fume and 40.0% (12/30) for manganese and its compounds, and the maximum over-standard rate of time-weighted average concentration was 26.7% (8/30) for welding fume and 23.3% (7/30) for manganese and its compounds. Abnormalities were observed in the occupational health examination of welding workers in 2016-2018, among which respiratory system abnormalities (cough, expectoration, and wheezing), nervous system abnormalities (dizziness, fatigue, sleep disorders, amnesia, hyperhidrosis, and palpitations), and electrocardiogram abnormalities (bundle conduction block) had an incidence rate of above 10.0%, and the incidence rate of abnormalities on posterior-anterior X-ray high-kV chest radiograph was close to 8.9% (30/336) . Conclusion: There is severe exposure to welding fume, manganese, and manganese compounds among workers in this enterprise, which cause great hazards to the health of workers. It is necessary to strengthen occupational health management, take measures to improve the welding environment, and enhance occupational disease prevention.