Objective: To analyze the post distribution of dust concentration in ferrous metal foundry enterprises and evaluate the occupational health risks, and provide basis for policies of the formulation of pneumoconiosis prevention and control. Methods: From August to September in 2020, the basic information, dust hazard information and occupational health management information of 59 ferrous metal casting enterprises were investigated, the dust concentration distribution was analyzed, and the risk assessment was carried out by using the quantitative assignment model. The dust concentration is tested by LSD method after logarithmic treatment. The 3 times time weighted average allowable exposure concentration of dust is taken as the peak concentration limit of dust; The time weighted average allowable exposure concentration of dust converted by exposure time is taken as the time weighted average exposure concentration limit of dust, and whether the time weighted average exposure concentration and peak concentration of dust at the same post exceed the limit is taken as the basis for exceeding the limit of dust post concentration to calculate the post exceeding the limit rate. Results: The dust hazards were mainly distributed in the posts of sand treatment, molding, sand falling, sand cleaning and cutting and grinding. Dust exposure time weighted average concentration was 0.44 (0.03, 5.11) mg/m(3), peak exposure concentration was 1.30 (0.18, 10.94) mg/m(3), and the over standard rate of Posts was 38.92% (79/203) . Weighted average exposure concentration of other dust (total dust) in the cutting and grinding post is 1.50 (0.15, 7.40) mg/m(3), peak exposure concentration is 0.90 (0.07, 12.48) mg/m(3), and the post exceedance rate is 4.88% (2/41) . Weighted average exposure concentration of silica dust (exhaling dust) in dust operation posts of investment casting enterprises is 0.43 (0.05, 6.35) mg/m(3), peak exposure concentration is 0.90 (0.12, 8.28) mg/m(3), and the post over standard rate is 35.77% (49/137) ; Weighted average exposure concentration of other dust (total dust) at the cutting and grinding post is 2.00 (11.00, 21.00) mg/m(3), and the post exceedance rate is 2.50% (2/80) . There was no significant difference in the concentration of respirable dust between sand casting and investment casting (P>0.05) . The concentration of respirable dust in sand casting was higher than that in sand treatment, molding and sand cleaning posts (P<0.05) . The concentration of silica dust in investment casting was higher than that in sand treatment and molding posts, and that in sand cleaning posts was higher than that in sand treatment posts (P<0.05) . 98.48% (454/461) of the dust operation posts have an occupational health risk value greater than or equal to 400, and 1.52% (7/461) of the dust operation posts have an occupational health risk value of 200~399. Conclusion: there is a high rate of exceeding the standard in the dust work posts in the ferrous metal foundry enterprises in Ningbo, and the workers have a high occupational health risk of pneumoconiosis or metal and its compound pneumoconiosis. Targeted measures should be taken to reduce the occupational health risk.
目的： 分析黑色金属铸造企业粉尘岗位浓度分布，评估其职业健康风险，为尘肺病防治政策制定提供依据。 方法： 于2020年8至9月，对59家黑色金属铸造企业的基本信息、粉尘危害信息和职业卫生管理信息等进行调查，分析粉尘浓度分布，并利用定量赋值模型进行风险评估。粉尘浓度经对数处理后采用LSD方法检验。以粉尘的3倍时间加权平均容许浓度作为粉尘的峰浓度限值；以接触时间折算后的粉尘时间加权平均容许浓度作为粉尘的时间加权平均接触浓度限值，并以同一岗位粉尘的时间加权平均容许浓度和峰浓度是否超过限值作为粉尘岗位浓度的超标依据计算岗位超标率。 结果： 粉尘危害主要分布在砂处理、造型、落砂、清砂和切割打磨岗位，其中，砂型铸造企业粉尘作业岗位呼尘时间加权平均容许浓度M（P(1)，P(100)）为0.44（0.03，5.11）mg/m(3)，峰接触浓度为1.30（0.18，10.94）mg/m(3)，岗位超标率为38.92%（79/203）。切割打磨岗位其他粉尘（总尘）时间加权平均容许浓度为1.50（0.15，7.40）mg/m(3)，峰接触浓度为0.90（0.07,12.48）mg/m(3)，岗位超标率为4.88%（2/41）。熔模铸造企业粉尘作业岗位矽尘（呼尘）时间加权平均容许浓度为0.43（0.05，6.35）mg/m(3)，峰接触浓度为0.90（0.12，8.28）mg/m(3)，岗位超标率为35.77%（49/137）；切割打磨岗位其他粉尘（总尘）时间加权平均容许浓度为2.00（0.11，11.00）mg/m(3)，岗位超标率为2.50%（2/80）。砂型铸造与熔模铸造的呼吸性粉尘浓度差异无统计学意义（P>0.05），砂型铸造落砂岗位呼吸性粉尘浓度较砂处理、造型和清砂岗位高（P<0.05），熔模铸造落砂岗位矽尘浓度较砂处理和造型岗位高，清砂岗位较砂处理岗位高（P<0.05）。98.48%（454/461）的粉尘作业岗位的职业健康风险值≥400，1.52%（7/461）的粉尘作业岗位的职业健康风险值200~399。 结论： 宁波市黑色金属铸造企业粉尘作业岗位超标率高，劳动者患尘肺或金属及其化合物粉尘肺沉着病的职业健康风险较高，需采取针对性措施，降低职业健康风险。.
Keywords: Analysis; Dust; Dust concentration distribution; Epidemiologic; Ferrous metal casting; Hazardous; Occupational hazard risk.