2014—2018年上海市松江区哨点企业电焊烟尘暴露水平及影响因素

Exposure level of welding fumes and influencing factors in sentinel enterprises in Songjiang District, Shanghai, 2014-2018

[背景]上海市松江区是上海市工业产业集中的郊区之一,辖区内接触职业病危害因素劳动者众多,其中因长期接触生产性粉尘导致的尘肺病是松江区最主要的职业病,尤其以电焊工尘肺为主。因此,如何有效控制辖区电焊作业场所电焊烟尘浓度成为劳动者、企业和职业卫生监管部门关注的重点。[目的]了解上海市松江区哨点企业中劳动者电焊烟尘暴露水平,并分析其影响因素。[方法]2014-2018年,采用三阶段分层抽样方法抽取松江区62家企业共228名焊接作业劳动者为研究对象。采用个体采样仪采样,采用重量法测定工作场所电焊烟尘8 h时间加权平均浓度(TWA)。采用现场调查问卷,收集和分析可能影响暴露的因素。[结果]本研究共获得228份电焊烟尘样品,8 h TWA中位数为1.76 mg/m^3,总超标率为17.54%。5年间电焊烟尘超标率差异有统计学意义(χ^2=17.46,P <0.01),呈现逐渐下降趋势(P趋势<0.01)。专用设备制造业企业电焊烟尘超标率(30.19%)和8 h TWA(2.40 mg/m^3)最高,不同行业间电焊烟尘超标率和8 h TWA差异有统计学意义(χ^2=10.66,P <0.05;H=15.78,P <0.01)。连续作业超标率(23.08%)和8 h TWA(2.10 mg/m^3)高于间歇作业(χ^2=4.05,P <0.05;Z=-3.17,P <0.01)。CO2气体保护焊的超标率(22.09%)高于氩弧焊和焊条电弧焊(χ^2=6.19,P <0.05;P <0.05);CO2气体保护焊的8 h TWA(1.92 mg/m^3)也高于氩弧焊(Z=-3.84,P <0.01)。通风效果较差的作业场所中电焊烟尘超标率(34.29%)和8 h TWA(3.63 mg/m^3)高于通风效果好的作业场所(χ^2=8.70,P <0.05;H=44.73,P <0.01)。[结论]2014-2018年上海市松江区哨点企业电焊烟尘暴露水平和超标率呈现下降趋势。作业场所通风效果、焊接工艺类型和作业特征是影响电焊烟尘暴露水平的主要因素。今后仍要对通风效果差、连续作业和CO2气体保护焊等重点岗位的电焊烟尘暴露进行防控。

[Background] Songjiang District is an industrial cluster in suburb Shanghai, where many workers are exposed to occupational factors, and pneumoconiosis caused by long-term exposure to productive dust is the most important occupational disease, especially welder’s pneumoconiosis.Therefore, how to effectively control the concentration of welding dust becomes the focus of workers, enterprises, and occupational health supervision departments.[Objective] This study aims to investigate the exposure level of welding fumes and analyze the influencing factors in monitoring enterprise in Songjiang District of Shanghai from 2014 to 2018.[Methods] A total of 228 welders from 62 enterprises in Songjiang District were recruited by three-phase stratified sampling method from 2014 to 2018. The 8 h time weighted average concentration(TWA) of welding fumes in workplace was determined by individual sampling and gravimetric method. A questionnaire survey was conducted to collect and analyze potential impact factors of the welding fume exposure.[Results] A total of 228 samples of welding fumes were obtained in this study. The median8 h TWA of welding fumes was 1.76 mg/m^3 and the total exceeding-standard rate was 17.54%. The annual exceeding-standard rates of welding fumes of the five years had significant difference(χ2=17.46, P < 0.01) and decreasing trend(Ptrend < 0.01). The 8 h TWA levels and exceeding-standard rates had significant difference between different industries(χ2=10.66, P < 0.05;H=15.78, P < 0.01), and special equipment manufacturing enterprises showed the highest values(2.40 mg/m^3, 30.19%). The exceeding-standard rate and 8 h TWA of welding fumes in continuous operation workplaces(23.08%, 2.10 mg/m^3) were significantly higher than those in intermittent operation workplaces(χ2=4.05, P < 0.05;Z=-3.17, P < 0.01). The 8 h TWA level(1.92 mg/m^3) of welding fumes by CO2 gas welding was significantly higher than that by argon arc welding(Z=-3.84, P < 0.01), and exceeding-standard rate of welding fumes by CO2 gas welding(22.09%) was significantly higher than that by argon arc welding and shielded metal arc welding(χ2=6.19, P < 0.05;P < 0.05). The exceeding-standard rate and 8 h TWA level of welding fumes in workplaces with poor ventilation(34.29%, 3.63 mg/m^3) were higher than those in workplaces with good ventilation(χ2=8.70, P < 0.05;H=44.73, P < 0.01).[Conclusion] There is a decreasing trend in workplace welding fume exposure level and exceeding-standard rate in Songjiang District of Shanghai from 2014 to 2018. Ventilation, welding technology, and operation mode are the major factors affecting welding fume exposure level. In the future, it is still necessary to prevent and control welding fume exposure in workplaces with poor ventilation, continuous operation, and CO2 gas welding.