男总裁被保镖c呻吟双腿大张bl,扒开学生双腿猛进入喷水小说,狠狠躁18三区二区一区,日本边添边摸边做边爱60分钟

探討石化生產中產生的聚乙烯、聚丙烯、尼龍六六鹽 3種有機粉塵的危害性及預防措施。方法　生產現場勞動衛生學調查 ,粉塵的毒性及對大鼠肺的致纖維化作用動物實驗。結果　作業場所粉塵濃度聚乙烯 14 2mg/m3 ,聚丙烯 4 1 6mg/m3 ,尼龍六六鹽 2 5 0mg/m3 ;3種有機粉塵LD50 >15 0 0 0～30 0 0 0mg/kg;大鼠支氣管染塵后經 1～ 18個月觀察 ,發現實驗動物肺組織切片上可見網織纖維增生和少量膠原纖維 ,染塵后的體外細胞培養液中巨噬細胞著色率和乳酸脫氫酶活性單位顯著高于正常對照組 ,但低于石英粉塵對照組。結論 3種有機粉塵雖均屬無毒物質 ,但據體外肺巨噬細胞實驗結果對肺巨噬細胞有輕微毒性 ,對大鼠肺有輕度致纖維化作用。生產現場粉塵污染嚴重 ,長期接觸可能造成職業危害 ,應積極采取預防措施
    Objective To investigate the hazardous effects and preventive measures of organic dusts of polyethylene,polypropylene and Nylon 66 salt.Methods Field survey and animal experiments were conducted.Results The dust concentrations of polyethylene,polypropylene and Nylon 66 salt were 14 2,41 6 and 250 0 mg/m 3 respectively.LD 50 of these three dusts was 15 000 ～ 30 000 mg/m 3 .After inhalation exposure of the dusts and sacrificed 18 months later,it was found that there were reticular fibers p...