Petsonk E L, Wang M L, Lewis D M, Siegel P D, Husberg B J
Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Morgantown, WV, USA.
Chest. 2000 Oct;118(4):1183-93. doi: 10.1378/chest.118.4.1183.
Diisocyanates, a group of highly reactive chemicals, have frequently been associated with occupational asthma. We evaluated respiratory health in workers at a new wood products manufacturing plant that uses methylene diphenyl diisocyanate (MDI), and was designed and operated with a goal of minimizing worker exposures.
Health surveys using standardized respiratory questionnaires were done prior to the initial use of diisocyanates in the plant, and semiannually thereafter for a period of 2 years. Other testing included occupational and work practice histories, serial peak flow measurements, spirometry, methacholine challenge, and measurement of specific IgE antibodies to MDI-albumin conjugate.
Of 214 plant employees who participated in at least one health survey, a follow-up survey was also available from 178 employees (83%). New-onset asthma-like symptoms (NAS) were reported by 15 of 56 workers (27%) in areas with the highest potential for exposures to liquid MDI monomer and prepolymer, vs 0 of 43 workers in the lowest potential exposure areas (p = 0.001). In the areas with high potential exposure, NAS developed in 47% of workers who had noted MDI skin staining, vs 19% without skin stains (p = 0.07). Working around and cleaning up liquid MDI represented a significant risk for asthma-like symptoms in both current smokers and nonsmokers; work with finished wood products did not. Asthma-like symptoms were associated with variable airflow limitation (odds ratio [OR], 5.0; confidence interval [CI], 1.4 to 18.7) and specific IgE to MDI-albumin (OR, 3.2; CI, 1.1 to 9.0), but not with skin prick tests to common aeroallergens (OR, 1.1; CI, 0.5 to 2.7).
During the first 2 years of operation, in a plant designed and operated to control exposure to diisocyanates, the development of asthma-like symptoms was reported in a relatively high proportion of the employees who worked with liquid MDI. To prevent asthma symptoms among workers, careful control of respiratory tract exposures associated with liquid MDI is important, especially during cleanup activities. Strict limitation of skin contact with diisocyanates may also be necessary.
二异氰酸酯是一类高反应性化学物质，常与职业性哮喘相关。我们评估了一家新的木制品制造工厂中使用二苯基甲烷二异氰酸酯（MDI）的工人的呼吸健康状况，该工厂的设计和运营目标是尽量减少工人接触。
在工厂首次使用二异氰酸酯之前，使用标准化呼吸问卷进行健康调查，此后每半年进行一次，为期2年。其他检测包括职业和工作实践史、连续峰值流量测量、肺功能测定、乙酰甲胆碱激发试验以及对MDI - 白蛋白结合物的特异性IgE抗体测量。
在参与至少一次健康调查的214名工厂员工中，178名员工（占83%）有后续调查数据。在液体MDI单体和预聚物暴露可能性最高的区域，56名工人中有15名（占27%）报告出现新发哮喘样症状（NAS），而在暴露可能性最低的区域，43名工人中无人出现（p = 0.001）。在高暴露可能性区域，有MDI皮肤染色的工人中47%出现了NAS，而无皮肤染色的工人中这一比例为19%（p = 0.07）。对于当前吸烟者和非吸烟者而言，接触和清理液体MDI都显著增加了出现哮喘样症状的风险；而接触成品木制品则无此风险。哮喘样症状与气流受限（优势比[OR]，5.0；置信区间[CI]，1.4至18.7）以及对MDI - 白蛋白的特异性IgE相关（OR，3.2；CI，1.1至9.0），但与常见气传变应原的皮肤点刺试验无关（OR，1.1；CI，0.5至2.7）。
在运营的头两年里，在一家设计和运营旨在控制二异氰酸酯暴露的工厂中，接触液体MDI的员工中报告出现哮喘样症状的比例相对较高。为预防工人出现哮喘症状，谨慎控制与液体MDI相关的呼吸道暴露很重要，尤其是在清理活动期间。可能还需要严格限制皮肤与二异氰酸酯的接触。
