Assessing isocyanate exposures in polyurethane industry sectors using biological and air monitoring methods
Assessing isocyanate exposures in polyurethane industry sectors using biological and air monitoring methods
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DOI：
10.1093/annhyg/mel024
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发表时间：
2006-08-01
影响因子：
--
通讯作者：
Jones, K.
中科院分区：
文献类型：
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作者：
Creely, K. S.;Hughson, G. W.;Jones, K.
异氰酸酯作为一种化学物质，被认为是英国职业性哮喘的最大原因。监测空气中总异氰酸酯的暴露成本很高，需要大量的专门知识，无论是在样本收集还是化学分析方面，都不能用于评估佩戴呼吸防护设备（RPE）的保护效果。通过分析尿液中的代谢物进行生物监测是评估异氰酸酯暴露的一种相对简单和廉价的方法。这也可能是评估现有控制措施有效性的一种有用方式。在这项研究中，进行了生物和吸入监测，以评估非机动车维修部门各种工作场所的接触情况。被选中参加调查的公司仅包括那些被认为在使用异氰酸酯配方时采用良好工作做法的公司。这包括使用异氰酸酯生产模塑聚氨酯产品、绝缘材料的公司和涉及工业油漆的公司。通过个人监测收集了空气样本，并分析了总异氰酸酯含量。在接触后不久收集尿样，分析不同异氰酸酯物质的代谢物，从而计算总代谢物浓度。还记录了所使用的控制措施和观察到的暴露皮肤污染的详细信息。共有21家公司同意参加这项研究，从22个地点收集了接触测量数据。空气中的异氰酸酯浓度通常很低（范围为0.0005-0.066 mg m（-3））。70份样品中共有50份< 0.001 mg m（-3），即定量限（LOQ），因此低于LOQ的样品被指定为1/2 LOQ（0.0005 mg m（-3））。在70个样本中，67个样本低于目前工作场所接触限值0.02 mg m（-3）。最高的吸入接触发生在一家卡车制造公司的喷漆活动期间（0.066 mg m（-3）），也发生在喷涂聚氨酯泡沫绝缘材料期间（0.023 mg m（-3））。尿液中最常检测到的异氰酸酯是二异氰酸酯，在21例病例中检测到。数据集的几何平均总异氰酸酯代谢物浓度为0.29 μ mol mol（-1）肌酐（范围0.05-12.64 wmol mol-1肌酐）。共采集了23份样本，高于商定的生物监测指导值1.0 μ mol mol（-1）肌酐。导致数据集最高生物监测结果的活动包括聚氨酯产品的混合和浇铸（12.64 μ mol mol-1肌酐）、半自动成型（4.80 μ mol mol-1肌酐）和树脂应用（3.91 μ mol mol-1肌酐）。生物监测结果表明，尽管空气中异氰酸酯浓度很低，但仍有可能显示出生物吸收。这往往表明生物监测方法的高灵敏度和/或在某些情况下，操作员使用的RPE无效，或者可能通过皮肤或其他接触途径发生吸收。这项研究表明，生物监测是一个有用的工具时，评估工人暴露于异氰酸酯，提供了一个更完整的图片的有效性控制措施到位比空气监测是可能的。结果还表明，在控制措施被认为是足够的，大多数生物样品接近或< 1 μ mol mol（-1）肌酐，商定的生物监测基准。
Isocyanates, as a chemical group, are considered to be the biggest cause of occupational asthma in the UK. Monitoring of airborne exposures to total isocyanate is costly, requiring considerable expertise, both in terms of sample collection and chemical analysis and cannot be used to assess the effectiveness of protection from wearing respiratory protective equipment (RPE). Biological monitoring by analysis of metabolites in urine can be a relatively simple and inexpensive way to assess exposure to isocyanates. It may also be a useful way to evaluate the effectiveness of control measures in place. In this study biological and inhalation monitoring were undertaken to assess exposure in a variety of workplaces in the non-motor vehicle repair sector. Companies selected to participate in the survey included only those judged to be using good working practices when using isocyanate formulations. This included companies that used isocyanates to produce moulded polyurethane products, insulation material and those involved in industrial painting. Air samples were collected by personal monitoring and were analysed for total isocyanate content. Urine samples were collected soon after exposure and analysed for the metabolites of different isocyanate species, allowing calculation of the total metabolite concentration. Details of the control measures used and observed contamination of exposed skin were also recorded. A total of 21 companies agreed to participate in the study, with exposure measurements being collected from 22 sites. The airborne isocyanate concentrations were generally very low (range 0.0005-0.066 mg m(-3)). A total of 50 of the 70 samples were < 0.001 mg m(-3), the limit of quantification (LOQ), therefore samples below the LOQ were assigned a value of 1/2 LOQ (0.0005 mg m(-3)). Of the 70 samples, 67 were below the current workplace exposure limit of 0.02 mg m(-3). The highest inhalation exposures occurred during spray painting activities in a truck manufacturing company (0.066 mg m(-3)) and also during spray application of polyurethane foam insulation (0.023 mg m(-3)). The most commonly detected isocyanate in the urine was hexamethylene diisocyanate, which was detected in 21 instances. The geometric mean total isocyanate metabolite concentration for the dataset was 0.29 mu mol mol(-1) creatinine (range 0.05-12.64 wmol mol-1 creatinine). A total of 23 samples collected were above the agreed biological monitoring guidance value of 1.0 mu mol mol(-1) creatinine. Activities that resulted in the highest biological monitoring results of the dataset included mixing and casting of polyurethane products (12.64 mu mol mol-(1) creatinine), semiautomatic moulding (4.80 mu mol mol(-1) creatinine) and resin application (3.91 mu mol mol(-1) creatinine). The biological monitoring results show that despite low airborne isocyanate concentrations, it was possible to demonstrate biological uptake. This tends to suggest high sensitivity of the biological monitoring method and/or that in some instances the RPE being used by operators was not effective or that absorption may have occurred via dermal or other routes of exposure. This study demonstrates that biological monitoring is a useful tool when assessing worker exposure to isocyanates, providing a more complete picture on the efficacy of control measures in place than is possible by air monitoring alone.The results also demonstrated that where control measures were judged to be adequate, most iological samples were close to or < 1 mu mol mol(-1) creatinine, the agreed biological monitoring benchmark.