Hofstetter Elizabeth, Spencer John W, Hiteshew Kathleen, Coutu Michelle, Nealley Mark
Environmental Profiles, Inc., 8805 Columbia 100 Parkway Suite 100, Columbia, MD, USA, 21045.
Ann Occup Hyg. 2013 Mar;57(2):210-20. doi: 10.1093/annhyg/mes062. Epub 2012 Sep 20.
Predictive modeling is an available tool to assess worker exposures to a variety of chemicals in different industries and product-use scenarios. The European Chemical Agency (ECHA)'s guidelines for manufacturers to fulfill the European Union's legal requirements pursuant to the Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) initiative include recommendations for the use of modeling to predict worker exposures. ECHA recommends different models for different target populations (i.e. workers, consumers, environment) and routes of exposure (i.e. skin absorption, ingestion, inhalation), and presents them hierarchically, with Tier 1 models presented as the most simplistic, conservative models and Tier 2 models recommended for further intensive evaluation of substances or preparations. In order to assess these models for one exposure (product-use) scenario, a simulation of the scenario was completed in a controlled environment and the measured results were compared with the modeling outputs. The authors predicted, based on the design of the modeling tools, that all models would overestimate worker exposures under the simulated product-use scenario, with the lower-tiered model producing the most conservative estimate of exposure. In this study, a Tier 1 model and a Tier 2 model were evaluated for comparison with the near-field, far-field (NF-FF) deterministic model and measured experimental results in a real-time worker inhalation exposure assessment. Modeling was conducted prior to actual air monitoring. The exposure scenario that was evaluated involved the application of a toluene-containing spray paint to a work surface. Air samples were collected to evaluate short-term (15-min) and long-term (240-min) exposures. Eight-hour time-weighted averages (8-h TWAs) were calculated and compared with the modeling outputs from the recommended REACH modeling tools and the NF-FF model. A comparison of each of the modeling tools with measured experimental results was generated. The Tier 1 Targeted Risk Assessment tool overestimated the 8-h TWA airborne concentration of toluene in the spray scenario by a factor of 3.61. The higher tiered Advanced REACH Tool and NF-FF models showed greater concordance with experimental results, overestimating the TWA exposure by a factor of 2.92 and 1.96, respectively. In conclusion, the Tier 1 and 2 exposure modeling tools performed as expected for the simulated exposure scenario, providing relatively accurate, though conservative, estimates according to the level of detail and precision accounted for in each model.
预测建模是一种可用工具，可用于评估不同行业和产品使用场景中工人接触各种化学品的情况。欧洲化学品管理局（ECHA）针对制造商的指南，旨在根据化学品注册、评估、授权和限制（REACH）倡议满足欧盟的法律要求，其中包括关于使用建模来预测工人接触情况的建议。ECHA针对不同的目标人群（即工人、消费者、环境）和接触途径（即皮肤吸收、摄入、吸入）推荐了不同的模型，并按层次结构呈现，其中一级模型是最简化、保守的模型，二级模型则推荐用于对物质或制剂进行进一步深入评估。为了评估一种接触（产品使用）场景下的这些模型，在受控环境中完成了该场景的模拟，并将测量结果与建模输出进行了比较。作者基于建模工具的设计预测，在模拟的产品使用场景下，所有模型都会高估工人的接触情况，其中较低层级的模型对接触情况的估计最为保守。在本研究中，对一级模型和二级模型进行了评估，以便与近场、远场（NF-FF）确定性模型以及实时工人吸入接触评估中的实测实验结果进行比较。建模在实际空气监测之前进行。所评估的接触场景涉及在工作表面喷涂含甲苯的喷漆。采集空气样本以评估短期（15分钟）和长期（240分钟）接触情况。计算了八小时时间加权平均值（8小时TWA），并与推荐的REACH建模工具和NF-FF模型的建模输出进行了比较。生成了每个建模工具与实测实验结果的比较。一级目标风险评估工具在喷漆场景中高估了甲苯的8小时TWA空气浓度3.61倍。层级较高的高级REACH工具和NF-FF模型与实验结果的一致性更高，分别高估TWA接触量2.92倍和1.96倍。总之，一级和二级接触建模工具在模拟接触场景中的表现符合预期，根据每个模型所考虑的细节程度和精度，提供了相对准确但保守的估计。
