Fenske R A
Department of Environmental Health, School of Public Health and Community Medicine, University of Washington, Seattle 98195.
Ann Occup Hyg. 1993 Dec;37(6):687-706. doi: 10.1093/annhyg/37.6.687.
Exposure of the skin to chemical substances can contribute significantly to total dose in many workplace situations, and its relative importance will increase when airborne occupational exposure limits are reduced, unless steps to reduce skin exposure are undertaken simultaneously. Its assessment employs personal sampling techniques to measure skin loading rates, and combines these measurements with models of percutaneous absorption to estimate absorbed dose. Knowledge of dermal exposure pathways is in many cases fundamental to hazard evaluation and control. When the skin is the primary contributor to absorbed dose, dermal exposure measurements and biological monitoring play complementary roles in defining occupational exposures. Exposure normally occurs by one of three pathways: (i) immersion (direct contact with a liquid or solid chemical substance); (ii) deposition of aerosol or uptake of vapour through the skin; or (iii) surface contact (residue transfer from contaminated surfaces). Sampling methods fall into three categories: surrogate skin; chemical removal; and fluorescent tracers. Surface sampling represents a supplementary approach, providing an estimate of dermal exposure potential. Surrogate skin techniques involve placing a chemical collection medium on the skin. Whole-body garment samplers do not require assumptions relating to distribution, an inherent limitation of patch sampling. The validity of these techniques rests on the ability of the sampling medium to capture and retain chemicals in a manner similar to skin. Removal techniques include skin washing and wiping, but these measure only what can be removed from the skin, not exposure: laboratory removal efficiency studies are required for proper interpretation of data. Fluorescent tracer techniques exploit the visual properties of fluorescent compounds, and combined with video imaging make quantification of dermal exposure patterns possible, but the need to introduce a chemical substance (tracer) into production processes represents an important limitation of this approach. Surface sampling techniques provide a measure of workplace chemical contamination. Wipe sampling has been used extensively, but is susceptible to high variability. Surface sampling requires definition of dermal transfer coefficients for specific work activities. A preliminary dermal exposure sampling strategy which addresses such issues as sampling method, representativeness and sample duration is proposed. Despite the limitations of current assessment techniques, it appears feasible to consider developing dermal occupational exposure limits (DOELs) for selected workplaces and chemical agents. Initial development of DOELs would be most practical where dermal exposure is from surface contact primarily, and where the work closely follows a routine. Improvement in the techniques of dermal exposure assessment is an important goal for occupational hygiene research, and is likely to lead to better health for worker populations.
在许多工作场所环境中，皮肤接触化学物质对总剂量的贡献可能很大，而且当空气中职业接触限值降低时，其相对重要性会增加，除非同时采取措施减少皮肤接触。对皮肤接触的评估采用个人采样技术来测量皮肤负荷率，并将这些测量结果与经皮吸收模型相结合，以估算吸收剂量。在许多情况下，了解皮肤接触途径是危害评估和控制的基础。当皮肤是吸收剂量的主要贡献者时，皮肤接触测量和生物监测在确定职业接触方面发挥着互补作用。接触通常通过以下三种途径之一发生：（i）浸没（直接接触液体或固体化学物质）；（ii）气溶胶沉积或通过皮肤吸收蒸气；或（iii）表面接触（从受污染表面转移残留物）。采样方法分为三类：替代皮肤；化学去除；以及荧光示踪剂。表面采样是一种补充方法，可提供皮肤接触潜力的估计值。替代皮肤技术涉及将化学收集介质放置在皮肤上。全身服装采样器不需要与分布相关的假设，而这是贴片采样固有的局限性。这些技术的有效性取决于采样介质以类似于皮肤的方式捕获和保留化学物质的能力。去除技术包括皮肤清洗和擦拭，但这些仅测量可以从皮肤上去除的物质，而非接触量：需要进行实验室去除效率研究才能正确解释数据。荧光示踪剂技术利用荧光化合物的视觉特性，并与视频成像相结合，使定量皮肤接触模式成为可能，但将化学物质（示踪剂）引入生产过程的必要性是这种方法的一个重要局限性。表面采样技术可测量工作场所的化学污染。擦拭采样已被广泛使用，但易受高变异性影响。表面采样需要为特定工作活动定义皮肤转移系数。本文提出了一种初步的皮肤接触采样策略，该策略解决了采样方法、代表性和采样持续时间等问题。尽管当前评估技术存在局限性，但考虑为选定的工作场所和化学制剂制定皮肤职业接触限值（DOELs）似乎是可行的。在皮肤接触主要来自表面接触且工作严格遵循常规的情况下，初步制定DOELs将最为实用。改进皮肤接触评估技术是职业卫生研究的一个重要目标，并且可能会使工人总体健康状况得到改善。
