Neurologic and Reproductive Effects of Hexane on Workers

描述（由申请人提供）：正己烷是1990-2002年期间汽车机械师使用的许多防腐产品的一种成分;当几名机械师被确定患有周围神经病变时，其使用停止。接触数据表明，这些工人接触的正己烷水平低于阈值限值（TLV）的一半。丙酮在动物研究中被证明可以增强正己烷的作用并增加持久性，1997年被添加到这些产品中。这项回顾性队列研究旨在研究停止暴露后正己烷和丙酮可能对神经系统、生殖系统和眼部造成的持续影响。样本将从1990年至2002年期间在湾区就业的机械师群体中抽取。将通过工会记录（国际机械师和航空航天工人协会第190区）确定潜在接触工人的队列。将从研究中所有潜在合格受试者的工会记录中提取数据。基于对雇主使用含己烷产品的了解，我们将招募600名曾在曾经使用过含己烷产品的汽车修理店工作的机械师，另外600名将从从未使用过含己烷产品的汽车修理店招募。将对受试者进行问卷调查，以获得经历的症状和溶剂使用史，以及人口统计学数据和潜在混杂因素暴露。他们还将接受一系列测试，以评估外周神经功能和认知功能，以及蓝黄色辨别力测试。将采集尿液样本用于测量促性腺激素FSH和LH。动物证据表明，正己烷可能导致睾丸萎缩，这将反映在尿中FSH代谢产物水平升高。问卷还将询问受试者可能经历的任何生育问题。将根据溶剂使用和使用历史，结合现有暴露测量值和历史产品成分信息，创建个体正己烷和其他溶剂暴露概况。数据的统计分析将调查暴露史与生殖学、临床和实验室检查结果以及妊娠时间的相关性。这些结果可能为重新评估正己烷的当前TLV提供依据，特别是当其与丙酮结合使用时。公共卫生相关性：己烷是工业、消费品和汽油中使用非常广泛的化学品，具有已知的毒性作用，特别是对神经系统。由于己烷暴露是普遍的，重要的是要了解目前允许的暴露水平是否具有保护作用。这项研究将通过调查对一大群汽车修理工的神经系统、生殖系统和眼睛可能产生的影响来评估这一点，其中许多人在工作中接触过己烷。

DESCRIPTION (provided by applicant): N-hexane was a component of many degreasing products used by auto mechanics from 1990-2002; its use ceased when several mechanics were identified as having peripheral neuropathy. Exposure data suggested that these workers were exposed to levels of n-hexane less than half the Threshold Limit Value (TLV). Acetone, which has been shown in animal studies to potentiate the effects of n-hexane and increase persistence, was added to these products in 1997. This retrospective cohort study aims to investigate possible persistent neurologic, reproductive and ocular effects of n-hexane and acetone after cessation of exposure. The sample will be drawn from the cohort of mechanics employed in the Bay Area during 1990- 2002. The cohort of potentially exposed workers will be identified through union records (District 190 of the International Association of Machinists and Aerospace Workers). Data will be abstracted from the union records for all potentially eligible participants in the study. Based on knowledge of which employers used hexane-containing products, we will recruit a sample of 600 mechanics who had worked at automotive repair shops that had once used hexane-containing products and another 600 will be recruited from such shops that never used hexane-containing products. Participants will be administered a questionnaire to obtain histories of symptoms experienced and solvent use, as well as demographic data and potential confounder exposures. They will also be administered batteries of tests to assess peripheral nerve function and cognitive function, as well as a test of blue-yellow color discrimination. Urine samples will be collected for measurement of the gonadotropins FSH and LH. Animal evidence indicates that n-hexane may cause testicular atrophy, which would be reflected by raised urinary metabolite levels of the FSH. The questionnaire will also inquire about any fertility problems subjects may have experienced. Individual n- hexane and other solvent exposure profiles will be created on the basis of solvent use and employment histories combined with existing exposure measurements and historical product composition information. Statistical analysis of the data will investigate associations of exposure histories with symptomatology, clinical and laboratory test results, and time-to-pregnancy. These results may provide a basis for reassessment of the current TLV for n-hexane, particularly when it is used in conjunction with acetone. PUBLIC HEALTH RELEVANCE: Hexane is a very widely used chemical in industry, consumer products and gasoline that has known toxic effects, particularly on the nervous system. As hexane exposure is widespread, it is important to understand whether current permitted exposure levels are protective. This study will assess this by investigating possible effects on the nervous system, the reproductive system and the eye in a large group of auto mechanics, many of whom have been exposed to hexane in their work.