A Study on Critical Effects of Environmental Hazard Factors on Humans

为进一步开展工作场所环境有害因素的风险管理，采用了无明显不良作用水平（NOAEL）和最低明显不良作用水平（LOAEL）方法。然而，由于这种方法有许多缺点，例如，由于不能充分反映剂量反应的形状，也不能适当说明研究规模，基准剂量（BMD）方法已被应用于职业和环境健康科学，为低剂量外推提供了一个出发点。BMD定义为导致基准反应（BMR）异常终点概率增加的水平，即，当P_0和BMR分别代表未暴露受试者终点的异常概率和暴露受试者的过度风险时，从P_0到P_0+BMR。基准剂量水平（BMDL）是骨密度（BMD）的统计学95%置信下限。 ...更多信息 影响血浆、血液和尿液中δ-氨基乙酰丙酸的铅的摄入量，（2）阐明日本儿童产前接触来自海产品的甲基汞对发育的影响，（3）估计酒精诱导肝细胞损伤的临界剂量，（4）有机溶剂对神经运动功能的亚临床效应，δ-铅作业工人血浆、血和尿中氨基乙酰丙酸含量低于10 μg/g，日本和马德拉群岛7岁儿童脑干听觉诱发电位下降低于10 μg/g。此外，肝细胞损伤（即，AST升高），建议出现在日本男性的乙醇水平超过50克/天。它的结论是，BMD计算提供了一个很有前途的方法来估计这些物质的阈值。为了循证预防环境和职业健康领域的有害因素，需要进一步研究以重新评估这些临界剂量。少

In furtherance of the risk management of environmental hazardous factors at workplaces, the no-observed-adverse-effect level (NOAEL) and lowest-observed-adverse-effect level (LOAEL) approach was used. However, since this approach has many shortcomings, e.g., not adequately reflecting the shape of the dose response and not appropriately accounting for study size, the benchmark dose (BMD) method has been applied in occupational and environmental health sciences, to provide a point of departure for low dose extrapolation. The BMD is defined as the level that results in an increased probability of abnormal endpoint by a benchmark response (BMR), i.e., from P_0 to P_0+BMR at the BMD, when the P_0 and BMR represent an abnormal probability of the endpoint in unexposed subjects and an excess risk in exposed subjects, respectively. The benchmark dose level (BMDL) is calculated as the statistical 95% lower confidence limit of the BMD.The objectives of this study are (1)to estimate the critical d … More ose of lead affecting δ-aminolevulinic acids in plasma, blood and urine, (2)to clarify the developmental effects of prenatal exposure to methylmercury from seafood in Japanese children, (3)to estimate the critical dose of alcohol inducing hepatocellular injury, and (4)to examine the subclinical effects of organic solvents on neuromotor functions.The BMDLs were below 10 μg/dl of the blood lead level for δ-aminolevulinic acids in plasma, blood and urine in lead-exposed workers, and below 10 μg/g of hair mercury for latencies of the brainstem auditory evoked potential in Japanese and Madeiran children at age of 7 years. Also, hepatocellular injury (i.e., AST elevation) in Japanese men was suggested to emerge at the ethanol level of more than 50 g/day. It is concluded that the BMD calculations provide a promising approach for estimating the threshold of such substances. For the evidence-based prevention of hazardous factors in fields of environmental and occupational health, further study is needed to reevaluate such critical doses. Less