MODELS FOR ASSESSING RISK OF OCCUPATIONAL HEARING LOSS

描述：(改编自《调查者摘要》)建议的工作 将确定有助于增强 化学性窒息所致的噪声性听力损失 一氧化碳和氰化物。很有可能这些因素结合在一起 暴露在空气中比单独接触噪声会产生更大的听力损失风险 以阳性实验动物为基础的人类允许接触水平 数据，以及对化学物质 窒息会扰乱听力。老鼠会暴露在各种类型的噪音中 单独或以噪声结合一氧化碳和氰化物进行评估 暂时性和永久性的听觉功能损害。这个 这项调查的主要目的是预防人类听力损失。 通过确定有利于协同作用的暴露条件 氰化物和一氧化碳等相互作用的化学窒息物质和 噪音。调查人员将确定暴露与 化学窒息持续时间、浓度和噪声强度 促进协同(大于相加的)互动，其指标为 耳蜗术后功能损害及组织病理学观察。 调查人员还将确定噪音与 频谱和与化学窒息物质的相互作用 准确的预测可应用于以下工作场所设置 可能存在有限的噪音。

DESCRIPTION: (Adapted from the Investigator's Abstract) The proposed work would identify the exposure conditions that facilitate the potentiation of noise induced hearing loss (NIHL) by the chemical asphyxiants carbon monoxide and cyanide. A strong likelihood exists that these combined exposures produce greater risk of hearing loss than noise alone at permissible exposure levels in humans, based upon positive laboratory animal data, and a preliminary understanding of the mechanisms by which chemical asphyxiants disrupt hearing. Rats will be exposed to various types of noise alone or to noise in combination with carbon monoxide and cyanide to assess both temporary and permanent impairments of auditory function. The principal objective of this investigation is to prevent human hearing loss by determining the exposure conditions that facilitate a synergistic interaction chemical asphyxiants such as cyanide and carbon monoxide and noise. The investigators will determine the relationship between exposure duration, concentration of chemical asphyxiants and noise intensity in promoting a synergistic (greater than additive) interaction as indexed by functional impairment of the cochlea and histopathological investigation. The investigators will also determine the relationship between the noise frequency spectrum and interactions with chemical asphyxiants so that accurate predictions can be applied to work place settings where band limited noise may be present.