1996年，据报道，来自拉斯维加斯华盛顿和拉斯维加斯湾的野生鲤鱼 血浆性类固醇和卵黄蛋白原水平与采集的鲤鱼显著不同 来自Callville Bay的一个参考网站。这些类型的内分泌干扰效应 与废水中发现的雌激素物质有关。 此外，还发现一些合成有机化学品的浓度 来自拉斯维加斯华盛顿和拉斯维加斯湾的水、沉积物和鱼组织中含量更高 与Callville Bay参考地点的类似样本进行比较。为了这些 由于种种原因，人们开始进行各种研究，以确定哪些化合物可能会对环境产生影响 拉斯维加斯湾的水环境，是否记录了野生动物的影响 鱼类可以在同一地点的网箱中繁殖，这些鱼类的来源是什么 异源化合物。 1997年，使用毒性鉴定和评估方法进行筛选 米德湖的水，包括生的和成品的饮用水，用于雌激素和 类似二恶英的化合物。从水样中提取有机化合物 采用固相萃取法。相应的有机提取物被分离成 基于极性的分数。对每种提取物和组分进行了测试 使用哺乳动物乳腺癌细胞生物测定的雌激素活性。这个手机 生物测定法对雌激素极为敏感。一旦提取物或部分表现出 鉴定了雌激素活性，并将其分离成更精细的组分，然后再次分离 使用生物测定法进行测试。这种生物测定方法指导了分馏和后续分析 仪器分析允许进行质量平衡评估。各种分析 仪器用于鉴定和定量存在的有机化合物。 尽管在任何饮用水样本中都没有检测到显著的生物活性， 在拉斯维加斯华盛顿和华盛顿的水样中观察到明显的雌激素活性 拉斯维加斯湾。本文讨论了生物分析的结果。1998年，一项规模更大的研究开始，其中包括提取100升水 在米德湖不同地点对“对照”鱼进行采样和圈养。起重要作用的 分析范围扩大到包括用于鉴定的高分辨率质谱 以前未在米德湖报告的化合物。滴滴涕、DDE和DDD（统称， 在一些地点检测到滴滴涕（DDTs）和六氯环己烷（HCH）的四种异构体， 浓度范围从低于检测到28纳克/升。烷基酚 在一些样品中检测到化合物，其浓度范围为 1500纳克/升咖啡因、尼古丁、苯氧酮、N，N-二乙基间甲苯胺的检测 （DEET）、磷酸盐基阻燃剂和几种药物都被检测到 一些样品的浓度从低于检测浓度到360纳克/升不等 使用高效液相色谱法验证了几种之前未报告的化合物的身份- 分辨率质谱。 此外，实验室的鱼被关在拉斯维加斯湾 在繁殖生理学方面，与笼中的鱼类相比，在统计学上存在显著差异 参考网站。最近，内华达州南部水务局（SNWA）启动了几项 与这些新出现的污染物有关的新研究。研究已经开始调查 这些化合物的饮用水处理策略。初步结果显示 活性炭和臭氧能有效去除选定的内分泌干扰物和 药物来自水。此外，还购买了新的分析设备 更准确、更灵敏地识别水中出现的污染物。 包括7个参考文献、图表。

In 1996, feral carp from the Las Vegas Wash and Las Vegas Bay were reported to have significantly different plasma sex steroid and vitellogenin levels than carp collected from a reference site in Callville Bay. These types of endocrine disruptive effects have been associated with estrogenic substances found in wastewater effluents. Furthermore, concentrations of some synthetic organic chemicals were found to be greater in water, sediment, and fish tissues from the Las Vegas Wash and Las Vegas Bay when compared with similar samples from the Callville Bay reference site. For these reasons, various studies were initiated to determine what compounds may be impacting the aquatic environment of the Las Vegas Bay, whether the effects documented in feral fish could be reproduced in fish caged at the same sites, and the source(s) of these xenobiotic compounds. In 1997, toxicity identification and evaluation methodology was used to screen the waters of Lake Mead, including raw and finished drinking water, for estrogenic and dioxin-like compounds. Organic compounds were extracted from water samples using solid-phase extraction. The corresponding organic extracts were separated into fractions based on polarity. Each extract and fraction was tested for estrogenicity using a mammalian breast carcinoma cellular bioassay. This cellular bioassay is extremely sensitive to estrogen. Once extracts or fractions exhibiting estrogenic activity were identified, they were separated into finer fractions and again tested using the bioassay. This bioassay-directed fractionation and subsequent instrumental analysis allowed for mass-balance evaluation. Various analytical instrumentation was used to identify and quantitate the organic compounds present. Although no significant bioactivity was detected in any drinking water samples, significant estrogenicity was observed in water samples from the Las Vegas Wash and Las Vegas Bay. Results of the bioanalyses are discussed in this paper. In 1998, a larger study began which included the extraction of 100 liter water samples and caging of "control" fish at various sites in Lake Mead. Instrumental analyses were expanded to include high-resolution mass spectrometry for identification of compound previously unreported in Lake Mead. DDT, DDE, and DDD (collectively, DDTs) and four isomers of hexachlorocyclohexane (HCH) were detected at some sites, with concentrations ranging from less than detection to 28 ng/L. Alkylphenolic compounds were detected in some samples, with concentrations ranging from less than detection to 1500 ng/L. Caffeine, nicotine, oxybenzone, N,N-diethyl-meta-toluamide (DEET), phosphate-based flame-retardants, and several pharmaceuticals were detected in some samples with concentrations ranging from less than detection to 360 ng/L. The identities of several of these previously unreported compounds were verified using high- resolution mass spectrometry. Furthermore, laboratory fish caged in Las Vegas Bay showed statistically significant differences in reproductive physiology from fish caged at the reference sites. Recently, the Southern Nevada Water Authority (SNWA) has initiated several new studies related to these emerging contaminants. Research has begun to investigate drinking water treatment strategies for these compounds. Initial results have shown activated carbon and ozone to be effective at removing selected endocrine disruptors and pharmaceuticals from water. Additionally, new analytical equipment has been purchased to more accurately and sensitively identify these emerging contaminants in water. Includes 7 references, figures.