Analysis of mycotoxins in dust samples from a water damaged building

自2,000年以来，NIOSH对潮湿/发霉建筑物居住者的呼吸和非呼吸健康进行了一些流行病学研究，并收集了2，000多个地板/椅子灰尘样本，这些样本被储存在-80 ° C的冰箱中。这些研究的现有数据库包括对可培养真菌和细菌、真菌细胞壁成分（麦角固醇和葡聚糖）和细菌细胞壁成分（内毒素和肽聚糖）以及居住者健康的测量。各种不良呼吸和非呼吸健康影响与暴露于真菌生物标志物之间的显著关联已被证明。本项目通过建立在单一样品分析中分析室内环境样品中多种真菌毒素的能力，来检查暴露于真菌毒素与居住者健康的关联。作为与奥地利一个研究小组合作的一部分，正在分析大约550个地板灰尘样本，并正在确定可能源自真菌的代谢物。 这些样本是从多个来源收集的，包括小学和一座有水损坏历史的办公楼。一些真菌毒素，包括杂色曲霉素，玉米赤霉烯酮，罗克福汀C，赭曲霉毒素A存在于样品中的低水平。令人惊讶的是，18%的地板灰尘样本含有脱氧雪腐镰刀菌烯醇（呕吐毒素;范围=4 - 72 pg/mg灰尘），这是一种可以从禾谷镰刀菌和其他镰刀菌物种释放的真菌毒素。为了证实他们的发现，NIOSH将把结果与真菌DNA测序数据进行比较。使用超性能LC-MSMS的样品提取和分析方法，NIOSH能够同时定量室内环境样品中的多种真菌次级代谢产物。在啮齿动物毒理学研究期间，在吸入暴露于Stachybocyanchartarum后，在AGS暴露室中收集的培养基样品（米粒）和过滤器样品中测量了真菌毒素杂色曲霉素和疣卡酚（大环槲皮素的水解产物）。 目前正在进行一项实验，以评估灰尘样本的最佳储存条件。

Since 2000, NIOSH has conducted a number of epidemiologic studies on respiratory and non-respiratory health in occupants of damp/moldy buildings, and collected more than 2,000 floor/chair dust samples which have been being stored in -80°C freezers. The existing database from those studies includes measurements on culturable fungi and bacteria, fungal cell wall components (ergosterol and glucan), and bacterial cell wall components (endotoxin and peptidoglycan) as well as occupants’ health. Significant associations between various adverse respiratory and non-respiratory health effects and exposure to fungal biomarkers have been demonstrated. This project examines associations of exposure to mycotoxins with occupants’ health by building the capability of analyzing indoor environmental samples for multiple mycotoxins in a single sample analysis. As part of a collaboration with a research group in Austria, approximately 550 floor dust samples are being analyzed and metabolites that are likely to have originated from fungi are being identified. These samples were collected from multiple sources including elementary schools and an office building with a history of water damage. A number of mycotoxins, including sterigmatocystin, zearalenone, roquefortine C, and ochratoxin A were present in the samples at low levels. Surprisingly, 18% of floor dust samples contained deoxynivalenol (vomitoxin; range=4 – 72 pg/mg of dust), a mycotoxin that can be released from Fusarium graminearum and other Fusarium species. To confirm their findings, NIOSH will compare the results to fungal DNA sequencing data. Using a sample extraction and analysis method for ultra-performance LC-MSMS, NIOSH has been able to simultaneously quantify targeted multiple fungal secondary metabolites in indoor environmental samples. The mycotoxins sterigmatocystin and verrucarol (a hydrolysis product of macrocyclic trichothecene) were measured in culture media samples (rice grains) and filter samples collected in the AGS exposure chamber following inhalation exposures to Stachybotrys chartarum during rodent toxicology studies. An experiment to assess optimal storage conditions for dust samples is ongoing.