研究：阻燃'Firemaster 550'是内分泌干扰

根据来自北卡罗来纳州立大学和杜克大学的研究人员的一项新的研究，称为“Firemaster 550”称为“Firemaster 550”的阻燃混合物是一种内分泌破坏剂，导致极端体重增加，在实验室动物中早期发作的青春期和心血管健康影响。

Firemaster 550 is made up of four principal component chemicals and is used in polyurethane foam in a wide variety of products, ranging from mattresses to infant nursing pillows. The flame-retardant mixture was developed by Chemtura Corp., and was first identified by the research community in 2008. It was developed to replace a class of fire retardants being phased out of use because of concerns regarding their safety. This new study represents the first public data on whether Firemaster 550 has potential health effects.

In this pilot study, pregnant lab rats were assigned to three groups: a control group, which was not exposed to Firemaster 550; a “low-dose” group, which ingested 100 micrograms of Firemaster 550 once per day throughout pregnancy and nursing; and a “high-dose” group, which ingested 1,000 micrograms on the same schedule. These environmentally relevant doses are lower than the doses used in industry-funded studies. Researchers then evaluated the physiological outcomes of the exposure in both the mothers (called dams) and the offspring (called pups).

重要的是，研究人员检测到Firemaster 550的组分化学品之一，在所有暴露的坝和后代的脂肪中，但都没有未曝光的动物。这意味着阻燃剂能够在妊娠期间穿过胎盘，通过母乳或两者到达婴儿。

Because flame retardants that have been phased out are known to disrupt thyroid function, and Firemaster 550 includes chemicals with structural similarities, the researchers looked at circulating thyroid hormone levels in dams at the end of the nursing period. The high-dose dams had much higher thyroid hormone levels than the control group, while low-dose dams had marginally higher thyroid hormone levels. This is significant because thyroid hormones influence brain development during pregnancy, as well as a host of other biological functions, such as metabolism.

研究人员还发现后代的体重增加迅速。当他们从护理断奶时，高剂量雄性幼虫比对照组更重60％ - 高剂量母幼崽比对照组更重31％。

女狗狗的体重增加s contributed to the early onset of puberty. The control group hit puberty at 33 days old, while the high-dose group hit puberty at 29 days.

高剂量女性幼犬也难以调节其作为成年人的葡萄糖水平。高剂量的男性在心脏的左心室里有加厚的壁，暗示心血管疾病。

“这项研究表明，Firemaster 550是一个内分泌干扰者，并提出了很多重要的问题，”NC国家生物学助理教授Heather Patisaul博士说，这是一个描述工作的纸张的牵头作者。“这是一个小型研究。我们需要继续使用更大的样本大小，看看与肥胖，甲状腺激素功能和代谢综合征相关的更广泛的潜在效果。我们还希望确定Firemaster 550中的哪些组成化学品负责各种效果。“

The paper, “Accumulation and Endocrine Disrupting Effects of the Flame Retardant Mixture Firemaster 550 in Rats: An Exploratory Assessment,” is published online in the中国生物化学与分子毒理学杂志. Co-authors include NC State undergraduate Natalie Mabrey; NC State research technician Katherine McCaffrey; Heather Stapleton and Simon Roberts of Duke University; Robin Gear and Scott Belcher of the University of Cincinnati; and Joe Braun of Brown University. The research was funded by the National Institute of Environmental Health Sciences.

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Note to Editors:这项研究摘要跟随。

“Accumulation and Endocrine Disrupting Effects of the Flame Retardant Mixture Firemaster 550 in Rats: An Exploratory Assessment”

作者: Heather B. Patisaul, Natalie Mabrey and Katherine A. McCaffrey, North Carolina State University; Simon C. Roberts and Heather M. Stapleton, Duke University; Robin B. Gear and Scott M. Belcher, University of Cincinnati; and Joe Braun, Brown University

Published：在线10月24日中国生物化学与分子毒理学杂志

Abstract:Firemaster 550 (FM 550), a fire-retardant mixture used in foam-based products, was recently identified as a common contaminant in household dust. The chemical structures of its principle components suggest they have endocrine disrupting activity, but nothing is known about their physiological effects at environmentally relevant exposure levels. The goal of this exploratory study was to evaluate accumulation, metabolism and endocrine disrupting effects of FM 550 in rats exposed to 100 or 1000 [micrograms]/day across gestation and lactation. FM 550 components accumulated in tissues of exposed dams and offspring and induced phenotypic hallmarks associated with metabolic syndrome in the offspring. Effects included increased serum thyroxine levels and reduced hepatic carboxylesterease activity in dams, and advanced female puberty, weight gain, male cardiac hypertrophy, and altered exploratory behaviors in offspring. Results of this study are the first to implicate FM 550 as an endocrine disruptor and an obesogen at environmentally relevant levels.