Exposure to BPA underestimated, new research says

     WASHINGTON, June 6 (Xinhua) -- A new University of Missouri study shows that the exposure to the controversial chemical Bisphenol A (BPA) through diet has been underestimated by previous lab tests.

    The findings were published on Monday in Environmental Health Perspectives.

    In the study, researchers compared BPA concentrations(浓度) in mice that were given a steady diet supplemented with BPA throughout the day, compared to the more common lab method of single exposure, and found an increased absorption and accumulation of BPA in the blood of the mice.

    The authors continuously exposed the mice to BPA through their feed, which is considered the primary route of exposure to this chemical in animals and humans. In previous studies examining the effects of BPA, mice were exposed to BPA only through a one-time administration.

    Following the exposure through the diet, a significantly greater increase in the active form of BPA, which is the greatest threat as it is the form that can bind¹ to sex steroid receptors and exert adverse² effects, was absorbed and accumulated in the animals.

    "People are primarily and unknowingly exposed to BPA through the diet because of the various plastic and paper containers used to store our food are formulated³ with BPA," said Cheryl Rosenfeld, associate professor in biomedical sciences and corresponding lead author. "We know that the active form of BPA binds⁴ to our steroid receptors, meaning it can affect estrogen, thyroid and testosterone function. It might also cause genetic⁵ mutations. Thus, this chemical can hinder our ability to reproduce and possibly cause behavioral abnormalities that we are just beginning to understand."The study notes that more than eight billion pounds of BPA are produced every year, and more than 90 percent of people in the United States have measurable amounts of BPA in their bodies.

    "When BPA is taken through the food, the active form may remain in the body for a longer period of time than when it is provided through a single treatment, which does not reflect the continuous exposure that occurs in animal and human populations," said Rosenfeld. "We need to study this further to determine where the ingested BPA becomes concentrated and subsequently released back into the bloodstream to be distributed throughout the body."

1 bind   

vt.捆，包扎；装订；约束；使凝固；vi.变硬

参考例句：

• I will let the waiter bind up the parcel for you.我让服务生帮你把包裹包起来。
• He wants a shirt that does not bind him.他要一件不使他觉得过紧的衬衫。

2 adverse   

adj.不利的；有害的；敌对的，不友好的

参考例句：

• He is adverse to going abroad.他反对出国。
• The improper use of medicine could lead to severe adverse reactions.用药不当会产生严重的不良反应。

3 formulated   

v.构想出( formulate的过去式和过去分词 )；规划；确切地阐述；用公式表示

参考例句：

• He claims that the writer never consciously formulated his own theoretical position. 他声称该作家从未有意识地阐明他自己的理论见解。 来自《简明英汉词典》
• This idea can be formulated in two different ways. 这个意思可以有两种说法。 来自《现代汉英综合大词典》

4 binds   

v.约束( bind的第三人称单数 )；装订；捆绑；（用长布条）缠绕

参考例句：

• Frost binds the soil. 霜使土壤凝结。 来自《简明英汉词典》
• Stones and cement binds strongly. 石头和水泥凝固得很牢。 来自《简明英汉词典》

5 genetic   

adj.遗传的，遗传学的

参考例句：

• It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
• Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。