出生前接觸雙酚A 女童易有心理問題? | 台灣環境資訊協會-環境資訊中心

出生前接觸雙酚A 女童易有心理問題?

2011年11月02日
摘譯自2011年10月24日ENS波士頓報導;黃健強編譯;蔡麗伶審校

情緒失控的女童 (Photo by fisita)

由哈佛大學的公共衛生學院、辛辛那提市兒童醫院和醫藥中心以及不列顛哥倫比亞省溫哥華的西門菲沙大學(Simon Fraser University)的研究人員所進行的新研究報告首次指出,胎兒於子宮內時暴露於雙酚A中,與年輕女孩的行為和情緒異常有關連,雙酚A是一種用於製造塑膠容器和罐頭內襯塗料的化學物。

許多產品都含有雙酚A(BPA),包括像罐裝食品的內層、聚碳酸脂塑膠、牙齒密封劑和由感熱紙所製成的現金收據等。

大多數生活在工業化國家的民眾都曝露在雙酚A中。此化學物已被指出會影響動物的正常發展,並且與人體的心血管疾病和糖尿病有關聯。

哈佛大學公共衛生學院研究人員2009年進行的研究中已顯示,用PC(聚碳酸脂)塑膠瓶喝飲料,會增加泌尿系統的BPA含量。

這份研究刊登在《小兒科》(Pediatrics)期刊上,其主要作者、也是哈佛公共衛生學院環境健康中心的研究人員Joe Braun表示,他和研究同仁發現,妊娠期間曝露在雙酚A環境下,與3歲的孩童有較多行為問題,兩者之間有關聯性,特別是對女童而言。

在辛辛那提地區,研究人員從環境研究的健康狀況評估測量中蒐集了244位母親和她們3歲孩童的相關資料。受試的母親於懷孕期間提供3份尿液樣本和產後1次,以檢驗其中的BPA含量。她們的小孩則從1歲到3歲期間,每年進行一次檢驗測試。當孩童3歲的時候,母親則完成了她們小孩的行為評估調查。

Braun表示:「沒有孩童有臨床上的異常行為,但有些孩童比起其他孩童有較多的行為問題。因此我們檢驗母親和孩童的BPA濃度和異常行為。超過85%的母親尿液樣本測出含有BPA,而超過96%的孩童尿液樣本含有BPA。」

研究人員發現母親的BPA濃度與第一次採集的樣本和產後的樣本相似。而孩童的BPA含量從1歲到3歲之間逐漸減少,但比起母親的BPA含量要高且更易產生變異。

在調整過相關可能的因素後,發現增加妊娠期間的BPA濃度與女童過動、具侵略性、緊張和壓抑等行為以及較差的情緒管理和控制有關連性。而在男孩身上卻未發現相同的關連性。

Braun說:「此研究證實了先前研究指出,在子宮內曝露於BPA中會對孩童的行為產生影響,但此研究是首次指出在子宮內期間曝露在BPA下所產生的影響,比在幼年時期接觸到BPA要來的重要。不是在幼年時期,而是在妊娠時期所接觸到的BPA會影響神經行為,而女童似乎比男童更容易受到BPA影響。」

研究報告指出:「雖然還需要有更多的研究來瞭解BPA對健康的影響,但臨床醫師仍可建議民眾盡量避免罐裝和包裝食品、營業收據的感熱紙,以及標示有數字7的可回收聚碳酸脂瓶以減少接觸BPA。」

Bruce Lanphear是西門菲沙大學的資深研究人員。於10月19日,Lanphear得到史特靈的爭議研究貢獻獎(Sterling Prize in Support of Cobntroversy)。

他表示:「其實我一開始並不是想要當一位研究員,我只是想要為大眾的健康做一點改變,我想要推動修改法令。」

BPA的研究經費有部份是由國家環境健康科學會和美國環境保護機構所贊助。

Girls' Behavior Problems Linked to Prenatal Bisphenol A Exposure
BOSTON, Massachusetts, October 24, 2011 (ENS)

Exposure in the womb to bisphenol A, a chemical used to make plastic containers and to line cans of food, is associated with behavior and emotional problems in young girls, new research has shown for the first time.

The study was led by researchers at Harvard School of Public Health, Cincinnati Children's Hospital and Medical Center, and Simon Fraser University in Vancouver, British Columbia.

BPA is found in many consumer products, including canned food linings, polycarbonate plastics, dental sealants, and some cash register receipts made from thermal paper.

Most people living in industrialized nations are exposed to BPA. The chemical has been shown to interfere with normal development in animals and has been linked with cardiovascular disease and diabetes in people.

In a 2009 study, researchers with the Harvard School of Public Health showed that drinking from clear plastic polycarbonate bottles increased the level of urinary BPA.

In this study, published today in an advance online edition of the journal "Pediatrics," lead author Joe Braun, research fellow in environmental health at HSPH, and his colleagues found that gestational BPA exposure was associated with more behavioral problems at age three, especially in girls.

The researchers collected data from 244 mothers and their three-year-old children in the Health Outcomes and Measures of the Environment Study, conducted in the Cincinnati area.

Mothers provided three urine samples during pregnancy and at birth that were tested for BPA; their children were tested each year from ages one to three. When the children were three years old, the mothers completed surveys about their children's behavior.

"None of the children had clinically abnormal behavior, but some children had more behavior problems than others. Thus, we examined the relationship between the mom's and children's BPA concentrations and the different behaviors," Braun said.

BPA was detected in over 85 percent of the urine samples from the mothers and over 96 percent of the children's urine samples.

The researchers found that maternal BPA concentrations were similar between the first sample and birth. The children's BPA levels decreased from ages one to three, but were higher and more variable than that of their mothers.

After adjusting for possible contributing factors, increasing gestational BPA concentrations were associated with more hyperactive, aggressive, anxious, and depressed behavior and poorer emotional control and inhibition in the girls. This relationship was not seen in the boys.

The study confirms two previous studies showing that exposure to BPA in the womb impacts child behavior, but is the first to show that in utero exposures are more important than exposures during childhood, Braun said.

"Gestational, but not childhood BPA exposures, may impact neurobehavioral function, and girls appear to be more sensitive to BPA than boys," he said.

Although more research is needed to fully understand the health effects of BPA exposure, clinicians can advise those concerned to reduce their BPA exposure by avoiding canned and packaged foods, thermal paper sales receipts, and polycarbonate bottles with the number 7 recycling symbol, the authors wrote.

Bruce Lanphear of Simon Fraser University was senior author of the study. On October 19, Lanphear received the "Sterling Prize in Support of Controversy."

"I didn't actually start out wanting to be a researcher," says Lanphear, an epidemiologist and father of three daughters. "I wanted to make a difference to public health. I wanted to help shape policy."

The BPA study was funded in part by the National Institute of Environmental Health Sciences and the U.S. Environmental Protection Agency.