一份由聯合國環境署(UNEP)和世界衛生組織(WHO)19日提出的報告指出,家用產品和工業產品中所含的環境荷爾蒙與全球乳癌、卵巢癌、前列腺癌、睪丸癌、甲狀腺癌的高罹癌率相關。
內分泌干擾物質(簡稱EDCs),又稱為環境荷爾蒙),除了常見於殺蟲劑、電子產品、化妝保養品等合成產品中,也會自然生成,另外EDCs也會以添加劑和汙染物的型態出現在食物中。
根據研究報告,EDCs也和造成兒童的健康問題有關,例如:年輕男性的隱睪症、影響神經系統發育和過動。
「現在已知或可能影響荷爾蒙受體的化學物質約有800種,但是只有其中一小部分經過實驗檢測,大部分目前在商業中使用的化學物質都尚未接受檢測。」
EDCs從工業和城市的排放、農業排水和燃燒及排放廢棄物等方式進入環境當中,人類在攝入被汙染的食物、灰塵和水、吸入空氣中的氣體與粒子或是皮膚接觸到受汙染的物質時讓EDCs進入體內。
WHO公共衛生暨環境部主任尼拉(Maria Neira)表示,「我們急需更多的研究來更完整的了解EDCs對人類健康和環境的影響。最新的科學研究顯示,全球的社群都被EDCs和它所帶來的風險籠罩。」
人類的健康依靠正常運作的內分泌系統來釋放特定的荷爾蒙,這些荷爾蒙對代謝、成長發展、睡眠和情緒等作用來說是必須的。環境荷爾蒙會改變這些內分泌系統的運作,增加罹患疾病的風險。
根據研究調查,許多與內分泌相關的疾病和症狀都增加了,例如:
- 在某些國家中,很高比例(將近40%)的年輕男性有精液品質下降的問題,這導致他們生育能力降低。
- 男嬰生殖器畸形(如隱睪症或陰莖畸形)的案例變多。
- 早產和嬰兒體重過輕等不良的生產結果,已在許多國家中發生。
- 缺乏甲狀腺素與神經行為障礙有關,在一些國家中有相當高比例的兒童受到影響,過去數十年來案例有增加的趨勢。
- 全球內分泌相關癌症的比例上升,乳癌、卵巢癌、前列腺癌、睪丸癌、甲狀腺癌在過去40~50年間都增加了。
- 在研究報告所調查的所有國家中,年輕女孩的胸部都有提早發育的現象,這將提高罹患乳癌的風險。
- 過去40年來全球肥胖和第二型糖尿病的患病率急遽的增加,WHO估計全球有15億成人超重或肥胖,而第二型糖尿病的患者在1980到2008年間從1億5300萬人增加到3億4700萬人。
UNEP執行長史坦納(Achim Steiner)表示,「致力於發展新檢驗方法和研究可以讓我們更加了解暴露在EDCs下所產生之影響,並協助我們降低患病風險、提高研究效益、做出更有智慧的選擇和替代方案,將成果反映在綠色經濟上。」
野生動物也受到EDCs的影響,水獺和海獅數量之所以減少可能就是因為暴露在PCBs的混合物、DDT殺蟲劑、其他持久性有機汙染物和水銀等金屬下的結果。
報告主要編輯者、斯德哥爾摩大學教授Ake Bergman指出,「過去10年來對EDCs的研究有大幅進展,我們對此類物質的認識,不論深度和廣度都已超過10年前。科學持續的在進步,是時候進一步展開對EDCs的管理和研究,以理解暴露EDCs中會對野生動物和人類產生的影響。」
Chemicals in household and industrial products that disrupt the human hormone system are linked to high global rates of breast, ovarian, prostate, testicular and thyroid cancers, warns a report released today by the UN Environment Programme and the World Health Organization.
Endocrine disrupting chemicals, or EDCs, can occur naturally, while synthetic varieties are found in pesticides, electronics, personal care products and cosmetics. They can also be found as additives or contaminants in food.
The report also links EDCs to childrens' health issues such as non-descended testes in young males, developmental effects on the nervous system and attention deficit hyperactivity.
"Close to 800 chemicals are known or suspected to be capable of interfering with hormone receptors. However, only a small fraction of these chemicals have been investigated in tests," states the report. "The vast majority of chemicals in current commercial use have not been tested at all."
EDCs enter the environment mainly through industrial and urban discharges, agricultural run-off and the burning and release of waste. People are exposed when they ingest contaminated food, dust and water, inhale gases and particles in the air, or make skin contact with contaminated substances.
"We urgently need more research to obtain a fuller picture of the health and environment impacts of endocrine disruptors," said Dr. Maria Neira, the World Health Organization's director for public health and environment.
"The latest science shows that communities across the globe are being exposed to EDCs, and their associated risks," she said.
Human health depends on a well-functioning endocrine system to regulate the release of certain hormones that are essential for functions such as metabolism, growth and development, sleep and mood. Endocrine disruptors can alter the functions of this hormonal system, increasing the risk of adverse health effects.
Many endocrine-related diseases and disorders are on the rise. According to the report:
- Large proportions (up to 40 percent) of young men in some countries have low semen quality, which reduces their ability to father children.
- The incidence of genital malformations, such as non-descending testes and penile malformations, in baby boys has increased.
- The incidence of adverse pregnancy outcomes, such as preterm birth and low birth weight, has increased in many countries.
- Neurobehavioural disorders associated with thyroid disruption affect a high proportion of children in some countries and have increased over past decades.
- Global rates of endocrine-related cancers – breast, endometrial, ovarian, prostate, testicular and thyroid – have been increasing over the past 40 to 50 years.
- There is a trend towards earlier onset of breast development in young girls in all countries where this has been studied. This is a risk factor for breast cancer.
- The prevalence of obesity and type 2 diabetes has dramatically increased worldwide over the last 40 years. WHO estimates that 1.5 billion adults worldwide are overweight or obese and that the number with type 2 diabetes increased from 153 million to 347 million between 1980 and 2008.
"Investing in new testing methods and research can enhance understanding of the costs of exposure to EDCs, and assist in reducing risks, maximizing benefits and spotlighting more intelligent options and alternatives that reflect a transition to a green economy," said Steiner.
Wild animals are also affected by exposure to EDCs. Population declines in species of otters and sea lions may also be linked to their exposure to mixtures of PCBs, the insecticide DDT, other persistent organic pollutants, and metals such as mercury.
"Research has made great strides in the last ten years showing endocrine disruption to be far more extensive and complicated than realized a decade ago," said Professor Ake Bergman of Stockholm University and chief editor of the report.
"As science continues to advance, it is time for both management of endocrine disrupting chemicals and further research on exposure and effects of these chemicals in wildlife and humans."
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