:::

淺談『環境,荷爾蒙』---干擾動物內分泌之化學物質
     
  在邁進公元二千年的前夕,讓我們回顧一下人類百年來的歷史文明。二十世
紀的科技發展固然為人類創造了空前的物質享受,但也為人類種下了潛伏的隱憂
;尤其是化學物質的氾濫。由於化學工業發展的結果,合成的化學物質或物品,
在吾人衣、食、住、行、育、樂日常生活中之應用,可以說無所不用其極,發揮
得淋漓盡致;諸如紡織品、塑膠製品、飲食調理、建材塗料、醫藥、清潔劑、殺
蟲劑、除草劑無一不是化學工業的傑作,我們幾乎沒有一天可以脫離化學物質而
生活。雖然多數的化學物質在正常情況下均很安全,但亦有因不當之使用或棄置
而造成危害環境或威脅人體健康之情況發生。亦即任何人不論是在工作環境或在
日常生活環境之中,因直接或間接接觸,都有可能暴露在許多不同的化學物質中
。固然大部分的化學物質在正常情況下,並不會產生危害,但卻有許多化學物質
具有潛在的危害性。
  全世界登錄有案之化學物質超過一千萬種,而且估計每年約有5000種化學物
質從實驗室內合成。二十世紀初期人類只注意到化學物質的急性危害,因此把具
急性毒之化學物質,依其對小白鼠之口服半數致死劑量(LD50)區分為極劇毒、劇
毒、中毒、輕毒、稍毒、實用上無毒等層次;但是『明槍易躲,暗箭難防』,許
多慢性危害化學物質卻傷人、破壞環境於無形。迨二十世紀中葉,1962年卡爾遜
(Carson)發表了一本『寂寞的春天』。喚醒世人大量的濫用化學藥品,將造成生
態的危機、人類的災難。此後人類始漸警覺到化學物質的慢性危害,尤過於急性
毒。於是各國紛紛的將有致腫瘤性、生育能力受損、致畸胎、遺傳因子突變及在
環境中不易分解、具生物蓄積性、生物濃縮性、生物轉化性之化學物質加以管制
。及至二十世紀末,近年來人類更發現一些化學物質雖然並不明顯危害生物體,
但其微量殘跡卻可干擾動物的內分泌系統,稱之為『環境荷爾蒙』(environm-ental
 hormone)。此等化學物質常透過食物鏈進入人體,形成假性荷爾蒙,傳遞假性的
化學訊號,也影響本來身體內荷爾蒙的量,進而干擾內分泌原來的機制,形成內
分泌失調(endocrine disruption),特別是生殖機能方面,終致絕其子嗣,禍延
子孫。
  內分泌干擾物質的可怕之處,在於其量甚微,即能產生深遠的影響;而這些
化學物質在我們文明生活中,卻又是無所不在。影響所及,諸如近年來許多夫婦
之不孕、男性精子減少四分之一至一半,性無能、女性子宮內膜症、女子男性化
等;化學污染物質由母乳傳給下一代,嬰兒產生學習障礙,長大形成暴力傾向,
甚至於神經異常,產生過動兒,注意力無法集中,免疫系統失調及癌症好發等後
果。
  據布勞烈(Broley)在加拿大賞鳥十三年的經驗報告,他曾觀察到禿鷹配偶的
怪異行為。發現有80%之禿鷹是不孕的,雌雄鳥遊手好閒,虛渡春光,而不在意
求偶築巢,浪漫的尋歡做愛。因其已失去求偶生育的本能,而使得美國東部、加
拿大的禿鷹族群為之迅速減少。蘇瑞博(Sch-reiber)則*在美國發現許多種母海鷗
有同性共巢的現象,但海鷗的數量卻相對的減少。福克斯(Fox)發現許多化合物包
括DDT等,具有某種程度的雌性動情素荷爾蒙效果,會影響雄鳥的性別發育,甚
至於發生性器官發育錯亂的情形,雄性生殖器官雌性化,雄性生殖腺出現典型的
雌性細胞,或是新生雄鳥出現雌性排卵用的輸卵管。傅來(Fry)在調查鯡鷗時亦
發現七公鷗有五隻相當的雌性化,可以說已經受到動情素荷爾蒙之化學污染;此
外,甚至於有人研究,在發育中的公鳥注射動情素化學物質加以驗證,不但會影
響雄鳥腦部及生殖器官的發育,而且會長期的壓抑性行為。
  前述美國五大湖區海鷗之雌性共巢現象,學者咸認為係因雄性失去求偶的興
緻,或生殖困難,因而使得雌鳥感受缺少雄性追求;為了族群之綿延生存,有些
雌鳥乃設法向有婦之夫的雄鳥求偶,孵育幼鳥,因而形成母鳥同性共巢的現象。
柯爾朋(Colborn)稱此為『同性戀鳥』。此係導因於雄性雌性化,亦即荷爾蒙受化
學物質干擾的結果。
  日本通產省及環境廳於1998年將67種化學物質(如附表)列為疑似干擾荷爾
蒙物質,稱之『環境荷爾蒙』,並進行深入的探討研究。這些化學物質有許多為
殺蟲劑、殺菌劑、除草劑或塑化劑,所幸表列多種物質我國已公告禁用。

    (環境檢驗所 副所長 王正雄)

附表 疑似干擾內分泌失調之化學物質

化學物質名稱                                                                    用 途

1.Dioxins and furans                                                                   非產品

2.Polychlorinated biphenyl(PCBs)                                    熱媒                                                                                                     
                                                                                  無碳複寫紙
電容器變壓器絕緣

3.Polybromobiphenyl(PBB)                                                      防火材料

4.Hexachlorobenzene(HCB)                                                         殺菌劑

5.Pentachlorophenol(PCP)                                   殺菌消毒劑除
                                                                                          草劑防

                                                                                             腐劑

6.2,4,5-Trichlorophenoxyacetic acid                                              除草劑

7.2,4-Dichlorophenoxyacetic acid                                                 除草劑

8.Amitrole                                                                  除草劑樹
                                                                                       脂硬化劑

9.Atrazine                                                                             除草劑

10.Alachlor                                                                                                   除草劑

11.Simazine(CAT)                                                                  除草劑

12.Hexachlorocyclohenane,                                                                             殺蟲劑
Ethyl parathion

13.Carbaryl                                                                           殺蟲劑

14.Chlordane                                                                                                殺蟲劑

15.Oxychlordane                                          Chlordane 之代謝中間產物

16.trans-Nonachlor                                                                  殺蟲劑

17.1,2-dibromo-3-chloropropane                                                                 殺蟲劑

18.DDT                                                                               殺蟲劑

19.DDE and DDD                                                               殺蟲劑
                                                                     (DDT之代謝中間產物)

20.Kelthane(Dicofol)                                                                殺蟲劑

21.Aldrin                                                                             殺蟲劑

22.Endrin                                                                             殺蟲劑

23.Dieldrin                                                                                                   殺蟲劑

24.Endosulfan (Benzoepin)                                                        殺蟲劑

25.Heptachlor                                                                        殺蟲劑

26.Heptachlor epoxide                                                   Heptachlor之代謝中間產物

27.Malathion                                                                         殺蟲劑

28.Methomyl                                                                        殺蟲劑

29.Methoxychlor                                                                    殺蟲劑

30.Mirex                                                                              殺蟲劑

31.Nitrofen                                                                           除草劑

32.Toxaphene (Campechlor)                                                       殺蟲劑

33.Tributyltin                                                 魚網之防腐劑船    
                                                                                上抗腐蝕油漆

34.Triphenyltin                                               船上抗腐蝕油漆

                                                                                 魚網之防腐劑

35.Trifluralin                                                                         除草劑

36.Alkyl phenol (from C5 to C9)  Raw material for

surface-active

Nonyl phenol  agents/decomposition

product

Octyl phenol  Raw material for

surface-active

37.Bisphenol A  Raw material for resins

38.Di-(2-ethlhexyl)phthalate                           塑膠之塑化劑

39.Butyl benzyl phthalate                                                 塑膠之塑化劑

40.Dicyclohexyl phthalate                                                塑膠之塑化劑

41.Dicyclohexyl phthalate                                                塑膠之塑化劑

42.Diethyl phthalate                                                       塑膠之塑化劑

43.Benzo(a)pyrene                                                                  非產品

44.Dichlorophenol                                                     染料之中間產品

45.Diethylhexyl adipate                                                  塑膠之塑化劑

46.Benzophenone  Synthetic raw

materials for medical

products, perfume,

etc.

47.4-Nitrotoluene                                        2,4-dinitrotoluene之中間產物

48.Octachlorostyrene                                               有機氯化物副產品

49.Aldicarb                                                                          殺蟲劑

50.Benomyl                                                                         殺菌劑

51.Kepone (Chlordecone)                                                         殺蟲劑

52.Manzeb (Mancozeb)                                                            殺菌劑

53.Maneb                                                                            殺菌劑

54.Metiram                                                                          殺菌劑

55.Metribuzin                                                                       除草劑

56.Cypermethrin                                                                    殺蟲劑

57.Esfenvalerate                                                                     殺蟲劑

58.Fenvalerate                                                                         殺蟲劑

59.Permethrin                                                                       殺蟲劑

60.Vinclozlolin                                                                      殺菌劑

61.Zineb                                                                               殺菌劑

62.Ziram                                                                              殺菌劑

63.Dipentyl phthalate

64.Dihexyl phthalate

65.Dipropyl phthalate

66.Styrens Non-reacting substance of

styrene-rubber plastic

67.n-Butylbenzene Synthesis intermediate, for

liquid crystal manufacture

附註:重金屬鉛、鎘、汞亦為內分泌干擾之疑似物質。



上一頁  回環保署回環檢所下一頁