根据美国教育部的统计,从1998到1999一年中,全美公立小学就增加了26%的自闭儿;在美国加州11年级内学龄的自闭儿增长210% (Testimony on April 25,2001 before the U.S. House of representative Committee on Government Reform by James J. Bradstreet, M.D.; direct of research for the International Autism Research Center.) 

对于起因，通过分析众多的案例,自然科学家总结为下列七种模式:

(1).遗传(Genetic)

基因研究已无法证实特定染色体(Y) 在某个基因有主要的自闭症缺陷, 但目前有许多医学着重于免疫相关的基因研究.

 (2).化学中毒 (The Toxic Chemical Model)

很难想象现今的孕妇每天都在喝已被污染的水, 呼吸中的空气已混入工业生产的毒气, 连食物都内含极重的化学农药和激素, 所有的化学成分以液体, 气体或固体形态存在于母体内, 使一个未出世的胎儿已被化学成份所侵蚀.

 在2000年, 美国全国科学学术报导中指出 (National Academics of science report, 2000), 由于脑神经中毒和遗传因素的结合, 导致近25%孩子脑部发育有问题, 这也包括了自闭症, 其中最严重的化学中毒是多氯的碳氢化合物 (PCBs) 和含磷酸酯 (organophosphate) 的杀虫剂.尤其是杀蟑螂和蚂蚁的杀虫剂, 其中的化学成分Dursban会造成脑损害. 因此美国在2000年, 禁止含化学成分Dursban应用于任何家用产品中.

    （3）.重金属污染 (The Heavy metal Contamination Model)

这是近年最震惊的发现, 许多婴孩免疫系统的基因被重金属破坏, 尤其是黑铅 (lead) 和水银/汞 (mercury).

     铅: 第一个问题就是铅毒的来源, 美国研究发现在1978年以前建的房子, 所有的油漆都含铅, 在老房子中的铅, 不但在老漆内, 也逐渐掉落沉淀在地板的夹缝内, 当婴孩在爬行的阶段, 喜欢将手放在嘴里, 灰尘中所有的铅也进入了体内, 在一份医学报导中指出, “少年帮派分子身上有极重的铅成分在他们的骨骼内.” (U.S. News &World report, June 19, 2000, p48), 用以解释铅对人体行为表现的影响. 

    实际上，当今社会最大的铅污染来源是：汽车尾气，每天繁忙拥挤的公路上，成千上万的汽车带给我们便利的同时，也给人类生存环境带来很难逆转的破坏。

水银/汞: 水银 (汞) 最常见就在老式的体温计内, 目前发现人工养殖的鱼含有极高的水银在体内. 若孕妇吃到含高汞的鱼, 水银会沉淀人体造成对胎儿的伤害; 另一汞的来源是在汞合金的补牙料, 当孕妇在怀胎期间去补牙, 水银也会因此进入母体对胎儿造成影响.

     另一个引起最多争议的汞中毒, 就是疫苗接种.它是局部抗菌剂的主要成分, 且许多案例研究中发现, 自闭儿体内的含汞量甚至超过成人所能承受的安全量, 近年一位英国医生 Andrew Wakefield提出自闭症与防天花、腮腺炎和德国痳疹的三合一疫苗 (MMR) 有联系关系 (阅 “Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive development[NextPage]al disorder in children”, Lancert 1998 Feb.28; 351(9103):637-41), 接着哈佛的消化疾病医学专家 (Harvard gastroenterologist) Timothy Buie, MD, 和日本的独立研究机构 Kawashima et al都提出疫苗与自闭症和脑损害相关联的医学研究报告. 

（4）.自动免疫性/过敏 (The Auto-Immunity/Allergy Model)

过敏是由于人体的自动免疫系统对不明侵入物, 亦称为 “过敏原” (allergen), 的反作用, 一般现象是充血 (congestion), 打喷嚏 (sneezing), 发炎 (inflamed)。对于过敏发痒的眼睛或者局部皮肤性的发痒, 我们会服用抗组织胺剂 (anti-histamines) .

     但许多自闭儿在过敏的反应上, 有超过正常的动态反应, 许多研究学者和医生就将此现象建立一个理论, 当一个过敏性体质的孩子承受从环境来的刺激, 例如汞进入体内, 孩子的免疫系统不仅有抗原反应 (antigens), 在他的脑部也会有分子结构 (molecular structures) 的过敏反应. 

在一篇研究报导中 (Brain, Behavior, and Immunity; Volume 7, pp91-103, 1993) 论述一个实验, 抽取自闭儿的血液中发现他们的自身抗体 (autoantibodies) 存在于中枢神经系统内产生髓素蛋白 (myelin basic protein), 这个发现解释若神经系统被自身抗体所攻击, 脑神经如同短路 (short-circuits) 会停止正常功能运作.

    （5）. 滤过性毒菌效应 (The Viral Model)

这个理论是由二位医生所提出的临床研究 (Sidney Baker, MD, 和Michael Goldberg, MD), 根据他们的研究有30%的自闭儿家长特别赞许抗滤过性毒菌药, acyclovir or Valtrex, 帮助自闭儿的免疫系统压制传染性的毒菌效应. 

（6）.面质和酪蛋白, 酵素缺乏和酵母生长过快理论 (The Gluten /Casein, Enzyme Deficiency and Yeast Overgrowth Model)

（7）. 金属新陈代谢理论 (The Metallothionein Theory)

这是由一位全美著名的生物化学博士 William Walsh, PhD, (works at Pfeiffer Treatment Center in Naperville, IL), 在数千位自闭儿身上发现共同现象: 

a.锌和铜在血液中的不平衡现象.

b.超量汞和其它有毒金属在体内.

c.免疫系统和脑神经的发展和功能相关联.

d.酵素不足不能消化面质和酪蛋白.

e.对肠炎有严重反应. 

这七种自闭症起因互相作用, 其综合作用的结果产生了复杂的自闭症的病因, 目前这些推论尚须更多的临床所确定，但汞中毒, 食物过敏和锌铜不平衡, 是在对于美国自闭儿的研究中所发现的具有代表性而不可忽略的原因.

附注:

 Vaccine Autism Claims Go to Court

By KEVIN FREKING

AP

WASHINGTON (June 4) - Science has spoken when it comes to the theory that some childhood vaccines ca[NextPage]n cause autism. They don't, the Institute of Medicine concluded three years ago.

Soon, it will be the courts turn to speak.

More than 4,800 claims have been filed against the federal government during the past six years alleging that a child contracted autism as a result of a vaccine. The first test case from among those claims will be the subject of a hearing that was to begin next Monday in a little-known "People's Court" - the U.S. Court of Federal Claims. A special master appointed by the court will hear the case.

For the parents filing a claim, there is the potential for vindication, and for financial redress.

The test case addresses the theory that the cause of autism is the measles, mumps and rubella vaccine in combination with other vaccines containing the preservative thimerosal. That preservative, which contains a form of mercury, is no longer in routine childhood vaccines. However, it is used in influenza vaccines.

One of the parents who has filed a claim against the federal government and has great interest in the case is Scott Bono of Durham, N.C. His son, Jackson, 18, has autism. While acknowledging the findings of the IOM's study, Bono believes those findings were preordained by the federal government.

"The charge before the IOM committee was: 'You're not going to find anything wrong here,"' Bono said.

He said that parents of children with autism have been marginalized, but they see specific outcomes in their children that are consistent with exposure to[NextPage] mercury. And those outcomes did not present themselves until after they received their vaccinations. In short, the children tell the story better than the numbers, he said.

"It's a thrill in the sense that, for the first time, the stories of these children are going to be heard in court," Bono said.

In July 1999, the U.S. government asked vaccine manufacturers to eliminate or reduce, as expeditiously as possible, the mercury content of their vaccines to avoid any possibility of infants who receive vaccines being exposed to more mercury than is recommended by federal guidelines.

Dr. Paul Offit, who developed a vaccine for the rotovirus, is chief of the division of infectious diseases at the Children's Hospital of Philadelphia. He said epidemiological studies pick up minute, almost invisible differences in the populations that have received a vaccine versus those that have not.

For example, a swine flu vaccine in the 1970s caused the sometimes paralyzing Guillain-Barre syndrome in 1 out of 100,000 cases, he said.

But no such correlations have been found for autism, which affects about 1 out of 150 children, he said.

"It should be easily picked up," he said. "It hasn't been and the reason it hasn't been is because vaccines do not cause autism."

Offit said mercury is part of the natural environment. There's no escaping it and, in fact, children will get more mercury from breast milk than they get from a vaccine. Yet, he's frustrated when he hears lawmakers speak of having[NextPage] zero tolerance for mercury.

"On this planet you can't have zero tolerance for mercury," he said. "You would have to move to another planet."

Autism is characterized by impaired social interaction. Those affected often have trouble communicating, and they exhibit unusual or severely limited activities and interests. Meanwhile, classic symptoms of mercury poisoning include anxiety, fatigue and abnormal irritation, as well as cognitive and motor dysfunction.

The report from the Institute of Medicine pointed to five large studies, here and abroad, that tracked thousands of children since 2001 and found no association between autism and vaccines containing the preservative thimerosal.

Members of the National Autism Association see drug manufacturers and the federal government as working too closely together to the point that the federal government is working to protect the industry from liability. The association says its mission is to raise awareness of environmental toxins as causing neurological damage that often results in an autism or related diagnosis.

Bono, a member of the association, said he doesn't believe his son was intentionally poisoned.

"I just want someone to step up and say, 'You're right, this did happen,"' he said.

During the hearing, lawyers for the parents were expected to present their expert testimony during the first week. Then lawyers representing the federal government were expected to present their case. The hearing was to be open to the public. [NextPage]

Officials planned to post transcripts on the court's Web site about 24 hours after each day's proceedings. 

(参考 Children with Starving Brain by J. McCandless, MD, pp17-36)

来源:自闭症的觉醒