火箭燃料所使用的有毒化學成分過氯酸鹽（perchlorate），目前至少污染了橫跨美國35個州以上的飲用水；不過，美國環保署已決定，不會把此項化學物質列入國家級管制標準。
環保署是在3日宣佈這項決定的，環保署說，不會管制飲用水中的過氯酸鹽含量，相反地，僅表示「承諾與州政府和地方合作，以確保保護公共健康」。
美國環保署說：「州政府有權力建立並實施飲用水標準，環保署會敦促州政府特別關注該州的特殊情況」。目前，加州和麻州已通過相關法案，管制飲用水中的過氯酸鹽含量。
過氯酸銨（ammonium perchlorate）為航空、軍需品和煙火製造工業在製造固體火箭和飛彈發射燃料、煙火和炸藥時所普遍使用的主要成分。根據美國國防部，超過350種軍需品皆含有過氯酸鹽成分。
不僅是在飲用水中，在萵苣和牛奶中皆可找到過氯酸鹽的殘留物。美國食品和藥品管制局（Food and Drug Administration, FDA）於2004年的檢驗發現，在15個州232個牛奶和萵苣的樣本中，已檢驗出217個含有過氯酸鹽。
過氯酸鹽會影響甲狀腺腺體吸收碘的能力，而經由碘才能製造甲狀腺賀爾蒙以調節許多身體功能。特別是幼兒和孕婦易受到過氯酸鹽的影響。
美國環保署3日經由聲明表示，在審核經由飲用水等來源接觸到過氯酸鹽的影響之科學數據後，已發現「99%比率的公共飲用水系統中，過氯酸鹽（含量）未達到足以構成公共衛生考量的程度。」環保署表示，基於「安全飲用水法」制定的標準，採用一個國家級的飲用水規定，並不會提高多少「降低健康風險」的機會。
美國環保署目前仍在徵求公眾意見，將在30天考量參考公眾所提供的資訊後，作出最後的裁決。
美國加州參議員鮑克瑟（Senator Barbara Boxter）毫不猶豫的提出她的公眾意見。她說，「過氯酸鹽的汙染危及我們的家庭，尤其是孕婦和幼兒們，而准許它存在於我們的飲用水中是違反道德。」
根據美國環保署的資料，全美有1660萬人民的飲用水中還有過氯酸鹽。但是巴斯特引用獨立研究者報告顯示，有超過2千萬的美國人民接觸到此毒物。
美國參議院環境和公共事務委員會（The Senate Environment and Public Works Committee）通過兩項防止公眾接觸於過氯酸鹽的保護措施。其中一項要求美國環保署重新啟動檢驗飲用水過氯酸鹽含量的測驗，並公開其檢驗結果給公眾。另一項則要求美國環保署近期內制定飲用水過氯酸鹽含量的標準，以保護孕婦和幼兒。這兩項措施尚未正式通過成為法案。
根據美國環保署的網站，加州6,400個公共水供應水源在經由檢驗後，發現有350個被檢驗出含有過氯酸鹽，「地下水和柯羅拉多河（Colorado River）的汙染影響了重要的飲用水和灌溉水供應系統。單論加州就可能有超過30個地點含有過氯酸鹽，其中有13個地點為美國環保署列管的超級基金汙染場址，而另有12個場址為州政府主導清除行動的高污染危險區。」
Perchlorate, a toxic component of rocket fuel that contaminates drinking water at sites in at least 35 states, will not be regulated at the national level the U.S. Environmental Protection Agency has decided.
The agency announced its preliminary decision not to regulate perchlorate in drinking water late Friday. Instead, the EPA said in a statement that it is "committed to working with states and localities to ensure public health is protected."
"States have the right to establish and enforce drinking water standards and EPA encourages state-specific situations to be addressed at the local level," the EPA said.
California and Massachusetts have already passed laws regulating perchlorate in drinking water.
Ammonium perchlorate is widely used throughout the aerospace, munitions, and pyrotechnics industries as a primary ingredient in solid rocket and missile propellants, fireworks, and explosive charges. It is a component of more than 350 types of munitions, according to the Department of Defense.
The chemical has been found not only in drinking water but also in lettuce and milk. In 2004, the Food and Drug Administration reported finding perchlorate in 217 of 232 samples of milk and lettuce in 15 states.
Perchlorate affects the ability of the thyroid gland to take up iodine, which is needed to make thyroid hormones that regulate many body functions. Children and pregnant women are are especially susceptible.
The EPA said in its statement Friday that after a review of scientific data on the health effects of exposure to perchlorate from drinking water and other sources the agency found that "in more than 99 percent of public drinking water systems, perchlorate was not at levels of public health concern."
Based on the Safe Water Drinking Act criteria, the agency said there is not a "meaningful opportunity for health risk reduction" through a national drinking water regulation.
The EPA is seeking public input on its decision and will make a final determination for perchlorate after considering information provided in the 30-day public comment period.
U.S. Senator Barbara Boxer of California lost no time in offering her public comment.
"Perchlorate contamination endangers the health of our families, especially pregnant women and children," she said, "and to simply allow it to remain in our drinking water is immoral."
Perchlorate is found in the drinking water supplies of up to 16.6 million Americans, according to EPA. But Boxer cites the estimates of independent researchers that 20 million or more Americans are exposed to the toxin.
In July, the Senate Environment and Public Works Committee passed two measures to protect the public from exposure to perchlorate. One requires the EPA to resume testing of drinking water for perchlorate and disclose the results of those tests to the public. The other requires the EPA to promptly set a standard for perchlorate in drinking water that protects pregnant women and children. Neither of these measures has become law.
Perchlorate has been discovered in over 350 of 6,400 public water supply wells tested in California, the EPA says on its website. "Contamination of groundwater and of the Colorado River affects important drinking water and irrigation water supplies. There may be over 30 sites with perchlorate in California alone. Thirteen of these are EPA Superfund sites and the state of California leads cleanup efforts at 12 other sites."
全文及圖片詳見：ENS
