美國處理最大鉛污染 指標性決策拍板定案 | 台灣環境資訊協會-環境資訊中心

美國處理最大鉛污染 指標性決策拍板定案

2009年05月19日
摘譯自2009年5月14日ENS美國,內布拉斯加州,奧馬哈市報導;張桂芳編譯;蔡麗伶審校

經過美國環保署、衛生機構、社區組織、學校、醫療團體及市民十多年來奔走努力下,美國史上最大宗住宅區鉛污染案,終於在14日簽署了最終決議書(Final Record of Decision)。


美國環保署土壤採樣與整治作業。照片來源:美國環保署

過去幾十年來,成千上萬奧馬哈市(Omaha)東部的住宅區土壤,因前全球礦業巨擘ASARCO煉油廠持續排出含鉛空氣而受到污染。目前除聯邦機構除鉛過的4600多住戶外,按決議,EPA還會追加清理整治近1000多戶。

環保署在決議書中聲明,斥資約2億3660萬美元的最終補救措施,包括挖鑿,回填,和植被9966戶土壤中鉛污染含量超過每百萬分之400的住戶,「足以控管現主要和潛在對人類健康和環境構成的風險」。

在做法上,更利用挖鑿和更換含鉛的表層土壤等方法,逐漸化解含鉛外漆長期危害人類健康的威脅。

此外,環保署第7區代理主管賴斯(William Rice)說:「由官方設立的超級基金計劃(Superfund program,屬最終補救措施之一)涵蓋的整治範圍和速度史無前例,凸顯EPA高度重視保護兒童健康的態度。」

經衛生調查和科學研究證實,幼兒生活中接觸表層含鉛過量的油漆、泥土,再把手放進嘴裏讓鉛進入體内。他還說,「血液中含鉛量過高對6歲及以下兒童尤其危險,易導致像具攻擊性、低智商、聽障、腎臟受損、神經紊亂等問題。」

1999年以來,環保署清除過奧馬哈市内4600多住戶的鉛污染物,並採樣過35000多住戶,同時,另有10000戶會因決議書新規而受惠。環保署預期整治後的物件可以放心使用,不會存留有害物質或污染物。

最後,文件中環保署還警告說,大多數鉛中毒的兒童沒有生病跡象。唯一確認的方法就是讓1到6嵗的孩童接受年檢。

ASARCO有限公司是一家總部設在亞利桑那州(Arizona)開採、加工處理銅和其他金屬的採礦、冶煉、精煉公司。該公司是世界第三大銅生產商、墨西哥最大礦業公司的子公司,在美國各地有20個超級基金場址(Superfund sites)。目前處於申請破產保護狀態並捲入多項污染訴訟案件。

Decision Taken on Nation's Largest Lead-Tainted Neighborhood
OMAHA, Nebraska, May 14, 2009 (ENS)

The nation's largest residential lead site reached a key milestone today with the signing of EPA's Final Record of Decision after more than 10 years of effort to address the toxic problem by the U.S. EPA, health agencies, community organizations, schools, medical groups, and the public.

Thousands of residential yards in eastern Omaha have been contaminated over a period of decades by airborne lead emissions from the former ASARCO lead refinery. By signing the Record of Decision, the EPA agrees to clean up nearly 1,000 of them in addition to the more than 4,600 properties the federal agency has already cleaned.

The selected final remedy with an estimated capital cost of $236.6 million "addresses the principal current and potential risks to human health and the environment," says the EPA in the Record of Decision. The remedy involves excavation, backfilling, and revegetation of lead-contaminated residential soils in the 9,966 residential properties where the lead levels exceed 400 parts per million.

The agency will stabilize exterior lead-based paint that threatens the long-term protectiveness achieved through excavation and replacement of lead contaminated surface soils.

"The pace and scope of this cleanup are unprecedented for the nation's Superfund program," Acting Region 7 Administrator William Rice said. "It reflects one of the agency's most important mission priorities, the protection of children's health."

Health research and other scientific studies have shown that young children ingest lead from environmental sources by touching the contaminated surface, such as paint or soil, and then putting their hands in their mouths. "Elevated lead levels in the blood of children ages six and under are considered particularly dangerous, and have been attributed to a host of physical and behavioral health problems, including aggressiveness, lower IQs, hearing deficiencies, kidney damage, and neurological disorders," Rice said.

Since 1999, EPA has cleaned up more than 4,600 properties and sampled more than 35,000 properties in Omaha. Under the final remedy outlined by the Record of Decision, an additional 10,000 properties will also be addressed. After the implementation of the final remedy outlined in the Record of Decision, EPA anticipates that hazardous substances, pollutants, or contaminants will not remain on-site at remediated properties above levels that allow for unlimited use and unrestricted exposure.

In the Decision document, the EPA warns that most children with lead poisoning do not look or act sick. The only way to know if your children have lead poisoning is to have them tested every year from one through six years old.

ASARCO LLC is a mining, smelting, and refining company based in Tucson, Arizona that mines and processes copper and other metals. The company, a subsidiary of Grupo Mexico, the largest mining corporation in Mexico and the third largest copper producer in the world, is currently in Chapter 11 bankruptcy. ASARCO has 20 Superfund sites across the United States, and the company is the subject of several pollution lawsuits.