巴金森氏症與都市污染物有關 | 環境資訊中心

巴金森氏症與都市污染物有關

2010年11月09日
摘譯自2010年11月2日ENS密蘇里州,聖路易斯報導;洪美惠編譯;蔡麗伶審校

根據位於聖路易的華盛頓大學醫學部科學家一項分析3萬5千位巴金森氏症患者的研究,都市區域高濃度的錳和銅污染會增加罹患巴金森氏症風險。

該研究小組發現,住在錳汙染濃度較高的人,比起居住在沒有汙染地區的人,罹患巴金森氏症的風險高出78%。

環境中高濃度銅,則會提高11%罹患巴金森氏症的風險。

「我們追蹤病人、檢查病人暴露在汙染物的往史、病況以及對治療的反應。如果這些研究可以確認相關性,那麼我們將要重新評估環境中排放這些汙染物的上限值。」華盛頓大學醫學部神經學助理教授威利斯博士(Allison Wright Willis)說。

實驗以對照比較醫療病歷數據和環保署的工業排放報告來進行研究,論文發表在「美國流行病學期刊」。

「從1988年以來,任何工廠或是其他產業,如果釋放出列管的650種汙染物任一種超過規定,就必須跟環保署申報。」威利斯博士說,「我們用那些數據來建構高錳、高銅、高鉛汙染含量的區域,比對很少或沒有這些汙染物的地方。」

研究不同的產業在不同地理區域產生的污染物排放量。

「沒有哪個產業是罪魁禍首。」威利斯博士說,「排放錳、銅、鉛的產業,含括了食品、香菸、飲料、木製品、家具、服飾以及石作產業。其他還有電子產品、電腦業、金屬加工業、化學設備業和金屬礦業。」

看到高汙染濃度區域的社經狀況,研究人員相當驚訝;許多地區都是經濟中等甚至是高等收入區域,而不是貧困或經濟匱乏的地方。

根據國家衛生研究院表示,在美國,至少有50萬人被診斷患有巴金森氏症,每年約有5萬名新病例。

巴金森氏症是一種神經系統疾病,1817年一位倫敦醫師詹姆斯巴金森(Dr. James Parkinson)最早描述這個病徵,因此此症以他名字命名。

大腦一小部份的細胞逐漸喪失,導致腦部傳遞訊息的化學物質多巴胺(dopamine)不足,產生的病徵包括:雙手顫抖、動作緩慢、僵硬、失去平衡。其他症狀還有:臉部失去表情、語音音量和清晰度漸漸變低、吞嚥困難;皮膚乾燥、便秘、解尿困難以及憂鬱。 巴金森氏症是持續漸進的疾病,這些症狀隨著時間越來越惡化。

巴金森氏症和耕作以及暴露在農業化學物質有相關性的報告很多;但是,對於此症在都市裡的危險因子卻知道不多。

威利斯博士和他同事的研究,將研究目標放在城市地區,以去除農藥這一因素。他們要研究那些會增加罹患巴金森氏症的險其他物質。

他們利用醫療數據,篩選出3萬5千名巴金森氏症患者,這些患者必須是居住同一區域並被確定診斷8年或更久。

隨著年齡、種族、性別而調整,每10萬人有274個巴金森氏症新病例的區域,且該地區很少或沒有錳、銅、鉛等污染。

在高錳污染區域,這一比例上升到489.4,而在高銅汙染區,則上升至304.2。

錳是一種微量元素,從食物或飲水中攝取少量是維持健康所必需的。暴露於過量的錳,尤其是錳用於製造業時,像是從空氣中呼吸進來,或是從飲水或食物。根據美國聯邦有毒物質及疾病登記署(Agency for Toxic Substances,ATS)表示,高濃度時,可能導致大腦損傷。

某些職業如焊接或在製鋼工廠做事,可能會增加暴露在高錳濃度環境的機會,ATS說。

高鉛排放量的區域,並沒有顯著增加巴金森事症的罹患率。早期幾個鉛暴露與巴金森氏症相關的研究,威利斯說,巴金森氏症患者的骨骼鉛含量增加。

威利斯推測,除了工業排放、水汙染之外,其他的鉛暴露來源,例如,遭受汙染的油漆,也可能是巴金森氏症的重要因素。

Parkinson's Disease Linked to Pollutants in Urban Areas
ST. LOUIS, Missouri, November 2, 2010 (ENS)

High levels of manganese and copper pollution in urban areas are linked to increased risk of Parkinson's disease, according to an analysis of 35,000 Parkinson's patients by scientists at Washington University School of Medicine in St. Louis.

The research team found that people living in areas with higher levels of manganese pollution had a 78 percent greater risk of Parkinson's disease than those living in areas free of such pollution.

High levels of copper in the environment increased the risk of Parkinson's disease by 11 percent.

"We're following up with individual patients, examining exposure histories, disease progression and responses to treatments, and if those studies confirm this correlation, we may need to reevaluate the limits we place on environmental discharges of these pollutants," said lead author Allison Wright Willis, MD, assistant professor of neurology at the Washington University School of Medicine.

The comparison, published in "American Journal of Epidemiology," was conducted using Medicare data and industrial discharge reports to the U.S. Environmental Protection Agency.

"Every year since 1988, any factory or other industry that releases more than a predefined amount of any of 650 chemicals into the environment has to report those discharges to the EPA," Dr. Willis says. "We used that data to construct a comparison of areas with high levels of manganese, copper and lead pollution versus areas where there were few or no releases of those elements."

Many different industries produced the pollutant emissions in the geographic areas studied.

"There's no one group to blame," says Dr. Willis. "Manganese, copper and lead emissions were reported by industries ranging from food, tobacco and beverages to wood products, furniture, apparel and stone work. Others included producers of electrical and computer equipment, metalworking and chemical facilities and metal mining."

The researchers were surprised when they looked at the socioeconomic status of areas with higher pollutant levels. Instead of being uniformly poor and economically depressed, many are middle-class and upper-income areas.

In the United States, at least 500,000 people are believed to suffer from Parkinson's disease, and about 50,000 new cases are reported annually, according to the National Institutes of Health.

Parkinson's Disease is a neurological illness named after Dr. James Parkinson, a London physician who was the first to describe it in 1817.

The gradual loss of cells in a small part of the brain creates a deficiency of the brain signaling chemical dopamine, producing symptoms that may include shaking of hands, slowing down of movement, stiffness, and loss of balance. Other symptoms may include loss of facial expression, reduction in speech volume and clarity, difficulty swallowing, dry skin, constipation, urinary difficulties, and depression.

Because Parkinson's disease is a progressive disorder, these symptoms worsen with time.

Parkinson disease associated with farming and exposure to agricultural chemicals has been reported in numerous studies; but little is known about Parkinson disease risk factors for those living in urban areas.

In their research, Willis and her colleagues focused only on urban areas to avoid pesticides, another group of compounds whose presence in the environment is believed to increase the risk of Parkinson's disease.

Willis and her colleagues then used Medicare data to identify 35,000 Parkinson's patients who were living in the area in which they were diagnosed eight years or more before diagnosis.

When adjusted for age, race, sex, there were 274 new cases of Parkinson's disease per 100,000 people in areas with little or no reported manganese, copper or lead pollution.

In areas with high manganese pollution, that number rose to 489.4, and in areas with high copper levels, it increased to 304.2.

Manganese is a trace element and eating a small amount from food or water is needed to stay healthy. Exposure to excess levels of manganese may occur from breathing air, particularly where manganese is used in manufacturing, and from drinking water and eating food. At high levels, it can cause damage to the brain, according to the federal Agency for Toxic Substances.

Certain occupations like welding or working in a factory where steel is made may increase the chances of being exposed to high levels of manganese, the agency says.

Areas with high lead emissions were not associated with a significant increase in Parkinson's disease. Several earlier studies have associated lead exposure with Parkinson's risk, Willis says, including research that has found increased lead levels in the bones of Parkinson's patients.

Willis speculates that other sources of lead exposure besides industrial emissions - water contamination, for example, or contaminated paint - may have a stronger influence on Parkinson's disease risk.

全文及圖片詳見:ENS報導