鉛毒進行式 研究:鉛暴露與少年反社會行為有關 | 台灣環境資訊協會-環境資訊中心

鉛毒進行式 研究:鉛暴露與少年反社會行為有關


根據最新一期的《犯罪學》期刊研究,兩位哈佛大學種族生態學者研究發現,兒童時期的鉛暴露與青少年時期的反社會行為有關,顯示鉛暴露是一種環境不正義(environmental inequity),不過研究沒有發現鉛暴露與逮捕行為有直接關係。

Joseph Mietus(CC BY-NC 2.0)
美國今日還有400萬個家庭生活在高濃度的鉛暴露環境。圖片來源:Joseph Mietus(CC BY-NC 2.0)


主要作者桑普森(Robert Sampson)博士是哈佛社會科學亨利福特二世教授、波士頓地區研究計畫的創辦人及主任、以及美國律師協會的合聘研究教授。

在這份研究中,桑普森和共同作者、哈佛大學社會學家溫特(Alix Winter)運用1995至2013年間超過100萬次芝加哥兒童血液檢測的全面性資料,與超過2300個地理區塊進行比對。



公共衛生勝利喊得太早 鉛毒還沒遠離




無明顯症狀  全美400萬個家庭生活於高鉛環境


約有50萬個一至五歲美國兒童,血鉛濃度超過每分升5微克(μg/ dL),已經達到CDC建議啟動公共衛生措施的參考水準。




當年黑人處於劣勢  鉛毒暴露驚人種族差異





Childhood Lead Exposure Linked to Teen Delinquency
CAMBRIDGE, Massachusetts, March 13, 2018 (ENS)

Two Harvard researchers who examined the racial ecology of lead exposure as a form of environmental inequity have concluded that lead exposure in childhood is linked to antisocial behavior in adolescence, although not directly linked to arrests.

Lead author Dr. Robert Sampson is the Henry Ford II Professor of the Social Sciences at Harvard, founding director of the Boston Area Research Initiative, and affiliated research professor at the American Bar Foundation.

For this study, Sampson and co-author Harvard sociologist Alix Winter drew on comprehensive data from over one million blood tests administered to Chicago children from 1995-2013 and matched to over 2,300 geographic block groups.

They found that contemporary lead exposure is linked to minority status and poverty at the individual level, as well as to racial segregation and concentrated poverty at the neighborhood level, “primarily because of the unequal distribution of dilapidated housing that contains remnants of lead paint.”

“The results underscore lead exposure as a trigger for poisoned development in the early life course and call for greater integration of the environment into theories of individual differences in criminal behavior,” the authors conclude.

Exposure to dangerous levels of lead was extensive for long stretches of the 20th century, the authors recount. Although environmental reforms such as the bans on lead in gasoline and paint in the 1970s were considered victories for public health at the time, lead toxicity is far from a hazard of the past, state Sampson and Winter.

High levels of lead have recently been found in thousands of cities in the United States and in both developed and developing countries around the world.

“The poisoning of the water in Flint, Michigan, in late 2015 and the evacuation in 2016 of an entire neighborhood contaminated by a smelting plant in East Chicago, Indiana, shone bright public lights on the contemporary perils of lead,” they write.

The U.S. Centers for Disease Control and Prevention, CDC, says that today at least four million U.S. households have children living in them that are being exposed to high levels of lead.

There are approximately half a million U.S. children ages one to five with blood lead levels above five micrograms per deciliter (µg/dL), the reference level at which CDC recommends public health actions be initiated.

Even parents are often unaware of lead levels in their children’s environments, write Sampson and Winter. “Lead-based paint has remained in millions of housing units despite being banned, sometimes stirred up by housing renovations or hidden by landlords with fresh coats of paint and then exposed when newer paint layers peel.”

They point out that lead smelting plants, most of which were built decades ago and have been shuttered for some time, are a major source of contemporary soil lead.

No safe blood lead level in children has been identified, the CDC warns. Lead exposure can affect nearly every system in the body. Because lead exposure often occurs with no obvious symptoms, it frequently goes unrecognized.

To make certain their conclusions are accurate, the authors assessed an array of structural explanations for observed racial disparities, including socioeconomic status, type and age of housing, proximity to freeways and smelting plants, and systematic observations of housing decay and neighborhood disorder.

Overall, the authors write, “our theoretical framework posits lead toxicity as a major environmental pathway through which racial segregation has contributed to the legacy of Black disadvantage in the United States.”

“Our findings support this hypothesis and show alarming racial disparities in toxic exposure, even after accounting for possible structural explanations,” they write.

At the same time, they say, our longitudinal results show the power of public health policies to reduce racial inequities.

The study is published in the current issue of the journal “Criminology.” 

※ 全文及圖片詳見:ENS