[미국] 플린트 물 위기 야기한 '누락된 납' 확인  

최근 발표된 한 연구는 미시간주 플린트(Flint)의 납 서비스 라인에서 '스위스 치즈 패턴(Swiss cheese pattern)'을 보여준다. 

미시간대학교의 연구원들은 물이 부식을 방지하기 위해 처리되지 않았기 때문에 납이 시스템에 이른다고 일반적으로 받아들여지는 이해를 지지한다고 밝혔다. 이는 부식 억제 화학물질이 물 위기를 예방하지 못했다는 규제기관의 주장을 거짓으로 증명한 최초의 직접적 증거이다.

 
미시간대학교의 보도 자료에 따르면 연구원들은 기본적으로 플린트 주변의 부식이 된, 납 서비스 라인 샘플 10개 안 금속 스케일 층에 집중했다. 이들은 화학 성분뿐만 아니라 부식(녹) 층의 질감을 연구했다. 그 분석을 활용해 연구원들은 부식 방지 없이 플린트 강물이 그 시스템을 통과한 17개월 동안 일반 납 서비스 라인이 납 18g을 방출했다고 추정했다.

[원문보기]

STUDY CONFIRMS 'MISSING LEAD' AS CAUSE FOR FLINT WATER CRISIS

A study released last week shows a "Swiss cheese pattern" in Flint, Michigan's lead service lines, with holes where the lead used to be.

 
Researchers at the University of Michigan say the findings support the generally accepted understanding that lead leached into the system because that water wasn't treated to prevent corrosion. This is the first direct evidence, proving false a regulator's claim that corrosion control chemicals would not have prevented the water crisis.

 
A press release from the University of Michigan stated that researchers focused on the layer of metal scale -- essentially lead rust -- inside 10 lead service line samples from around Flint. They studied the texture of the rust layer, as well as its chemical composition. Then they used their analysis to estimate that the average lead service line released 18 grams of lead during the 17 months that Flint river water (without corrosion control) flowed through the system.

 
So, where did that lead go?

 
"Some was consumed," Terese Olson, a U-M associate professor of civil and environmental engineering and lead author of a study in Environmental Science and Technology Letters said. "Some washed down the drain. Some might still be stored in the homes' plumbing. In other words, there is a chance that some of that lead is a potential health risk even after the lead service line is removed."

 
The study is titled "Forensic Estimates of Lead Release from Lead Service Lines during the Water Crisis in Flint, Michigan." The research team included six undergraduate students, four graduate students, two postdocs and six faculty from U-M's Flint and Ann Arbor campuses. It was funded by U-M's Schlissel Research Fund for Flint, U-M's MCubed research funding program and the Dow Sustainability Fellows program.

[출처 = Water World / 2017년 7월 31일]