Mucha Amy Pelka, Stites Nicole, Evens Anne, MacRoy Patrick M, Persky Victoria W, Jacobs David E
Division of Environmental and Occupational Health Sciences, School of Public Health, University of Illinois at Chicago, Chicago, IL 60612, USA.
Environ Res. 2009 Feb;109(2):143-8. doi: 10.1016/j.envres.2008.10.010. Epub 2008 Dec 21.
Over 3000 older homes containing lead-based paint are demolished in Chicago each year. While previous studies investigating large multifamily housing demolitions have shown high levels of lead in dustfall, dispersed single-family housing demolition have yet to be assessed. Presently, no standards exist to regulate the extent of lead dustfall from housing demolition.
We studied ten residences in Chicago undergoing demolition and debris removal and compared dustfall rates to five standing homes from March to October 2006.
Dustfall was measured using a modification of APHA Method 502; samplers consisted of plastic buckets filled with 1l of deionized water, elevated to breathing zone height and placed around the demolition site perimeter. Laboratory analysis consisted of filtration, acid digestion and analysis by ICP/MS.
During demolition, the geometric mean lead dustfall (n=43 at 10 locations) was 64.1 microgPb/m(2)/h (range: 1.3-3902.5), while the geometric mean lead dustfall for areas with no demolition (n=18 at 6 locations) was 12.9 microgPb/m(2)/h (range: 1.8-54.5). This difference was highly statistically significant (p=0.0004). When dust suppression measures were used, dustfall lead levels were lower, although the difference was not statistically significant. The geometric mean lead dustfall with dust suppression (n=25 at five locations) and without (n=22 at six locations) was 48 Pbmicrog/m(2)/h and 74.6 microgPb/m(2)/h, respectively.
Demolition dustfall lead levels are much higher than background levels of lead during demolition of single-family housing and may constitute a yet uncharacterized but important source of lead exposure to nearby residents. Simple dust suppression methods are likely to reduce the contamination considerably.
芝加哥每年拆除3000多所含有铅基涂料的老房子。虽然之前对大型多户住宅拆除的研究表明降尘中铅含量很高,但分散的单户住宅拆除情况尚未得到评估。目前,尚无标准来规范房屋拆除过程中铅降尘的程度。
我们研究了芝加哥10处正在进行拆除和碎片清理的住宅,并在2006年3月至10月期间将降尘率与5处未拆除的住宅进行了比较。
降尘量采用对美国公共卫生协会(APHA)502方法的改良进行测量;采样器由装满1升去离子水的塑料桶组成,放置在呼吸带高度并环绕拆除场地周边。实验室分析包括过滤、酸消解以及通过电感耦合等离子体质谱法(ICP/MS)进行分析。
拆除期间,10个地点的43个样本的几何平均铅降尘量为64.1微克铅/平方米/小时(范围:1.3 - 3902.5),而未拆除区域(6个地点的18个样本)的几何平均铅降尘量为12.9微克铅/平方米/小时(范围:1.8 - 54.5)。这种差异具有高度统计学意义(p = 0.0004)。当采取降尘措施时,降尘中的铅含量较低,尽管差异无统计学意义。采取降尘措施(5个地点的25个样本)和未采取降尘措施(6个地点的22个样本)的几何平均铅降尘量分别为48微克铅/平方米/小时和74.6微克铅/平方米/小时。
在单户住宅拆除过程中,拆除降尘中的铅含量远高于背景铅含量,可能构成附近居民铅暴露的一个尚未明确但重要的来源。简单的降尘方法可能会大幅减少污染。