Tier Screening Value Basis Action
I > 1.5 ug/m^ NAAQS (intended to keep Aggressive cleaning - if
99.5% of childhood levels persist, take additional
population below 30 ug/dl action to reduce exposure
II .1 ug/m^ - 1.5 ug/m3 .1 ug/m3 - UBK Lead Model Maintain recommended
default value for urban (diligent wet/HEPA) cleaning
background methods -consider additional
monitoring
III .1 ug/m^ (orbackground) Determination of local No further action
background
*PAHs (settled dust)
NYC-WTC_000140647
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NYC-WTC_000140647Source: NYC Law Department, mirrored locally
Introduction to a cross-agency group tasked with identifying contaminants of concern and establishing health-based screening levels for the indoor environment.