Tier Screening Value Basis Action
I > 70 ng/m^ * ♦Risk-based screening level Aggressive cleaning - if
for residential setting levels persist, take additional
(E-04 X lyr), 1/10 average action to reduce exposure
dietary intake
II 2 ng/m^ (or background) - 2 ng/m^ - ♦♦Risk based Maintain recommended
70 ng/m^ screening level for residential (diligent wet/HEPA) cleaning
setting methods -consider additional
(E-04 X 30 yr) monitoring
III <2ng/m2 pr background) Determination of local No further action
background
*based on proposed dioxin cancer slope factor
*♦ Methodology based on NYSDOH assessment of office building in Binghamton, NY
Dioxin (indoor air)
NYC-WTC_000140650
OCR can misread numbers and units. Confirm readings against the page image before using them.
NYC-WTC_000140650Source: 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.