OCR status: ok · source: pdftotext
NYC 9/11 Public Portal Document
t'
Determination of .0009f/cc as clearance value for asbestos air monitoring
Risk Assessment
The IRIS inhalation unit risk for asbestos is 2.3 E-01 per fee. Here's how this unit risk is interpreted. Exposure over a lifetime (i.e., 70 yrs) to 1 ficc of asbestos results in a cancer risk of 2.3 E-1. To get the fiber concentration equating to a 1 E-04 (one-in ten thousand risk - for lifetime exposure) the following equation is used:
23= .0001 1 fZee X
x = ,0001 .23
X = .0004 f/cc this is the fiber concentration that equates to a 1 E-04 risk for 70 year exposure.
To adjust the exposure duration to 30 years, multiply .0004 f/cc by 70 = .0009 f/cc 30
Analytical Methods
PCM NIOSH 7400 followed by AHERA TEM analysis should be used on all samples. AHERA TEM measures all fibers > .5 um. Additionally, the lab should record all fibers that are > 5 um to determine the PCMe value.
PCMe is determined by counting all fibers > 5 um with a 3:1 aspect ratio by TEM analysis. In our PCMe calculations we are using a conservative approach of counting all fibers >5um.
Therefore, the analytical result of fibers >5 um will be compared to .0009 f/cc to measure success in achieving the clearance value.
Sampling Approach
Air sampling pumps with a maximum flow rate of 15 liters per minute should be used along with sample cassettes with mixed cellulose ester filters having a pore size of .8 um. The minimum sampling volume required is 3600 liters to achieve the clearance criteria.
NYC-WTC_000155982
OCR can misread numbers and units. Confirm readings against the page image before using them.
Ranked by indexed similarity. Reasons describe shared subjects and filing context; check the source records.
NYC-WTC_000154652
Internal tracking document for managing reports, comments, and actions related to environmental compliance cases.
1 shared non-person entities · 1 shared topics · Same agency, volume and box · similarity 0.921
machine-extracted · confidence unavailable · Check page ↗NYC-WTC_000163229
Official directive instructing staff to retain specific scanned WTC documents as evidence for potential future litigation against the City.
2 shared non-person entities · 1 shared topics · similarity 0.998
machine-extracted · confidence unavailable · Check page ↗2 shared non-person entities · 1 shared topics · similarity 0.989
machine-extracted · confidence unavailable · Check page ↗NYC-WTC_000162403
Correspondence adjusting salary and travel budget figures for EPA oversight of cleaning contractors.
1 shared non-person entities · 1 shared topics · similarity 0.960
machine-extracted · confidence unavailable · Check page ↗NYC-WTC_000164830
DEP internal memo circulating draft EPA screening level standards for asbestos, fiberglass, and silica in indoor air and settled dust for agency comment.
2 shared non-person entities · 1 shared topics · similarity 0.929
machine-extracted · confidence unavailable · Check page ↗NYC-WTC_000125845
Draft fact sheet from DOH and DEP addressing tenant concerns regarding asbestos fibers at 105 Duane Street.
1 shared non-person entities · 1 shared topics · similarity 0.925
machine-extracted · confidence unavailable · Check page ↗NYC-WTC_000163599
Draft screening levels for asbestos, fiberglass and silica in indoor air and settled dust.
2 shared non-person entities · 1 shared topics · similarity 0.923
machine-extracted · confidence unavailable · Check page ↗NYC-WTC_000149346
A chain of custody cover sheet for air monitoring samples sent to the EPA Region 1 laboratory in January 2003.
2 shared non-person entities · 1 shared topics · similarity 0.920
machine-extracted · confidence unavailable · Check page ↗NYC-WTC_000162838
Correspondence regarding Schedule A forms and a draft scope of work for cleaning and air monitoring contracts at the site.
2 shared non-person entities · similarity 0.919
machine-extracted · confidence unavailable · Check page ↗NYC-WTC_000107277
Transmission journal record confirming receipt of asbestos and lead analysis data on November 14, 2002.
1 shared non-person entities · 1 shared topics · similarity 0.918
machine-extracted · confidence unavailable · Check page ↗NYC-WTC_000162222
EPA staff distributed an environmental laboratory report to federal and city agencies on May 15, 2002.
1 shared non-person entities · 1 shared topics · similarity 0.917
machine-extracted · confidence unavailable · Check page ↗NYC-WTC_000149432
DEP asbestos project notification form and inspection report dated December 12, 2002.
2 shared non-person entities · similarity 0.917
machine-extracted · confidence unavailable · Check page ↗Similar subjects in other documents. Similarity does not establish the same event, measurement or conclusion.
Page similarity is temporarily unavailable or this page has no indexed vector.
Readers open these alongside this record — through an Ask answer, the same folder, or indexed similarity. Not a claim they are about the same event.
NYC-WTC_000155793
Notice instructing recipients to preserve original World Trade Center documents as evidence and prohibiting their disposal.
Filed in the same folder
NYC-WTC_000155794
Cover sheet for a fax transmission sent from the US EPA Region 2 office in August 2002.
Filed in the same folder
NYC-WTC_000155800
Cover sheet for a fax transmission sent from the US EPA Region 2 office in August 2002.
Filed in the same folder
NYC-WTC_000155806
Cover sheet for a fax transmission sent from the US EPA Region 2 office to an external recipient in August 2002.
Filed in the same folder
Filed in the same folder