Bulk soil and surface wipe sampling report, Jan 2002

NYC 9/11 Public Portal Document

Mr. Vincent McGowan BPCPC January 14, 2001 Page 4 of 4

they are the most current and state specific guidelines available. As listed in Table 1 below, all results for soils are less than the state mandated cleanup objectives as listed in Table 4 attached to this report.

In addition, Colden has compared all sample - results to the background levels of these heavy metals found in the Eastern United States for additional comparison. Below is a table summarizing our findings by each contaminant (metal): Table 1: Results of Metals in Soils Samples and Guideline Standards Contaminant Range of Analytical Eastern USA (Metal): Recommended US EPA Results of (4) Bulk Background Soil Cleanup (ppm) Soil Samples (ppml): Levels (ppm): Objective(ppm): Arsenic 2.67 - 3.01 3 - 12 7.5 or SB2 20 Barium 21.60-30.13 15-600 300 or SB N/A Cadmium ND - 0.45 0.1 - 1.0 1.0 or SB N/A Chromium 7.19- 17.04 1.5 -40 10 or SB N/A Lead 15.92 - 35.44 See Footnote SB 400 for play Mercury areas ND 0.001 - 0.2 0.1 Selenium N/A ND 0.1 - 3.9 2.0 or SB Silver N/A 0.33-0.79 N/A4 SB N/A I - For the purpose of clarity, all results are presented in parts per million (ppm). Laboratory results were reported in mg/Kg, which is equal to ppm on a one-to-one ratio.

2 - New York State Background Level (SB)

3 - Background levels for lead vary widely. Average levels in undeveloped, rural areas may range from 4 - 61 ppm. Average background levels in metropolitan or suburban areas or near highways are much higher and typically range from 200-500 ppm.

4 - Even though silver is not associated with adverse health effects, the EPA establishes exposure limits for many materials based on various endpoints of concern. To our knowledge, silver is the only chemical or substance which has an RfD that is not based on an adverse health effect, but rather on a cosmetic effect (argyria). While an RID for silver still exists, in 1991 the EPA deleted the maximum contaminant level, or MCL for silver in drinking water (an enforceable value) and replaced it with a secondary maximum contaminant level (SMCL) goal (non-enforceable) of an action that was driven by the recognized low toxicity 0.1 ppm that is twice the previous level, associated with silver. (The Silver Council) ND = None Detected N/A = Not Available

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