NYC-WTC_000199812

NYC 9/11 Public Portal Document

4.0 INORGANIC METALS

4.1 Collection

4.1.1 Surface Wipe

Disposable wipes were used to collect surface wipe samples from furniture with hard surfaces such as table tops. Sampling was conducted in accordance with the procedure specified in Appendix 13.1, “Wipe Sampling for Settled Lead-Contaminated Dust” of the HUD Guidelines for the Evaluation and Control of Lead-Based Paint Hazards in Housing (HUD 1995). The sample area was measured and recorded.

4.1.2 Surface Dust

A new stiff bristle toothbrush was used to collect surface dust samples from table tops and other furniture with hard surfaces. The dust was swept into a pile and then collected using a scoop constructed of paper. The dust was then placed in a clean 50-ml polyethylene centrifuge tube with a screw-cap lid. The sample area was measured and recorded.

4.1.3 Bulk Dust

Bulk dust samples were collected from exterior surfaces (including a window ledge and a roof top) showing heavy deposits of dust. The dust was placed in either a clean zip-lock plastic bag or 50-ml plastic centrifuge tube.

4.2 Analysis

4.2.1 Surface Wipe

The samples were prepared in accordance with EPA SW-846 Method 3050 and / analyzed to determine the presence of 22 metals (excluding mercury). The samples were analyzed in accordance with EPA'SW-846 Method 6010 using inductively coupled plasma atomic absorption spectrometry (ICP-AES). The samples for mercury were prepared and analyzed for mercury in accordance with EPA SW-846 Method 7471.

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NYC-WTC_000199829