NYC-WTC_000232959

NYC 9/11 Public Portal Document

Table 7 Summary of Mineral Components of Settled Surface Dust by Sampling Location Outdoor Settled Surface Dust of Lower Manhattan Number of Minimum Maximum Average of Number Occurrences, Detected Detected Detections Above 14 samples (% by weight) (% by weight) (% by weight) Comparison’’ totaf Outdoor samples were not taken from comparison areas above Quartz 14 (100%) 11'’ 27 J 121 NA" 59th Street because no settled surface dust was visible. Calcite 13 (93%) 0.81 19 J 61 NA Portlandite 12 (86%) 0.071 61 21 NA Gypsum 11 (79%) 0.031 271 61 NA Mica 9 (64%) 0.051 0.31 0.11 NA Halite 7 (50%) <0.03 1 0.11 0.051 NA Common Area Settled Surface Dust of Lower Manhattan Common Areas of Comparison Areas Above 59th Street Number of Minimum Maximum Average of Number Number of Minimum Maximum Average of Occurrences, Detected Detected Detections Above Occurrences, Detected Detected Detected Values 26 samples (% by weight) (% by weight) (% by weight) Comparison’’ 3 samples total (% by weight) (% by weight) (% by weight) a total” Quartz 21 (81%) 0.03 J 251 51 6 (23%) 2 (67%) 1 .1 1 .1 NA Calcite 15 (58%) 0.02 J 101 31 9 (35%) 2 (67%) 0.031 0.41 NA Portlandite 13 (50%) 0.04 J 41 21 9 (35%) 1 (33%) 0.0.5 .1 0.0.5 .1 NA Gypsum 23 (88%) 0.07 J 201 51 6 (23%) 2 (67%) 21 31 NA Mica 5 (19%) 0.06 J 0.61 0.21 5 (19%) 0 (0%) ND ND NA Halite 4 (15%) 0.04 J 0.061 0.051 1 (4%) 1 (33%) 0.041 0.041 NA Residential Units Settled Surface Dust of Lower Manhattan Residential Units of Comparison Areas Above 59th Street Number of Minimum Maximum Average of Number Number of Minimum Maximum Average of Occurrences, Detected Detected Detections Above Occurrences, Detected Detected Detected Values 57 samples (% by weight) (% by weight) (% by weight) Comparison’’ 5 samples (% by weight) (% by weight) (% by weight) totaf total” Quartz 30 (53%) 0.05 J 311 91 15 (26%) 2 (40%) 11 21 NA Calcite 20 (35%) 0.02 J 211 81 13 (23%) 1 (20%) 0.91 0.91 NA Portlandite 21 (37%) 0.05 J 81 21 17 (30%) 2 (40%) 0.081 0.081 NA Gypsum 45 (79%) 0.05 J 301 41 9 (16%) 4 (80%) 21 41 3J Mica 5 (9%) 0.03 J 0.31 0.11 1 (2%) 1 (20%) 0.081 0.081 NA O Halite 6 (11%) 0.03 J 0.11 0.061 0 (0%) 1 (20%) 0.41 0.41 NA H a. .Shows the ntimher of samples where the mineral was detected and the percentage hased on the ntimher of samples obtained from this area. to b. Shows the number of results, and the percentage of samples obtained from this area, that had estimated values greater than the maximum levels found at locations above 59th Street. c. NA = not applicable. S O d. J = estimated. o o I o

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NYC-WTC_000233026