NYC-WTC_000208359

NYC 9/11 Public Portal Document

Crystalline Minerals in Air

Table la shows the presence or absence of crystalline minerals in the air in your building. All of the crystalline minerals analyzed in this project are commonly used in building construction materials. Quartz, a form of crystalline silica, is a naturally occurring mineral and is a component of concrete. Cristobalite and tridymite are different crystalline forms of silica. Calcite and portlandite are naturally occurring, alkaline minerals used in cements and mortars. Gypsum is a naturally occurring mineral used in plaster, wallboard, and in some concrete. Mica is a group of naturally occurring minerals used in paint, joint cements, plastics, roofing, and rubber. Halite (also known as rock salt or sodium chloride) is used in ceramic glazes, fire extinguishers, metallurgy, highway de-icing, and table salt.

The particle size determines how deeply a particle can travel into the respiratory tract. Inhalable particles (particulate matter with a average diameter less than 100 micrometers, or PMIOO) include larger particles that can land in the nose and throat and cause irritation. Smaller thoracic-respirable particles (PM10-PM2.5) can travel deep inside the lungs. The method used to analyze the samples could only estimate the quantity of minerals present in air. These estimated quantities were low for all minerals. Therefore, in the tables below, results are shown as detected or not detected (see full report for estimated values).

Trace amoimts of halite were detected in only a few samples and do not indicate potential for health concerns. The levels of mica found were many times lower than occupational health standards and are not likely to contribute to adverse health effects. Short-term exposures to quartz, even for a continuous year of exposure at the highest estimated level found in the air, is not expected to result in any adverse health effects.

Overall, the mineral components of concrete (quartz, calcite, and portlandite) and wallboard (gypsum, mica, and halite) were sometimes detected in air samples at higher estimated levels in lower Manhattan residential areas than in samples taken at comparison residential areas, where only gypsum was detected. Although sometimes higher than comparison buildings, these levels are still low and do not pose potential health hazards (see Conclusioiis/Recommendations).

Table la Crystalline Minerals in Air for 31 N Moore Street and the upper Manhattan Comparison Area

31 N Moore Street Comparison Area Minerals in Inhalable Thoracic - Inhalable Thoracic - Air (PMIOO) Respirable (PMIOO) Respirable (PM10-PM4) (PM10-PM2.5) Quartz Detected Detected ND ND Cristobalite ND ND ND ND Tridymite NA NA NA NA Calcite Detected Detected ND ND Portlandite Detected Detected ND ND Gypsum Detected Detected Detected Detected Mica ND ND ND ND Halite ND ND ND ND NA = not analyzed ND = not detected

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