VOC sampling locations table for Ground Zero area, Jan 2002

NYC 9/11 Public Portal Document

different distances. Some monitors for particulate matter (PM), operated by New York State, existed prior to the disaster.

This report focuses on; PM, metals (lead, chromium and nickel compounds), polychlorinated biphenyls (PCBs), dioxin-like compounds, asbestos, and volatile organic compounds (VOCs). These substances are included because monitoring indicated that they correlated with the disaster site in both time and space, and because they pose a potential concern for health impacts. PM was generated by the collapse of the WTC buildings, the recovery and demolition operations, and the lingering fire. Lead and asbestos were believed to be components of the WTC building materials. PCBs were used as dielectric fluid in transformers and capacitors. Dioxin and VOCs are produced as a result of combustion and volatilization from fuels. The assessment is limited to an evaluation mainly of the inhalation of airborne contaminants, although dust ingestion and dermal contact may also have led to exposures within and near Ground Zero.

Elevated concentrations of these contaminants were found within and near Ground Zero for a short period of time after September 11. “Elevated” is used in this discussion to denote concentrations of a contaminant that were significantly higher, by a factor of 10 or more and often by factors of 100 or 1000, compared to other measurements of the contaminant taken in the WTC monitoring program or compared to concentrations that are typically found in New York City or in general United States urban settings. Many of these elevated measurements were identified as having occurred in “restricted zones,” that is, zones where access was limited to emergency management and rescue personnel and to other credentialed people. In general, the monitoring data, even within Ground Zero, indicate that ambient air levels for all of these substances decreased to background ambient concentrations that are characteristic of pre­ September 11 levels in the New York City metropolitan area by around January or February of 2002,

The analysis in this reportfinds that:

• Persons exposed to the extremely high levels of ambient particulate matter and its components during the collapse of the World Trade Center towers andfor several hours afierwards were at risk for immediate acute (and possibly chronic) respiratory and other types (e.g., cardiovascular) ofsymptoms.

• The first measurements ofsome of the contaminants were on September 14, while other contaminants were not measured until September 23. Available data suggests that the concentrations within and near Ground Zero were likely to be highest in the few days following September 11. Because there are only limited data on these criticalfew days, aqjosures and potential health impacts cannot be evaluated with certainty for this time period.

• Exceptfor exposures on September 11 and possibly during the nextfew days, persons in the surrounding community were unlikely to suffer short-term or long-term adverse health effects caused by exposure to elevations in ambient air concentrations ofthe contaminants evaluated in this report. These elevated concentrations were

DRAFT-DO NOT QUOTE OR CITE 2 October 2002

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