Residential sampling protocol, World Trade Center, Oct 2001

NYC 9/11 Public Portal Document

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1. Evaluate data, including trends over time Clean up should follow OSHA standards for training and worker protection and any state laws for licensing 2. Evaluate need to warn sensitive groups (people with breathing problems) Consideration should be given to removing hard to Settled dust clean furnishings, like carpet and upholstery, if > 5% crystalline 3. Evaluate the need to restrict general public sampling data remains elevated after repeated cleaning silica access NIOSH REL occupational standard for 8 hour TWA 4. Identify source and take action to reduce levels exposure. Should limit exposure of general public to below 6 pg/m’ levels above occupational standards 5 Air > 50 pg/m’ 5. Evaluate dust loading and silica content to determine if dust clean up is needed

6. Resample after actions have been taken, or if no action, continue to monitor to confirm elevated levels

1. Evaluate data, including trends over time Lower limit for air considers detection limit and 1/10 3

NIOSH REL Settled dust 2. Evaluate need to warn sensitive group (people >5% crystalline with breathing problems) silica 3. Identify source and take action to reduce levels below 6 pg/m’

Air 4. Evaluate dust loading and silica content to 6 to 49 pg/m’ determine if dust clean up is needed I 5. Resample after actions have been take, or if no action, continue to monitor to confirm elevated n levels

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