Air Quality Monitoring in Manhattan, NY Dan Vallero
Example of Measurement Results in Lower Manhattan following WTC Collapse • Particle/fibers • SVOCs • VOCs
Sampling Approach at WTC • Screening level approach to identify chemical species in air and bulk dust which may be of human health concern • Three air monitoring sites ~ 100 m around Ground Zero • 24-hour PM2.5 samples and grab samples for volatile organic compounds (VOCs) • Air monitoring site established at 290 Broadway on 16th floor with same measurements as Ground Zero • Also, semi-volatile organic compounds (SVOCs); continuous measurements of elemental carbon, particle sizing and particle counts • Settled dust collected at Ground Zero to determine dioxin concentrations and elemental composition of dust • Additional monitoring sites away from Ground Zero (AC Power) to measure dioxins and furans in the air.
K AQ Team’s Monitoring Sites
Nephelometers at WTC Time trace of 1848 ten-minute averages shows moderate levels of light scattering punctuated by periods of high to very high scattering, as would be expected near a source of dust and with variable wind speeds and directions
Scanning Electron Microscopy at WTC Evidence of the fibrous nature of the particles is presented, which show three randomly selected fields of view taken at low magnification.
Individual WTC fiber analysis by SEM Bulk material quite fibrous and tended to aggregate into large clumps
Morphology and Chemical Composition of WTC Fibers • SEM is not the definitive or sole method for identifying asbestos • Unlikely that the fibers found in this particular sample are asbestos fibers, based on their variable size and chemical composition.
WTC Fiber Characterization • Most particles or fibers of Ca-S or Ca-Si-Al-Mg-S composition, similar to that of plaster or wallboard • Ranged in diameter between approximately 1 and 10 μm
Particles < 10 μm diameter • Most particles less than 10 μm in diameter had compositions similar to the fibers • Likely to have originated from the same building materials.
Particles < 10 μm diameter • Some metals including Fe and Zn, were also found.
The Urban Dispersion Program (UDP) NYC MSG05 Experiment: The Participation and Collaboration of US EPA, NERL and EOHSI Investigators: EOHSI – P. J. Lioy, PhD and P.G. Georgopoulos, PhD EPA - Gary Foley, PhD, Jerry Blancato, PhD James Daloia, Ph.D., Dan Vallero, PhD March, 2005 Participating organizations: NOAA, DHS, DARPA, NYCOEM, EPA Region II, Brookhaven National Laboratory, Battelle Northwest, Private Consultants O
Goals of MSG05 • Understand flow and dispersion in a deep urban canyon. • Understand rapid vertical transport and dispersion in re-circulating eddies adjacent to very tall buildings. • Complete tracer experiments with concurrent detailed meteorology to improve he above, and develop and evaluate dispersion models. • Obtain a high quality field data that will be distributed to others. • Improve design of future field experiments in NYC. • Understand the concentration distribution of and personal exposure to the tracers at the surface and indoors away from release points.
Study design • There were: • two one-hour continuous releases, separated by a one and one-half hour interval with no release, • pattern selected because • 1) there were ten sequential “bags” in the PFT samplers, • 2) a 30-minute averaging time was optimum for continuous releases, • 3) the concentrations are expected to decrease significantly (by at least one or two orders of magnitude) during the “no-release” interval so that the two clouds can be distinguished by the samplers. • The six-hour sampling period was from 9 am to 2 pm ( the part of day when stabilities are fairly constant at nearly-neutral). • Two days of experiments were completed in MSG05 – March 10 and 14, 2005 .
Approach to Exposure Characterization Study in MSG05 The EPA and EOHSI jointly designed a personal exposure characterization experiment that ran concurrently with the other measurements completed within MSG05 on 3/10/2005
Goals of the Exposure Characterization • Quantify the levels of exposure to PFT’s, using the personal BNL-PFT monitors within: • the near field, <20m, of an MSG release point • areas >20m from an MSG release point • Define specific outdoor and indoor activity patterns used by volunteers (12) during a two hour time period after a release of the PFT’s • Each pattern was intended to represent a different pre- or post-release activity scenarios
Goals of the Exposure Characterization(continued) 3. Examine the field results for the patterns of PFT emissions and the activities of the personal monitoring volunteer • one or ten minute integrated personal PFT samples will be collected during each 1 hour release period • collection will also occur during the hour immediately after a release period 4. Construct personal exposure profiles for each person and for each release event • examine for coherence in location/time with the stationary dispersion monitoring/MSG05 dispersion modeling results
Goals of the Exposure Characterization (continued) 5. Employ the exposure measurements within the Modeling Environment for Total Risk (MENTOR) system using its Individual Based Exposure Modeling (IBEM) framework to • Evaluate and refine exposure/dose characterization for individuals affected by emergency events involving atmospheric release of hazardous agents • Use the personal monitoring results and activities of volunteer to improve simulations of exposures for emergency events • Use the personal monitoring results to improve modules in MENTOR individual exposures associated with emergency events
Goals of the Exposure Characterization(continued) • Provide results that can be used to develop response and interdiction activities to mitigate casualties and protect emergency responders • Yield a better sense of what may be encountered after an attack • Identify what must be done to protect emergency responders while being in harms way 7. Apply near field exposure/concentrate data to help evaluate the predictions of air movement in street canyons around MSG by meteorological models