Network Plan Part 14 - NATTS, Toxics, PAMS
5. EPA's National Toxics Program
In general, EPA plans to use ambient air toxics monitoring to support the air toxics program's efforts to reduce human exposure and health risks from air toxics. The monitoring data provided by the ambient air toxics monitoring program is intended to support four major objectives:
- Establish trends and evaluate the effectiveness of air toxics emissions reduction strategies.
- Characterize ambient concentrations (and deposition) in local areas. Air toxics originate from local sources and can concentrate in relatively small geographical areas, producing the greatest risks to human health.
- Provide data to support, evaluate, and improve air quality models. Air quality models are used to develop emission control strategies, perform exposure assessments, and assess program effectiveness.
- Provide data to support scientific studies to better understand the relationship between ambient air toxics concentrations, human exposure, and health effects from these exposures.
EPA's national air toxics monitoring program is comprised of four different monitoring efforts:
- National Air Toxics Trends Stations (NATTS)
- EPA funded local-scale projects to assess conditions at the local level
- Existing State and local program monitoring
- Persistent bio-accumulative toxics monitoring
The objective for the NATTS network is to provide long-term monitoring data for certain priority air toxics across representative areas of the country in order to establish overall trends for these pollutants. Currently there are 23 NATTS established in 22 cities. The two New York NATTS sites are located in the Bronx, and Rochester, respectively.
EPA's initial ambient air toxics monitoring pilot studies disclosed that significant variations in pollutant concentrations occurred across a city and that these variations cannot be characterized by a single monitoring site. As a result, EPA decided that local-scale projects consisting of several monitors operated for a period of 1 to 2 years should be incorporated into the national air toxics monitoring strategy. In 2006 New York was awarded a grant for a community air quality air study in Tonawanda which began in July 2007. Hazardous air pollutants (HAPs) and fine particulate matter are measured at 4 locations in the Tonawanda community to address citizen concerns. The field sampling portion of this study was completed in July, 2008.
New York State has been operating a toxics monitoring network since 1990, funded entirely by State monies. Currently there are 11 sites statewide collecting 24 hr canister samples for VOC analysis in a 1 in 6 days interval. See section on NY Toxics Monitoring Network
The monitoring program for persistent bio-accumulative toxics primarily consists of deposition monitoring, not ambient air monitoring. Several monitoring programs operated by various Federal agencies have been established to measure the presence of toxics in various media. In 2010 New York completed an EPA funded community grant study titled "New York State Ambient Mercury Baseline Study" for the measurement of speciated mercury in ambient air, as well as mercury in wet deposition. Instruments at the two study sites are still operating with other funding sources and additional funding is being sought to continue this important monitoring.
In addition to air toxic-specific monitoring activities, several other monitoring programs that are primarily intended to address other air pollution concerns incorporate some aspects of air toxics monitoring. For example, the Photochemical Assessment Monitoring Stations (PAMS) collect data on certain volatile organic compound and carbonyl air toxics. Further, the results of some particulate matter monitoring is speciated (i.e., the individual compounds comprising the particulate matter are analyzed) to identify certain air toxics compounds.
5.1 National Air Toxics Trends Stations (NATTS)
EPA's Urban Air Toxics Program identified 33 high-priority urban air toxics. From these 33 air toxics EPA developed a list of 19 "core" air toxics representing the pollutants for which EPA eventually wants to develop trends information. However, because of limitations in available methodologies, EPA decided that at a minimum, in starting the network, each of the NATTS should monitor for at least 6 of these 19 pollutants. These six pollutants are considered national air toxics "drivers" (i.e., pollutants of concern in all areas of the country).
|Required Monitoring||Desired Monitoring|
For the two NATTS sites, New York will perform analysis of 42 VOCs (Table 5.2), and 12 carbonyls (Table 5.6). More details on the sampling and analysis are provided in the NY Toxics Monitoring, and Photochemical Assessment Monitoring Stations sections, respectively. In addition, low volume PM10 teflon filters are collected for trace metals analysis using ICP-MS. The targeted metals include: arsenic, beryllium, cadmium, lead, manganese, nickel, antimony, cobalt, and selenium, with the last three being potential future HAPs. Hexavalent chromium sampling commenced in November 2007 at the Rochester and Bronx sites. The cellulose filter samples are shipped to EPA/ERG for laboratory analysis. Recently, EPA determined that area wide Chromium VI monitoring should only be applicable in areas with known sources. Sampling at New York NATTS sites was suspended at the end of June, 2013.
Polycyclic Aromatic Hydrocarbons (PAHs) sampling at the Rochester and IS 52 sites began in July, 2008. The collection media consists of one 110 mm diameter glass microfiber filter and a tubular glass cartridge containing a combination of Polyurethane Foam (PUF) and XAD-2 resin. The exposed samples are shipped to an EPA contract laboratory (ERG) for analysis.
Due to roof construction work at IS 52, sampling for NATTS parameters was temporarily moved to the Morrisania site, 1.7 miles NW of the original location beginning in mid June, 2010. The relocation interrupted some sample collection. The EPA was notified of the temporary relocation prior to the move and the data will be submitted using the AQS code for the Morrisania site: 36-005-0080. The construction work at IS 52 was completed in the summer of 2012, and monitoring resumed at this site in July, 2012.
5.2 NY Toxics Monitoring Network
The NY ambient air toxics monitoring program was first established in 1985 as part of the Governor's Air Monitoring Modernization Capital Budget Program. This monitoring network measures Volatile Organic Compounds (VOCs) across the State. The initial development of the network and analytical capabilities was part of a joint Staten Island/New Jersey Urban Air Toxics Assessment Project (SI/NJ Study) coordinated with U.S. EPA Region II from 1987 through 1989. The network expanded in 1990 to a statewide network.
The goal is to monitor air quality related to toxics in the State's urban, industrial, residential, and rural areas. Implementation of this program starts the development of a long-term toxics air quality database for New York State. The database will be used to define, attain, and preserve good air quality in New York State. The data defines actual air quality impacts of the VOCs. The data is used in the design and management of New York's air quality, including risk assessment, modeling, planning and trend analysis.
Initially, only seventeen VOCs were monitored. In 1995, the number of analytes was increased to nineteen. In 2002, the list of VOCs was further expanded to include 42 compounds as shown in Table 5.2 below:
|Methyl Tert Butyl Ether||1634-04-4|
Volatile organic compounds are collected in stainless steel canisters contained in a sampler known as an ambient air canister sampler. The sampler is an air flow calibrated sampling device that pumps ambient air into the canister. A special stainless steel diaphragm pump provides a constant pressure to push the sample through the sampler. A relief valve is used to maintain a steady pressure for the sample flow controller. Samples are collected at a one in six days frequency and shipped back to the Rensselaer laboratory facility for analysis.
The analysis methodology is a modified version of EPA method TO-15. An aliquot of air sample is taken from the canister at a controlled flow and temperature onto an Entech Model 7100A preconcentrator. The preconcentration process involves a series of steps. The first trap consists of glass beads/Tenax held at -110°C which is then heated to room temperature in order to remove water/moisture in the sample. The next trap in line consists of Tenax held at - 30°C. The contaminants of interest are then desorbed at 150°C and collected on the cryofocuser held at -150°C. The sample is then rapidly heated for column injection using a Varian GC coupled with a Saturn MS detection. This method of analysis allows positive identification by retention time and molecular mass.
Concentration trends charts for some ubiquitous VOCs are provided below.
Note that for 2011, the values shown for IS 52 actually represent those from the site at Morrisania, as all monitoring at IS 52 was relocated to Morrisania in July of 2010 due to roof construction work. In August, 2012 all equipment for NATTS was relocated back to IS 52. The values presented for 2012 represent a composite of the two locations.
Figure 5.1 Annual Averages for Benzene
Figure 5.2 Annual Averages for Toluene
Figure 5.3 Annual Averages for m,p-Xylene
Figure 5.4 Annual Averages for o-Xylene
Figure 5.5 Annual Averages for 1,3-Butadiene
Figure 5.6 Annual Averages for Dichloromethane
Figure 5.7 Annual Averages for Chloroform
Figure 5.8 Annual Averages for 1,4-Dichlorobenzene
Figure 5.9 Annual Averages for Formaldehyde†
Figure 5.10 Annual Averages for Acetaldehyde
†Note that the toxics monitoring operation at IS 52 was temporarily moved to the Morrisania II site in mid June 2010 due to extensive construction work. In late July 2012, work was completed and monitoring resumed at IS 52. The values shown for 2010 and 2012 represent partial year average only.
Currently there are 11 toxics monitoring sites in operation for the measurement of VOCs, and 8 sites for carbonyls statewide. These locations are shown in Figure 5.12 below.
Figure 5.11 Location Map of Toxics Monitoring Sites
5.3 Photochemical Assessment Monitoring Stations (PAMS)
The 1993 revisions to 40 CFR Part 58 provide for the establishment and maintenance of network of air monitoring stations called Photochemical Assessment Monitoring Stations (PAMS) which will supplement the existing State and Local Air Monitoring Stations (SLAMS) network. The selection of parameters to be measured at a PAMS site varies with the site's ozone nonattainment designation and whether a site is upwind or downwind from O3 precursor source areas. These parameters are O3, total oxides of nitrogen (NOx), nitric oxide (NO), nitrogen dioxide (NO2), speciated volatile organic compounds (VOCs) and specific meteorological measurements.
The purpose of the PAMS program is to provide an air quality database that will assist in evaluating and modifying control strategies for attaining the O3 National Ambient Air Quality Standard (NAAQS). PAMS data will also be used to better characterize the nature and extent of the O3 problem, track VOC and NOx emission inventory reductions, assess air quality trends and determine whether areas of New York remain in nonattainment of the O3 NAAQS.
NYSDEC is required to operate and maintain two sites for metropolitan New York. The New York Botanical Gardens PAMS site (located in Northern Bronx) has been operational since 1994. The Queensborough Community College PAMS station (located in Queens) began monitoring of some species in late 1997. The Queens site was fully operational for the 1998 ozone monitoring season. This site moved to Queens College in the spring of 2001 as the QBCC building was undergoing a major renovation and the equipment had to be removed from the site. The Table 5.3 lists the chronology of monitoring at these sites.
|New York Botanical Garden||NOx||Jun-94|
|Queens Community College
For gaseous parameters, Table 5.4 lists the sampling instruments and analysis methods.
The following applies to meteorological measurements.
|Relative Humidity||Hydroscopic Capacitor||Continuous|
|Barometric Pressure||Piezoresistive Sensor||Continuous|
Carbonyls are sampled using DNPH cartridges and analyzed with HPLC according to EPA Method TO-11a. The target compound list is provided in Table 5.6 below.
Volatile organic compounds are monitored using Summa canisters samples followed by laboratory GCMS analysis as well as by an on-site realtime GC. The methods and sampling frequencies are provided in Table 5.7 below.
|Sampling Method||Analytical Method||Frequency|
|TO-15 (24-hr)||GC/MS||Every 6 day|
|TO-15 (40 min)||GC/MS||Once a week|
The targeted compounds are listed below:
|3-methyl-1-butene dropped 1995||43282|
|2-methyl-2-butene dropped 1995||43227|
|4-methyl-1-pentene dropped 1995||43234|
|cyclopentene dropped 1995||43283|
|2-methyl-1-pentene dropped 1997||43246|
|trans-2-hexene dropped 1995||43289|
|cis-2-hexene dropped 1995||43290|
|n-hexene added 1997||43245|
|m-ethyltoluene added 1995||45212|
|p-ethyltoluene added 1995||45213|
|o-ethyltoluene added 1995||45211|
|1,2,3 trimethylbenzene added 1995||45225|
|1,3-diethylbenzene added 1995||45218|
|1,4 diethylbenzene added 1995||45219|
|dodecane added 1997||45218|
All parameters except for the summer intensive VOCs and carbonyls are run on a continuous basis year round. VOC system startup is scheduled for May 15th each year. The carbonyl's schedule of eight (3 hour) samples every third day ended in September 2005 as the requirement was dropped by EPA to reduce overall cost of the PAMS program. The VOC intensive sampling ends in September after the final system audit. Twenty-four hour carbonyl and canister samples are continued on a six day schedule throughout the year.
The on-site GC system consists of a Markes Unity Air Server-Thermal Desorber System integrated with an Agilent GC. The Summa canisters are shipped to the Rensselaer laboratory facility and analyzed with an Entech preconcentrator with a Varian GCMS System.