Ambient air sampling

In the United States, the largest concentration of atmospheric vanadium occurs over Eastern seaboard cities where residual fuels of high vanadium content from Venezuela are burned ia utility boilers. Coal ash ia the atmosphere also coataias vanadium (36). Ambient air samples from New York and Boston contain as much as 600—1300 ng V/m, whereas air samples from Los Angeles and Honolulu contained 1—12 ng V/m. Adverse pubHc health effects attributable to vanadium ia the ambieat air have aot beea deteroiiaed. lacreased emphasis by iadustry oa controlling all plant emissions may have resulted ia more internal reclamation and recycle of vanadium catalysts. An apparent drop ia consumption of vanadium chemicals ia the United States since 1974 may be attributed, in part, to such reclamation activities. 

PCBs have been identified in ambient air samples from diverse locations (15—17,18). In one study of the atmospheric levels of several halogenated... 

Hydrocarbon Compounds Identified in Ambient Air Samples from St. Petersburg, Florida... 

Regardless of the configuration or the specific material sampled, several characteristics are important for all ambient air sampling systems. These are collection efficiency, sample stability, recovery, minimal interference, and an understanding of the mechanism of collection. Ideally, the first three would be 100% and there would be no interference or change in the material when collected. 

Table 3 provides general guidelines used in toxic air assessments in California for sampling common agricultural pesticides in ambient air at near-field sampling monitors before, during, and shortly after a field application. For communities that are near the site of the candidate pesticide application, concurrent ambient air samples are taken over durations of 24 h and are collected 4 days per week for a period of 4 weeks. 

The widespread use of -hexanc as an extractant in the laboratory creates problems in interpreting concentration readings at low levels. Even with good quality control, it may often be impossible to determine whether to attribute a measured value to the actual levels in a sample or to contamination from M-hexanc in the laboratory environment (Otson et al. 1994). For the most part, -hexane is not a common target analyte from water or soil samples. While data based on ambient air samples or sampling in the air of various workplace or residential environments are more numerous, most EPA regulatory programs rely on bulk measurements of total hydrocarbons or total volatile compounds rather than on measurements of specific compounds such as -hexane (Bishop et al. 1994 DeLuchi 1993). 

Disulfoton was detected at maximum and mean concentrations of 4.7 and 0.1 ng/m3 in only I of 123 ambient air samples collected from 10 locations in the United States in 1980 (Carey and Kutz 1985 Kutz 1983 Kutz and Carey 1986). No other air monitoring data were located. 

The Netherlands Organization of Applied Scientific Research (TNO) carried out a comparative study with Teflon-FEP-bags. Ratios between the dynamic and static method ranged from 0.7 to 1.1 after a storage time of 24 hours (7). These Teflon-bags can be used several times. Normally the sample size is 50 to 100 litres but for ambient air samples of 1600 litres are sometimes necessary. 

CHROMATOGRAM OF THE GC-MS ANALYSES OF AMBIENT AIR, SAMPLED IN THE NEIGHBOURHOOD OF A RENDERING PLANT... 

Dibromoethane has also been detected in ambient air samples collected at two hazardous waste sites in New Jersey at geometric mean concentrations of 20- 50 ppt the maximum value reported was 6,710 ppt (La Regina et al. 1986). 

Long-range transport of 1,2-dibromoethane from industrialized areas may have been the source of the compound found in ambient air samples collected in the Arctic by Rasmussen and Khalil (1984). 

Natural production was speculated to be the source of 1,2-dibromoethane found in ambient air samples collected from open areas of the North and South Atlantic Ocean by Class and Ballschmitter (1988) concentration levels were reported to be less than 0.001-0.003 ppt. 

Ambient air samples are collected on adsorbents such as Tenax (Wallace 1987), or multisorbent (Heavner et al. 1992 Oliver et al. 1996), or in passivated canisters (EPA 1988a). Tenax traps are thermally desorbed, concentrated cryogenically, and analyzed by capillary GC/MS (Wallace et al. 1987). Recovery is good (81-110%), precision for side-by-side samples is acceptable (9-45% RSD), and the detection limit is 1 g/m (Wallace 1987). Multisorbent traps may be solvent desorbed and analyzed by capillary GC/MS. Recovery and precision are good and detection limits as low as 0.019 ppb have been reported (Oliver et al. 1996). Collection of air samples in passivated stainless steel canisters is also widely utilized (EPA 1988a), but performance data are unavailable. Passive sampling devices are also widely used, due in part to their ease of use and small size (Lewis et al. 1985). 

Area (or ambient) air sampling is conducted to get an estimate of the numbers of airborne asbestos fibers present in a building. It is used as an assessment tool in evaluating the potential hazard posed by asbestos to aU building occupants. 

Analyses of ambient air samples have thus far failed to detect the presence of sulfuric acid. However, considerable quantities of ammonium sulfate salts have been detected. One possible explanation is that sulfuric acid aerosol trapped on a filter is converted to ammonium salts by reaction with ammonia in the air pulled through the filter. A laboratory generated sulfuric acid aerosol collected on a Fluoropore filter was placed in a filter holder. Arbitrarily selected suburban and urban air was passed through the filter at a rate or 30 liters/minute for approximately one hour. In every case > 95% of the sulfuric acid was apparently converted to ammonium salts of sulfate. A strict material balance was not performed. A blank sample of laboratory generated sulfuric acid aerosols was transported to and from the field with proper precautions. Less than 5% conversion of the sulfuric acid to ammonium sulfate was observed for this sample. 

Ambient air sampling on plant property of industrial bromine extraction and bromo-organics synthesis facilities revealed the presence of tetrabromobisphenol A (N.D. —28 ng/m ), decabromobiphenyl ether (N.D. —72 ng/m3), tris(2,3-dibromopro-pyljphosphate (N.D. —60 ng/m3) and l,2-bis(tribromophenoxy)ethane (N.D. —183 ng/m3). 

FIGURE 9.64 Plot of logKp for 10 PAHs in ambient air samples collected at seven sites worldwide as a function of calculated values of log KI)A. FLE fluorene, PH phenanthrene, AN anthracene, PY pyrene, FL fluoranthene, BaA benz a anthracene, CHR chrysene, BaP benzo a pyrene, BeP benzo e pyrene, BkF benzo k fluoranthene (adapted from Finizio ei al., 1997). 

Bodzek, D K. Luks-Betlej, and L. Warzecha, Determination of Particle-Associated Polycyclic Aromatic Hydrocarbons in Ambient Air Samples from the Upper Silesia Region of Poland, Atmos. Environ., 27A, 759-764 (1993). 

Coutant, R. W L. Brown, J. C. Chuang, R. M. Riggin, and R. G. Lewis, Phase Distribution and Artifact Formation in Ambient Air Sampling for Polynuclear Aromatic Hydrocarbons, Atmos. Environ., 22, 403-409 (1988). 

Gupta, P., W. P. Harger, and J. Arey, The Contribution of Nitro-and Methylnitronaphthalenes to the Vapor-Phase Mutagenicity of Ambient Air Samples, Atmos. Environ., 30, 3157-3166 (1996). 

In a study of pesticide residues in ambient air sampled in 14-16 states during 1970, 1971, and 1972, diazinon was detected in 50% of the 2,479 samples analyzed, with a mean concentration of 2.5 ng/m3 and a maximum concentration of 62.2 ng/m3 (Kutz et al. 1976). Carey and Kutz (1985) reported that ambient air concentrations of diazinon collected from February through September 1980 in Perkin, Illinois, ranged from 1.3 to 10 ng/m3. 

Diazinon residues in ambient air sampled within 800 m of two pesticide formulation plants in Arkansas (from 1970 to 1972) and within 275 m of a pesticide formulation plant in Tennessee (in 1971) ranged from... 

Dichloromethane has been detected in ambient air samples taken around the world, with background levels usually at about 0.17 pg/m. Concentrations in urban areas and in the vicinity of hazardous waste sites may be one to two orders of magnitude higher (up to 43 pg/m3). Even higher levels (mean, 670 pg/m C peak level, 5000 pg/m ) have been found in the indoor air of residences (WHO, 1996). 

Dimethylformamide has been measured in ambient air near a fibre plant and near waste facilities. It has rarely been found in water samples in the United States, other than at sewage treatment plants or in effluents of plants likely to have been using dimethylformamide. Levels measured were very low (WHO, 1991). It has been detected at low levels in drinking-water, surface water, wastewater and ambient air samples (United States National Library of Medicine, 1997). 

Dioxane has been detected in ambient air samples at low levels at several sites in die United States (United States National Library of Medicine, 1997). 

Vinyl bromide may form in air as a degradation product of 1,2-dibromoethane. It may also be released to the environment from facilities which manufacture or use vinyl bromide as a flame retardant for acrylic fibres. Vinyl bromide has been qualitatively identified in ambient air samples (United States National Library of Medicine, 1998a)... 

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