Air sample collection

As an example, several air samples collected during an 8-hour work shift for benzene (8-hour time-weighted average = 10 ppm) were 3 hours at 4 ppm, 1 hour at 15 ppm, 2 hours at 6 ppm and 2 hours at 9 ppm. The employee s time-weighted average exposure would be ... 

Fig. 18-11 Records of atmospheric CO2 in Antarctica for the past 1000 years. Open circles are ice-core data from Law Dome, on the coast of east Antarctica (Etheridge et al., 1996). Plus signs are direct measurements of CO2 in air samples collected monthly at the South Pole (NOAA Climate Monitoring and Diagnostics Laboratory, Boulder, Colorado).

No information was found on the occurrence of methyl parathion in air samples collected at NPL sites. 

Air samples collected in the Sacramento Valley area of California near sites where methyl parathion was heavily used on rice were analyzed by Seiber et al. (1989). Methyl parathion concentrations ranged from 0.2 (minimum detectable level) to 25.67 ng/m depending on the location and time of sampling. Methyl paraoxon, the oxygen analog of methyl parathion, was also detected at a maximum of 3.07 ng/m. The highest concentrations of both compounds were found at sites near locations of heaviest use. 

Endosulfan (one or both of its isomers) has been identified in air samples collected at only 4 of the 164 NPL hazardous waste sites where it was detected in some environmental media (HazDat 2000). 

As a result of its use as an insecticide on fruit trees, vegetables, and other crops, endosulfan is released directly to the atmosphere during application. The compound is applied principally by air-blast equipment or boom sprayers (WHO 1984). No information was found in the available literature regarding atmospheric releases from manufacturing or formulation operations, or occurrence of the compound in air samples collected at NPL sites. 

Denmark 1.5 days after the explosion. Air samples collected at Roskilde, Denmark on April 27-28, contained a mean air concentration of 241Am of 5.2 pBq/m3 (0.14 fCi/m3). In May 1986, the mean concentration was 11 pBq/m3 (0.30 fCi/m3) (Aarkrog 1988). Whereas debris from nuclear weapons testing is injected into the stratosphere, debris from Chernobyl was injected into the troposphere. As the mean residence time in the troposphere is 20-40 days, it would appear that the fallout would have decreased to very low levels by the end of 1986. However, from the levels of other radioactive elements, this was not the case. Sequential extraction studies were performed on aerosols collected in Lithuania after dust storms in September 1992 carried radioactive aerosols to the region from contaminated areas of the Ukraine and Belarus. The fraction distribution of241 Am in the aerosol samples was approximately (fraction, percent) organically-bound, 18% oxide-bound, 10% acid-soluble, 36% and residual, 32% (Lujaniene et al. 1999). Very little americium was found in the more readily extractable exchangeable and water soluble and specifically adsorbed fractions. 

Air Sample collection on cellulose filter, dry ashed, solvent extracted Biphasic liquid scintillation 1 pCi 95% Bomben et al. 1994... 

Air samples collected in one acrylonitrile-fiber plant ranged from 3 to 20 mg/m3 (EPA 1980a). Mean 24-hour acrylonitrile concentrations in atmospheric samples collected within 5 km of 11 factories producing or using acrylonitrile ranged from less than 0.1 to 325 pg/m (Suta 1979). The occurrence of acrylonitrile was correlated to wind patterns the highest concentrations were downwind of and in close proximity to the plant. The median concentration of acrylonitrile for 43 measurements in "source-dominated areas" (i.e., near chemical plants) was 2.1 pg/m (Brodzinsky and Sing 1983). There were no data available on the concentration of acrylonitrile in air near chemical waste sites, but because acrylonitrile is easily volatilized, this is an exposure pathway of concern. 

Sonication helps improve solid-liquid extractions. Usually a finely ground sample is covered with solvent and placed in an ultrasonic bath. The ultrasonic action facilitates dissolution, and the heating aids the extraction. There are many EPA methods for solids such as soils and sludges that use sonication for extraction. The type of solvent used is determined by the nature of the analytes. This technique is still in widespread use because of its simplicity and good extraction efficiency. For example, in research to determine the amount of pesticide in air after application to rice paddy systems, air samples collected on PUF were extracted by sonication, using acetone as the solvent. The extraction recoveries were between 92% and 103% [21]. 

There is also a potential for atmospheric release of endrin, endrin aldehyde, and endrin ketone from hazardous waste sites. Endrin has been detected in air samples collected at 4 of the 102 NPL sites where endrin has been detected in some environmental medium (HazDat 1996). No information was found on detections of endrin aldehyde or endrin ketone in air at any NPL hazardous waste site (HazDat 1996)... 

The field test was conducted from May 2003, towards the end of the Severe Acute Respiratory Syndrome (SARS) outbreak in Hong Kong, until January 2004. The students taking part in the field tests were properly trained and equipped with medical safety equipment. Air samples collected at the reception area was designated as control samples (Fig. 12.9-12b). The Prototype Unit was located in the doctor s consultation room (Fig. 12.9-12c) and was operated 10 h/day, 6 days/week during the six months test period. 

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. 

Urban air Sample collected in bubbler containing NaOH, derivatized as nitrobenzeneazo compound HPLC-UV 0.05 ppb for 150-L sample 58-60% at 0.33-0.5 pg phenol 72.3% at 10-50 pg phenol... 

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. 

Decabrom, Tetrabrom, and Firemaster 680. All of these compounds are amenable to analysis by selected ion monitor glc/ms/comp. However, substantially lower detection limits for TRIS were attained using glc/ecd. Thin-layer chromatography was used for the analysis of Decabrom in some air samples collected during a preliminary study. 

Sheppard 1980). The level of thorium measured in 1969 in East Chicago, IN, a heavily polluted industrial area, was 1.3 ng/m compared to a value of 0.27 ng/m at a rural location in Michigan (Niles, Ml) (Dams et al. 1970). The air particulate samples collected from 250 sites in the United States by the National Air Surveillance Network (NASN) of ERA during 1975 and 1976 were analyzed for thorium-232 by neutron activation analysis. The measured concentrations at 250 urban and nonurban sites in the United States ranged from 0.2-1.0 ng/m, with a mean concentration of 0.3 ng/m (Lambert and Wilshire 1979). The mean concentrations of thorium-228, thorium-230 and thorium-232 in New York City air (sample collected on the roof above the 14th floor) were 36 aCi/m (aCi = 10 Ci), 36 aCi/m, and 37 aCi/m, respectively (Wrenn et al. 1981). 

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). 

Air Samples NMOR, NDMA, and NPYR were found during the first NIOSH visit in air samples collected at a tire manufacturing plant in Maryland. One process sample, collected at a feedmill, contained 250 yg/M3 of NMOR, a level several times higher than has been reported for any airborne nitrosamine at any industrial site (1). Maximum concentrations of NDMA and NPYR found in the hot process areas were 4.4 yg/M3 and 3.4 yg/M3, respectively. Over the following 7 months, ventilation improvements and changes in chemical formulation of the rubber resulted in a 200-fold reduction in NMOR levels and elimination or reduction of other nitrosamines at most sites. Results are shown in Figure 2, and Table I. 

Results. No N-nitroso compounds were found in any of the air samples collected at the facility. 

In a study of pesticide levels in ambient suburban air, diazinon was detected in 80, 80, and 40% of samples collected in three cities (Miami, Florida Jackson, Mississippi and Fort Collins, Colorado), respectively. The maximum diazinon concentration detected in each city was 3.9, 2.0, and 2.2 ng/m3 for Miami, Florida Jackson, Mississippi and Fort Collins, Colorado, respectively (Kutz et al. 1976). During 1973-1974, diazinon concentrations in air were measured in urban Miami, Florida, and in the adjacent Everglades National Park. Urban diazinon levels ranged from not detectable to 3.3 ng/m3 (1.5 ng/m3 mean) corresponding levels in Everglades National Park ranged from not detectable to 1.9 ng/m3 (0.6 ng/m3 mean) (Lewis and Lee 1976). Nationwide, diazinon was detected in 48% of 123 urban air samples collected in ten U S. cities during 1980. The maximum diazinon concentration reported was 23 ng/m3 (mean 2.1 ng/m3) (Carey and Kutz 1985). 

PBBs have been identified in 1 air sample, collected from 1,613 NPL hazardous waste sites, where they were detected in some environmental media (HazDat2002). 

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