130
Pesticides, Organic Contaminants, and Pathogens in Air
FIGURE 8.6
Field design for measuring downwind concentrations of MeBr from a fallow downwind feld.
FIGURE 8.7
Detail of the air sampling masts for sampling MeBr in air prior to analysis by headspaceGC. (Reprinted (adapted) with permission from (Woodrow, J.E., LePage, J.T., Miller, G.C., and
Hebert, V.R. (2014). Determination of MIC in outdoor residential air near metam-sodium soil
fumigations. J. Agri. Food Chem. 62, 8921–8927.). Copyright (2014) American Chemical Society.)
adsorbent was subsequently extracted and subjected to gas chromatography (GC) analysis (see Chapter 6) (Figure 8.7). Air concentrations of MeBr
measured above a bare fumigated feld and downwind from the feld along
with meteorological data were used to calculate vertical (aerodynamic) and
horizontal fux, respectively. Mid-feld vertical fux and average horizontal fux measured on the downwind edge of the feld were all but identical (~99%). Vertical air concentration and fux profles farther downwind
showed depletion of MeBr near the surface of an adjoining mature strawberry feld (Figure 8.6) and adsorbed MeBr was found in the surface soil
of the same feld (preliminary evidence that soil is a sink for MeBr) (Seiber
et al., 1996). Another objective was to compare downwind air concentration
data to concentrations predicted by a dispersion model (Industrial Source
Pesticides, Organic Contaminants, and Pathogens in Air
FIGURE 8.6
Field design for measuring downwind concentrations of MeBr from a fallow downwind feld.
FIGURE 8.7
Detail of the air sampling masts for sampling MeBr in air prior to analysis by headspaceGC. (Reprinted (adapted) with permission from (Woodrow, J.E., LePage, J.T., Miller, G.C., and
Hebert, V.R. (2014). Determination of MIC in outdoor residential air near metam-sodium soil
fumigations. J. Agri. Food Chem. 62, 8921–8927.). Copyright (2014) American Chemical Society.)
adsorbent was subsequently extracted and subjected to gas chromatography (GC) analysis (see Chapter 6) (Figure 8.7). Air concentrations of MeBr
measured above a bare fumigated feld and downwind from the feld along
with meteorological data were used to calculate vertical (aerodynamic) and
horizontal fux, respectively. Mid-feld vertical fux and average horizontal fux measured on the downwind edge of the feld were all but identical (~99%). Vertical air concentration and fux profles farther downwind
showed depletion of MeBr near the surface of an adjoining mature strawberry feld (Figure 8.6) and adsorbed MeBr was found in the surface soil
of the same feld (preliminary evidence that soil is a sink for MeBr) (Seiber
et al., 1996). Another objective was to compare downwind air concentration
data to concentrations predicted by a dispersion model (Industrial Source