Measured and computed concentrations of 1,3‐dichloropropene in the air around fumigated fields

Abstract

Concentration patterns of both isomers of 1,3‐dichloropropene in air around two fields were computed with a gaussian plume model for six time intervals after injection of the fumigant into the soil and compared with concentrations measured in the air. During the first three days after the injection of 1,3‐dichloropropene into the soil of one field, the downwind concentrations of 1,3‐dichloropropene in air computed for a height of 1.5 m above the ground ranged up to 19 μg m−3, whereas the downwind concentrations measured ranged up to 29 μg m−3. For the period from five to ten days after injection, the concentrations computed and those measured ranged up to 36 μg m−3 and 16 μg m−3, respectively. For the other field, the computed downwind concentrations in air ranged up to 0.6 μg m−3 during the first three days after injection, whereas those measured ranged up to 23 μg m−3. For the period from four to nine days after injection, the concentrations computed and those measured ranged up to 2.3 and 1.3 μg m−3, respectively. The computations under‐estimated the concentrations in air during the first three days following application, but on later days the computed and measured concentrations were mostly at the same level.