Comparison of regional air dispersion simulation and ambient air monitoring data for the soil fumigant 1,3-dichloropropene

• Published in: The Science of the total environment 2016-11, Vol.569-570, p.603-610
• Main Authors: van Wesenbeeck, I.J., Cryer, S.A., de Cirugeda Helle, O., Li, C., Driver, J.H.
• Format: Article
• Language: English
• Subjects: 1,3-Dichloropropene; Agriculture - methods; Air dispersion modeling; Air monitoring; Air Pollutants - analysis; Allyl Compounds - analysis; California; Environmental Monitoring - methods; Exposure assessment; Fumigation; Geography; Hydrocarbons, Chlorinated - analysis; Insecticides - analysis; Weather
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2016.06.150

SOFEA v2.0 is an air dispersion modeling tool used to predict acute and chronic pesticide concentrations in air for large air sheds resulting from agronomic practices. A 1,3-dichloropropene (1,3-D) air monitoring study in high use townships in Merced County, CA, logged 3-day average air concentrations at nine locations over a 14.5month period. SOFEA, using weather data measured at the site, and using a historical CDPR regulatory assumption of a constant 320m mixing height, predicted the general pattern and correct order of magnitude for 1,3-D air concentrations as a function of time, but failed to estimate the highest observed 1,3-D concentrations of the monitoring study. A time series and statistical comparison of the measured and modeled data indicated that the model underestimated 1,3-D concentrations during calm periods (wind speed