Assessing natural isothiocyanate air emissions after field incorporation of mustard cover crop.

A regional air assessment was performed to characterize volatile natural isothiocyanate (NITC) compounds in air during soil incorporation of mustard cover crops in Washington State. Field air sampling and analytical methods were developed specific to three NITCs known to be present in air at appreciable concentrations during/after field incorporation. The maximum observed concentrations in air for the allyl, benzyl, and phenethyl isothiocyanates were respectively 188, 6.1, and 0.7 μg m(-3) during mustard incorporation. Based on limited inhalation toxicity information, airborne NITC concentrations did not appear to pose an acute human inhalation exposure concern to field operators and bystanders.