Dust and VOC risks during cultural operations in citrus orchards

The paper reports the results of some experimental tests aimed at measuring the concentration of volatile organic compounds (VOC) and dust in the air breathed by operators during the main cultural operations in citrus groves. The in field activity was developed by considering soil tillage (by means of tooth harrow, disk arrow, and rototiller), fertilisation (by means of centrifugal fertiliser spreader), and pesticide application (by means of air-assisted sprayer and handheld spray lance). The operating machines were applied to tractors with and without cab. Measurements were carried out by means of portable instruments which sampled the air at some 20 cm from the operator’s respiratory tract. The measured average values of dust and VOC concentration were quite low and under the threshold limit values suggested by the American Conference of Governmental Industrial Hygienists (ACGIH). Being the cab not equipped with filtering devices, the differences in VOC concentrations were mainly due to the different characteristics of the tractors’ internal combustion engines, while the cab proved its efficiency in protecting against dust exposure: on average, the dust concentration was a fourth (36 μg/m3) when using the tractor equipped with cab.