Dust exposure of operators during citrus orchard cultivation

This study is focused on operator’s dust exposure during some cultural operations: soil tillage,fertilisation, and pruning trituration. Soil tillage was performed by using a disc harrow, a toothharrow, and a rototiller, fertilisation by using a centrifugal fertiliser, and pruning trituration byusing a pruning triturator. Moreover, tractors equipped or not with cab were used. Dust wasmeasured by using a portable particle dust monitor, whose operating principle lies in lightscattering, and results were expressed as count per minute (cpm). They can be converted inmg/m3 by using the standard calibration factor (1 cpm = 0.001 mg/m3During soil tillage and fertilisation, the experiments showed a significant reduction (from 124 to37 cpm, less than a third) in the exposure when working with the tractor equipped with cab. Thehighest exposure was measured during pruning trituration (1825 cpm). Assuming the standardcalibration factor, these values are lower than the ACIGH exposure limits, but STEL valuesover 15 minute when working with pruning triturator without cab are near to those establishedby ACGIH.