Environmental pesticide distribution in horticultural and floricultural periurban production units.

The environmental pesticide distribution on non-target systems (soil, drift and agricultural plastics) during the application step at small periurban production units, was studied in open field and greenhouses, for different crops (tomato, lettuce, broccoli, strawberry and flowers) using different pesticides (endosulfan, procymidone, chlorothalonil, chlorpyrifos and deltamethrin). In all cases, soil was the most exposed non-target system. For greenhouses, a general pesticide distribution was found of approximately 2/3 for crop, 1/4 for soil and 1/20 for plastic, of the total amount applied. In horticultural open fields, although the distribution was very dependent on the crop size and type, soil was also the most exposed non-target subsystem. Pesticide drift seems not to be significant in these production units, whilst pesticide accumulation on agricultural plastics reached up to 45% of the total applied, for polyethylene mulching in strawberry fields.

Pesticide risk assessment in flower greenhouses in Argentina: the importance of manipulating concentrated products.

An evaluation of the Potential Dermal Exposure of workers to endosulfan and procymidone at the mix/load and application stages was done in small floricultural production units in Argentina. Seven experiments were performed with different operators under typical greenhouse conditions, based on the whole body dosimetry methodology. These results indicate that the mean Potential Dermal Exposure of the application step was 45.0 ± 55.0 mL h(-1) with the highest proportion on torso, head, arms and hands. When the mix/load and application stages were compared, the first was found to contribute the most to the total exposure. Also, the Margin of Safety for the different operations was calculated, and a pesticide surrogate was developed and used to make comparative evaluations of hand exposure for different groups of operators. These results emphasize the importance of the mix/load stage in the exposure process.

Potential dermal exposure in greenhouses for manual sprayers: analysis of the mix/load, application and re-entry stages.

An evaluation of the Potential Dermal Exposure for the mix/load, application and re-entry stages, associated with procymidone and deltamethrin usage, was carried out for tomatoes grown in greenhouses of small production units in Argentina. Eight experiments were done with four different operators, under typical field conditions with a lever operated backpack sprayer. The methodology applied was based on the Whole Body Dosimetry technique, evaluating a set of different data for the mix and load, application and re-entry operations. These results indicated that the Potential Dermal Exposure of the application step was (38+/-17)mLh(-1) with the highest proportion on torso, head and arms. When the three stages were compared, re-entry was found to contribute least towards the total Potential Dermal Exposure; meanwhile in all cases, except one, the mix/load operation was the stage with highest exposure. The Margin of Safety for each different operation was also calculated and the proportion of pesticide drift from the greenhouse to the environment is presented. These results emphasize the importance of improving the personal protection measures in the mix and load stage, an operation that is not usually associated with high-risk in small production units.

Potential dermal exposure to deltamethrin and risk assessment for manual sprayers: influence of crop type.

A comparison of the Potential Dermal Exposure (PDE) of workers to the insecticide deltamethrin was made as a function of crop type, in small agricultural production units in Argentina. Seven experiments were done with two different crops (maize and broccoli, treated area between 600 and 1000 m(2)) with three different operators under typical field conditions using a lever operated knapsack. The methodology is based on the whole body dosimetry technique, presenting separately the data for mixing/loading and application activities. These results indicate a higher concentration of pesticide in lower body sections for broccoli and a wider distribution for maize. The risk inherent in these agricultural procedures is estimated through Margin of Safety (MOS) values and was found to be generally safe. Preliminary results of a mass balance distribution of the pesticide between crop, soil and operator are also presented.

Analytical method for assessing potential dermal exposure to captan, using whole body dosimetry, in small vegetable production units in Argentina.

An analytical method has been developed that can be used to determine the potential dermal exposure (PDE) of workers to the pesticide captan in small-scale horticultural production units. The methodology is based on the whole body dosimetry technique, using a cotton coverall and cotton gloves as sampling media, with protective clothing worn beneath the cotton media to protect the operator. The quantitative determination of captan was done by gas chromatography-electron capture detector (GC-ECD), with the analytical method validated by measuring limits of detection and quantification, linear ranges, sample recovery and precision. Special emphasis is placed on factors that affected the stability of captan during chromatographic determination. The data generated for potential dermal exposure are presented separately for mixing/loading and application activities. These data are compared with values obtained with visible tracers using a similar field technique. Margin of safety (MOS) values are also calculated for the agricultural procedures studied.