Evaluation of inhaled and cutaneous doses of imidacloprid during stapling ornamental plants in tunnels or greenhouses

Abstract

The aim of this research was to assess dermal and respiratory exposure of workers to imidacloprid during manual operations with ornamental plants previously treated in greenhouses or tunnels. A total of 10 female workers, 5 in greenhouses and 5 in tunnels, were monitored for 3 or 5 consecutive days. Actual skin contamination, excluding hands, was evaluated using nine filter paper pads placed directly on the skin. To evaluate the efficacy of protective clothing in reducing occupational exposure we also placed four pads on top of the outer clothing. Hand contamination was evaluated by washing with 95% ethanol. Respiratory exposure was evaluated by personal air sampling. Respiratory dose was calculated on the basis of a lung ventilation of 15 l/min. Absorbed doses were calculated assuming a skin penetration of 10% and a respiratory retention of 100%. Dislodgeable foliar residues (DFRs) were determined during the days of re-entry in order to determine the dermal transfer factor. From the dependence of dermal exposure of hands from DFRs, a mean transfer factor was estimated to be 36.4 cm 2 /h. Imidacloprid was determined by liquid chromatography with selective mass detection and electrospray interface in all matrices analysed. Respiratory dose was 4.1 ± 4.0 (0.1-14.3)% and 3.0 ± 2.0 (0.6-6.9)% (mean ± SD (range)) of the total real dose during work in tunnels and greenhouses, respectively. The estimated absorbed doses, 0.29 ± 0.45 mg/kg (0.06-2.25 mg/kg) body weight and 0.32±0.18 mg/kg (0.07-0.66 mg/kg) body weight (mean±SD (range)) in tunnels and in greenhouses, respectively, were less than the acceptable operator exposure level of 0.15 mg/kg body weight and than the acceptable daily intake of 0.05 mg/kg body weight. The hands and exposed skin of all workers were found to be contaminated, indicating that greater precautions, such as daily changing of gloves and clothing, are necessary to reduce skin exposure.

Monitoring and Control of Exposure to Buprofezin in Greenhouses

“…Another study conducted during re-entry (stapling) in tunnels of ornamental plants previously treated with Imidacloprid showed 13% penetration [16], confirming the mean penetration values of the present study.…”

“…The differences in dermal transfer coefficients may be due to the protection afforded by latex gloves used constantly by the women during their work, and above all to daily replacement of cotton gloves. This was sustained by the fact that hand contamination contributed more than 50% and 80% to real doses of Chlorthalonil [13] and Imidacloprid [16], respectively, against 24% for Buprofezin in the present study.…”

“…The coefficients of dermal transfer between hands and leaves and between cotton gloves and leaves were 0.94 cm 2 /h and 3.43 cm 2 /h (geometric mean), respectively. These values are much lower than that observed during stapling of Shindapsus treated with Chlorthalonil [13] and Imidacloprid [16]. In the former study on Chlorthalonil, for DFR levels similar to the present ones, hand contamination was much higher, whereas in the latter study with Imidacloprid, hand contamination was of the same order of magnitude as in the present study but DFR was lower.…”

“…Evaluation of skin exposure by means of filter paper pads and hand washing with 95% ethanol has likewise been reported in other studies [10][11][12][13][14][15][16]. The methods used to extract samples are fast and give good recovery of analyte and good precision within and between series.…”

Skin symptoms in bakery and auto body shop workers: associations with exposure and respiratory symptoms

“…In two other studies, both involving pesticide exposure, there was no association found between skin and airborne exposure. The authors attribute this lack of association to the fact that the primary source of skin exposure was likely contact with contaminated foliage rather than the settling of airborne pesticide (Flack et al 2008; Aprea et al 2009). …”