TY - JOUR

T1 - The aqueous photodegradation of fenitrothion under various agricultural plastics : implications for pesticide longevity in agricultural 'micro-environments'.

AU - Weber, Jan

AU - Halsall, Crispin J.

AU - Wargent, Jason J.

AU - Paul, Nigel D.

PY - 2009/6

Y1 - 2009/6

N2 - Plastic cladding is increasingly used in agriculture to create micro-environments to improve crop yield/growth. Many of these plastics can alter the solar light spectrum by inhibiting or reducing the transmittance of certain parts of the solar spectrum. In this study, we investigated the aqueous photolysis of fenitrothion, under a selection of different plastic films commonly used in agriculture. Three different grades of polyethylene film were used: ‘standard’, ‘transparent’ and ‘opaque’. The transmittance of light wavelengths in the UV region (290–400 nm), measured with a spectroradiometer, was found to decrease in the order of transparent > standard > opaque. Fenitrothion, an organophosphorothioate insecticide possesses molar absorptivity in the solar wavelength range of 290–400 nm. Aqueous first order degradation rate constants for fenitrothion determined over a 12 h period were found to be considerably less for those experiments conducted under the standard and opaque plastic films, compared to the transparent film and no-film control. The experiments were conducted in an Atlas Suntest solar simulator using a UV-filtered Xenon arc lamp to simulate sunlight. The first order half-life for fenitrothion was 100 and 250 h under the standard and opaque films, respectively, compared to 10 h for the transparent film and no-film experiments. Our results suggest that pesticide longevity could be greatly extended within these plastic micro-environments, especially for those chemicals which may degrade/transform via photolytic or photochemical pathways.

AB - Plastic cladding is increasingly used in agriculture to create micro-environments to improve crop yield/growth. Many of these plastics can alter the solar light spectrum by inhibiting or reducing the transmittance of certain parts of the solar spectrum. In this study, we investigated the aqueous photolysis of fenitrothion, under a selection of different plastic films commonly used in agriculture. Three different grades of polyethylene film were used: ‘standard’, ‘transparent’ and ‘opaque’. The transmittance of light wavelengths in the UV region (290–400 nm), measured with a spectroradiometer, was found to decrease in the order of transparent > standard > opaque. Fenitrothion, an organophosphorothioate insecticide possesses molar absorptivity in the solar wavelength range of 290–400 nm. Aqueous first order degradation rate constants for fenitrothion determined over a 12 h period were found to be considerably less for those experiments conducted under the standard and opaque plastic films, compared to the transparent film and no-film control. The experiments were conducted in an Atlas Suntest solar simulator using a UV-filtered Xenon arc lamp to simulate sunlight. The first order half-life for fenitrothion was 100 and 250 h under the standard and opaque films, respectively, compared to 10 h for the transparent film and no-film experiments. Our results suggest that pesticide longevity could be greatly extended within these plastic micro-environments, especially for those chemicals which may degrade/transform via photolytic or photochemical pathways.

KW - Pesticides

KW - Greenhouse

KW - Photodegradation

KW - Environmental persistence

U2 - 10.1016/j.chemosphere.2009.01.084

DO - 10.1016/j.chemosphere.2009.01.084

M3 - Journal article

VL - 76

SP - 147

EP - 150

JO - Chemosphere

JF - Chemosphere

SN - 0045-6535

IS - 1

ER -