Dust and Endosulfan Deposition in a Cotton-Growing Area of Northern New South Wales, Australia
- Francis J. Larney *,
- John F. Leys,
- Jochen F. Müller and
- Grant H. McTainsh
Agriculture and Agri-Food Canada, Research Centre, P.O. Box 3000, Lethbridge, AB, Canada T1J 4B1; New South Wales Dep. of Land and Water Conservation, Gunnedah Research Centre, P.O. Box 462, Gunnedah NSW 2380, Australia; Natl. Research Centre for Environmental Toxicology, 39 Kessels Rd., Coopers Plains Qld. 4108, Australia; Faculty of Environmental Sciences, Griffith Univ., Nathan Qld. 4111, Australia. Abstract
The pesticide endosulfan (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepin-3-oxide) has been detected in rivers in the cotton (Gossypium hirsutum L.)-growing area of northern New South Wales at a 5 yr mean (1991–1995) concentration of 0.06 µg L−1. One pathway by which endosulfan reaches the riverine environment is transport on contaminated dust. Our objectives were to examine: (i) dust deposition from vehicular traffic on an unsealed road on a cotton farm, and around a cotton field in the 11 to 65 h period after endosulfan application; (ii) endosulfan deposition in the 11 to 65 h period after endosulfan application, and over a 3-mo period at on-farm and off-farm (nontarget) locations. Dust deposition rates from vehicular traffic varied from 0.013 g m−2 vehicle−1 at 1 m distance, to 0.002 g m−2 vehicle−1 at 100 m distance from an unsealed road (soil surface, no gravel added). The maximum endosulfan deposition in the 11 to 65 h post-spraying period was 95 µg m−2 at 5 m from the field. Over a 3-mo monitoring period (December 1996–March 1997), the average daily deposition rate of endosulfan was 0.16 µg m−2 d−1 for the off-farm sites compared with 0.35 µg m−2 d−1 for the on-farm site. As the measurement period was one of the wettest on record and the number of endosulfan applications was less-than-normal, the dust and endosulfan deposition results may be interpreted as minima.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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