| Alkyl Phenols and Diethylhexyl Phthalate in Tissues of Sheep Grazing Pastures Fertilized with Sewage Sludge or Inorganic Fertilizer Stewart M. Rhind,1 Carol E. Kyle,1 Gillian Telfer,1 Elizabeth I. Duff,2 and Alistair Smith1 1Macaulay Institute, Craigiebuckler, Aberdeen, United Kingdom; 2Biomathematics and Statistics Scotland, Macaulay Institute, Craigiebuckler, Aberdeen, United Kingdom Abstract
We studied selected tissues from ewes and their lambs that were grazing pastures fertilized with either sewage sludge (treated) or inorganic fertilizer (control) and determined concentrations of alkylphenols and phthalates in these tissues. Mean tissue concentrations of alkylphenols were relatively low (< 10-400 µg/kg) in all animals and tissues. Phthalates were detected in tissues of both control and treated animals at relatively high concentrations (> 20,000 µg/kg in many tissue samples) . The use of sludge as a fertilizer was not associated with consistently increased concentrations of either alkylphenols or phthalates in the tissues of animals grazing treated pastures relative to levels in control animal tissues. Concentrations of the two classes of chemicals differed but were of a similar order of magnitude in liver and muscle as well as in fat. Concentrations of each class of compound were broadly similar in tissues derived from ewes and lambs. Although there were significant differences (p < 0.01 or p < 0.001) between years (cohorts) in mean tissue concentrations of both nonylphenol (NP) and phthalate in each of the tissues from both ewes and lambs, the differences were not attributable to either the age (6 months or 5 years) of the animal or the duration of exposure to treatments. Octylphenol concentrations were generally undetectable. There was no consistent cumulative outcome of prolonged exposure on the tissue concentrations of either class of pollutant in any ewe tissue. Mean tissue concentrations of phthalate were higher (p <0.001) in the liver and kidney fat of male compared with female lambs. We suggest that the addition of sewage sludge to pasture is unlikely to cause large increases in tissue concentrations of NP and phthalates in sheep and other animals with broadly similar diets and digestive systems (i.e., domestic ruminants) grazing such pasture. Key words: alkylphenol, bioaccumulation, diethylhexyl phthalate, pasture, sewage sludge, sheep, tissue. Environ Health Perspect 113:447-453 (2005) . doi:10.1289/ehp.7469 available via http://dx.doi.org/ [Online 20 January 2005]
Address correspondence to S.M. Rhind, Macaulay Institute, Craigiebuckler, Aberdeen AB15 8QH, UK. Telephone: +44 (0) 1224 498200. Fax: +44 (0) 1224 311556. E-mail: s.rhind@macaulay.ac.uk We acknowledge the staff of the Macaulay Institute, Hartwood Research Station, for their management of the experimental animals. We thank J. Bacon for his critical review of the manuscript. This work was funded by the Scottish Executive Environment and Rural Affairs Department. The authors declare they have no competing financial interests. Received 30 July 2004 ; accepted 19 January 2005.
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