Exposure to pastures fertilised with sewage sludge disrupts bone tissue homeostasis in sheep.
The femurs of male and female sheep (Ovis aries), aged 18 months, bred on pastures fertilized twice annually with sewage sludge (2.25 tonnes dry matter/ha; Treated; T)) or on pastures treated with inorganic fertilizer (Control; C) were studied, using peripheral Quantitative Computed Tomography (pQCT) and the three-point bending test. Males were maintained on the respective treatments from conception to weaning and then maintained on control pastures while the females were maintained on the respective treatments until slaughter. T rams exhibited increased total bone mineral density (BMD) at the metaphyseal part of femur (+10.5%, p<0.01) compared with C rams but had a reduced total cross sectional area (CSA, -11.5%, p<0.001), trabecular CSA (-17.1%, p<0.01) and periosteal circumference (-5.7%, p<0.001). In the mid-diaphyseal part, T rams had an increased total BMD (+13.8%, p<0.0001) and stiffness (+6.4%, p<0.01) but reduced total CSA (-12.1%, p<0.0001) and marrow cavity (-25.8%, p<0.0001), relative to C rams. In ewes although pQCT analysis of neither the metaphyseal nor the mid-diaphyseal part of the female femur bones showed any significant differences with treatment, the biomechanical method revealed a reduction in load at failure (-17.3%, p<0.01) and stiffness (-10.7%, p<0.05) amongst T ewes. It is concluded that exposure to pollutants present in sewage sludge can perturb bone tissue homeostasis in sheep, but particularly in males.
Lind
P Monica
PM
Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden. Monica.Lind@ki.se
Gustafsson
Magnus
M
Hermsen
Sanne A B
SA
Larsson
Sune
S
Kyle
Carol E
CE
Orberg
Jan
J
Rhind
Stewart M
SM
D000818:Animals; D015415:Biomarkers / Q000032:analysis; D015519:Bone Density / Q000187:drug effects; D001842:Bone and Bones / Q000187:drug effects* / Q000473:pathology; D004785:Environmental Pollutants / Q000633:toxicity*; D005260:Female; D005269:Femur; D005308:Fertilizers / Q000633:toxicity*; D055768:Halogenated Diphenyl Ethers / Q000032:analysis; D006706:Homeostasis; D008297:Male; D011078:Polychlorinated Biphenyls / Q000032:analysis; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis; D012722:Sewage / Q000737:chemistry*; D012737:Sex Factors; D012756:Sheep / Q000033:anatomy & histology* / Q000254:growth & development
D015415:Biomarkers; D004785:Environmental Pollutants; D005308:Fertilizers; D055768:Halogenated Diphenyl Ethers; D011084:Polycyclic Aromatic Hydrocarbons; D012722:Sewage; D011078:Polychlorinated Biphenyls