title: Predicting PCB concentrations in cow milk: validation of a fugacity model in high-mountain pasture conditions.
abstract: A fugacity model reported in the literature was applied to a high-altitude pasture in the Italian Alps. The model takes into account three compartments (digestive tract, blood and fat tissues) in unsteady-state conditions using food as the contamination source. Disregarding biotransformation inside cow tissues, the predicted concentrations of 14 polychlorinated biphenyls (PCBs) in milk were in good agreement with the observed data, especially for congeners known for their resistance to biotransformation (e.g., CB-138 and 153). In contrast, the predicted concentrations were clearly overestimated for congeners with high biotransformation susceptibilities. Therefore data measured in milk and faeces were used to calculate the first-order-biotransformation rate constants in dairy cows. The PCB absorption efficiency observed for pasture conditions was lower than that observed in the cowshed. The final version of the model included biotransformation and observed PCB absorption and was able to predict PCB concentrations in cow milk with mean differences between the predicted and measured data below ± 20% for most congeners.
authors.affiliation: Department of Biosciences, University of Milan, Via Celoria 26, Milan I-20133, Italy. Electronic address: paolo.tremolada@unimi.it.
authors.forename: Paolo
authors.initials: P
authors.lastname: Tremolada
authors.affiliation: Department of Biosciences, University of Milan, Via Celoria 26, Milan I-20133, Italy.
authors.forename: Niccolò
authors.initials: N
authors.lastname: Guazzoni
authors.affiliation: Department of Biosciences, University of Milan, Via Celoria 26, Milan I-20133, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Parolini
authors.affiliation: Department of Food, Environmental and Nutritional Sciences, University of Milan, Via Celoria 2, Milan I-20133, Italy.
authors.forename: Bruno
authors.initials: B
authors.lastname: Rossaro
authors.affiliation: Department of Biosciences, University of Milan, Via Celoria 26, Milan I-20133, Italy.
authors.forename: Marta Maria
authors.initials: MM
authors.lastname: Bignazzi
authors.affiliation: Department of Biosciences, University of Milan, Via Celoria 26, Milan I-20133, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Binelli
mesh_terms: D000818:Animals; D002417:Cattle; D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants / Q000032:analysis*; D005260:Female; D008892:Milk / Q000737:chemistry*; D008954:Models, Biological; D011078:Polychlorinated Biphenyls / Q000032:analysis*
chemical_list: D004785:Environmental Pollutants; D011078:Polychlorinated Biphenyls
keywords: Cow milk; Fugacity model; Mountain contamination; POP modelling; Polychlorinated biphenyls (PCBs)