title: Toxicity of Pb-contaminated soil to Japanese quail (Coturnix japonica) and the use of the blood-dietary Pb slope in risk assessment.
abstract: This study relates tissue concentrations and toxic effects of Pb in Japanese quail (Coturnix japonica) to the dietary exposure of soil-borne Pb associated with mining and smelting. From 0% to 12% contaminated soil, by weight, was added to 5 experimental diets (0.12 to 382 mg Pb/kg, dry wt) and fed to the quail for 6 weeks. Benchmark doses associated with a 50% reduction in delta-aminolevulinic acid dehydratase activity were 0.62 mg Pb/kg in the blood, dry wt, and 27 mg Pb/kg in the diet. Benchmark doses associated with a 20% increase in the concentration of erythrocyte protoporphyrin were 2.7 mg Pb/kg in the blood and 152 mg Pb/kg in the diet. The quail showed no other signs of toxicity (histopathological lesions, alterations in plasma-testosterone concentration, and body and organ weights). The relation of the blood Pb concentration to the soil Pb concentration was linear, with a slope of 0.013 mg Pb/kg of blood (dry wt) divided by mg Pb/kg of diet. We suggest that this slope is potentially useful in ecological risk assessments on birds in the same way that the intake slope factor is an important parameter in risk assessments of children exposed to Pb. The slope may also be used in a tissue-residue approach as an additional line of evidence in ecological risk assessment, supplementary to an estimate of hazard based on dietary toxicity reference values.
authors.affiliation: US Geological Survey, Patuxent Wildlife Research Center, Beltsville, Maryland, USA.
authors.forename: W Nelson
authors.initials: WN
authors.lastname: Beyer
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.forename: Paula
authors.initials: P
authors.lastname: Henry
authors.forename: Thomas
authors.initials: T
authors.lastname: May
authors.forename: David
authors.initials: D
authors.lastname: Mosby
authors.forename: Barnett A
authors.initials: BA
authors.lastname: Rattner
authors.forename: Valerie I
authors.initials: VI
authors.lastname: Shearn-Bochsler
authors.forename: Daniel
authors.initials: D
authors.lastname: Sprague
authors.forename: John
authors.initials: J
authors.lastname: Weber
mesh_terms: D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D003370:Coturnix; D054750:Ecotoxicology / Q000379:methods; D004781:Environmental Exposure / Q000032:analysis; D004912:Erythrocytes / Q000187:drug effects; D007854:Lead / Q000097:blood* / Q000633:toxicity*; D008297:Male; D008923:Missouri; D000623:Porphobilinogen Synthase / Q000097:blood; D011524:Protoporphyrins / Q000097:blood; D018570:Risk Assessment / Q000379:methods*; D012989:Soil Pollutants / Q000633:toxicity*
chemical_list: D011524:Protoporphyrins; D012989:Soil Pollutants; D007854:Lead; D000623:Porphobilinogen Synthase
keywords: ALAD; Benchmark; Liver; Protoporphyrin