Lead in teeth from lead-dosed goats: Microdistribution and relationship to the cumulative lead dose

• Published in: Environmental research Vol. 106; no. 1; pp. 34 - 41
• Main Authors: Bellis, David J., Hetter, Katherine M., Jones, Joseph, Amarasiriwardena, Dula, Parsons, Patrick J.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01-01-2008; Elsevier
• Subjects: 60 APPLIED LIFE SCIENCES; ABLATION; ABSORPTION SPECTROSCOPY; Administration, Oral; Animals; Biological and medical sciences; BIOLOGICAL MARKERS; BLOOD; Capra hircus; Chemical and industrial products toxicology. Toxic occupational diseases; Dentin - chemistry; DOSES; Environmental Monitoring - methods; Environmental Pollutants - analysis; Environmental Pollutants - pharmacokinetics; GOATS; Goats - metabolism; ICP MASS SPECTROSCOPY; Laser ablation; LASERS; LEAD; Lead - analysis; Lead - pharmacokinetics; Lead exposure; Linear Models; Medical sciences; Metals and various inorganic compounds; SPATIAL RESOLUTION; Spectrophotometry, Atomic; TEETH; Tissue Distribution; Tooth - chemistry; Toxicology; Capra hircus; Lead; Laser ablation; Lead exposure; Teeth; Dentin; Biological indicator; Exposure; Cumulated dose; Heavy metal; Concentration measurement; Vertebrata; Mammalia; Animal; Dentition; Goat; Artiodactyla; Tooth; Ungulata; Public health
• ISSN: 0013-9351; 1096-0953
• DOI: 10.1016/j.envres.2007.05.010

Teeth are commonly used as a biomarker of long-term lead exposure. There appear to be few data, however, on the content or distribution of lead in teeth where data on specific lead intake (dose) are also available. This study describes the analysis of a convenience sample of teeth from animals that were dosed with lead for other purposes, i.e., a proficiency testing program for blood lead. Lead concentration of whole teeth obtained from 23 animals, as determined by atomic absorption spectrometry, varied from 0.6 to 80
μg
g
−1. Linear regression of whole tooth lead (μg
g
−1) on the cumulative lead dose received by the animal (g) yielded a slope of 1.2, with
r
2=0.647 (
p<0.0001). Laser ablation inductively coupled plasma mass spectrometry was employed to determine lead content at micrometer scale spatial resolution in the teeth of seven goats representing the dosing range. Highly localized concentrations of lead, ranging from about 10 to 2000
μg
g
−1, were found in circumpulpal dentine. Linear regression of circumpulpal lead (μg
g
−1) on cumulative lead dose (g) yielded a slope of 23 with
r
2=0.961 (
p=0.0001). The data indicated that whole tooth lead, and especially circumpulpal lead, of dosed goats increased linearly with cumulative lead exposure. These data suggest that circumpulpal dentine is a better biomarker of cumulative lead exposure than is whole tooth lead, at least for lead-dosed goats.