title: Lead line in rodents: an old sign of lead intoxication turned into a new method for environmental surveillance.
abstract: The "lead line" was described by Henry Burton in 1840. Rodents are used as sentinels to monitor environmental pollution, but their teeth have not been used to determine lead. To determine whether lead deposits can be observed in the teeth of lead-exposed animals, since the gingival deposits known as "lead line" would likely have a correlate in the calcified tissue to which the gums are opposed during life. Male Wistar rats were exposed to lead in the drinking water (30 mg/L) since birth until 60 days-old. Molars and the incisors of each hemimandible were analyzed by scanning electron microscopy (SEM) on regular and backscattered electrons (BSE) mode. Elements were determined using electron dispersive spectroscopy (EDS). Clean cervical margins were observed on control teeth, as opposed to the findings of extensive deposits on lead-exposed animals, even in hemimandibles that had been exhumed after being buried for 90 days. BSE/EDS indicated that those deposits were an exogenous material compatible with lead sulfite. Presence of calcium, phosphorus, magnesium, carbon, lead, and oxygen is presented. Lead-exposed animals presented marked root resorption. The lead deposits characterized here for the first time show that the "lead line" seen in gums has a calcified tissue counterpart, that is detectable post-mortem even in animals exposed to a low dose of lead. This is likely a good method to detect undue lead exposure and will likely have wide application for pollution surveillance using sentinels.
authors: Department of Morphology, Physiology, and Basic Pathology, School of Dentistry of Ribeirao Preto (FORP), University of Sao Paulo (USP), Avenida do Cafe S/N, Monte Alegre, Ribeirao Preto, Sao Paulo, CEP 14040-904, Brazil. fellipe.figueiredo@usp.br.
authors: Fellipe Augusto Tocchini
authors: FA
authors: de Figueiredo
authors: Department of Morphology, Physiology, and Basic Pathology, School of Dentistry of Ribeirao Preto (FORP), University of Sao Paulo (USP), Avenida do Cafe S/N, Monte Alegre, Ribeirao Preto, Sao Paulo, CEP 14040-904, Brazil.
authors: Junia
authors: J
authors: Ramos
authors: Department of Morphology, Physiology, and Basic Pathology, School of Dentistry of Ribeirao Preto (FORP), University of Sao Paulo (USP), Avenida do Cafe S/N, Monte Alegre, Ribeirao Preto, Sao Paulo, CEP 14040-904, Brazil.
authors: Erika R Hashimoto
authors: ER
authors: Kawakita
authors: Department of Morphology, Physiology, and Basic Pathology, School of Dentistry of Ribeirao Preto (FORP), University of Sao Paulo (USP), Avenida do Cafe S/N, Monte Alegre, Ribeirao Preto, Sao Paulo, CEP 14040-904, Brazil.
authors: Alina S
authors: AS
authors: Bilal
authors: Department of Morphology, Science Health Center, Federal University of Paraiba (UFPB), Joao Pessoa, Paraiba, Brazil.
authors: Frederico B
authors: FB
authors: de Sousa
authors: National Institute for Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, MD, USA.
authors: William D
authors: WD
authors: Swaim
authors: Department of Morphology, Physiology, and Basic Pathology, School of Dentistry of Ribeirao Preto (FORP), University of Sao Paulo (USP), Avenida do Cafe S/N, Monte Alegre, Ribeirao Preto, Sao Paulo, CEP 14040-904, Brazil.
authors: Joao P Mardegan
authors: JP
authors: Issa
authors: Department of Morphology, Physiology, and Basic Pathology, School of Dentistry of Ribeirao Preto (FORP), University of Sao Paulo (USP), Avenida do Cafe S/N, Monte Alegre, Ribeirao Preto, Sao Paulo, CEP 14040-904, Brazil.|Graduate Program in Pharmacology and Toxicology, Faculty of Medicine of Ribeirao Preto (FMRP), University of Sao Paulo (USP), Avenida Bandeirantes 3400, Ribeirao Preto, Sao Paulo, CEP: 14049-900, Brazil.
authors: Raquel F
authors: RF
authors: Gerlach
mesh_terms: D000818:Animals; D004781:Environmental Exposure; D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants / Q000378:metabolism*; D007854:Lead / Q000032:analysis*; D008297:Male; D008855:Microscopy, Electron, Scanning; D008963:Molar / Q000737:chemistry* / Q000648:ultrastructure; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
chemical_list: D004785:Environmental Pollutants; D007854:Lead
keywords: Dental enamel; Environmental monitoring; Lead; Lead line; Sentinels; Tooth