title: First detection of lead in black paper from intraoral film: an environmental concern.
abstract: Lead (Pb) contamination in the black paper that recovers intraoral films (BKP) has been investigated. BKP samples were collected from the Radiology Clinics of the Dental School of Ribeirão Preto, University of São Paulo, Brazil. For sake of comparison, four different methods were used. The results revealed the presence of high lead levels, well above the maximum limit allowed by the legislation. Pb contamination levels achieved after the following treatments: paper digestion in nitric acid, microwave treatment, DIN38414-54 method and TCLP method were 997 microg g(-1), 189 microg g(-1), 20.8 microg g(-1), and 54.0 microg g(-1), respectively. Flame atomic absorption spectrometry (FAAS) and inductively coupled plasma mass spectrometry (ICP-MS) were employed for lead determination according to the protocols of the applied methods. Lead contamination in used BKP was confirmed by scanning electron microscopy coupled with energy dispersive X-ray microanalysis (SEM-EDS). All the SEM imaging was carried out in the secondary electron mode (SE) and backscattered-electron mode (QBSD) following punctual X-ray fluorescence spectra. Soil contamination derived from this product revealed the urgent need of addressing this problem. These elevated Pb levels, show that a preliminary treatment of BKP is mandatory before it is disposed into the common trash. The high lead content of this material makes its direct dumping into the environment unwise.
authors.affiliation: Departamento de Odontologia Restauradora, Faculdade de Odontologia de Ribeirão Preto, Universidade de São Paulo, Av. do Café, S/N, Monte Alegre, CEP 14040-904, Ribeirão Preto, SP, Brazil. defcg@usp.br
authors.forename: Débora F C
authors.initials: DF
authors.lastname: Guedes
authors.forename: Reginaldo S
authors.initials: RS
authors.lastname: Silva
authors.forename: Márcia A M S
authors.initials: MA
authors.lastname: da Veiga
authors.forename: Jesus D
authors.initials: JD
authors.lastname: Pecora
mesh_terms: D000143:Acids; D003764:Dental Materials / Q000032:analysis*; D004785:Environmental Pollutants / Q000032:analysis*; D004787:Environmental Pollution / Q000032:analysis*; D007854:Lead / Q000032:analysis*; D013058:Mass Spectrometry; D017744:Medical Waste Disposal / Q000379:methods*; D008670:Metals / Q000302:isolation & purification; D008855:Microscopy, Electron, Scanning; D008872:Microwaves; D010209:Paper; D012995:Solubility; D013054:Spectrophotometry, Atomic; D014874:Water Pollutants, Chemical / Q000032:analysis; D014881:Water Supply / Q000032:analysis; D014962:X-Ray Film
chemical_list: D000143:Acids; D003764:Dental Materials; D004785:Environmental Pollutants; D017744:Medical Waste Disposal; D008670:Metals; D014874:Water Pollutants, Chemical; D007854:Lead