Lead Levels In Teeth Research Articles

Lead levels in deciduous teeth of Queensland children.

Lead levels in the deciduous teeth of 292 Queensland children aged between 4 and 9 years are reported. Samples were obtained through the cooperation of parents of children attending kindergartens throughout the State in 1981. Information relating to the child's place of residence, home environment and parents' occupation was also gathered with the aid of a questionnaire. Tooth lead levels ranged from 0 to 29 micrograms/g (mean, 3.4 micrograms/g; SD, 4.1 micrograms/g). Possible relationships between aspects of the subject's history and lead levels are discussed and the data are compared with those of similar, already published studies.

Neuropsychological effects of lead in children: interactions with social background variables.

Following a short and selective summary of findings from psychological studies on lead-induced cognitive dysfunction in man, our own studies in lead-exposed children are briefly described in more detail. These studies, run in the cities of Duisburg and Stolberg, were based on tooth lead levels as the principal indicator of long-term cumulative lead exposure. From a comprehensive sample of neuropsychological outcome measures, only few significant findings emerged, namely lead-related deficits of visual-motor integration and of reaction performance, but not of general intelligence. Without exception, the observed lead effects were small compared to those of social background. An interesting interaction was found between lead exposure and social background for visual-motor integration and for reaction performance: for both these measures, but not for intelligence, the degree of association between performance deficit and lead exposure was more pronounced in socially disadvantaged children than in those from a more middle-class background. This finding was tentatively discussed within a transactional model of development. The common practice of simply controlling the effects of confounding social factors by analysis of covariance or related techniques appears doubtful in this context.

X-ray fluorescence analysis of lead in teeth of urban children in situ: Correlation between the tooth lead level and the concentration of blood lead and free erythroporphyrins

The tooth lead level of 30 lead-exposed children was measured in situ using an X-ray fluorescence technique. The tooth lead concentration divided by the child's age correlated with the free erythroporphyrin (FEP) ( r = 0.51) and the blood lead levels ( r = 0.31). The mean tooth lead concentrations of 10 Class IV children (FEP⩾ 190 μg/100 ml; blood lead 30–80 μg/100 ml) was 14.5 ± 5.5 ppm/year. Reexamination of the histories of children who had been classified as Class II or III, but who had tooth lead concentrations within 1 SD of the Class IV level, indicated that many of these children could also be considered to be Class IV children. When the x-ray fluorescence technique was used to screen an urban population of 300 children, the tooth lead values indicated that 72% of the children had been exposed to low levels of environmental lead. Six percent of the children were found to have tooth lead concentrations in excess of 9 ppm/year and within 1 SD of the mean value exhibited by Class IV children. These children were considered to have a high body lead burden. The percentage of children having an elevated tooth lead level is similar to the number previously reported using exfoliated deciduous teeth.

The association between lead concentrations in teeth and domestic water lead concentrations

Tooth lead levels have been measured in 109 children living in Glasgow. A significant association has been demonstrated between molar tooth lead concentrations and domestic drinking water lead concentrations. Tooth lead concentrations were found to be greater the longer a child had lived in older housing with lead plumbing during foetal life and following birth. Tooth lead concentrations were also found to be age-related although no difference with respect to social class could be found.

Lead in deciduous teeth of Norwegian children.

Two thousand two-hundred and thirty-three deciduous teeth were collected from cities, industrialized areas, and rural and fishing communities in several Norwegian counties. Teeth from Medieval Bergen were also included. Lead analysis of whole teeth revelant that in Norway there are many communities where lead absorption is minimal and comparable to background absorption in ancient societies. Such conditions are reflected in a lead level of 2.92 microgram/g in deciduous teeth. However, the analysis also revealed that urbaization and industrialization increased lead absorption, although the mean level recorded in Norway of 3.73 microgram/g was far lower than normal levels found in other countries. Automobile exhaust was rejected as an important source of undue lead absorption. This study indicated that 0.18% of Norwegian children from the ages of 7 to 12 yr may have been victims of undue absorption, reflected in a tooth lead level of about 70 microgram/g.

Tooth lead levels in Birmingham children.

The mean lead content of deciduous teeth from children living in the city of Birmingham (U.K.) has been shown to be 11.8 ppm dry weight, irrespective of the sex of the donor. Lead content varies according to type of tooth, and there is a gradient from incisors, with the highest level, to second molars, with the lowest. A relationship was shown between age of donor and lead content of canines and (when lognormalized data were considered) first molars. We were not able to demonstrate a correlation between tooth lead levels and residence near a potential industrial lead source, and we conclude that pollution from a general source is responsible for the body burdens we found.

Child Lead Exposure Determined from Measurement of X-Ray Fluorescence of Teeth in Situ

X-ray fluorescence from lead when irradiated by gamma rays from a Co-57 source was utilized to measure the lead concentration in children's teeth in situ. The sensitivity of the method was adequate to detect 15 PPM from a gamma ray exposure to the tooth approximately 1/10 the exposure of a routine dental x-ray examination. The tooth lead levels assayed using x-ray fluorescence correlated well with chemical assay techniques for both extracted permanent and shed primary teeth. Thirty children from the Children's Hospital of Philadelphia suspected of having elevated lead levels had tooth lead levels measured in situ determined using the x-ray fluorescent technique. The tooth lead concentration varied from a low of 16 PPM to a high of 56 PPM.

Lead levels in human deciduous teeth in Tennessee.

Deciduous teeth were analyzed by atomic absorption spectroscopy for lead content to ascertain the extent of lead exposure in certain areas in Tennessee. The data were analyzed to clarify the relationships between tooth lead content and race, sex, age, tooth type, economic status, and place of residence. Results indicated that blacks had slightly higher lead concentrations than whites; however, the age and sex of the person or the type of tooth analyzed had little effect upon the lead content. The major factors were shown to be economic status and, indirectly, place of residence.

Follow-Up of Children Overexposed to Lead

The purpose of this study is to assess the nature and magnitude of the deleterious health effects of subclinical over-exposure to lead in children. The study stems from concerns about the impact on the health of children in city slums who ingest leaded paint without overt evidence of poisoning and the health implication of rising levels of lead in the environment from automotive emissions. The study sample was derived mainly from a registry of children on whom blood lead determinations had been made by the New York City Department of Health and was supplemented by siblings of the registry cases and children from a lead belt area who had extractions of deciduous teeth in dental clinics. Information was obtained through parental interview, medical records, and psychometric evaluation. The data show that deleterious health effects occur in children who were treated for severe lead poisoning and in children without diagnosed lead poisoning who had elevated blood leads (>/=0.06 mg-%). In the absence of diagnosed lead poisoning or elevated blood leads, excess lead exposure, measured in terms of high levels of lead in teeth, was not associated with deleterious health effects.

Follow-up of Children Overexposed to Lead

The purpose of this study is to assess the nature and magnitude of the deleterious health effects of subclinical over-exposure to lead in children. The study stems from concerns about the impact on the health of children in city slums who ingest leaded paint without overt evidence of poisoning and the health implication of rising levels of lead in the environment from automotive emissions. The study sample was derived mainly from a registry of children on whom blood lead determinations had been made by the New York City Department of Health and was supplemented by siblings of the registry cases and children from a lead belt area who had extractions of deciduous teeth in dental clinics. Information was obtained through parental interview, medical records, and psychometric evaluation. The data show that deleterious health effects occur in children who were treated for severe lead poisoning and in children without diagnosed lead poisoning who had elevated blood leads (>/=0.06 mg-%). In the absence of diagnosed lead poisoning or elevated blood leads, excess lead exposure, measured in terms of high levels of lead in teeth, was not associated with deleterious health effects.

Lead levels in dentine and circumpulpal dentine of deciduous teeth of normal and lead poisoned children

A method for the preparation of circumpulpal dentine for lead analysis is described. The technique consists of cutting 600-μ-thin sections of deciduous teeth, and, utilizing a vice, fracturing off the circumpulpal dentine from the coronal dentine. Both dentine and circumpulpal dentine of teeth of normal American children and previously identified lead-poisoned children were prepared in this fashion and analyzed for lead. Comparing the lead-poisoned teeth with normal teeth, the results indicate that a 6-fold difference in the mean lead content existed between the two groups. The uptake of lead by the two dentine zones at low levels of lead intake was also examined. Thus, comparing tooth lead levels of normal American and Icelandic children, 2–3 times less lead was found in the teeth of Icelandic children. The sensitivity of the dentinal zones for lead, the simplicity of the preparative method and the ease of collection of the teeth supports the use of teeth as useful indicators of previous lead exposure.

Lead levels in deciduous teeth of urban and suburban American children.

LEAD poisoning is a serious threat to the health of American children living in urban ghettoes. Perlstein and Attala, studying 425 children treated for lead poisoning, found mental retardation in 22%, recurrent seizures in 20%, and cerebral palsy in 2%1. Many more children eat lead-containing substances and bear raised body levels of lead, but are not identified as being intoxicated2. If children with elevated tissue lead could be reliably identified, and their neurological and psychological function evaluated, the incidence of silent brain damage from lead ingestion could be established. Because elevations in blood lead are transitory, and decline once ingestion has stopped, blood lead levels are unsatisfactory indices of earlier exposure. Calcified tissues, however, store lead: bone biopsy procedures are impractical for large scale surveys, but it occurred to us that the exfoliated primary tooth might offer a way to examine the lead content of children who are at risk. Alshuler et al. reported a substantial increase in the lead content of deciduous teeth of children with fatal and treated plumbism3.