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PubMed2006

Lead exposure in an urban community: investigation of risk factors and assessment of the impact of lead abatement measures.

INTRODUCTION: A battery recycling plant located in an urbanized area contaminated the environment with lead oxides. The Secretary of Environment of the State of São Paulo demanded an evaluation of lead exposure among the population in the vicinity of the plant. OBJECTIVES: To assess the lead exposure of children, to propose control measures and evaluate the impact of these measures. METHODS: Cross-sectional study of all children<13 years old in a radius of 1km from the plant responsible for the contamination. Blood lead levels (BLL) were determined for each child and questionnaires were applied to their parents. Mean BLL were compared before and after control measures were implemented. Logistic regression identified risk factors of lead exposure. RESULTS: Of the 850 investigated children, 311 presented BLL above the action limit established by the World Health Organization. Overall, the median BLL was 7.3 micro g/dL and it varied according to age of children (higher among 1-5 years old) and distance of the residence from the plant. Risk factors identified for BLL>10 micro g/dL were: to live in unpaved areas, parent working in the plant, distance from the plant, to play on the ground, pica, and to drink locally produced milk. After control measures were implemented (closing the plant, soil removal, dust vacuum-cleaning in the households, etc.), a reduction of 46% in BLL was observed considering the 241 re-evaluated children with levels >10 micro g/dL. CONCLUSIONS: This study showed that combined abatement measures were effective in reducing BLL in children living close to a contaminating source. These results informed the decision-making process regarding management of contaminated areas in Brazil.

Air Pollutants↗
PubMed2005

Lead bioaccumulation in earthworms, Lumbricus terrestris, from exposure to lead compounds of differing solubility.

This study examined the relative effects of soluble and less soluble Pb compounds on Pb accumulation by Lumbricus terrestris. The earthworms were exposed to composted cattle manure contaminated with a range of concentrations of either soluble lead acetate trihydrate (PbAc) (14.5, 72.2, 137, 257, and 603 microg/g) or less soluble lead carbonate (Pb(CO(3))(2)) (5.09, 171, 575, and 710 microg/g). Relative Pb bioaccumulation rates in earthworms from the PbAc and Pb(CO(3))(2) lead carbonate trials were compared over time (0, 20, 40, and 60 days). The two molecular forms of Pb were heavily adsorbed onto the organic matter. Relative soluble Pb concentrations in the manure pore water were very low, at 0.049% and 0.022% of total Pb for PbAc and Pb(CO(3))(2), respectively. There was a significant uptake of lead by earthworms from both the readily soluble and less soluble forms of Pb. Regression surfaces relating organic matter total Pb concentration to exposure time and Pb body burden were compared. For the PbAc trial, the following equation was fitted: Body burden=2.3429+0.0014 x--0.0632 y+0.0008 xy (R(2)=0.8494, p<0.0001). For the Pb(CO(3))(2) trial, the equation was: Body burden=-2.0760--0.0067 x-0.2297 y-0.0038 y(2)+0.0003 xy (R(2)=0.5686, p<0.0001) (for x=organic matter Pb concentration in microg/g and y=time in days). The Pb bioaccumulation resulting from the PbAc exposure was significantly higher than that from Pb(CO(3))(2). Body burdens of earthworms exposed to PbAc were linearly related to exposure time and total Pb concentration. Worms exposed to Pb(CO(3))(2) had non-linear Pb accumulation over time that suggested a decrease in Pb bioavailability with increasing exposure time. The results indicate that L. terrestris feeding on detritus in the upper soil levels can mobilize and accumulate Pb from the principal transformation products of metallic Pb, as at shooting ranges and lead smelter sites.

Animals↗
PubMed2005

Lead associated caries development in children living in a lead contaminated area, Thailand.

In an observational cross-sectional design, a sample of 292 children aged 6-11 years from two primary schools around a shipyard area, known to be an area contaminated with lead (from the industry), were examined to verify the cariogenicity of lead. The number of decayed and filled surfaces on deciduous teeth (dfs), and the number of decayed, missing, and filled surfaces on permanent teeth (DMFS), the salivary flow rate, pH, buffer capacity, oral hygiene, Lactobacillus spp. and mutans streptococci counts were recorded. The mean (range) of DMFS and dfs were respectively 1.3 (range 0-17) and 13.2 (range 0-45); and the geometric mean blood lead level (PbB) and SD were 7.2 and 1.5 microg/dl. The level of dfs, but not DMFS correlated with the blood lead level (R(s)=0.25, p=0.00 / R(s)=0.09, p=0.14). The odds ratio for DMFS>or=1 and dfs>5 for a doubling of PbB after adjusting for other factors were 1.28 (95%CI, 0.81-2.04; p value=0.35) and 2.39 (95%CI, 1.36-4.20; p value=0.004), respectively. The cariogenicity of lead is evident in deciduous teeth but not in permanent teeth for this age group.

Child↗
PubMed2005

Influence of natural organic matter on the morphology of corroding lead surfaces and behavior of lead-containing particles.

Influence of natural organic matter (NOM) on the morphology of lead surfaces exposed to drinking water and on the properties of lead-containing colloidal particles was explored based on the data of scanning electron microscopy, sequential filtrations, measurements of particle size distributions and electrophoretic potential. It was demonstrated that NOM prevented the formation of cerussite and hindered the growth of hydrocerussite crystals. Measurements of zeta-potential showed that the surface activity was highest for unaltered NOM, while ozonation and chlorination decreased it. The concentrations of soluble lead and tin increased several fold in the presence of NOM, while large colloidal particles of lead and solder corrosion products tended to break down to form smaller fragments. It is suggested that these phenomena are important for understanding of lead release mechanisms in drinking water.

Carbon↗
PubMed1992

Monitoring human exposure to lead: an assessment of current laboratory performance for the determination of blood lead.

The performance of a small group (9-13) of experienced reference laboratories performing the determination of lead in blood is assessed by means of repeated analyses of lyophilized animal blood. Both interlaboratory precision and intralaboratory precision are reported for the reference laboratory group. Results indicate that at the new blood lead action level of 10 micrograms/100 ml, this group can achieve results that are accurate to within +/- 2 micrograms/100 ml. The capability of routine clinical laboratories participating in the New York State Department of Health's Proficiency Testing Program for Blood Lead from 1979 to 1991 is also examined. These data indicate a steady improvement in laboratory performance over the last 10 years. Analysis of the most recent data suggests that laboratories using anodic stripping voltammetry tend to underestimate the concentration of lead in blood at levels greater than 40 micrograms/100 ml (1.93 mumole/L). The accuracy and precision of electrothermal atomization and Delves-cup atomic absorption spectrometry for the determination of blood lead in one laboratory are compared and discussed.

Animals↗
PubMed1986

Effects of lead in the laboratory mouse. 1. Influence of pregnancy upon absorption, retention, and tissue distribution of radiolabeled lead.

Whole-body retention and excretion following a single oral dose of radiolabeled lead (203Pb) in chronically lead-exposed pregnant BK:W mice were examined over 10-13 days. This was compared with values in similarly treated nonpregnant females and in ip injected females. Whole-body and bone retention were greater in injected than in orally dosed nonpregnant females; gastrointestinal absorption was estimated from this difference. Whole-body retention in the pups was measured at birth and at the end of the experiment. Whole-body retentions in pregnant females and in their pups at birth were significantly raised after treatment at Gestational Day 17, but not after treatment at Gestational Day 11, 14, 20, 23, or 26. Pup body burdens at birth were significantly and positively correlated with maternal retention. Measurement of radioactivity in bone, kidney, brain, heart, and liver of adults at the end of the experiments showed significantly increased levels in bone and kidney from females treated at Gestational Day 17 and in bone from females treated at Gestational Day 11. Lead excretion did not differ significantly among the groups but the total lead content of the femur was significantly raised in females treated at Gestational Days 17 and 26. Thus, these experiments provide evidence that lead absorption and retention in mice are markedly increased in the latter stages of pregnancy.

Animals↗
PubMed1990

Phosphorus, calcium and lead distribution in collagen in lead induced soft tissue calcification. An ultrastructural and X-ray microanalytical study.

Repeated intraperitoneal injections of lead acetate in rats caused a calcification of the skin of the abdomen near the site of the injections. In the lead-induced calcifications, electron dense collagen bundles could be observed. On the surface of the collagen fibrils, needle-like crystals were visible. With energy-dispersive X-ray analysis, phosphorus, calcium and lead were detected in the electron dense collagen bundles. X-ray maps of the P-K alpha, Ca-K alpha, and Pb-L alpha plus Pb-L beta lines showed an equivalent distribution along the collagen fibrils for phosphorus and calcium. The occurrence of the most electron dense areas in the STEM-image was comparable to the lead distribution. A good correlation existed between the structural and the elemental images of the same area. Although the medicinal use of preparations containing lead is no longer recommended, some are still prescribed. From our results we can conclude that they should not be applied to injured or inflamed skin.

Animals↗
PubMed2002

Determination of lead in whole blood: comparison of the LeadCare blood lead testing system with Zeeman longitudinal electrothermal atomic absorption spectrometry.

This study compares the efficiency of blood lead level analysis by graphite furnace atomic absorption spectrometry (GFAAS) and the portable LeadCare Blood Lead Testing System (LCS). Recoveries of two added lead concentrations of 22 and 42 micrograms/dL ranged from 102.4 to 105.5% for LCS and from 96.3 to 97.2% for GFAAS. Measurement of a certified sample (Certified Danish Whole Blood) at a blood lead concentration of 26.2 micrograms/dL gave within- and between-run coefficients of variation which were both approximately 8% by LCS and 2% by GFAAS. Comparison of the tested method (LCS) versus GFAAS from analysis of 76 samples of blood lead collected from workers in different industrial sectors showed imperfect overall correlation (r = 0.95). The LCS is quite suitable for screening purposes, but requires the use of non-frozen blood collected less than 24 h before. Conservative threshold values should be applied when using the LCS for initial screening in the field.

Humans↗
PubMed2003

Lead-tin mirror formation from mixtures of red lead and tin sulphide.

Mosaic gold, tin (IV) sulphide, is a yellow pigment which was known in antiquity but whose use was superseded by other more easily obtainable yellow pigments by the Renaissance. The identification of mosaic gold residues in a burnished golden mirror decoration on a XIIIth Century Spanish polychrome statue is important in that the first reference to the use of mosaic gold in the European literature dates from the XIVth Century, although the use of this material in China had been recorded some time before. In this paper, Raman spectroscopy, XRD and SEM are used in the analysis of the conditions required for the formation of golden mirrors using tin (IV) sulphide in admixture with dilead (II) lead (IV) tetroxide and mercury (II) sulphide. From these results, it is proposed that the major reactions are the reduction of Sn(IV) to Sn(0) with the accompanying oxidation of lead (II) oxide to lead (IV) oxide and the formation of lead (0) and lead (II) sulphide. From these results it was possible to explain the process of creation of the golden mirror from mosaic gold in the XIIIth Century.

Lead↗
PubMed2004

Addressing lead toxicity: complexation of lead(II) with thiopyrone and hydroxypyridinethione O,S mixed chelators.

The lead(II) ion is regarded as a serious environmental contaminant. A considerable need exists to develop selective ligands for remediation of this metal ion. Herein, the coordination chemistry of lead(II) is investigated with three O,S donor ligands: thiomaltol, 3-hydroxy-1-methyl-2(1H)-pyridinethione (3,2-HOPTO), and 3-hydroxy-1,2-dimethyl-4(1H)-pyridinethione (3,4-HOPTO). The X-ray structures of [Pb(thiomaltolato)(2)] and [Pb(3,4-HOPTO)(2)] have been solved, revealing the expected 4-coordinate geometries. Electronic spectra have been obtained for the lead(II) complexes with all three ligands. Preliminary solution studies show that the thiomaltol ligand binds lead(II) preferentially over magnesium(II) and calcium(II); however, [Pb(thiomaltolato)(2)] is not stable in the presence of 1 equiv of EDTA. Tetradentate ligands derived from these O,S chelators are expected to generate higher affinity ligands for lead(II) sequestration.

Chelating Agents↗
PubMed2004

Blood lead levels in preprimary school-age children in Nicosia, Cyprus, and their relationship with leaded soil dust exposure.

The authors conducted a cross-sectional study to determine blood lead levels in children who attended kindergarten schools and nurseries in Nicosia, Cyprus, and to correlate their findings with (a) home and school environments, (b) behavior of the children, and (c) socioeconomic characteristics. Capillary blood for lead assay was collected from March 2001 to September 2001 from children who lived and attended school in Nicosia. Children who lived and attended school in a rural setting served as controls. Parental questionnaires and interviews yielded information about socioeconomic background, environment, and children's habits and health. Overall findings indicated that children in Nicosia had mean blood lead levels similar to controls (i.e., <10 microg/dl)--the level of concern defined by the U.S. Centers for Disease Control and Prevention. The findings of our study likely represent high standards of hygiene adopted by parents and teachers, rather than knowledge embraced by parents and teachers about risks associated with lead exposure and sources of lead exposure.

Child↗
PubMedDate not supplied

Effects of exposure to lead among lead-acid battery factory workers in Sudan.

Health effects of occupational exposure to lead were investigated among 92 exposed workers in lead-acid battery factory and 40 nonexposed workers serving as a control group from an oil mill in Khartoum North industrial area. The two groups were closely similar in age, stature, body weight, and socioeconomic conditions. A highly significant increase (P less than .01) was recorded in blood lead, urinary coproporphyrin, and basophilic stippled red blood cells of the exposed group in comparison to the control group. Central nervous system symptoms (insomnia, fatigue, weakness, and drowsiness) were reported by 50% and other symptoms such as abdominal colic and constipation were reported by 41% of the exposed group. Blue line on the gum was detected only on 2% of the exposed group. Strong associations between exposure to lead and the prevalence of central nervous system symptoms, abdominal colic, and constipation were recorded. Exposure to exceedingly high levels of lead in the working environment causes adverse health effects.

Adult↗
PubMedDate not supplied

Determinants of blood lead concentrations to age 5 years in a birth cohort study of children living in the lead smelting city of Port Pirie and surrounding areas.

Sources of variation and some principal determinants of blood lead concentration (PbB) were investigated in a cohort of children, followed to age 5 y, who were born near a lead smelter in Port Pirie, South Australia. The child's age and place of residence were the two variables most strongly predictive of PbB. A sharp increase in PbB occurred between 6 and 15 mo of age and was followed by a peak concentration that occurred at approximately 2 y of age, after which PbB steadily and consistently declined. Irrespective of age, the PbBs in children who lived in Port Pirie were significantly higher than levels identified in children who resided outside the city. There was no significant difference in PbB between boys and girls. Elevated PbB at each specific age was associated mainly with increased lead concentrations in the topsoil of the local residential area, employment of the father in the lead industry, parental smoking, and behaviors likely to cause ingestion of dirt. Blood samples taken from children at certain ages and during the warmer months contained more lead than samples obtained during the cooler months. The effects of these determinants on PbB during early childhood were basically consistent in both single and multivariable analyses.

Age Factors↗
PubMed1990

Lead lines in young infants with acute lead encephalopathy: a reliable diagnostic test.

Fifteen Omani infants, ranging between 2 and 4 months of age, with acute lead encephalopathy underwent plain skeletal radiology. X-rays in all 15 infants revealed dense metaphyseal bands in long bones. These were best seen around the knee joint. Six infants had evidence of multiple lead lines indicating previous episodes of exposure to lead while four infants also had lead lines in the axial skeleton. We suggest that any young infant presenting with an unexplained encephalopathy should undergo an X-ray of the knee and that the presence of dense metaphyseal bands strongly supports the diagnosis of lead poisoning. A plain X-ray of the knee is a cheap, widely available investigation which can be rapidly obtained.

Bone and Bones↗
PubMed2003

Occurrence of lead-related symptoms below the current occupational safety and health act allowable blood lead levels.

To determine the occurrence of symptoms of lead toxicity at levels below the current allowable Occupational Safety and Health Act blood lead level of 50 micrograms/dL, standardized telephone interviews were conducted of individuals reported to a statewide laboratory-based surveillance system. Four hundred and ninety-seven, or 75%, of the eligible participants were interviewed. Gastrointestinal, musculoskeletal, and nervous system symptoms increased with increasing blood lead levels. Nervous, gastrointestinal, and musculoskeletal symptoms all began to be increased in individuals with blood leads between 30-39 micrograms/dL and possibly at levels as low as 25-30 micrograms/dL for nervous system symptoms. The results of this study of increased symptoms are consistent with and provide added weight to previous results showing subclinical changes in the neurologic and renal systems and sperm counts at blood lead levels currently allowed by the Occupational Safety and Health Act.

Adolescent↗
PubMed1989

Low-level exposures to lead: the Sydney lead study.

The Sydney Lead Study is a prospective investigation of the relationship between low-level lead exposure and neurobehavioural development during the first five years of life. Of the initial cohort of 318 children, 207 remained at the end of the fourth year. Average blood lead levels at 42 and 48 months were 10.7 and 10.1 micrograms/dl, respectively, with only a minority of observations exceeding 15 micrograms/dl. The regression analyses support earlier findings from the study, in that exposure to lead resulting in the range of blood lead levels found in this cohort is not associated with mental or motor deficits in the preschool years.

Adult↗
PubMed1977

Lead in umbilical cord blood correlated with the blood lead of the mother in areas with low, medium or high atmospheric pollution.

Lead concentrations in 541 samples of umbilical cord blood from different parts of Sweden were determined. The mean concentration was 7.6 mug lead/100 ml (=0.367 mumol/l). The blood lead values were also determined for 297 mothers and a mean value of 8.7 mug/100 ml (=0.420 mumol/l) was found. There was a significant correlation between the blood lead level of the mother and the infant as studied in 253 pairs. The slope of the regression line was 0.5 r (r=0.6). Significantly lower blood values for both mother and infant were found in areas with low pollution as estimated from the lead content in moss. No seasonal variation could be ascertained. Hematocrit versus lead concentration was also studied. A flameless atomic absorption method was used with a standard deviation of 0.9 mug lead/100 ml. The storage time and sample treatment were also studied.

Air Pollutants↗
PubMed1992

Relation between urinary beta-aminoisobutyric acid excretion and concentration of lead in the blood of workers occupationally exposed to lead.

Urinary beta-aminoisobutyric acid (ABA) concentration was determined by fluorometric high performance liquid chromatography in 22 workers occupationally exposed to lead. The urinary excretion of ABA was increased with increasing exposure to lead. The excretion of urinary ABA had a significant correlation with concentration of lead in blood (Pb-B) (r = 0.581), similar to the correlation of Pb-B with urinary delta-aminolaevulinic acid (ALA) concentration (r = 0.563). The determination of urinary ABA concentration in workers exposed to lead, therefore, may offer a new approach for evaluating the health effect of lead.

Adult↗