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PubMed2003

Prevalence of blood lead levels >or= 5 micro g/dL among US children 1 to 5 years of age and socioeconomic and demographic factors associated with blood of lead levels 5 to 10 micro g/dL, Third National Health and Nutrition Examination Survey, 1988-1994.

OBJECTIVES: As part of an investigation into the impact of a potential revision in federal childhood lead poisoning prevention policy that would result in screening children for blood lead levels (BLLs) >or=5 micro g/dL rather than the current 10 micro g/dL, we analyzed the most recent available, nationally representative data to identify prevalence of BLLs >or=5 micro g/dL and socioeconomic and demographic characteristics of 1- to 5-year-old children with BLLs >or=5 but <10 micro g/dL. METHODS: We performed statistical analyses on data from the Third National Health and Nutrition Examination Survey (NHANES III) (1988-1994) to describe trends in BLLs >or=5 micro g/dL overall and among subpopulations of children <6 years old and to compare risk factors for falling within 1 of 3 groups of children (those with BLLs >or=5 but <10 micro g/dL; >or=10 but <20 micro g/dL; and >or=20 micro g/dL) using the group reported as 0.7 to <5 micro g/dL as the referent. RESULTS: Overall prevalence of BLLs >or=5 micro g/dL among 1- to 5-year-old children was 25.6%, although most (76%) of these children had BLLs <10 micro g/dL. Children with BLLs >or=5 micro g/dL included 46.8% of non-Hispanic black children, 27.9% of Mexican American children, and 18.7% of non-Hispanic white children; 42.5% of children in housing built before 1946, 38.9% of children in housing built between 1946 and 1973, and 14.1% of children in housing built after 1973 had BLLs >or=5 micro g/dL. Compared with non-Hispanic white children, non-Hispanic black children were 3 times more likely to have a BLL >or=5 but <10 micro g/dL, 7 times more likely to have a BLL of 10-20 micro g/dL, and 13.5 times more likely to have a BLL >or=20 micro g/dL. Similar increases in the association between risk factor and BLL were seen with respect to other known risk factors including age of housing, region of the country, and poverty. CONCLUSIONS: The high prevalence of BLLs >or=5 micro g/dL overall and within US subpopulations will be an important variable in any change in screening and intervention criteria. However, most children with BLLs >or=5 micro g/dL are below the current intervention level of 10 micro g/dL. Exposure to lead from multiple sources is suggested by the prevalence of BLLs >or=5 micro g/dL but <10 micro g/dL among children with uncertain risk factors. The probable presence of one or more known risk factors for childhood lead poisoning increases as BLL increases.

Child, Preschool↗

PubMed2000

Relationship between blood lead level and urinary ALA level in workers exposed to very low levels of lead.

The relationship between blood lead (PbB) level and urinary delta-aminolevulinic acid (ALAU) level was examined in a total of 3,636 lead-exposed workers in a periodic medical examination in 1992, in accordance with the Ordinance on Prevention of Lead Poisoning. The results were consistent with previously reported results in that ALAU level was found to increase with an increase in PbB level above 22.4 micrograms/dl (1.35 as a logarithmic value) and to rise markedly above 35.5 micrograms/dl (1.55). On the contrary, the geometric means of ALAU levels appeared to decrease with an increase in PbB levels within a range between a logarithmic value of 0.15 (1.4 micrograms/dl) and 1.25 (17.8 micrograms/dl). Because the earliest sign of the adverse health effects of lead is reported to occur at a PbB level of of 20 micrograms/dl, the relationship between PbB level and ALAU level was examined at PbB levels below 20 micrograms/dl. A regression formula was obtained, Y (log ALAU (mg/l)) = -0.0570X (log PbB (microgram/dl) + 0.4099. This result indicates that ALAU level decreases with a concomitant increase in PbB level lower than 20 micrograms/dl.

Aminolevulinic Acid↗

PubMed1985

Mortality among employees of lead battery plants and lead-producing plants, 1947-1980.

Two cohorts of male lead workers, 4 519 battery plant workers and 2 300 lead production workers, all of whom had been employed for at least one year during the period 1 January 1946 through 31 December 1970, were observed for mortality during the 34 years from 1 January 1947 through 31 December 1980. Vital status as of the closing date was determined for 94.7% of the former group and 91.6% of the latter. There were 1 718 deaths in the first cohort and 621 in the second. Mortality from all causes combined was significantly greater than expected in each cohort, the standardized mortality ratio (SMR) being 107 and 113, respectively. Among the battery plant workers the greater than expected mortality rate resulted in large part from a significant number of excess deaths from malignant neoplasms (SMR 113), other hypertensive disease (mainly renal) (SMR 320), chronic nephritis (SMR 222), and a group of ill-defined conditions (SMR 355). Among the lead production workers the pattern was similar, with a significant number of excess deaths from other hypertensive disease (SMR 475), hypertensive heart disease (SMR 203), chronic nephritis (SMR 265), and ill-defined conditions (SMR 214). There was also a significant excess of deaths from external causes (SMR 143). The SMR for total malignancies was 113, but this value was not significantly elevated at the 5% level. In neither cohort were deaths from cerebrovascular disease in significant excess, the SMR being 93 and 132, respectively. A proportionate mortality analysis showed that the excess deaths from cerebrovascular disease and from hypertensive heart disease among smelter workers were in part due to the high proportion of nonwhites in the smelter populations. The stomach, liver, and lungs were the sites responsible for most excess cancer deaths in both cohorts, but the elevated SMR values were statistically significant only for gastric and lung cancers in battery plant workers. There were no excess deaths from malignancies of the kidney, brain, or lymphopoietic system in either cohort. It is impossible to relate the observed mortality to levels of lead exposure; because of meager quantitative information prior to 1960. It is known that past exposures had been very high. Ethnicity, diet, alcohol, and cigarette smoking could not be ruled out as possible confounding etiologic factors for the cancer deaths.

Humans↗

PubMed1979

[Urinary lead concentration as a risk factor during mixed exposure to lead, zinc and cadmium].

Six groups of subjects with different exposure to lead, zinc and cadmium, selected from among workers of zinc works, were studied. The concentration of the metals in the air was in the range: 0.04--0.70 mg Pb/m3; 0.16--1.84 mg ZnO/m3 and below 0.020 mg CdO/m3. Urine specimens were taken several times from the same subjects in mid -- week between the 3rd and 5th work hour. The concentration of the metals in urine was determined by the atomic absorption spectrophotometric method. The exposure to the metals was based on the relation between their concentrations in the air and urine. Statistical analysis indicated that under the conditions of mixed exposure to lead, zinc and cadmium, lead concentration in urine -- with prevailing toxic effects of lead -- may be used to evaluate occupational exposure.

Adult↗

PubMed1977

[To the behaviour of cadmium and lead in children with a different cadmium or lead burden].

An epidemiological study of 413 randomly chosen children in age of 2--14 years living in an industrial town is presented. According to their place of residence they were either burdened with cadmium from a forge or with lead from the traffic. The different burden was refelcted not only in the blood lead level but also in blood cadmium level respectively. Both contaminants showed in their separate effects the same behaviour. The intensity of the absorption of lead or cadmium respectively influences not only the relationship between blood lead level or blood cadmium level and the other parameters (Pb-H, Pb-U, Cd-H, Cd-U, d-ALA-U) but also the distribution of these parameters.

Adolescent↗

PubMed1993

Relationship between alpha-aminolevulinic acid dehydratase activity, free erythrocyte protoporphyrin concentration and blood lead in calves from lead contaminated farm.

In order to investigate useful indicators of lead contamination, 108 Japanese Black calves from a lead-contaminated farm were used. The lead concentrations in blood (Ph-B), delta-aminolevulinic acid dehydratase (ALA-D) activities, and free erythrocyte protoporphyrin (FEP) concentrations were examined. A significant negative correlation was obtained between Pb-B concentrations and ALA-D activities (r = -0.621, p < 0.01). A significant positive correlation was obtained between Ph-B concentrations and FEP concentrations (r = 0.850, p < 0.01). The calves were divided by Pb-B concentrations (micrograms/100 ml) into 5 groups (A = < or = 30, B = 31 approximately 90, C = 91 approximately 150, D = 151 approximately 210, E = > or = 211) to observe the relation of ALA-D activities, FEP concentrations and ALA-D activities in group B (r = -0.706, p < 0.05). A significant positive correlation was obtained between Pb-B concentrations and FEP concentrations in groups A, B and D (A = r = 0.496, p < 0.01; B = r = 0.686, p < 0.01; D = r = 0.529, p < 0.05). These results indicate that FEP concentrations were good indicators of lead contamination.

Animals↗

PubMed1995

Lead arthropathy: a cause of delayed onset lead poisoning.

Patients who suffer gun shot wounds often have retained bullet fragments within their bodies. These are usually of no clinical consequence. We describe three patients with retained bullets within their hip joints. One of these patients, who had extensive ground intra-articular bullet fragments and secondary osteoarthritis of the hip, presented with signs, symptoms, and laboratory data consistent with lead intoxication. The bullet and metallic fragments were removed surgically with good clinical response. Two patients whose bullets were implanted entirely within the femoral head and whose joints showed smaller degrees of lead fragmentation had no symptoms of lead intoxication. The degree of intra-articular fragmentation of the bullet and the surface area of lead exposed to synovial fluid are emphasized as decisive factors with respect to appropriate therapy.

Aged↗

PubMed1990

Work hygienic behaviour as modifier of the lead air-lead blood relation.

Knowledge of hygienic behaviour at the workplace appears to explain the low correlation between external and internal exposure. Differences in hygienic behaviour explain at least the same magnitude of variation in levels of lead in blood as the level of lead in air. Adding hygienic behaviour to the lead air-lead blood model increases the accuracy of prediction of PbB. In this study, the frequency of putting on/off gloves and the frequency of hand-mouth nose/shunt are the strongest modifiers of the PbA-PbB relation. In general, the actual behaviour of workers exposed to chemical agents may explain the often observed poor or moderate relationships between environmental and biological monitoring parameters of chemical exposure in occupational health studies.

Air Pollutants, Occupational↗

PubMed1980

Fecal lead excretion in young children as related to sources of lead in their environments.

Fecal lead excretion (PbF) was studied in young children with elevated lead exposure. PbB was generally 40-70 microgram/dl. The children's home environments were classified as to lead-base paint hazard and traffic density. There was a significant correlation between paint hazard classification and PbF but not between traffic density and PbF. There also was a correlation of PbB with paint hazard classification. Long-term fecal collections were instituted using 10 children who lived in high hazard homes and three children with low PbB's, whose PbF's were considered normal. Among the children living in high hazard homes, median fecal lead excretion generally was only moderately elevated. Grossly elevated amounts of led were found only occasionally and only in a few of the children. Movement of two children from a high hazard home to a low hazard home resulted in prompt and substantial reduction in PbF. By contrast, PbB fell only very slowly.

Child↗

PubMed2005

Daily rhythms in blood and milk lead toxicokinetics following intravenous administration of lead acetate to dairy cows in summer.

The objective of this study was to investigate circadian variations of blood and milk lead toxicokinetics in dairy cows in summer. Twenty lactating Holstein animals were randomly assigned to four treatments corresponding to different hours after onset of light (HALO): 2, 8, 14, and 20. Cows received a single intravenous administration of 2.5 mg/kg lead as lead acetate. Blood and milk samples were taken and analyzed by atomic absorption spectrophotometry. For each toxicokinetic parameter, a one-way analysis of variance (ANOVA) was performed to outline the existence of daily variations. Significant blood differences as a function of HALO were found for the hybrid constant of distribution (alpha), hybrid constant of elimination (beta), elimination half-life (t(1/2)beta), area under the curve (AUC), volume of distribution at steady state (V(ss)) and clearance (Cl(B)) (p<0.05). Half-life of elimination presented two peaks at 2 and 14 HALO. Milk data showed significant differences for maximum concentration and AUC (p<0.05). The ratio AUC(milk)/AUC(blood) was utilized to estimate penetration of lead in milk. It differed significantly throughout the day (p<0.05). Milk data for the significant parameters could be fitted to circadian rhythms. No circadian rhythms were detected in blood parameters or in the ratio AUC(milk)/AUC(blood).

Animals↗

PubMed1985

Multicompartment kinetic models for lead. II. Linear kinetics and variable absorption in humans without excessive lead exposures.

Multicompartment models with constant fractional transfer rates have been fitted to experimental data on lead metabolism in four subjects studied by M. B. Rabinowitz, G. W. Wetherill, and J. D. Kopple (Science 182, 725-727, 1973; Environ. Health Perspect. 7, 145-153, 1974; Arch. Environ. Health 31, 220-223, 1976; J. Clin. Invest. 58, 260-270, 1976; J. Lab. Clin. Med. 90, 238-248, 1977). Long-term retention is estimated for blood, soft tissue, cortical and trabecular bone pools, and for facial hair. The absorption of lead from diet is shown to change with time, but no evidence was found for other variable or nonlinear kinetic mechanisms of lead metabolism in humans without excessive lead exposure.

Diffusion↗

PubMed1985

Multicompartment kinetic model for lead. III. Lead in blood plasma and erythrocytes.

Multicompartment models have been fitted to experimental data on plasma lead and blood lead concentrations of subjects studied by P. E. deSilva (Brit. J. Ind. Med. 38, 209-217, 1981) and one subject studied by W.I. Manton and C.R. Malloy (Brit. J. Ind. Med. 40, 51-57, 1983). Nonlinear models for plasma lead vs blood lead in populations provide significantly better descriptions than does a linear model. Short-term kinetic data do not clearly resolve the precise nonlinear mechanism, however, Parameters of plasma and erythrocyte distribution in a single subject were significantly different on two occasions.

Erythrocytes↗

PubMed1995

DMSA chelation during co-exposure to lead: increased locomotor activity in lead-exposed mice but not controls.

We investigated the effect of chelating agent meso-2,3 dimercaptosuccinic acid (DMSA) on indices of "hyperactive" behavior in lead-exposed and control Binghamton Heterogeneous Stock (Het) mice. As expected, 6 weeks of ingestion of 0.5% lead acetate in drinking water reduced immobility in a forced water swim relative to controls. DMSA did not attenuate this behavioral change. In fact, DMSA interacted with lead exposure to increase locomotor activity in the forced water swim. DMSA also apparently excacerbated lead's tendency to reduce immobility. While any generalizations to human populations should be cautioned, these results and others suggest the need for further research.

Animals↗

PubMed1988

Redecoration of external leaded paintwork and lead-in-dust concentrations in school playgrounds.

Playground lead-in-dust concentrations have been measured immediately after the external redecoration of 216 schools in 1983/4 and of 63 schools in 1984/5. Schools were divided into four age categories: A, pre-1914; B, 1914-1939; C, 1945-1965; and D, post-1965. The results show that concentrations can vary widely from school to school within a given age category. For each school, dust samples were collected from an area adjacent to the facade which had been redecorated, referred to here as the 'corridor' area, and from the 'remaining' playground area. The highest mean corridor concentrations were found in playgrounds of schools of age categories A and B, the highest mean value being 74,400 micrograms g-1. The highest value for age category D schools was 2600 micrograms g-1. The mean concentration for all schools in age categories A to D, was respectively 4720, 2820, 820 and 630 micrograms g-1 for the corridor area and 1180, 730, 400 and 440 micrograms g-1 for the remaining area. The highest lead-in-dust concentrations tended to occur within 2.5 m of the building facade. A limited number of measurements showed that concentrations in the corridor area tended to reduce with time, falling to half their initial value (after correcting for the local background level) in about 90-170 days. A model is suggested linking lead-in-dust concentrations in the corridor and remaining areas to lead-in-paint debris dust concentrations.

Child↗

PubMed1988

The effect of reducing petrol lead on airborne lead in Wales, U.K.

Airborne lead has been measured at four urban, one semi-urban and one rural site in Wales during 1984, 1985 and 1986 to assess the effect of the reduction in lead additives in petrol which was required by an EC Directive at the beginning of 1986. The results showed a 52-61% fall in air lead in accord with the 63% reduction in petrol lead.

Air Pollutants↗

PubMed1994

Blood lead and tap water lead levels in Ibadan, Nigeria.

Blood lead levels of a segment of the population in Ibadan were determined using atomic absorption spectrophotometry. Mean blood lead levels of 11.4 micrograms/dl and 12.3 micrograms/dl were recorded for females and males, respectively. Tap water lead levels at various locations in the city were < 5 micrograms/l. Although current levels of lead in the environment are within acceptable limits, the trend of increasing industrialization in the city indicates the need for pollution control in the environment.

Female↗

PubMed1990

Tolerance to lead-induced porphyrin metabolic disorders following lead pretreatment in mice.

The protective effect of pretreatment with lead on lead-induced toxicity was investigated in mice, using some biological parameters such as urinary excretion of delta-aminolevulinic acid (ALA) and coproporphyrin, accumulation of erythrocyte protoporphyrin and inhibition of erythrocyte delta-aminolevulinic acid dehydratase; these are useful indicators for evaluating the effects on health of lead. It was demonstrated that pretreatment with a single intraperitoneal dose of 2 mg Pb/kg, 7 days prior to the challenge dose, prevents in part the increasing excretion of urinary ALA induced by a challenge exposure to lead (200 ppm) in the drinking water for 7 days.

Administration, Oral↗

PubMed2006

Growth and lead accumulation by the grasses Vetiveria zizanioides and Thysanolaena maxima in lead-contaminated soil amended with pig manure and fertilizer: a glasshouse study.

Bo Ngam lead mine soils contain high concentrations of lead (up 1% total Pb) and low amounts of organic matter and major nutrients (N, P, K). A glasshouse study was conducted to compare growth performance, metal tolerance and metal uptake by two grasses, Thysanolaena maxima (Roxb.) O. Kuntze and four ecotypes of Vetiveria zizanioides (L.) Nash, syn. Chrysopogon zizanioides (L.) Roberty (three from Thailand: Surat Thani, Songkhla and Kamphaeng Phet, and one from Sri Lanka) and to study the effects of pig manure (20% and 40% w/w) and inorganic fertilizer (75 and 150 mg kg(-1)) amendments to this lead mine soil. The results showed that both T. maxima and V. zizanioides (Surat Thani and Songkhla) could tolerate high Pb concentrations in soil (10750 mg kg(-1)) and had very good growth performance. Application of pig manure increased electrical conductivity (EC) and reduced DTPA-extractable Pb concentration in the soils. Pig manure application improved the growth of vetiver, especially at 20%, application dosage. Vetiver had the highest biomass. T. maxima could not tolerate high EC values. The uptake by roots and transport of Pb to shoots of both species was reduced when soils were amended with pig manure. Application of inorganic fertilizer did not improve growth of vetiver but did improve that of T. maxima. Fertilizer application did not have any great influence on the Pb uptake in vetiver while T. maxima took up more Pb as a result of the fertilizer enhancing its biomass yield. Both species transported low Pb concentrations to shoots (8.3-179 mg kg(-1)) and accumulated higher concentrations in roots (107-911 mg kg(-1)). In summary, both species may be species well suited for phytostabilization in tropical lead mine areas.

Animals↗