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Lead Levels (lead + level)

Distribution by Scientific Domains

Medical Sciences	44%
Life Sciences	27%

Kinds of Lead Levels

blood lead level

Selected Abstracts

Parental exposure to lead and small for gestational age births

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 6 2006
Pau-Chung Chen MD
Abstract Background Previous studies about the effect of lead exposure on adverse birth outcomes are still inconsistent and few studies estimate the relationship between parental lead exposure and small for gestational age (SGA) infants. An occupational cohort study to assess whether parental lead exposure would be related to decreased birth weight and shortened gestational ages of their offspring was conducted. Whether higher lead exposure doses would increase risks of low birth weight (LBW), preterm delivery, and SGA births was also investigated. Methods A Program to Reduce Exposure by Surveillance System,Blood Lead Levels (Press-BLLS) was established in Taiwan in July 1993. The names of workers exposed to lead was collected from this occupational blood-lead notification database. The birth outcomes of their offspring were determined by linking to the Taiwan birth registration database from 1993 to 1997. Only singleton births whose parental blood-lead concentrations were tested during pregnancy or prior to conception, or within a 1-year span before these two periods were included. Results Among 1,611 eligible births, 72 births were LBW, 74 were preterm deliveries, and 135 were SGA. Maternal blood-lead concentrations (PbBs) equal to or more than 20 µg/dl had a higher risk of mothering a SGA child (risk ratio (RR),=,2.15; 95% confidence interval (CI), 1.15,3.83). Conclusions Additional evidence of the effects of lead on adverse birth outcomes, especially for SGA births is reported. Maternal exposure to lead plays a more important role in the adverse effect on birth outcome than does paternal exposure. Am. J. Ind. Med. 2006. © 2006 Wiley-Liss, Inc. [source]

Teeth and blood lead levels in egyptian schoolchildren: relationship to health effects

JOURNAL OF APPLIED TOXICOLOGY, Issue 4 2001
Magdy Omar
Abstract The objective of this work was to study teeth and blood lead levels in Egyptian schoolchildren and to relate lead levels to sociodemographic and environmental factors, the degree of urbanization and suspected manifestations of possible lead exposure. The study was conducted on 60 children aged 6,12 years: 30 children living in an urban area at Alexandria City and 30 children living in a rural area at Kafr El-Sheikh Province. Both groups are matched for age and gender. Every child was subjected to history taking, clinical examination and IQ measurements. Laboratory investigations included measuring teeth and blood lead levels, haemoglobin, serum iron and total iron binding capacity. The results showed that the mean blood lead level of children in Alexandria was significantly higher than that of the children in Kafr El-Sheikh; also 56.7% and 6.7% of children from Alexandria and Kafr El-Sheikh had a blood lead level of >20 µg dl,1, with the most frequent symptoms of headache, arthralgia and lack of school interest. The children in Alexandria had significantly lower mean teeth lead and haemoglobin levels than those of the Kafr El-Sheikh group. A history of wrapping sandwiches in newspapers, age and distance between the home and school were significant predictors of lead exposure. These findings support the concept that teeth lead concentration may be a valid addition to the indicators used for assessment of the body burden of environmental lead. In addition, children living in urban areas such as Alexandria need special consideration regarding protection from lead exposure, as well as teeth and blood lead evaluation. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Blood lead levels in Egyptian children from high and low lead-polluted areas: impact on cognitive function

ACTA NEUROLOGICA SCANDINAVICA, Issue 1 2009
G. A. Mostafa
Objectives,,, Many children are harmed by low-level lead exposure which impairs cognitive development with subsequent poor scholastic achievement. We investigated blood lead levels in children in relation to cognitive function. Materials and methods,,, Blood lead levels were measured in 100 children recruited from high (n = 50) and low (n = 50) lead-polluted areas. Results,,, Blood lead levels ranged between 3 and 28 ,g/dl (median 9, interquartile range 6 ,g/dl). In addition, 43% of children had levels ,10 ,g/dl, of whom 90.1% were living in high-risk areas for lead pollution. Cognitive dysfunction was found in 37% of children. Children with cognitive dysfunction had significantly higher blood lead and lower hemoglobin than those without (P < 0.001). Conclusions,,, Increased blood lead level in many children is one of the health problems in Egypt which may be the reason, at least in part, for cognitive dysfunction with subsequent poor scholastic achievement. Thus, interventions to control lead exposure are mandatory. [source]

Lack of association of ,-aminolevulinic acid dehydratase genotype with blood lead levels in environmentally exposed children of Uygur and Han populations

ACTA PAEDIATRICA, Issue 12 2008
Yan Chen
Abstract Aim: A cross-section study was conducted to explore the association between polymorphism of ,-aminolevulinic acid dehydratase (ALAD) and lead poisoning in Uygur and Han children in China. Methods: The ALAD genotyping was determined by PCR-RFLP in 443 Uygur and 469 Han children aged 6,10 years from Urumqi in Xinjiang province. Results: The blood lead levels of 912 environmentally exposed children ranged from 0.5 to 48.2 ,g/dL, with a mean of 5.45 ,g/dL and a standard deviation of 0.22 ,g/dL, and 23. Thirty-one percent individuals were with blood lead level ,10 ,g/dL. The mean and standard deviation of blood lead levels were 5.57 ± 0.223 ,g/dL and 5.30 ± 0.224 ,g/dL in Uygur and Han children, respectively. The frequencies of the allele ALAD1 and ALAD2 in Uygur subjects were 90.52% and 9.48%, and in Han subjects were 95.73% and 4.27%, respectively (chi-square = 19.55, p < 0.05). No statistic correlation between the distribution of ALAD alleles and the blood lead level was found in both populations. Conclusion: A significant difference was seen in the frequency distribution of ALAD genotype between the different races. The genetic susceptibility of ALAD polymorphism to lead toxicity may exhibit in a lead dose-dependent manner. [source]

Teeth and blood lead levels in egyptian schoolchildren: relationship to health effects

Exposure to lead elevates induction of zif268 and Arc mRNA in rats after electroconvulsive shock: The involvement of protein kinase C

JOURNAL OF NEUROSCIENCE RESEARCH, Issue 2 2002
Kyung-Ah Kim
Abstract Exposure to lead is well known to impair cognitive function in young children. Because of the importance of gene regulation for neurodevelopment, we examined the effect of lead on the induction of the mRNA of the immediate early genes zif268 and Arc. The time course for the induction of zif268 mRNA and Arc mRNA by electroconvulsant shock (ECS) was altered in the area of the dentate gyrus of the hippocampus in rats exposed to lead from postnatal days (PND) 1 to 28. Other areas of the hippocampus were not affected by lead. The effects on the induction of zif268 mRNA were observed at blood lead levels as low as 12 ,g/dl. No change in the induction of zif268 mRNA was observed in the hippocampus of rats exposed to lead from PND 28 to PND 56. Because of the possible involvement of protein kinase C (PKC) in the effect of lead, activation of different isoforms of PKC was investigated. An increase in the amount of PKC, and PKC, was observed at 60 min after ECS in the membrane fraction from hippocampus, indicating activation of these isoforms. The amount of PKC, in membranes was higher in rats exposed to lead than in rats not exposed to lead after ECS. Taken together, the data suggest that lead may disturb regulation of specific immediate early genes by activating PKC,. © 2002 Wiley-Liss, Inc. [source]

Variations in the contents of heavy metals in arable soils of a major urban wetland inlet drainage system of Lake Victoria, Uganda

LAKES & RESERVOIRS: RESEARCH AND MANAGEMENT, Issue 2 2010
Jolocam Mbabazi
Abstract Little is known about the effects of urbanization on the chemical quality of soils in suburban wetland inlet drainage systems to the Uganda side of Lake Victoria, on which food crops are extensively grown. It is feared that pollution in the soils might eventually enter food chains through such crops being consumed by urban populations unaware of their occurrence. Soil samples were collected from cultivated areas of a major wetland drainage system (Nakivubo Channel), at Kampala, Ubanda, near Lake Victoria and from a rural control wetland site (Senge). The soil from this site had similar properties as those from the urban test site (i.e., soil texture; porosity; humus content). Analysis of heavy metals with atomic absorption spectrophotometry (AAS) yielded the following soil concentration ranges: manganese (190,780), cadmium (<0.001,1.0), zinc (6.0,10.0) and lead (10,20 mg kg,1) dry weight for the control site, and 450,900, 1.0,2.0, 131,185, 40,60 mg kg,1 dry weight, respectively, for the urban wetland, indicative of relatively heavy metal pollution in the suburban drainage system. Heavy metal levels in cocoyam (Colocasia Esculenta) and sugarcane (Saccharum Officinarum) grown on both wetland soils also were evaluated via AAS with a modified wet-acid-digestion technique. The results highlighted high cadium and lead levels (P , 0.0003) in the crops from urban wetland cultivation. Cadmium and lead concentrations in cocoyam from urban wetland soils exceeded those from the control site by 0.17 and 3.54 mg kg,1, respectively. The corresponding results for sugarcane indicated a similar increase of 0.56 and 2.14 mg kg,1 of juice extract. Cadmium and lead levels in both urban wetland crops were higher than the maximum permissible limits of the Codex Alimentarius Commission, indicating that these concentrations pose potential health risks to urban consumers, and call for early counter-measures to combat urban pollution entering the lake. [source]

Lead promotes abasic site accumulation and co-mutagenesis in mammalian cells by inhibiting the major abasic endonuclease Ape1,

MOLECULAR CARCINOGENESIS, Issue 2 2007
Daniel R. McNeill
Abstract Lead is a widespread environmental toxin, found in contaminated water sources, household paints, and certain occupational settings. Classified as a probable carcinogen by the International Agency for Research on Cancer (IARC), lead promotes mutagenesis when combined with alkylating and oxidizing DNA-damaging agents. We previously reported that lead inhibits the in vitro repair activity of Ape1, the major endonuclease for repairing mutagenic and cytotoxic abasic sites in DNA. We investigated here whether lead targets Ape1 in cultured mammalian cells. We report a concentration-dependent inhibition of apurinic/apyrimidinic (AP) site incision activity of Chinese hamster ovary (CHO) AA8 whole cell extracts by lead. In addition, lead exposure results in a concentration-dependent accumulation of AP sites in the genomic DNA of AA8 cells. An increase in the oxidative base lesion 8-oxoguanine was observed only at high lead levels (500 µM), suggesting that non-specific oxidation plays little role in the production of lead-related AP lesions at physiological metal concentrations,a conclusion corroborated by "thiobarbituric acid reactive substances" assays. Notably, Ape1 overexpression in AA8 (hApe1-3 cell line) abrogated the lead-dependent increase in AP site steady-state levels. Moreover, lead functioned cooperatively to promote a further increase in abasic sites with agents known to generate AP sites in DNA (i.e., methyl methansulfonate (MMS) and hydrogen peroxide (H2O2)), but not the DNA crosslinking agent mitomycin C. Hypoxanthine guanine phosphoribosyltransferase (hprt) mutation analysis revealed that, whereas lead alone had no effect on mutation frequencies, mutagenesis increased in MMS treated, and to a greater extent lead/MMS treated, AA8 cells. With the hApe1-3 cell line, the number of mutant colonies in all treatment groups was found to be equal to that of the background level, indicating that Ape1 overexpression reverses MMS- and lead-associated hprt mutagenesis. Our studies in total indicate that Ape1 is a member of an emerging group of DNA surveillance proteins that are inhibited by environmental heavy metals, and suggest an underlying mechanism by which lead promotes co-carcinogenesis. Published 2006 Wiley-Liss, Inc., [source]

Growth of infants' length, weight, head and arm circumferences in relation to low levels of blood lead measured serially

AMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 2 2009
Lawrence M. Schell
To determine whether levels of blood lead during gestation and infancy that are below the CDC action level of 10 ,g/dl affect infant growth, we studied 211 disadvantaged mother,infant pairs from Albany, NY. Mothers' lead levels were low (second trimester = 2.8 ,g/dl) as were infants' ( = 3.3 ,g/dl at 6 months; 6.4 ,g/dl at 12 months). Multiple linear regression analyses showed that second trimester lead levels were related to reduced head circumference at 6 and 12 months. Infants of mothers with second trimester lead at or above the median (,3 ,g/dl) exhibited negative associations between blood lead and head circumference at 6 and 12 months, and with weight-for-age, weight-for-length, and upper arm circumference at 6 months, but those below the median did not. Infants' 6-month lead level was related to head circumference at 12 months in the total sample, and in the subsample of infants whose blood lead was above the infants' 6-month blood lead median. Infants were also grouped by changes in their relative blood lead status, that is, above vs. below the median, from second trimester to 12 months of age. Infants whose lead levels changed from above to below the median were larger than infants whose lead levels went from below to above the median. The results suggest that lead may affect some dimensions of infant growth at levels below 10 ,g/dl, but effects of lead levels less than 3 ,g/dl are not evident in this sample. Am. J. Hum. Biol., 2009. © 2008 Wiley-Liss, Inc. [source]

Lead exposure in mexican radiator repair workers

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 3 2002
Ronald Dykeman
Abstract Background Lead exposure was investigated among 73 Mexican radiator repair workers (RRWs), 12 members of their family (4 children and 8 wives), and 36 working controls. RRWs were employed at 4 radiator repair shops in Mexico City and 27 shops in Cuernavaca and surrounding areas. Methods Exposure was assessed directly through the use of personal air sampling and hand wipe samples. In addition, industrial hygiene inspections were performed and detailed questionnaires were administered. Blood lead levels were measured by graphite furnace atomic absorption spectroscopy (AAS). Results The mean (SD) values for blood lead of the RRWs, 35.5 (13.5) ,g/dl, was significantly greater than the same values for the working controls, 13.6 (8.7) ,g/dl; P,<,001. After excluding a single outlier (247 ,g/m3), air lead levels ranged from 0 to 99 ,g/m3 with a mean (SD) value of 19 (23) ,g/m3 (median,=,7.9 ,g/m3). In a final multivariate regression model of elevated blood lead levels, the strongest predictors were smoking (vs. non-smoking), the number of radiators repaired per day on average, and the use (vs. non-use) of a uniform while at work, which were associated with blood lead elevations of 11.4 ,g/dl, 1.95 ,g/dl/radiator/day, and 16.4 ,g/dl, respectively (all P,<,.05). Uniform use was probably a risk factor because they were not laundered regularly and consequently served as reservoir of contamination on which RRWs frequently wiped their hands. Conclusions Lead exposure is a significant problem of radiator repair work, a small industry that is abundant in Mexico and other developing countries. Am. J. Ind. Med. 41:179,187, 2002. © 2002 Wiley-Liss, Inc. [source]

Synanthropic primates in Asia: Potential sentinels for environmental toxins

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2010
Gregory Engel
Abstract Macaques are similar to humans both physiologically and behaviorally. In South and Southeast Asia they are also synanthropic, ecologically associated with humans. Synanthropy with humans raises the possibility that macaques come into contact with anthropogenic toxicants, such as lead and mercury, and might be appropriate sentinels for human exposures to certain toxic materials. We measured lead (Pb) and mercury (Hg) levels and characterized the stable isotopic compositions of ,15N and ,13C in hair from three groups of free-ranging macaques at the Swoyambhu temple in Kathmandhu, Nepal, an urban population that has abundant contact with humans. Hair lead levels were significantly higher among young macaques and differed among the three groups of macaques that were sampled. Hair Hg levels were low. No statistical association was found between stable isotopic compositions (,15N and ,13C) and Pb and Hg levels. Our data did not find evidence that lead levels were associated with diet. We conclude that, in this population of macaques, behavioral and/or physiologic factors may play a significant role in determining exposure to lead. Chemical analysis of hair is a promising, noninvasive technique for determining exposure to toxic elements in free-ranging nonhuman primates. Am J Phys Anthropol, 2010. © 2009 Wiley-Liss, Inc. [source]

Problems in determination of skeletal lead burden in archaeological samples: An example from the First African Baptist Church population

AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2008
L.E. Wittmers Jr.
Abstract Human bone lead content has been demonstrated to be related to socioeconomic status, occupation and other social and environmental correlates. Skeletal tissue samples from 135 individuals from an early nineteenth century Philadelphia cemetery (First African Baptist Church) were studied by electrothermal atomic absorption spectrometry and X-ray fluorescence for lead content. High bone lead levels led to investigation of possible diagenetic effects. These were investigated by several different approaches including distribution of lead within bone by X-ray fluorescence, histological preservation, soil lead concentration and acidity as well as location and depth of burial. Bone lead levels were very high in children, exceeding those of the adult population that were buried in the cemetery, and also those of present day adults. The antemortem age-related increase in bone lead, reported in other studies, was not evidenced in this population. Lead was evenly deposited in areas of taphonomic bone destruction. Synchrotron X-ray fluorescence studies revealed no consistent pattern of lead microdistribution within the bone. Our conclusions are that postmortem diagenesis of lead ion has penetrated these archaeological bones to a degree that makes their original bone lead content irretrievable by any known method. Increased bone porosity is most likely responsible for the very high levels of lead found in bones of newborns and children. Am J Phys Anthropol, 2008. © 2008 Wiley-Liss, Inc. [source]

Blood lead levels in Egyptian children from high and low lead-polluted areas: impact on cognitive function

Lack of association of ,-aminolevulinic acid dehydratase genotype with blood lead levels in environmentally exposed children of Uygur and Han populations