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PubMed2006

Lead contamination of small cetaceans in European waters--the use of stable isotopes for identifying the sources of lead exposure.

Lead concentrations and isotopic composition have been measured in bone and teeth of small cetaceans belonging to three species (Delphinus delphis, Phocoena phocoena and Stenella coeruleoalba), to evaluate the toxicological risk and to determine sources of lead in the European waters. Lead concentrations, far lower than threshold value inducing toxic effects in human, were higher in teeth than in bones, but highly correlated between the two tissues (r=0.92, p<0.001). Large variations of 206Pb/207Pb values in bone tissue showed that cetaceans must be submitted to various atmospheric influences. No geographical differences appeared which is consistent with studies on their distribution indicating seasonal movements between Brittany waters and the Bay of Biscay. The negative correlation between 206Pb/207Pb ratios and age of the individuals reflected the decrease in the production of alkyl lead in Europe, i.e., the increasing use of unleaded gasoline.

Animals↗

PubMed1988

Ultrastructural aspects of the small intestinal lead toxicology. Part I: Surface ultrastructure of the small intestine mucosa in rats with lead acetate poisoning.

The effects of low concentration of lead acetate on the apical surface of the jejunal enterocytes were studied. Young male rats were divided into 2 groups which received 0.01% lead acetate solution in drinking water during 30 and 60 d respectively. Blood lead concentrations of poisoned rats were elevated to 30.33 micrograms Pb/100 ml at d 30 of intoxication, then slightly depressed at the end of experiment. Weight gain was impaired only in the 60-d group in comparison with controls. Samples from jejunum were processed for scanning electron microscopy using a critical point drying method and gold evaporation. The fine structure of the surface enterocytes was always determined in the epithelial bands above the levels of crypts nearly half a distance from crypt to villous top. The shape of the jejunal villi in poisoned rats was similar to that in non-poisoned rats. A marked feature of the rats' jejunum exposed to heavy metal for 30 d was a rough appearance of the surface villi, probably associated with distortion of the glycocalyx layer. Extensive areas with degenerative lesions were observed on the surface of the most villi on the 60th d of intoxication. Microvilli of enterocytes distributed within these areas were deformed and sometimes could be completely absent. All enterocytes exhibited various degrees of glycocalyx disturbance. It was concluded that the pronounced toxic effects of lead were related to modification of biochemical properties of the surface coat of enterocytes. This abnormal function of the glycocalyx could result in damage and microvillous malformations.

Animals↗

PubMed2000

The effects of lead sulfate on new sealed lead acid batteries.

Emergency Medical Services (EMS) rely on batteries to power external cardiac defibrillators. While maintenance protocols should be followed to ensure that batteries possess adequate capacity to power their defibrillator, they are not often applied to new batteries. This study examines the effects of prolonged storage on sealed lead acid (SLA) batteries, the number of batteries that are affected by lead sulfate, and the ability of a protocol to restore the capacity in SLA batteries. A prospective cohort of new batteries was subjected to testing and discharge protocols. Initial battery capacities were measured using a battery analyzer. An "over-discharge" protocol fully discharged the battery over a 24-h period, and batteries were recharged and reanalyzed. Capacity measurements were repeated twice. Sulfate buildup was defined a priori as final capacity measurements greater than predischarge measurements. There were 126 batteries studied, a mean of 14 months after manufacture. Overall, 47 batteries (36.5%) had measured capacity that was insufficient (< 65% capacity). Batteries possessing very low initial capacities (< 55%) responded with a significant improvement on average of 54.7% compared with batteries within a normal capacity range (> 65%) whose average improvement was 9.3%. After discharge, there was an average of 17% improvement in the measured capacity, with no differences in the final capacity readings in each battery type. In conclusion, sealed lead acid batteries are affected by prolonged storage. The loss of capacity created by accumulation of lead sulfate can be reversed if battery maintenance protocols are used as part of EMS quality assurance programs.

Analysis of Variance↗

PubMed1981

Lead in bone. I. Direct analysis for lead in milligram quantities of bone ash by graphite furnace atomic absorption spectroscopy.

A method for direct lead content analysis of milligram quantities of bone ash by flameless atomic absorption spectroscopy is described. Bone ash (25 mg) is dissolved with HNO3 and diluted with H2O and La2O3 (1,000 micrograms/ml) solution. Lanthanum ion is used to suppress matrix interferences possibly arising in part from sulfate components of the bone ash. Two bulk bone samples (about 14 and 60 micrograms Pb/g ash, respectively) were used to determine daily, within-day, and overall variability of the method. Values for "low lead" bone samples were 14.08 +/- 1.74 (SD) microgram Pb/g ash and for "high lead" bone samples were 60.85 +/- 5.24 (SD) microgram Pb/b ash. The overall value of 58 lead recovery determinations from bone ash analysis was 103.5% (+/- 12.9% SD). These values compare favorably with results previously reported using gram amounts of sample.

Bone and Bones↗

PubMed1998

Blood lead concentration and biological effects in workers exposed to very low lead levels.

A longitudinal study was carried out on two groups of workers engaged in tin/lead alloy welding in the telecommunication sector. The risk of exposure was evaluated by measuring levels of airborne lead (PbA) and the amount of lead absorbed (PbB). The-correlated effects were assessed by determining zinc protoporphyrin (ZPP) and hemoglobin levels (Hb) and red blood cell (RBC) count. We also recorded subjective symptoms reported by workers. One group of welders composed of 365 subjects underwent two monitoring sessions performed in 1991 and 1995, respectively (Group A). A second group of welders (whose number fluctuated between 148 and 247 subjects) underwent yearly testing for 7 consecutive years (1988-1994; Group B). Results indicated a very low risk of lead exposure during microwelding operations (PbA range, 1.5-24 micrograms/m3). In fact, blood concentrations of Pb (range, 5-55, micrograms/dL) among both groups of welders were significantly higher than those in the general population in Rome (PbB range, 5-16 micrograms/dL); nevertheless, they were significantly lower than the Occupational Safety and Health Administration's permissible exposure limits ZPP determined only in Group B of welders ranged from 5 to 16 micrograms/dL (median, 22 micrograms/dL). No variation was found in the other biological parameters investigated, and no health effects were observed. During the study period, the introduction of some technological innovations led to a further reduction in Pb exposure and, subsequently, to its total elimination. PbB concentrations gradually declined to lower values (6-36 micrograms/dL), and it was interesting to note that ZPP concentrations also decreased to normal levels (range, 2-47 micrograms/dL; median, 11 micrograms/dL), demonstrating that the effect of lead on heme synthesis may occur even at very low levels of Pb exposure.

Adult↗

PubMed1997

Childhood lead poisoning on the US-Mexico border: a case study in environmental health nursing lead poisoning.

Human exposure to environmental hazards is a major public health problem along the US-Mexico border due to socioeconomic, cultural and political factors. Childhood lead exposure is endemic in areas of extreme poverty and substandard housing. Hispanic children of indigent, poorly-educated, disenfranchised families are at disproportionate risk. Risk management is contingent upon consideration of the interrelationships between socioeconomics, politics, and culture. This case study explains childhood lead poisoning in a colonia family living at subsistence level from such a perspective. The purpose of the study was to identify, explain, and ameliorate lead exposure pathways. Case study methodology was used to support or refute the proposition that these children were exposed to occupational lead. The children were the study sampling unit and the family a subunit. An embedded single case explanatory design was appropriate. Data were collected from exposure surveys, environmental and blood specimens, and review of medical records. Pattern-matching and explanation-building techniques were used to analyze data. The study illustrated how extreme poverty, lack of access to health services, social isolation, language and legal barriers, and hazardous occupations may be singularly common risk factors for Hispanic children on the US-Mexico border. The study is pertinent to public health nurses who work with this population.

Child↗

PubMed1974

Lead aerosol pollution in the High Sierra overrides natural mechanism which exclude lead from a food chain.

Most of the lead contained in sedge and voles (mountain meadow mice) within one of the most pristine, remote valleys in the United States is not natural but came from smelter fumes and gasoline exhausts. In a food chain, natural mechanisms do not allow lead to accompany the bulk of the nutritive metals as they proceed to higher trophic levels. This exclusion can be expressed quantitatively by a comparison of lead/calcium ratios at successive trophic levels. This ratio decreased by an overall factor of 200 in proceeding from rock, to soil moisture, to sedge, to vole. This factor would have been 1200 if lead aerosols had not collected on sedge leaves and circtumvented the tendency by sedge to exclude lead from the nutritive metals it absorbed from soil moisture.

Air Pollution↗

PubMed1992

A longitudinal study of the relation of lead in blood to lead in air concentrations among battery workers.

The relation between lead in air (PbA) and lead in blood (PbB), concentrations was investigated among 44 workers in five major operations in a United States high volume, lead acid battery plant. The study covered a 30 month period in which workers received frequent PbA and PbB determinations, workers remained in a single job, and PbA concentrations averaged below the US Occupational Safety and Health Administration (OSHA) permissible exposure limit of 50 micrograms/m3. In both univariate and multivariable linear regressions, longitudinal analyses averaging PbA concentrations over the 30 month study period appeared superior to cross sectional analyses using only six month PbA averages to model PbB concentrations. The covariate adjusted coefficient (alpha value) for PbA (mu/m3) in models of PbB (micrograms/100 g) was 1.14. This figure is strikingly higher than that reported in previous studies in the lead acid battery industry in all of which PbA concentrations were substantially higher than in the current study. Plausible explanations for the difference in alpha values include non-linearity of the PbA-PbB curve, a higher fraction of large size particulate associated with higher PbA concentrations, survivor bias among workers exposed to higher PbA concentrations, and the cross sectional designs of most previous studies. Despite previously reported problems with the model used by OSHA to predict PbA-PbB relations, the findings of this study are in good agreement with the predictions of that model.

Chemical Industry↗

PubMed2003

Can salivary lead be used for biological monitoring of lead exposed individuals?

BACKGROUND: Measurement of blood lead (BPb) is the usual method for biomonitoring of persons exposed to inorganic lead. AIM: To explore the use of salivary lead (SPb) as an alternative. METHODS: BPb and SPb levels were measured in a group of 82 lead exposed adults. RESULTS: The mean BPb of the workers was 26.6 microg/dl (SD 8.6, range 10-48) and the mean SPb level 0.77 microg/dl, or 3% of the BPb level. As the SPb distribution was skewed, logarithmic transformation was performed to normalise the distribution. A bivariate scattergram of BPb and logSPb (r = 0.41, p = 0.00) had a line of best fit expressed as BPb = 29.7 + 8.95logSPb. The relation of logSPb and BPb was stronger among non-smokers (r = 0.42) compared to smokers (r = 0.3); and among those without a medical condition (r = 0.44). Multiple linear regression analysis (fitting smoking and medical condition into the model) yielded an R of 0.54, and an adjusted R(2) of 0.26. CONCLUSION: The study findings do not support the use of SPb for biomonitoring at BPb levels ranging from 10 to 50 microg/dl.

Adult↗

PubMed1982

An appraisal of the analytical significance of tooth-lead measurements as possible indices of environmental exposure of children to lead.

The analysis for lead of whole-crowns from deciduous incisors has been used as an index of the cumulative exposure to lead of children during the prenatal period and until the time of shedding the tooth. The lead was determined by solvent extraction followed by atomic absorption, and strict analytical quality control was employed. The concentrations of lead in pairs of central and lateral incisors from children revealed unexpectedly large differences for some individuals.

Child↗

PubMed2004

Recent trends and current practices for secondary processing of zinc and lead. Part I: lead recovery from secondary sources.

Implementation of stricter environmental laws and economic reasons has forced all the metallurgical industries to go for eco-friendly technologies to produce metal and other related products. However, generation of wastes is an integral part of metallurgical industries. If the wastes/residues are hazardous in nature, they generally have to be treated or/and disposed of in safe and designated dumping sites. If these wastes/residues are non-hazardous in nature, then they may be suitable for use as secondary raw material to recover metals such as lead, copper etc., which are in growing demand all over the world. The processing of lead secondaries is important because of their relative high metal content, as well as the low energy and cost involved in recovering the metal. This paper mainly focuses on the current practices and recent trends in the secondary processing of lead. Various processes, particularly hydrometallurgical ones, already developed or in the development stages, are discussed. Attempts made by various Council of Scientific and Industrial Research (CSIR) Laboratories including the National Metallurgical Laboratory (NML) and industries such as Binani Zinc to develop eco-friendly processes for the recovery of lead from secondary raw materials are also described.

Conservation of Natural Resources↗

PubMed1974

Red cell lead, whole blood lead, and red cell enzymes.

Simultaneous assay of blood lead (Pb-B) and red cell lead (Pb-Rbc) in 123 samples from 104 urban and suburban students, ages 10-18, shows the ratio of concentration (Pb-Rbc)/(Pb-B) to increase as the hematocrit decreases. On direct assay in 40 samples, plasma lead (Pb-P) was fixed in a narrow range. In 28 students with Pb-Rbc >40 mug/100 ml, the mean red cell 2,3-diphosphoglycerate (2,3-DPG) was 6.05+/-0.28 (+/-S.E.), significantly higher (P<.025) than the 5.25+/-0.18 of 51 students with Pb-Rbc<40 mug/100 ml, although hemoglobin values were comparable (13.83+/-0.31 versus 13.55+/-0.20). Analysis of the individual population groups showed this correlation of Pb-Rbc with 2,3-DPG to be primarily related to the intercorrelation of each parameter with hemoglobin.Rbc membrane Na/K ATPase, as per cent of total membrane ATPase, had a median value of 60% in 48 subjects. Na/K ATPase below 60% was found in 10 (77%) of the 13 students with Pb-Rbc>/=40 mug/100 ml, but in only 14 of the 35 with Pb-Rbc<40 mug/100 ml (chi(2)=5.1, df=1, P<0.05). Correlation of significant enzyme changes with Pb-Rbc, but not with Pb-B in the normal urban range of Pb-B<35 mug/100 ml suggests Pb-Rbc, increased in anemia, to be a critical factor in the hematotoxicity of lead.

Adenosine Triphosphatases↗

PubMed1980

Relation of pediatric blood lead levels to lead in gasoline.

Analysis of a large data set of pediatric blood lead levels collected in New York City (1970-1976) shows a highly significant association between geometric mean blood lead levels and the amount of lead present in gasoline sold during the same period. This association was observed for all age and ethnic groups studied, and it suggests that possible exposure pathways other than ambient air should be considered. Even without detailed knowledge of the exact exposure pathways, sufficient information now exists for policy analysis and decisions relevant to controls and standards related to lead in gasoline and its effect on subsets of the population.

Air Pollutants↗

PubMed1984

Tissue lead distribution and hematologic effects in American kestrels (Falco sparverius L.) fed biologically incorporated lead.

American kestrels were fed a diet containing 0.5, 120, 212, and 448 ppm (dry wt) biologically incorporated lead (Pb) for 60 days. The diet consisted of homogenized 4-wk-old cockerels raised on feed mixed with and without lead. No kestrels died and weights did not differ among treatment groups. The control group (0.5 ppm Pb) had the lowest mean concentration of lead and the high dietary group had the highest for the following tissues: Kidney, liver, femur, brain, and blood. Concentrations of lead were significantly correlated among tissues. There were no differences among treatment groups for packed cell volume, hemoglobin concentration, or erythrocyte count.

Animal Feed↗

PubMedDate not supplied

[Experimental-hygienic assessment of 2 binary mixtures: lead-copper and lead-zinc].

The paper presents the results of experiments to examine the effects of zinc and copper on some indices of the total toxic and specific action of lead. Experiments were conducted on non-inbred albino rats intraperitoneally given the acetates of lead and zinc, as well as copper sulfate alone and in combination with the acetates. Antagonism is a determining type of combined effects of the binary mixtures lead-copper and lead-zinc upon acute and subacute exposures.

Animals↗

PubMed2002

Childhood lead poisoning investigations: evaluating a portable instrument for testing soil lead.

The Childhood Lead Poisoning Prevention Branch of the California Department of Health Services evaluated a portable X-ray fluorescence (XRF) instrument for use as a soil lead-testing tool during environmental investigations of lead-poisoned children's homes. A Niton XRF was used to test soil at 119 sampling locations in the yards of 11 San Francisco Bay Area houses. Niton XRF readings were highly correlated with laboratory results and met the study criteria for an acceptable screening method. The data suggest that the most health-protective and time-efficient approach to testing for soil lead above regulatory levels is to take either surface readings or readings of a test cup of soil prepared by grinding with a mortar and pestle. The advantage of the test cup method is that the test cup with soil may be submitted to a laboratory for confirmatory analysis.

Child↗

PubMed1989

The effect of lead on the metabolism of a nuclear matrix protein which becomes prominent in lead-induced intranuclear inclusion bodies.

The influence of lead and calcium on the metabolism of a nuclear matrix protein has been studied in mouse neuroblastoma 2a (Nb2a) cells. This protein, p32/6.3, has an unusual distribution in that it is relatively abundant only in normal neural tissues and in intranuclear inclusion bodies induced in kidney tubule-lining cells of chronically lead-intoxicated animals (Egle, P. M., and Shelton, K. R. (1986) J. Biol. Chem. 261, 2294-2298). The mechanism(s) whereby lead increases p32/6.3 content are of interest, but its slow accumulation in intact animals over a period of weeks to months precludes studies with metabolic inhibitors. However, the enriched levels of p32/6.3 in mouse neuroblastoma 2a (Nb2a) cells permit these studies. The relative abundance of this protein was found to increase in mouse Nb2a cells after 1- and 3-day exposures to lead. This increase could be attributed to a decreased rate of degradation rather than either increased transcription or increased translation. A role for calcium in p32/6.3 regulation was also explored. Although neither increased extracellular calcium nor calcium ionophores had an effect, treatment of the cells with the calcium chelator [ethylenebis(oxyethylenenitrilo)]tetraacetic acid decreased p32/6.3 levels in a concentration-dependent manner, suggesting a role for calcium in the normal metabolism of the protein.

Animals↗

PubMed1996

Blood lead dynamics of lead-exposed pregnant women and its effects on fetus development.

The dynamics of blood lead (Pb-B) and blood zinc protoporphyrin (ZPP-B) of women in early pregnancy and parturient women with lead exposure and the effects on fetus development were investigated. Pb-B of lead-exposed women was high: 0.984 mumol/L (20.38 micrograms/dl) and ZPP was 84.52 micrograms/dl. Cord blood Pb-B was 0.896 mumol/L (18.56 micrograms/dl) and cord blood ZPP was 69.24 micrograms/dl. In the control group, Pb-B was 0.261 mumol/L (5.41 micrograms/dl), ZPP-B, 37.59 micrograms/dl, cord blood, Pb-B 0.34 mumol/L (7.03 micrograms/dl), and cord ZPP-B 49.0 micrograms/dl. There was a significant correlation between blood lead and blood ZPP, maternal Pb-B and cord Pb-B, maternal Pb-B and cord ZPP-B. The significance of the consistency of high level Pb-B and the effects on fetus development is discussed.

Adult↗