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PubMed2001

Correlation between lead exposure indicators and sister chromatid exchange (SCE) frequencies in lymphocytes from inorganic lead exposed workers.

Inorganic lead exposure was studied in 31 volunteers employed in storage battery plant. The genotoxicity of lead was measured in terms of sister chromatid exchange (SCE). Erythrocyte delta-aminolevulinic acid dehydrogenase (ALAD) activity, urinary delta-aminolevulinic acid (U-ALA), and blood lead levels (PbBs) were also determined to evaluate some possible relations between these lead exposure indicators and the observed SCE frequencies. Blood lead concentration of 36.31 microg/dl was determined as an average level in the workers. Consequently decreased ALAD activity in erythrocytes and increased U-ALA excretion was observed in statistically higher PbBs when compared with the control group. A statistically significant correlation was observed between the PbBs and SCE frequencies (p < 0.05). Moreover, the correlation between U-ALA excretion and SCE frequencies (p < 0.01) was relatively higher than the correlation between PbBs and SCE frequencies. These results might indicate a possible mechanism of ALA mediation in the genotoxic effects of lead.

Adult↗
PubMed2002

Relationship between blood lead levels and renal function in lead battery workers.

OBJECTIVES: The aim of this study was to investigate the correlation between blood lead (PbB) levels and renal function indices of blood-urea nitrogen (BUN), serum creatinine (SC) and uric acid (UA) among lead battery workers with exposure to lead. METHODS: A total of 229 workers of both genders from two lead battery factories were recruited in this cross-sectional study. The personal airborne and blood samples were collected on the same day. The airborne lead (PbA) and PbB levels, and individual renal function parameters were measured and statistically analyzed. RESULTS: A positive correlation between PbB levels and individual renal function index of BUN, SC, and UA was found ( P<0.01). The PbB levels and renal function indices showed significant difference between male and female workers. Based on a multiple regression model, an increment of 10 micro g/dl PbB produced an increase of 0.62 mg/dl BUN, after being adjusted for work duration and age, and an increase of 0.085 mg/dl UA, after being adjusted for gender and body weight. Workers with PbB 60 microg/dl showed a positive dose-effect relationship with significant difference in BUN ( P<0.001) and UA ( P<0.05), and the percentage of workers with BUN and UA over the reference value also showed an increasing trend. CONCLUSION: Blood-urea nitrogen and uric acid could be considered as suitable prognostic indicators of renal dysfunction in lead-exposed workers. Our results showed that PbB levels higher than 60 micro g/dl had increasing chances of inducing adverse renal effects.

Adolescent↗
PubMed1991

The effect of airborne lead on lead levels of blood, incisors and alveolar bone of rats.

Groups of 20 inbred rats were exposed to: (1) "clean air" (0.05 micrograms Pb/m3) for 70 days; (2) 77 micrograms Pb/m3 for 70 days; (3) 249 micrograms Pb/m3 for 28 days; and (4) 1546 micrograms Pb/m3 for 50 days. Half the rats in each group were then killed and the other half kept in "clean air" until the blood lead of groups 1-3 had returned to normal. That half of the incisors which had been completely renewed during the experimental period, as well as the alveolar bone of each rat, were analysed for lead by atomic absorption spectrophotometry. In the rats killed immediately after exposure, the lead levels by atomic absorption alveolar bone showed significant differences (p less than 0.05) among all four groups, except between groups 2 and 3, indicating the importance of the combined effect of airborne lead concentration and length of exposure. For blood, significant differences (p less than 0.05) were found among all groups. For the post-exposure rats, the incisors and blood showed no significant differences (p greater than 0.05) among groups 1, 2, and 3. For alveolar bone, significant differences were not found (p greater than 0.05) between groups 2 and 3. It can be concluded that during lead exposure the alveolar bone transformation was the highest and that of incisor tissue just lower, and that blood lead became supplemented through the process of remobilization from alveolar bone, as reported for other bones.

Aerosols↗
PubMed1978

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 liver 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.

Adolescent↗
PubMed1989

A longitudinal study of dentine lead levels and intelligence, school performance and behaviour: the measurement of dentine lead.

Shed deciduous teeth were obtained from a sample of 996 New Zealand children who were participants in a longitudinal study. For each child, estimates of dentine lead were obtained from two samples of dentine. The information was used to estimate the magnitude of random errors of measurement in dentine lead values and it was estimated that between 15 and 20% of the variance in dentine lead values was attributable to random errors of measurement. In addition, dentine lead levels were influenced by small systematic errors of measurement arising from the age at which the tooth was collected and the type of tooth analysed. These sampling factors, however, accounted for less that 3% of the variance in dentine lead values. The implications of these findings for the interpretation of correlations between dentine lead levels and other variables are discussed.

Child↗
PubMed1984

Biological availability of lead in a paint aerosol. 1. Physical and chemical characterization of a lead paint aerosol.

This study was conducted to determine the physical and chemical characteristics of an aerosol of lead-based paint, generated in an industrial spray operation, that might influence the biological availability of lead present in inhaled aerosols. Paint aerosols were collected, and mass-size distribution was determined using a portable cascade impactor under actual occupational conditions. Approx. 2% of the particulate mass collected was in the respirable range (less than 10 micron mean aerodynamic diameter), although the maximum airborne concentration of lead was found to be 2-3 mg/m3. The lead concentration in a dried aerosol was very resistant to chemical digestion. Analysis by X-ray diffraction, atomic absorption spectroscopy and inductively coupled plasma emission spectroscopy showed approx. 11% lead by dry weight, although the wet weight concentration of lead reported by the manufacturer was 12.8%.

Aerosols↗
PubMed2006

Contrasting effects of age on the plasma/whole blood lead ratio in men and women with a history of lead exposure.

We examined the effect of age and sex on the relationship between the concentrations of Pb in blood (Pb-B) and in plasma (Pb-P) in an adult population with a history of lead exposure. Pb-P was determined by inductively coupled plasma mass spectrometry (ICP-MS) and Pb-B by graphite furnace atomic absorption spectrometry (GF AAS). We studied 154 adults (56 men and 98 women) from 18 to 60-year old. Pb-B levels varied from 10.0 to 428.0 microg/L, with a mean of 76 microg/L. Blood lead levels varied from 10.0 to 428.0 microg/L in men (mean, 98.3 microg/L) and from 10.0 to 263.0 microg/L (mean, 62.8 microg/L) in women. Corresponding Pb-Ps were 0.02-2.9 microg/L (mean, 0.66 microg/L) and 0.02-1.5 microg/L (mean, 0.42 microg/L) in men and women, respectively. The relationship between Pb-B and Pb-P was found to be curvilinear (r = 0.757, P < 0.001 Spearman's correlation). The two quantities are related by the line y = 0.0006x(1492) (y = Pb-P, and x = Pb-B). The %Pb-P/Pb-B ratio ranged from 0.03% to 1.85%. A positive association was found between %Pb-P/Pb-B ratio and Pb-B levels. When data were separated by sex, this association was also relevant for men (y = 0.0184x(0.702)) and women (y = 0.0534x(0.5209)) (y = %Pb-P/Pb-B and x = Pb-B). Moreover, we found an interesting positive correlation between Log (Pb-P/Pb-B) and age for women (r = 0.31, P < 0.0001) and a negative correlation for men (r = -0.164, P = 0.07). Taken together, these results suggest contrasting effects of age on the plasma/whole blood lead ratio in men and women with a history of lead exposure. Moreover, sex might play an important role in the metabolism of lead, implying further consideration on the kinetic models constructed of lead toxicity.

Adolescent↗
PubMed2003

Residential arsenic and lead levels in an agricultural community with a history of lead arsenate use.

Lead arsenate (PbHAsO4) was used as an insecticide in Washington fruit orchards from 1905 to 1947. We examined exposure potential for children living in an agricultural community with historic PbHAsO4 use. Soil and housedust samples were collected from 58 residences. Families were asked about land use history, age of home, and remodeling activities. Median concentrations of arsenic were higher in housedust than in soil (9.0 and 4.2 microg/g, respectively; P=0.05), as were lead concentrations (129 and 46 microg/g, respectively; P=0.0001). Significant associations were observed between indoor and outdoor levels of each metal, indicating track-in as an important exposure pathway. Homes on or near land use for pear or apple production between 1905 and 1947 had significantly higher soil (P=0.005) and housedust (P=0.004) lead, and soil arsenic (P=0.04) than did the other homes. Homes more than 30 years old had significantly higher soil and housedust lead than did newer homes (P=0.01). Homes remodeled within the past two years had significantly higher soil (P=0.01) and housedust (P=0.04) lead. Child doses extrapolated from these data indicate that 36% of homes had soil or dust arsenic levels above the minimum risk level estimated by the Agency for Toxic Substances and Disease Registry. None of the measured lead levels exceeded current US Environmental Protection Agency guidelines. Public health education programs focused on residential hygiene would be of value in areas of historic PbHAsO4 use.

Adult↗
PubMed2002

Reconstruction of a decline of ambient lead levels in the Ruhr area (Germany) by studying lead concentrations in antlers of roe deer (Capreolus capreolus).

We determined lead concentrations in antlers (n = 132) of roe bucks > or = 2 years of age, killed between 1951 and 1999 in the northern Ruhr area, Germany. The lead content of the antlers ranged between 0.6 and 19.0 mg/kg dry weight of bone, and overall markedly declined over the study period. As a consequence, mean lead levels in younger samples were always significantly (P<0.001) lower than those in older ones (for the periods: 1951-1969, 1970-1979, 1980-1989 and 1990-1999). Annual mean antler lead concentrations were positively correlated (r(s) = 0.74, P<0.001) with annual mean lead concentrations in airborne particulate matter of the Rhine-Ruhr area during the period 1974-1999. The findings of the present study underscore that roe deer antlers are well suited for a monitoring of temporal trends in environmental lead levels in a cost-effective way.

Animals↗
PubMed2002

Calcium supplementation during lactation blunts erythrocyte lead levels and delta-aminolevulinic acid dehydratase zinc-reactivation in women non-exposed to lead and with marginal calcium intakes.

The purpose of this study was to evaluate the effect of calcium supplementation during lactation on changes in blood lead indices from late pregnancy to early lactation in women with low calcium intakes and low lead-exposure. Forty-seven women, non-occupationally exposed to lead and with habitually low calcium intake ( approximately 600 mg/d), participated in the study from 29 to 38 weeks of pregnancy to 7-8 weeks post-partum, non-supplemented (n=25) and supplemented (n=22) with calcium (500 mg/d) during 6 weeks after delivery. Erythrocyte lead (PbRBC) and in vitro reactivation with zinc of blood delta-aminolevulinic acid dehydratase (Zn-delta-ALAD% reactivation) were used as lead indices. In the non-supplemented group, PbRBC and Zn-delta-ALAD% reactivation increased significantly (P<0.001) from pregnancy (0.202+/-0.049 microg Pb/g protein and 18.3+/-6.0%) to lactation (0.272+/-0.070 microg Pb/g protein and 22.7+/-6.2%). No significant changes of these indices were observed in the calcium-supplemented group from pregnancy (0.203+/-0.080 microg Pb/g protein and 15.8+/-4.5%) to lactation (0.214+/-0.066 microg Pb/g protein and 16.3+/-4.1%). PbRBC levels and Zn-delta-ALAD% reactivation at lactation were lower (P<0.05) and hematocrit levels were higher (P<0.05) in the calcium-supplemented compared to the non-supplemented women. Calcium supplementation during lactation appears to blunt the lactation-induced increase in maternal blood lead and its inhibitory effect on delta-ALAD and possibly on maternal erythropoiesis.

Adolescent↗
PubMed2006

Tissue lead concentration during chronic exposure of Pimephales promelas (fathead minnow) to lead nitrate in aquarium water.

The fathead minnow is a useful species for evaluating the toxicity of wastewater effluents. While this fish is widely used for "survival" studies of metal toxicity, little or no work has been done on the tissue distribution of metals in fathead minnows. To determine the distribution of tissue lead, aquarium studies were conducted for several weeks with fish maintained in soft synthetic freshwater. Lead- (II) nitrate was added to three aquaria attaining concentrations of 20-30 ppb (aquarium B), 100-140 ppb (aquarium C), and roughly 200 ppb (aquarium D). Results were compared to controls (aquarium A). During the initial week, the majority of aquarium D fish died, whereas few deaths occurred in the other groups. Lead accumulation was dose- and tissue-dependent, with highest uptake by the gills. Gill concentrations of aquarium D fish averaged about 4-fold higherthan in skeleton or skin and muscle. In vitro, lead (2.5-25 ppm) caused dose-dependent reductions in the ratio of reduced glutathione/oxidized glutathione (GSH/GSSG) in gills incubated in physiological buffer. These findings demonstrate that fathead minnow gills bind and accumulate waterborne lead rapidly and preferentially and raise the possibility that gill lipid peroxidation contributes to lead toxicity at low water hardness.

Animals↗
PubMed2006

An investigation of dust lead sampling locations and children's blood lead levels.

The objective of this study is to provide guidance on where to collect dust lead wipe samples in homes to best characterize the risk of a resident child having a blood lead level at or above the CDC level of concern (10 microg/dl). In 1998, the Milwaukee Health Department enrolled 72 children living in pre-1950 buildings: 34 had elevated (i.e., > or = 10 microg/dl) blood lead levels (EBL); and 38 had non-elevated blood lead levels (non-EBL). This study explored dust lead sampling locations by examining loading differences between homes where children with EBL and non-EBL lived. Floor, windowsill, and window trough samples were collected in the living room, kitchen, bathroom, and child's bedroom and play area. Floor samples were collected at four locations: room entry; center of the room; under a window; and against the wall opposite the window (perimeter). Geometric mean floor dust lead levels were generally two to three times higher in homes of EBL children than homes of non-EBL children. Sampling the floor at the room entry or center is preferable to sampling under the window or from the perimeter of the room. When the central floor average was used, the room combinations that had the greatest differences between homes of EBL children and non-EBL children all included a sample from the child's bedroom and excluded the bathroom. When the entry floor average was used, the greatest differences also excluded bathrooms, but otherwise included a mix of all of the other rooms. Window samples did not distinguish where children with EBLs versus non-EBLs resided. This paper is based on Milwaukee alone, so generalizing results to other locations should be done with caution.

Case-Control Studies↗
PubMed2000

The changing nature of the 206Pb/207Pb isotopic ratio of lead in rainwater, atmospheric particulates, pine needles and leaded petrol in Scotland, 1982-1998.

The inductively coupled plasma-mass spectrometry (ICP-MS)-determined 206Pb/207Pb ratio of 145 samples of rainwater collected at 25 locations around Scotland during December 1997 and January 1998 and at three longterm monitoring stations in the northeast, central belt and southeast of the country from November 1997 to December 1998 averaged 1.144+/-0.017 (1 s). This represents a significant increase from the mean value of 1.120+/-0.016 recorded for the long-term sites in 1989 1991, only partly attributable to a concomitant increase in the 206Pb/207Pb ratio of leaded petrol from 1.075+/-0.013 to 1.088+/-0.007. The rainwater 206Pb/207Pb data for the late 1990s also contrast markedly with the lower 206Pb/207Pb ratios found for pine needle and atmospheric particulate samples from Scotland (e.g. Glasgow: 1.085+/-0.012 in 1985-1986, 1.099+/-0.007 in 1991-1992), England and Western Europe in this study for the period 1982-1992 when emissions of lead to the atmosphere from petrol-engined vehicles in the UK were approximately 2-9 times higher. The observed change in the lead isotopic signature of rainwater predominantly reflects the impact of measures, such as the introduction and growing uptake of unleaded petrol, to reduce car exhaust emissions of lead to the atmosphere in the UK. Based on the rainwater data, source apportionment calculations suggest a general decline in the contribution of leaded petrol to atmospheric lead in Scotland from 53-61% in 1989-1991 to 32-45% in 1997-1998, with a corresponding decline in the urban environment from 84-86% to 48-58%.

Air Pollutants↗
PubMed2005

Old Masters' lead white pigments: investigations of paintings from the 16th to the 17th century using high precision lead isotope abundance ratios.

White lead (2PbCO(3).Pb(OH)(2)), a common component in 17c. artists' painting materials, was singled out to investigate the potential of lead isotope abundance ratios in the field of authentication and origin assignment. Paintings by Peter Paul Rubens, Anthony van Dyck and other Old Masters of the Northern and Southern schools were chosen for this study. An interdisciplinary approach was chosen using both analytical instrumental methods, art technological and art historical knowledge. Minute samples taken from paintings from selected art collections worldwide were investigated using mass spectrometry, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The high precision lead isotope abundance ratios were measured by multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS). The determination of the calcium matrix influence with respect to possible bias effects to the isotope ratios gave clear decision support, to whether a result lies within the stated combined measurement uncertainty of the result, to eliminate time-consuming matrix separations. The scatter plots of the measured isotope abundance ratios for the painting pigments from P. P. Rubens, A. van Dyck and other Flemish painters exhibit a very narrow distribution forming a cluster. The range of the measured ratio (206)Pb/(204)Pb amounts to 0.55% and for the ratio (207)Pb/(204)Pb to 0.2%. The comparison of the data to cis-alpine (Italian) sample pigments from paintings from the same time period reveals a clear distinction between the two fields. With respect to the lead isotope data originating from the ores it is assumed that the pigment isotope ratio distribution can be explained by very distinct origin of raw materials. Presumably, no mixing of different lead ores from Europe took place. The comparison of the measured white lead isotope ratio values (Flemish paintings) and the data from ore samples led to the unexpected conclusion that local ores were not used for the pigment production but British or German sources.

Carbonates↗
PubMed2000

Urinary lead isotopes during pregnancy and postpartum indicate no preferential partitioning of endogenous lead into plasma.

We have compared lead isotopic ratios and lead concentrations in 51 matched blood and spot urine samples from 13 subjects covering the interval from before pregnancy through 180 days postpartum to evaluate whether mobilization of lead from the maternal skeleton is preferentially partitioned into plasma; we have used urine as an isotopic proxy for plasma. There was no statistically significant difference in the lead 206/lead 204 and lead 207/lead 206 ratios over pregnancy. The urine data for the postpartum period are in the opposite relationships to that predicted for a preferential partitioning hypothesis. These data provide no support for the hypothesis that lead released from the skeleton is preferentially partitioned into plasma.

Adolescent↗
PubMed2001

Task-specific lead exposure during residential lead hazard reduction projects.

This article describes a study of worker airborne lead exposure during residential lead hazard reduction projects. The study was performed to characterize short-term, task-specific exposures and to test an airborne lead exposure prediction equation that could assist residential lead abatement contractors in selecting engineering controls and personal protection prior to bidding on a project. A total of 224 personal air samples were collected from 16 workers employed by three contractors at 11 San Francisco Bay-area homes. Exposures ranged from <1.0 microg/m3 to 146.0 microg/m3. Although exposures were low overall (geometric mean = 4.2 microg/m3), there was considerable variability (geometric standard deviation = 4.3 microg/m3). The task-specific approach to exposure assessment used in this study was effective in revealing short-term, high exposures that would be missed during full shift sampling. The highest exposures occurred during paint scraping, demolition, and chemical stripping. Task-specific sampling was also effective in identifying tasks with low exposure potential, such as wet sanding, component removal, and clean-up. Since exposures were not significantly correlated with paint lead content or task area size, two of the variables of the prediction equation, the equation does not appear to be an effective means of predicting airborne lead exposures. Additionally, other factors such as water usage and contractor type had a significant effect on exposure levels. By controlling for these factors, exposures were significantly correlated with the third variable of the prediction equation, the proportion of paint removed from task areas. This study also demonstrates the importance of contractor specific exposure assessments, as there were significant differences in exposures between contractors, even with similar work methods and water use frequency.

Air Pollutants, Occupational↗
PubMed1981

Gastrointestinal absorption of lead (203Pb) in chicks: influence of lead, calcium, and age.

The present study was designed to investigate, in more detail, the mechanism of lead transport by the gastrointestinal tract and particularly the similarities or dissimilarities between lead and calcium in this process. The absorption of these metals was determined in 3-week-old white Leghorn cockerels, raised on a commercial diet or special diets, using an in vivo ligated loop procedure. The dose administered into the loop usually contained 0.5 microCi 203Pb (and/or 0.1 microCi 47Ca), 0.01 mM lead acetate (and/or 1 mM CaCl2) in 0.5 ml of 0.15 M NaCl, pH 6.5. It was shown that lead is rapidly taken up by the intestinal tissue, and only slowly transferred into the circulation whereas calcium, also accumulated rapidly by the tissue, is rapidly released from the tissue in the serosal direction. The absorption processes of these cations show similar responses to various experimental conditions (low calcium intake, age of the animal, pH of the dosing solution). However, increasing luminal stable lead concentration from 0.01 to 1 mM Pb, significantly reduced the percentage of radiolead absorbed, but did not inhibit the absorption of radiocalcium, Also, luminal Ca (0-25 mM) did not significantly affect the absorption of 203Pb. These data imply that, in spite of the similarities in the response of the lead and calcium absorptive processes to various treatments, there is no direct interaction between these cations in the intestine of the chick.

Aging↗
PubMed1999

A community-developed, community-based lead poisoning prevention program: Lead Awareness North Philly Style.

This work describes a demonstration/research project to implement and evaluate community-developed, community-based strategies that address childhood lead poisoning. The project will increase knowledge of childhood lead poisoning as an environmental health risk, as well as hazard, exposure, and outcome surveillance for lead as an environmental agent. At the end of the second year of this study the data indicate increased knowledge about lead poisoning and that more children are being tested for lead poisoning in the experimental census tracts (CTs), when compared with the control CTs, with lower lead levels.

Adult↗