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PubMed1987

Effect of food intake on blood lead concentration in workers occupationally exposed to lead.

Results from a cross-sectional study showed the concentration of lead in the blood of male workers, aged 20-55 years, occupationally exposed to lead in a steel factory, to be negatively correlated with the daily nutritional content of dietary fiber, iron and vitamin B1 (thiamine) intake. Furthermore, in experiments with rats injected subcutaneously with lead acetate, lead levels in blood and femur of animals on a vitamin-rich laboratory chow were lower than those fed a general laboratory chow. Moreover, in the group fed the vitamin-rich chow, lead excretion in feces increased, while excretion in urine did not. These results suggest that lead excretion from the body may be increased by a high intake of nutrients such as thiamine, iron and fiber, that lead excretion in feces via bile may be enhanced by a large intake of vitamins such as thiamine and that accordingly the lead concentration in the blood of the workers is reduced.

Adult↗
PubMed1990

Relationships between blood lead and indicators of effect in cows environmentally exposed to lead.

Biological indicators of lead exposure and its effects were measured in 83 cows from a lead-contaminated area in the vicinity of a lead smeltery and in 53 cows from a control area. Differences between the groups were highly significant for blood lead (PbB) content, activity of erythrocyte delta-aminolevulinic acid dehydratase (ALAD) and erythrocyte protoporphyrin (EP) content, but considerably less significant for blood hemoglobin (Hb) content and not significant for hematocrit (Hct). An exponential, rather than linear, characteristic form was observed for the relationships between ALAD activity, EP, Hb and Hct with respect to PbB. This finding supports the hypothesis that lead-induced effects are dependent on the long-term integrated level of lead exposure, rather than the recent lead exposure level as mainly reflected by PbB. The use of ALAD activity and EP as cumulative lead exposure indicators is suggested.

Animals↗
PubMedDate not supplied

A neuropsychological study of children with elevated dentine lead level: assessment of the effect of lead in different socio-economic groups.

The study was carried out in the municipality of Aarhus, a city of 250,000 inhabitants. The study was designed as a cross-sectional cohort study of school children in first grade in 1982-83. A total of 2,412 children were contacted and asked to submit their shed teeth to the teacher, and 1,291 children delivered at least one usable tooth (response rate, 54 percent). The lead level in circumpulpal dentin showed an average of 10.7 micrograms/g. Eight percent of the children (N = 110) had a lead level above 18.7 micrograms/g and were selected as a "high" lead exposure group. This group was matched by sex and socio-economic status of the parents with control children with a dentin lead level below 5 micrograms/g. Following a detailed interview with the parents, children were excluded from the study if medical risk factors were present. A clinical psychologist, blind to the lead data, administered selected psychometric tests to 162 of the children selected. The high-lead children scored lower on the WISC when compared to low-lead children, especially on the Verbal IQ (p less than 0.001) and Full Scale IQ (p less than 0.01). No significant difference was seen between the high- and low-exposure groups on the Performance IQ and on several experimental tests. Impaired function associated with lead exposure was also found on the Bender Visual Motor Gestalt Test (p less than 0.001) and on a behavioral rating scale (p less than 0.01). These results remained statistically significant even after controlling for socio-economic status and other confounding variables.

Child↗
PubMed2004

Through metal binding, curcumin protects against lead- and cadmium-induced lipid peroxidation in rat brain homogenates and against lead-induced tissue damage in rat brain.

Curcumin, the major constituent of turmeric is a known, naturally occurring antioxidant. The present study examined the ability of this compound to protect against lead-induced damage to hippocampal cells of male Wistar rats, as well as lipid peroxidation induced by lead and cadmium in rat brain homogenate. The thiobarbituric assay (TBA) was used to measure the extent of lipid peroxidation induced by lead and cadmium in rat brain homogenate. The results show that curcumin significantly protects against lipid peroxidation induced by both these toxic metals. Coronal brain sections of rats injected intraperitoneally with lead acetate (20 mg/kg) in the presence and absence of curcumin (30 mg/kg) were compared microscopically to determine the extent of lead-induced damage to the cells in the hippocampal CA1 and CA3 regions, and to establish the capacity of curcumin to prevent such damage. Lead-induced damage to the neurons was significantly curtailed in the rats injected with curcumin. Possible chelation of lead and cadmium by curcumin as its mechanism of neuroprotection against such heavy metal insult to the brain was investigated using electrochemical, ultraviolet spectrophotometric and infrared spectroscopic analyses. The results of the study show that there is an interaction between curcumin and both cadmium and lead, with the possible formation of a complex between the metal and this ligand. These results imply that curcumin could be used therapeutically to chelate these toxic metals, thus potentially reducing their neurotoxicity and tissue damage.

Animals↗
PubMed2001

Relationship between soil lead and airborne lead concentrations at Springfield, Missouri, USA.

This study tests whether lead deposited to soil from automobiles during past years in a medium-sized US city (population 150,000) may present a current health risk. It examines the relationship between current soil lead concentrations at nine locations within the city of Springfield, Missouri, and airborne lead levels measured at the same locations during years (1975-1981) when lead emissions from automobiles were much greater than at present. A strong, significant correlation is found between soil and airborne lead levels at eight of the sites (r = 0.91, P < 0.005 for soil lead vs. 1979 airborne lead), in low-traffic areas as well as in areas adjacent to heavy traffic flow. Residual lead concentrations in these soils are relatively low, even for the high-traffic sites, as expected for a medium sized city.

Air Pollutants↗
PubMed2002

Evaluation of lead exposure in workers at secondary lead smelters in South Korea: with focus on activity of erythrocyte pyrimidine 5'-nucleotidase (P5N).

To evaluate lead exposure among secondary lead-smelting workers with a focus on erythrocyte pyrimidine 5'-nucleotidase (P5N) activity, blood lead concentration (PbB), activity of P5N and other biological variables were examined in 88 exposed workers in five secondary lead smelters and in 24 non-exposed workers in Korea. All of the mean values of air lead concentration (PbA) in the three processes, scrap pretreatment, blast furnace smelting, and refining and casting of the secondary lead smelters, markedly exceeded 0.05 mg/m3. In this survey, 29 (97%) of 30 air samples for lead exceeded 0.05 mg/m3. The highest mean PbA and PbB values were found in the section of blast furnace smelting. All of the mean PbB values in all the sections were higher than 30 microg/dl. PbB of 71 (81%) of the 88 exposed workers exceeded 30 microg/dl. In 31 (35%) of the exposed workers, PbB was above 60 microg/dl. Compared with the non-exposed group, zinc protoporphyrin (ZPP) in the exposed group was significantly increased, whereas erythrocyte P5N activity and activity of erythrocyte delta-aminolevulinic acid dehydratase (ALAD) were significantly inhibited. Erythrocyte P5N activity had valid biological correlation with PbB and with other biological variables, such as ALAD activity or ZPP. Lead exposure affected hemoglobin levels via inhibition of P5N activity, as well as the heme biosynthetic pathway, in the high-exposure state.

5'-Nucleotidase↗
PubMed1997

Lead in primary teeth from Norway: changes in lead levels from the 1970s to the 1990s.

Lead is one of the most important and widely distributed pollutants in the environment. In the human population children are particularly at risk. Local dentists in all 19 counties in Norway collected 2746 primary teeth from 1990 to 1994. Tooth substance from whole, ground teeth were analyzed for lead concentration by electrothermal atomic absorption spectrophotometry. The geometrical mean for the entire material was 1.27 micrograms lead/g tooth substance (S.D. 1.87). The mean lead levels in each of the counties were significantly lower than those obtained in a corresponding study in the 1970s. Two counties, Oslo and Vest-Agder, had significantly higher lead levels than the majority of the other counties. Tooth lead concentration and atmospheric deposition of lead in the same areas were significantly and positively correlated, as shown by analysis of naturally growing moss. We conclude that lead concentrations in primary teeth from children in Norway have been reduced by approx. 50% from the 1970s to the 1990s. The reduction probably reflects a decrease in the environmental lead burden in Norway.

Air Pollutants↗
PubMed2001

A review of the contamination of soil with lead II. Spatial distribution and risk assessment of soil lead.

Contamination of soil with lead has occurred on a global scale. Exposure to lead may cause adverse effects to human health and the environment. It is therefore desirable to obtain a quantitative estimate of the potential risk of lead contamination. Numerous studies have been conducted collecting lead concentration data from both natural and contaminated soil on a range of scales. Very few of these studies have made serious attempts to spatially describe the data. In order to identify contaminated land and to enable development of appropriate environmental guidelines, it is essential to have an understanding of the universal range of lead concentrations. Such data also assists in assessing any potential risk to the environment or human health. This paper reviews the multitude of data collected on soil Pb concentrations. Lead surveys are discussed on the basis of land use, with Australian data presented separately. Data from lead surveys of agricultural, urban and industrial areas, as well as nationwide surveys are summarised. A small but increasing number of studies have employed spatial prediction techniques such as kriging to map the distribution of lead concentrations in soil. These studies are also summarised and a brief description of the basis for their use presented. Finally, environmental and health risk assessment is discussed and some methodologies in use around the world reviewed.

Agriculture↗
PubMedDate not supplied

Children's blood lead levels in the lead smelting town of Port Pirie, South Australia.

This survey included 1,239 children, representing 50% of the elementary school population of the lead smelting town of Port Pirie. Of these children, 7% had a capillary blood lead level equal to or greater than 30 micrograms/dl, which is the Australian National Health and Medical Research Council's "level of concern." There was a statistically significant difference in capillary lead levels by area of residence that was independent of age, sex, soil lead, rainwater tank lead, and school attended. A case-control study indicated that the following subset of factors was most predictive of an elevated blood lead level: household members who worked with lead in their occupations; living in a house with flaking paint on the outside walls; biting finger nails; eating lunch at home on school days; when at school, appearing to have relatively dirty clothing; when at school, appearing to have relatively dirty hands; and living on a household block with a large area of exposed dirt. A program to reduce the risk of elevated blood lead levels in Port Pirie children has been introduced.

Adolescent↗
PubMedDate not supplied

Lead in vertebral bone biopsies from active and retired lead workers.

Samples of vertebral bone were obtained by skeletal biopsy and lead concentrations were determined by atomic absorption spectroscopy. The median level of lead in bone in 27 active lead workers was 29 micrograms/g wet weight (range 2-155), corresponding to 370 micrograms/g calcium (range 30-1,120). In 9 retired workers, the corresponding levels were 19 micrograms/g (5-76) and 250 micrograms/g calcium (60-700); in 14 reference subjects without occupational exposure, 1.3 micrograms/g (1-4) and 13 micrograms/g calcium (8-40). The bone lead content rose with time of exposure. Comparison of levels in vertebra with those in fingerbone, as measured by in vivo x-ray fluorescence in the same subjects, strongly suggested the presence of lead pools with different kinetics. The accumulation pattern, as well as the relation between levels in vertebra and fingerbone, suggests a much shorter half-time of lead in the mainly trabecular vertebral bone as compared to the mainly cortical fingerbone. Further, there was an association between vertebral and blood lead levels in the retired workers, which shows a considerable endogenous lead exposure from the skeletal pool.

Adult↗
PubMedDate not supplied

Lead contamination during domestic preparation and cooking of potatoes and leaching of bone-derived lead on roasting, marinading and boiling beef.

Lead concentrations were measured in boiled, mashed potatoes and in baked potatoes that had been prepared and cooked in domestic kitchens. Levels of lead in the boiled, mashed potatoes ranged from below the 1 microgram/kg limit of detection up to 18 micrograms/kg with a mean of 6 micrograms/kg (wet weight). In the large majority of cases the lead in the tap water was the predominant source of the metal. Higher amounts of lead (range 11 micrograms/kg to 56 micrograms/kg, mean 27 micrograms/kg) were present in baked potatoes and this was attributed to soil adhering to the potato skin. The extent of leaching of lead from bone during cooking has also been investigated. For beef stocks there was little evidence to suggest that significant migration of bone lead occurred. For beef casseroles, marinaded in red wine, some leaching did occur from beef joints containing elevated amounts of bone lead; however the levels were all below 350 micrograms/kg and, on average, less than double that found in casseroles prepared from normal joints where the bone lead levels were an order of magnitude less.

Animals↗
PubMed1977

Lead intoxication among demolition workers: the effect of lead on the hepatic cytochrome P-450 system in humans.

Overt clinical disease from undue lead exposure has become a relatively rare phenomenon in adult populations. However, exposure situations that may result in subclinical disease are not uncommon in various occupational settings. Five demolition workers, dismantling an old iron structure covered with lead-content paint, were studied. The use of cutting torches resulted in lead fumes, with significant exposure, albeit without gross 'lead poisoning." All five workers showed biochemical manifestations of chronic lead intoxication-that is, elevated blood lead level, inhibition of delta-aminolevulinic acid dehydratase (ALA-D), and elevated erythrocytic protoporphyrin concentration (PROTO). The effect of lead on the biosynthesis of heme was assessed by investigating the functional capacity of the cytochrome P-45O system of the liver, through drug metabolism studies. The plasma elimination rates (half-lives) of antipyrine and phenylbutazone-drugs primarily metabolized by the hemeprotein P-450 dependent hepatic microsomal enzyme system-were measured before and after chelation therapy. Prior to chelation therapy all half-lives were within the normal range. A slight decrease in the half-life of antipyrine was found after treatment. These studies show that chronic exposure to lead has only a minimal effect on hepatic cytochrome p-450 dependent enzymatic activities in adult males.

Adult↗
PubMed1982

The effects of dietary fat and lead ingestion on blood lead levels in mice.

To examine the effects of dietary fat on the levels of lead in the blood, 34-40-d-old male mice were fed normal or high-fat diets along with distilled water for an initial 48-h exposure period. Following this session, subjects from each diet condition were administered either 0, 0.075, or 0.5% lead acetate through the drinking water during the next 48 h along with their respective diets. Atomic absorption was used to analyze blood-lead levels. At each concentration of lead, the high-fat diet increased the blood lead content over subjects fed the control diet. The highest blood lead levels were found in the 0.5% lead acetate, high-fat diet condition. The importance of nutritional considerations in understanding lead toxicity is discussed.

Animals↗
PubMed1997

Effect of personal hygiene on blood lead levels of workers at a lead processing facility.

The relationship between personal hygiene and blood lead levels was tested at a lead processing facility. During the workers' semiannual respirator fit test, when they were confident their hands were clean, the amount of lead on their right hands was measured. Samples were obtained by cleaning one entire hand with a wiping towel treated with a proprietary mixture of alcohol, surfactants, and ethylenediaminetetraacetic acid. Wipe samples were analyzed for total lead and then compared with the worker's blood lead level. Each worker's personal habits at rest were also observed. Workers with more than 1 year's experience had a significantly positive correlation between lead on the hand tested and their blood level. The study strongly suggests that lead on the skin ultimately enters the bloodstream. The route of entry was not investigated. Personal habits of the workers with high blood lead levels were observed to include actions that would quickly contaminate their hands shortly after washing.

Chemical Industry↗
PubMed2006

Association of blood lead and tibia lead with blood pressure and hypertension in a community sample of older adults.

Few studies have compared associations of blood lead and tibia lead with blood pressure and hypertension, and associations have differed in samples with occupational exposure compared with those with mainly environmental lead exposure. African Americans have been underrepresented in prior studies. The authors performed a cross-sectional analysis of 2001-2002 data from a community-based cohort in Baltimore, Maryland, of 964 men and women aged 50-70 years (40% African American, 55% White, 5% other race/ethnicity) to evaluate associations of blood lead and tibia lead with systolic and diastolic blood pressure and hypertension while adjusting for a large set of potential confounding variables. Blood lead was a strong and consistent predictor of both systolic and diastolic blood pressure in models adjusted and not adjusted for race/ethnicity and socioeconomic status. Tibia lead was associated with hypertension status before adjustment for race/ethnicity and socioeconomic status (p = 0.01); after such adjustment, the association was borderline significant (p = 0.09). Propensity score analysis suggested that standard regression analysis may have exaggerated the attenuation. These findings are discussed in the context of complex causal pathways. The data suggest that lead has an acute effect on blood pressure via recent dose and a chronic effect on hypertension risk via cumulative dose.

Black or African American↗
PubMedDate not supplied

Fluorometric HPLC determination of delta-aminolevulinic acid (ALA) in the plasma and urine of lead workers: biological indicators of lead exposure.

A fluorometric high-performance liquid chromatographic (HPLC) method was developed for the highly sensitive measurement of delta-aminolevulinic acid (ALA) in biological materials. By using this method, we determined ALA in the plasma and urine of 418 workers occupationally exposed to lead and in the plasma and urine of 227 controls. The concentrations of ALA in the plasma and urine of lead workers were significantly elevated as compared with those of the controls. The concentration of ALA in plasma and urine was highly correlated with that of lead in blood in lead workers. It was found that the correlation (r = 0.742) between log of plasma ALA concentrations and blood lead concentrations in lead workers was similar to that (r = 0.711) between log of urine ALA concentrations and blood lead concentrations. These results demonstrated that the measurement of ALA in plasma or in urine using a fluorometric HPLC method was useful for the biological monitoring of lead workers.

Adolescent↗
PubMed1978

Increased lead absorption in children of workers in a lead storage battery plant.

Exposure to toxic materials originating in the workplace has been recognized in families of workers in several industries. However, to date this problem has not been studied in the storage battery production industry. Twenty-seven one- to six-year-old children of 22 workers at a storage battery plant at high risk of exposure to lead oxide were compared with 32 one- to six-year-old children in 22 neighborhood control families for evidence of increased lead absorption. Workers' children had significantly higher blood lead (p less than 0.001) and erythrocyte protoporphyrin (p less than 0.003) values than control children. Household exposures to lead in paint and water were similar for the two groups, but workers' homes had significantly higher concentrations of lead in dust (p less than 0.001). It is postulated that lead is brought home on the skin, hair and clothing of the workers and that their children are ingesting or inhaling the lead in household dust. This is the first report of increased lead absorption in children of workers in this industry.

Absorption↗
PubMed1995

Substantial decrease of blood lead in Swedish children, 1978-94, associated with petrol lead.

OBJECTIVES: To study the potential impact of environmental exposure to petrol lead, residential area, age, sex, and lead exposing hobby, on blood lead concentrations (BPb) in children. METHODS: In the south of Sweden, yearly from 1978-94, BPb was measured in 1230 boys and 1211 girls, aged between 3 and 19 (median 10; quartiles 9 and 12) years. RESULTS: For the samples of 1978, the geometric mean (GM) was 67 (range 30-250) micrograms/l in boys and 53 (18-161) micrograms/l in girls, whereas the corresponding GMs for 1994 were 27 (12-122) and 23 (12-97) micrograms/l. The sex difference was present only in children over eight. Moreover, residential area affected BPb; in particular, children living near a smelter area had raised BPbs. There was a clear ecological relation between BPb (adjusted GM) and annual lead quantity in petrol sold in Sweden, which was estimated to be 1637 tonnes in 1976 and 133 tonnes in 1993 (P < 0.001, ecological linear regression analysis, where a two year lag of petrol lead was applied). In the 171 boys and 165 girls who were sampled twice with an interval of one to four years, the decreases in BPb were estimated to be 6% (95% confidence interval 4%-8%) and 10% (8%-13%)/year, respectively. CONCLUSIONS: The present report points out the considerable beneficial effect of the gradual banning of petrol lead on the lead exposure affecting the population and differential sex specific BPb patterns due to a pronounced age effect in girls, which may be caused by older girls' lower food intake per kg of body weight, lower lung ventilation, cleaner life style, and loss of blood lead through menstrual bleedings.

Adolescent↗