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At least 1,099 records · Page 61Linked to original sources
PubMed1990

Determination of numbers of lead-exposed women of childbearing age and pregnant women: an integrated summary of a report to the U.S. Congress on childhood lead poisoning.

In a Congressionally mandated study carried out under the aegis of the U.S. Agency for Toxic Substances and Disease Registry (ATSDR) and summarized in this article, the authors have provided estimates of the numbers of American women of childbearing age and the numbers of American pregnant women whose lead exposure is sufficiently elevated to pose an intrauterine toxicity risk. Exposures associated with such risk were defined as blood lead (PbB) levels greater than 10, greater than 15, greater than 20, and greater than 25 micrograms/dL. Using PbB prevalence projection techniques based on the Second National Health and Nutrition Examination Survey (NHANES II), we first generated projected 1984 prevalences of these PbB levels in white and black women of childbearing age, ages 15 to 19 and 20 to 44. White women in the two age bands had rates of PbBs greater than 10 micrograms/dL of 9.2 and 9.7%, respectively. For black women, the corresponding rates were 8.2 and 19.7%, respectively. Combining these rates with standard metropolitan statistical areas (SMSAs) based 1980 Census and other population enumerations show, for example, that 4.4 million U.S. women of childbearing age are estimated to have had PbBs greater than 10 micrograms/dL. Pregnant black and white women in U.S. SMSAs are approximately 9% of the U.S. black and white childbearing age total, i.e. 3.6 million out of a 41.3 million SMSA total. Of these, 403,200 pregnant women were estimated to have PbB levels greater than 10 micrograms/dL.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1983

Lead concentrations in inner-city soils as a factor in the child lead problem.

Soil samples were randomly collected from 422 vegetable gardens in a study area centered in downtown Baltimore, Maryland, and having a radius of 48.28 km (30 miles). The levels of lead, four other metals (cadmium, copper, nickel, and zinc), and pH were measured for each location. The application of multi-response permutation procedures, which are compatible with mapping techniques, reveals that lead (as well as cadmium, copper, nickel, and zinc) is concentrated and ubiquitous within the soils of the inner-city area of Metropolitan Baltimore. The probability values that the concentration of metals occurred by chance alone vary from about 10(-15) to 10(-23) depending on the metal considered. Our findings pose environmental and public health issues, especially to children living within the inner-city.

Child↗
PubMed1992

Lead chromate exposures and elevated blood lead levels in workers in the plastics pigmenting industry--Texas, 1990.

In June 1990, the Dallas (Texas) County Health Department received a physician's report of an elevated blood lead level (BLL) (52 micrograms/dL) for an employee of a company that formulates color concentrates for the plastics industry. The physician had been evaluating the employee for severe headaches of uncertain etiology; however, he requested a BLL analysis when the employee's occupational history suggested possible lead exposure.

Air Pollutants, Occupational↗
PubMed1985

[Effect of lead and tetraethyl lead poisoning on the microcirculatory bed of the conjunctiva of the eye].

The ultrastructure of the bulbar conjunctiva bioptates have been studied in 12 persons suffering from lead intoxication (saturnism), 2-from tetraethyl-lead (TEL) intoxication and 3-are practically healthy persons; they make the control group. In all the patients manifested disturbances in the microcirculatory bed of the bulbar conjunctiva are revealed, the general character being identical at saturnism and TEL-intoxication. The main changes are observed in the wall of the blood microvessels: destruction of the endothelial lining up to revealing the basal membrane with adhesion of the blood formed elements and their diapedesis. This results in disorders of vascular permeability, in edema of the perivascular space and in appearance of cells and cellular detritus in it. An essential role in morphogenesis of the vascular disturbances produced by intoxication play certain rheological imparements: sludge-syndrome and microthrombosis. They produce certain distrophic changes.

Adult↗
PubMed1982

Experimental lead toxicosis in ponies: comparison of the effects of smelter effluent-contaminated hay and lead acetate.

Grass hay produced in the Coeur d'Alene River Basin of northern Idaho was fed to a group of 4 ponies. The hay contained Pb in concentration of 423 +/- 82 mg/kg and Cd in concentration of 10.8 +/- 1.4 mg/kg, resulting in daily exposures of the ponies to approximately 7.4 mg of Pb/kg and 0.19 mg of Cd/kg/day. The results in this group of ponies were compared with those from a group fed noncontaminated grass hay and given a daily dose of 10 mg of Pb/kg of body weight, in the form of lead acetate. Clinical toxicologic signs, hematologic changes, and blood and tissue Pb concentrations were similar in the 2 groups. However, the severity of the disease process appeared to be greater in the ponies fed the Pb- and Cd-contaminated hay. This was shown clearly by the shorter interval between onset of clinical changes and death in the ponies fed contaminated hay. The possibility of multiple heavy metal effects is discussed. Clinical toxicologic signs observed include incoordination, labial paresis, pharyngeal paresis, CNS depression, anorexia, and body weight loss. Anemia or marginal anemia was common and was often accompanied by the appearance of nucleated RBC and Howell-Jolly bodies in peripheral blood. Neither the hematologic response nor the blood Pb concentrations were reflective of the severity of poisoning, although blood Pb concentrations were greater than 0.35 micrograms/ml once clinical signs of toxicity were observed. Liver, kidney, spleen, brain, and bone Pb concentrations and liver, kidney, and brain Cd concentrations were increased in both the ponies fed contaminated hay and the ponies given lead acetate.

Animals↗
PubMedDate not supplied

Exposure of Rana ridibunda to lead II. Impact of lead on various parameters of liver metabolism of the frog Rana ridibunda.

There are no data at present on the impact of lead (Pb) on amphibian metabolism, although declines of amphibian populations due to man-made changes in the environment have been recorded in recent years. We studied the impact of Pb on the liver metabolism of the frog Rana ridibunda by measuring the hepatic levels of glycogen, lactate, total fat, protein and glucose. Liver is one of the primary target organs of Pb bioaccumulation. Frogs were exposed for 4, 10 and 30 days to 14 mg l(-1) of Pb (in the form of Pb(NO(3))(2) dissolved in water) and compared with matched controls. The level of glycogen in the liver increased until day 30. The increase of the metabolite was time-dependent because there was a positive correlation (r = 0.994, P = 0.006) between glycogen concentration and the days of Pb exposure. Lactate concentration declined continuously up to day 30. Liver fat content decreased from day 10 to day 30. Protein concentration declined continuously until day 30. Glucose concentration increased up to day 30. Glycogen concentration was correlated negatively with liver fat content (r = -0.474, P = 0.005), liver protein content (r = -0.562, P = 0.0004) and lactate concentration (r = -0.472, P = 0.005), whereas it was correlated positively with the Pb burden of the liver (r = 0.578, P = 0.0005). The frog appeared to face a metabolic stress over the 30 days of Pb exposure, without being able to control it. We concluded that the increase of liver glycogen concentration was due to gluconeogenesis via lactate and lipolysis. Further experimentation on key gluconeogenic and lipolytic enzymes over the 30 days of Pb exposure would elucidate the mechanisms that may lead to such phenomena.

Animals↗
PubMed1995

A comparative study of cadmium, lead, zinc, pH, and bulk density from the Enyigba lead and zinc mine in two different seasons.

Soil pH and bulk density, as well as the concentrations of cadmium (Cd), lead (Pb), and zinc (Zn) in soils and these metal levels in the leaves of cassava (Manihot esculenta) and rice (Oryza sativa), both collected, respectively, in the dry season (December) of 1991 and the rainy season (September) of 1992 from the Enyigba lead and zinc mine, Nigeria, were investigated. Interspecific variations in trace element levels in the plant leaves were detected and may reflect the predilection of these plants to particular elements rather than their variability being due to different climatic conditions, such as precipitation, or other environmental factors.

Cadmium↗
PubMed1982

Relationships between three indicators of lead exposure in workers: blood lead, delta-aminolevulinic acid and free erythrocyte protoporphyrin.

Whole blood lead (Pb-B), urinary delta-aminolevulinic acid (ALA-U) and free erythrocyte protoporphyrin (FEP) were measured in three groups of workers (n = 196) with different degrees of exposure to lead, and one group of men with no previous exposure to the metal (n = 48). Inter-group comparison showed a correlation of r = 0.73 between Pb-B and log of ALA-U, and r = 0.91 between Pb-B and log of FEP. ALA-U and FEP values rose sharply after Pb-B values reached 450-500 micrograms/l.

Adolescent↗
PubMed1976

[Lead- and cadmium-content of foodstuffs. 2. Lead- and cadmium-content of commercially prepared soups (authors transl)].

The lead and cadmium contents in 30 commercially prepared soup products (soup powders and cubes) of several producers were determined. The average lead value was 0.28 ppm. 29 samples contained between 0,095 ppm and 0.45 ppm, whereas in 1 product 1.4 ppm was found. The average cadmium concentration in 21 products was 0.025 ppm (highest value 0.052 ppm). In the other samples cadmium was not found (less than 0.004 ppm Cd).

Cadmium↗
PubMed1975

[Lead-content of foodstuffs. 3. Lead intake from total daily diets (author's transl)].

The lead contents in the total daily diets of four adults were determined over a period of one week. On average, the weekly intake was found to be 0,85 mg Pb per person. This value is less than one third of the "provisional tolerable weekly intake" of 3 mg Pb, as recommended by the FAO/WHO expert committee on food additives. The average weekly intake of lead per kg body-weight was found to be 11,8 mug Pb.

Adult↗
PubMed1995

Lead-binding proteins in brain tissue of environmentally lead-exposed humans.

This study reports the partial purification and characterization of cytosolic lead binding proteins (PbBPs) in human brain tissue of environmentally Pb-exposed subjects. The isolated proteins were initially characterized based upon the presence of endogenously associated Pb. Following partial purification (Sephadex G-75 and A-25 DEAE anion-exchange chromatography), the isolated PbBPs (contained within a single DEAE peak) showed a single class of high affinity binding sites with an apparent Kd of 10(-9) M, based upon competition assays using radioactive 203Pb and Hill and Scatchard analysis. The presence of endogenously bound Pb with the isolated proteins indicated the association of Pb with the protein(s) in vivo in these environmentally Pb-exposed subjects, since the samples were prepared in an ultraclean lead analysis laboratory. Moreover, the persistence of Pb-protein binding throughout the initial two steps (Sephadex G-75 and A-25 DEAE) of the purification scheme is consistent with the high affinity and stability of binding measured with the radiolead competition assays. The DEAE isolated PbBPs were further purified by denaturing reversed-phase HPLC analysis, resulting in the isolation of two proteins, thymosin beta 4 (5 kDa, pI 5.1) and a second as yet unidentified protein with an approximate molecular mass of 20 kDa and a pI of 5.9. Qualitative 203Pb-binding analysis of these HPLC purified proteins suggested that they may be primarily responsible for the observed Pb binding in the single DEAE peak. Nearly identical results were obtained in brain cytosols from male and female, and young and adult individuals, although further quantitative analyses are needed to investigate possible sex and age relationships. These data are significant because they contribute to a better understanding of the presence of PbBPs in a sensitive target organ for Pb toxicity in humans, suggesting a possible role of these or similar proteins as sensitive biomarkers of Pb exposure and toxicity.

Adult↗
PubMed1984

Epidemiological-environmental study of lead acid battery workers. I. Environmental study of five lead acid battery plants.

Industrial hygiene measurements were taken at five lead acid battery plants. The average of all personal samples for H2SO4 was 0.18 mg/m3 with a range of "nondetectable" to 1.7 mg/m3. Highest levels of acid were found in the charging and forming areas of the plants. Stibine and arsine were also detected in the charging and forming areas (means = 0.44 and 0.042 mg/m3, respectively). Arsenic in particulate form was also detected, but levels were low (means = 0.00083 mg/m3). The average mass median aerodynamic diameter of the acid mist as measured by cascade impactors was approximately 5 micron. Air lead results were variable with an overall average of 0.072 mg/m3 and a standard deviation of 0.11 mg/m3.

Air Pollutants, Occupational↗
PubMed1983

Biliary excretion of lead in rats drinking lead-containing water.

In three groups of rats, drinking lead-containing water (at 100, 250 and 2500 mg lead (Pb)/l) for 80 days, biliary excretion of Pb was studied. In comparison with a control group (0.05 +/- 0.04 micrograms Pb/ml) biliary excretion of Pb in the exposed groups reached 0.08 +/- 0.01, 0.20 +/- 0.04 and 1.46 +/- 0.09 micrograms/ml, respectively. In rats receiving 2500 mg Pb/l, i.v. administration of CaEDTA (0.2 mumol/kg body weight) significantly decreased biliary Pb excretion and increased the concentration of Pb in the kidneys.

Animals↗
PubMed1993

Tension inhibitory effect of lead ions and lead uptake in ileal longitudinal muscle of the guinea-pig.

1. In ileal longitudinal smooth muscle of the guinea-pig, lead ions (Pb2+) inhibited the phasic response to high-K+ (60 mM) solution more strongly than the tonic response. 2. Pb2+ displaced Ca2+ concentration-response curves to the right. Moreover, Pb2+ inhibited the 45Ca binding at high affinity sites determined by the La3+ method than low affinity sites during K(+)-induced contraction. 3. After treatment with Pb2+, the tonic tension caused by high-K+ was fairly restored by a wash with normal medium. The lead bound to the muscle cells was almost eliminated after 20-30 min with a normal medium. 4. We suggest that Pb2+ binds loosely to the surface membrane of ileal longitudinal muscle. Pb2+ probably reduced the tension in response to the high-K+ mainly by inhibiting Ca2+ release rather than by affecting Ca2+ influx.

Animals↗
PubMed2006

Effects of lead contamination on soil enzymatic activities, microbial biomass, and rice physiological indices in soil-lead-rice (Oryza sativa L.) system.

The effect of lead (Pb) treatment on the soil enzymatic activities, soil microbial biomass, rice physiological indices and rice biomass were studied in a greenhouse pot experiment. Six levels of Pb viz. 0(CK), 100, 300, 500, 700, 900 mg/kg soil were applied in two types of paddy soils. The results showed that Pb treatment had a stimulating effect on soil enzymatic activities and microbial biomass carbon (Cmic) at low concentration and an inhibitory influence at higher concentration. The degree of influence on enzymatic activities and Cmic by Pb was related to the clay and organic matter contents of the soils. When the Pb treatment was raised to the level of 500 mg/kg, ecological risk appeared both to soil microorganisms and plants. The results also revealed a consistent trend of increased chlorophyll contents and rice biomass initially, maximum at a certain Pb treatment, and then decreased gradually with the increase in Pb concentration. Pb was effective in inducing proline accumulation and its toxicity causes oxidative stress in rice plants. Therefore, it was concluded that soil enzymatic activities, Cmic and rice physiological indices, could be sensitive indicators to reflect environmental stress in soil-lead-rice system.

Acid Phosphatase↗
PubMed2004

Lead contamination in shooting range soils from abrasion of lead bullets and subsequent weathering.

Contamination of shooting range soils from the use of Pb bullets is under increasing scrutiny. Past research on Pb contamination of shooting ranges has focused on weathering reactions of Pb bullets in soil. The objective of this study was to determine the significance of abrasion of Pb bullets in contributing to soil Pb contamination. This was accomplished by firing a known mass of bullets into sand and analyzing for total Pb after removing bullets, through field sampling of a newly opened shooting range, and a laboratory weathering study. Forty-one mg of Pb were abraded per bullet as it passed through the sand, which accounted for 1.5% of the bullet mass being physically removed. At a shooting range that had been open for 3 months, the highest Pb concentration from the pistol range berm soil was 193 mg/kg at 0.5 m height, and from the rifle range berm soil was 1142 mg/kg at 1.0 m height. Most soils from the field abrasion experiment as well as soil collected from the rifle range had SPLP-Pb >15 microg/l (Synthetic Precipitation Leaching Procedure). Typically, Pb concentration in the rifle range was greater than that of the pistol range. Based on a laboratory weathering study, virtually all metallic Pb was converted to hydrocerussite (Pb3(CO3)2(OH)2), as well as to a lesser extent cerussite (PbCO3) and massicot (PbO) within one week. Our study demonstrated that abrasion of lead bullets and their subsequent weathering can be a significant source of lead contamination in soils of a newly opened shooting range.

Firearms↗