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At least 325 records · Page 18Linked to original sources
PubMed1983

Childhood lead poisoning. A controlled trial of the effect of dust-control measures on blood lead levels.

Lead-contaminated house dust is one factor in childhood lead poisoning; however, most lead-reduction programs do not emphasize the control of house dust. We studied whether lead-reduction plus dust-control measures would lower blood lead levels in children with Class II or III poisoning (blood lead levels, 30 to 49 micrograms per deciliter) more effectively than lead reduction alone. An experimental group of 14 children and a control group of 35 children whose homes had already been treated were studied. In experimental homes, sites with elevated lead levels (greater than 100 micrograms per 930 cm2) were wet-mopped twice monthly and families were encouraged to clean and to wash the child's hands frequently. After one year blood lead levels fell an average of 6.9 micrograms per deciliter in the experimental group, as compared with 0.7 micrograms per deciliter in controls (P less than 0.001). Children in the experimental group with the highest blood lead levels had the most marked reduction. Four children in the control group (and none in the experimental group) required chelation therapy for blood levels greater than 50 micrograms per deciliter. These results show that a focused dust-control program can reduce blood lead levels more than standard lead removal in the home.

Child↗
PubMed2003

Lead and lead toxicity in domestic and free living birds.

At present, domestic and wild fauna are being exposed to aspects and factors which are foreign to the habitat in which they live. One that stands out is the enormous amount and variety of chemical compounds which, in many cases, are highly complex and which are constantly being released into the atmosphere, mainly from agricultural and industrial activity. All these substances affect some species more than others, whether they be plants or animals, from the most insignificant micro-organism to the most evolved species, among them birds. Finally, another cause of mortality in many birds is plumbism, namely death caused by the ingestion of lead. Lead has been one of the main causes of poisoning in man since ancient times due to its use in many activities although it is only recently that this toxicity has been recognized. Moreover, the use of lead pellets for shooting has resulted in the release into the environment of millions of these over many years, with serious repercussions for many bird species populations, which have ingested them either directly or indirectly. Added to this use of lead in cynegetic activities is the fate of the lead weights (sinkers or ballast) used by rod fishers, which sink to the bottom or accumulate on the banks of rivers, lakes, lagoons or reservoirs. The problem arises when these pellets or weights are ingested by birds, mainly Anatidae, which mistake them for the small stones or grit they use to triturate food in their gizzards. Small particles of lead enter the digestive tract, start dissolving in the form of lead salts, are incorporated into the bloodstream and the rest of the body, accumulate in organs like the liver or kidneys, and cause physiological or behavioural changes. When certain concentrations of lead are reached, the birds then die. If lead-poisoned birds are consumed by carrions or predators, the latter also ingest the lead so that they may also be affected or die from plumbism since, being a heavy metal, its degradation and/or elimination is very difficult. There is, therefore, no doubt that millions of birds die annually worldwide from lead poisoning (in the U.S.A., around 3,000,000), this problem being most acute in marshland. The solutions could include the introduction of legislation regulating or banning shooting, in the use of non-toxic ammunition in marshes and protected areas, the substitution of lead pellets for other non-toxic ones, such as steel, bismuth, tungsten or other suitable metals, and to go on studying other possible alternatives to end such a dramatic situation for birds all over the world.

Animals↗
PubMed2000

Acute elevation of blood lead levels within hours of ingestion of large quantities of lead shot.

BACKGROUND: Ingestion of elemental lead foreign bodies is felt to have a low risk of clinically significant lead absorption unless gastrointestinal pathology and/or prolonged transit time are present. We present a case of ingestion of a large quantity of small diameter lead shot accompanied by rapid elevation of blood lead levels. CASE REPORT: A 5 1/2-year-old previously healthy girl was found eating the pellets from an ankle weight. She vomited and complained of abdominal pain. In the emergency department, she had no complaints and normal vital signs. An abdominal X-ray showed thousands of small, round, metallic density objects in the stomach. Her white blood cell count was 14,700/mm3, and the hemoglobin, mean corpuscular volume, free erythrocyte protoporphyrin, zinc protoporphyrin, biochemistry panel 21, and urinalysis were normal. She had no prior lead level for comparison. Whole-bowel irrigation was begun and she passed over 11 stools with pellets as well as other foreign bodies (erasers, bead, etc.) in the first 24 hours. Pellets were still seen on X-ray the following day so she received a high-fiber diet and bisacodyl tablets 10 mg/d. On hospital day 2, her admission blood lead (drawn 13 hours after ingestion) was reported as 57 microg/dL (2.7 microm/L) and chelation was begun with oral 2,3-dimercaptosuccinic acid 10 mg/kg 3x/d for 5 days, then 2x/d for 14 days. Her peak measured lead level was 79 microg/dL approximately 36 hours after ingestion. She excreted 2,273 microg lead in the urine during her first 24 hours of chelation. Her blood lead dropped to 14.3 microg/dL by the end of chelation. She did not develop any apparent signs of lead poisoning. CONCLUSION: Acute elevations of blood lead concentrations may occur rapidly after ingestion of multiple small elemental lead objects.

Antidotes↗
PubMed2005

Influence of maternal bone lead burden and calcium intake on levels of lead in breast milk over the course of lactation.

The authors studied 367 women who were breastfeeding their infants in Mexico City, Mexico, between 1994 and 1995 to evaluate the effect of cumulative lead exposure, breastfeeding practices, and calcium intake on breast milk lead levels over the course of lactation. Maternal blood and breast milk lead levels were measured at 1, 4, and 7 months postpartum. Bone lead measurements were obtained at 1 month postpartum. At 1, 4, and 7 months postpartum, respectively, the mean breast milk lead levels were 1.4 (standard deviation (SD), 1.1), 1.2 (SD, 1.0), and 0.9 (SD, 0.8) microg/liter and showed a significant decreasing trend over the course of lactation (p < 0.00001). The relations of bone lead and blood lead to breast milk lead were modified by breastfeeding practice, with the highest breast milk lead levels among women with a high level of patella lead who were exclusively breastfeeding. Dietary calcium supplementation increased the rate of decline in breast milk lead by 5-10%, in comparison with a placebo, over the course of lactation, suggesting that calcium supplementation may constitute an important intervention strategy, albeit with a modest effect, for reducing lead in breast milk and thus the potential for exposure by infants.

Adult↗
PubMed1994

Retrospective study of the impact of lead-based paint hazard remediation on children's blood lead levels in St. Louis, Missouri.

A retrospective follow-up study was conducted to evaluate the effectiveness of lead-based paint hazard remediation in reducing children's blood lead levels. The authors reviewed existing St. Louis, Missouri, City Health Department records, identified 185 children younger than age 6 years who had blood lead levels > or = 25 micrograms/dl during 1989 or 1990, and compared changes in blood lead levels among children whose dwellings did and those whose dwellings did not undergo remediation. Among 54 children who had not moved or received chelation therapy and whose blood lead levels were measured 10-14 months after diagnosis, the geometric mean blood lead level decreased 23% among children living in remediated dwellings (n = 37) and 12% among children in nonremediated dwellings (n = 17) (p = 0.07, t test). The estimated size of the remediation effect was similar using multiple regression (-13%; 95% confidence interval (CI) -25 to 1; p = 0.06) and an approach based on generalized estimating equations (-16%, 95% CI -25 to -7; p = 0.002), when adjusted for covariates. The effect of remediation was greater among children whose blood lead levels at diagnosis were > or = 35 micrograms/dl (-22%) than among those whose blood lead levels at diagnosis were between 25 and 34 micrograms/dl (-1%). Among lead-poisoned children in St. Louis, children whose dwellings undergo lead-based paint hazard remediation have a greater decline in geometric mean blood lead level than do children whose dwellings do not, but the effect of remediation may be influenced by the blood lead level at diagnosis.

Child, Preschool↗
PubMed2000

Effects of lead counseling for children with lead levels > or = 20 microgram/dL: impact on parental knowledge, attitudes, and behavior.

The purpose of this study was to assess parental knowledge, attitudes, and behavior concerning lead reduction counseling. Of 108 children with confirmed venous lead levels > or = 20 microg/dL, 75 (69%) of the parents were interviewed by telephone 6-9 months later. The majority of parents recalled being given specific lead reduction strategies. Knowledge of cleaning interventions was associated with parents who could state the lead level, who perceived a benefit from knowing it was elevated, and whose children were referred to a specialty lead clinic. Recall of nutritional interventions was associated with parents who could state the lead level and whose children were referred to a specialty lead clinic. Although 79% of parents thought that it was beneficial to know their child's lead level was elevated, only 65% reported implementing lead reduction strategies. The majority of parents recalled receiving lead reduction counseling but reported low compliance with lead reduction strategies. Further research is needed to determine the causes of the discrepancy between knowledge and making the behavior changes necessary to comply with lead reduction interventions.

Child, Preschool↗
PubMed1990

Lead concentrations in blood and milk from periparturient dairy heifers seven months after an episode of acute lead toxicosis.

In September 1988, 100 of 300 yearling dairy heifers developed blindness, tachypnea, foaming at the mouth, chewing, and facial fasciculations. Twenty-five animals died. Lead toxicosis was diagnosed based on the clinical signs and the presence of excessive concentrations of lead in whole blood, liver, kidney, and rumen contents of affected animals. The source of the lead was sudan grass silage that had been contaminated by soil that contained up to 77,000 mg/kg of lead. Lead concentrations were determined approximately 7 months after the acute episode of lead toxicosis. Whole blood and milk samples were obtained from heifers and a group of control cows 2 weeks prior to (blood only), at the time of, and 2 and 4 weeks after freshening. No lead was found in any of the milk samples (detection limit = 0.055 mg/liter). Animals that had been severely affected by lead toxicosis experienced a transient increase in whole blood lead concentrations at freshening that was not high enough to be considered toxic. No similar increases in blood lead were observed for control cows or heifers that had experienced milder toxicosis. These findings suggest that at parturition lead is mobilized into the blood of cattle previously exposed to excessive lead.

Animals↗
PubMed2005

IQ and blood lead from 2 to 7 years of age: are the effects in older children the residual of high blood lead concentrations in 2-year-olds?

Increases in peak blood lead concentrations, which occur at 18-30 months of age in the United States, are thought to result in lower IQ scores at 4-6 years of age, when IQ becomes stable and measurable. Data from a prospective study conducted in Boston suggested that blood lead concentrations at 2 years of age were more predictive of cognitive deficits in older children than were later blood lead concentrations or blood lead concentrations measured concurrently with IQ. Therefore, cross-sectional associations between blood lead and IQ in school-age children have been widely interpreted as the residual effects of higher blood lead concentrations at an earlier age or the tendency of less intelligent children to ingest more leaded dust or paint chips, rather than as a causal relationship in older children. Here we analyze data from a clinical trial in which children were treated for elevated blood lead concentrations (20-44 microg/dL) at about 2 years of age and followed until 7 years of age with serial IQ tests and measurements of blood lead. We found that cross-sectional associations increased in strength as the children became older, whereas the relation between baseline blood lead and IQ attenuated. Peak blood lead level thus does not fully account for the observed association in older children between their lower blood lead concentrations and IQ. The effect of concurrent blood level on IQ may therefore be greater than currently believed.

Age Factors↗
PubMed1999

Effects of weight loss and exercise on the distribution of lead and essential trace elements in rats with prior lead exposure.

We studied the effects of weight loss and non-weight-bearing exercise (swimming) on blood and organ lead and essential metal concentrations in rats with prior lead exposure. Nine-week-old female Sprague-Dawley rats (n = 37) received lead acetate in their drinking water for 2 weeks, followed by a 4-day latency period without lead exposure. Rats were then randomly assigned to one of six treatment groups: weight maintenance with ad libitum feeding, moderate weight loss with 20% food restriction, and substantial weight loss with 40% food restriction, either with or without swimming. Blood lead concentrations were measured weekly. The rats were euthanized after a 4-week period of food restriction, and the brain, liver, kidneys, quadriceps muscle, lumbar spinal column bones, and femur were harvested for analysis for lead, calcium, copper, iron, magnesium, and zinc using atomic absorption spectrophotometry. Both swimming and nonswimming rats fed restricted diets had consistently higher blood lead concentrations than the ad libitum controls. Rats in the substantial weight loss group had higher organ lead concentrations than rats in the weight maintenance group. Rats in the moderate weight loss group had intermediate values. There were no significant differences in blood and organ lead concentrations between the swimming and nonswimming groups. Organ iron concentrations increased with weight loss, but those of the other metals studied did not. Weight loss also increased hematocrits and decreased bone density of the nonswimming rats. The response of lead stores to weight loss was similar to that of iron stores because both were conserved during food restriction in contrast to decreased stores of the other metals studied. It is possible that weight loss, especially rapid weight loss, could result in lead toxicity in people with a history of prior excessive lead exposure.

Animals↗
PubMed2003

Determining lead sources in Mexico using the lead isotope ratio.

OBJECTIVE: Lead poisoning can, in some cases, be traced to a specific route or source of exposure on the basis of the individual's blood lead isotope ratio. To assess the major source of lead exposure among women residing in Mexico City, we compared blood, ceramic, and gasoline lead isotope ratios. MATERIAL AND METHODS: The study population, randomly selected from participants of a large trial, (1/1996-12/1996) comprised of 16 women whose lead levels exceeded 10 micrograms/dl and who reported using lead-glazed ceramics. Lead isotope ratios were performed on a Perkin Elmer 5000 Inductively Coupled Plasma Mass Spectrometer (ICP-MS) interfaced with a Perkin Elmer HGA-600MS Electrothermal Vaporization System (ETV). RESULTS: The isotope ratios (206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb) of both the blood specimens and their corresponding ceramic specimens were highly correlated, with r = 0.9979, r2 = 0.9958, r = 0.9957, r2 = 0.9915 and r = 0.9945, r2 = 0.9890 values for the three isotope ratios, respectively, suggesting that the lead exposure most likely resulted from the use of these ceramic. Measurements of lead isotope ratios from leaded gasoline in use at the time of blood sampling, differed from those in blood and ceramics. CONCLUSIONS: Determining lead isotope ratios can be an efficient tool to identify a major source of lead exposure and to support the implementation of public health prevention and control measures. This paper is available too at: http://www.insp.mx/salud/index.html.

Ceramics↗
PubMed2006

Exposure to lead and length of time needed to make homes lead-safe for young children.

OBJECTIVES: We determined the length of time needed to make homes lead-safe in a population of children aged 0 to 6 years with blood lead levels (BLLs) of 20 micrograms per deciliter (mug/dL) or greater. Reducing this time would reduce children's exposure to lead. METHODS: Data came from the Wisconsin Childhood Lead Poisoning Prevention Program's comprehensive blood lead surveillance system. Analysis was restricted to children whose first BLL test value during 1996-1999 was between 20 and 40 mug/dL and for whom housing intervention data were available (n=382). RESULTS: The median length of time required to make a home lead-safe was 465 days. Only 18% of children lived in homes that were made lead-safe within 6 months; 45% lived in homes requiring more than 18 months to be lead-safe. CONCLUSIONS: Efforts are needed to reduce the time it takes to make a home lead-safe. Although abatement orders always include time limits, improved compliance with the orders must be enforced. Greater emphasis should be placed on securing lead-safe or lead-free housing for families, thus reducing lead exposure.

Black or African American↗
PubMed1999

Lead risk assessment for children in Hungary by predicting their blood lead levels using US EPA integrated Exposure Uptake Biokinetic model.

The US EPA integrated Exposure Uptake Biokinetic (IEUBK 0.99d) lead exposure for children was validated, updated, and applied to predict mean blood lead levels based on lead uptake from multiple sources and provide assessment of risk. Surveys were carried out around houses in a polluted area (Heves, Hungary) in 1995. The collected data from that area have shown very high levels of lead in soil. In some cases the level of lead in soil has reached more than 1000 times the allowable limit value used (100 mg/kg) in Hungary. Moreover, the concentration of lead in air was measured and the concentration of lead in air varied from 0.05-1.83 micrograms/m3. The environmental data within the community were used to predict the children blood lead levels and to compare the observed estimates with the other predicted ones. The age of the investigated group of children varied from 0-60 months. The estimated blood lead levels have illustrated variation according to age, sex, and the specific site. It can be concluded from this study that the model can be used on a wide range to give us an excellent picture for site cleanup, to decision makers, and finally to use the environmental data to predict blood lead level for the community or population. Results of several validation exercises utilizing the IEUBK model comparing predicted and measured blood lead levels with international guidelines and the percent of risk of exceeding a specific blood lead level (i.e., 10 micrograms/dl) are presented in this paper.

Age Distribution↗
PubMed1986

Chelation in metal intoxication. XXIII: Effect of N-(2-mercaptopropionyl) glycine on lead or lead and ethanol intoxicated rats.

Efficacy of N-(2-mercaptopropionyl) glycine to reduce the body burden of lead and restore the altered biochemical parameters in lead or lead and ethanol intoxicated rats was investigated. The investigation was aimed to suggest suitable prophylaxis of lead poisoning prevalent among workers in lead industry who may also be exposed to ethanol. The rats were given lead (10 mg/kg, p.o.) or lead and ethanol (10% v/v in drinking water) daily for 8 weeks. Following exposure period a single dose of N-(2-mercaptopropionyl) glycine (0.3 mmole/kg, intraperitoneal) was given daily for 4 days. The chelator was effective in enhancing the urinary and faecal excretion of lead, reducing the concentration of lead in liver and kidney and lowering the excretion of delta-aminolevulinic acid in lead treated rats. However, the protection was more noticeable in animals treated with lead alone than with lead and ethanol.

Alcoholic Intoxication↗