Low levels of zinc in hair and blood, pica, anorexia, and poor growth in Chinese preschool children.
(65/90)
Zinc concentrations in plasma and hair were measured in 703 children, aged between 1 and 6 yr, and correlated with parameters of physical development. In the first group of 187 children brought to the Child Health Clinic for routine observation there was a positive correlation of hair zinc content and height for age, with an increased prevalence of low hair zinc content in children of shorter stature. A second group of 303 children in nurseries and kindergartens in Beijing exhibited a hair zinc content of 92 micrograms/g, and 34% of these had very low zinc values below 70 micrograms/g. The third group consisted of 213 children who were brought into the outpatient clinic for a variety of complaints, including pica, anorexia, and poor growth; these had significantly lower values of zinc in hair and plasma than well-nourished children and responded to zinc supplementation with improvement of growth and the disappearance of pica and anorexia. These results suggest that the diet consumed by the population studied may be marginal or inadequate in its content of available zinc. (+info)
Role of airborne lead in increased body burden of lead in Hartford children.
(66/90)
The ingestion of airborne lead fallout is the mechanism responsible for increased lead body burdens found in 10 urban Connecticut children. The mean indoor lead levels found in housedust was 11,000 mug/g; highest concentrations occurred on windowsills and in floor dust. The mean lead content of Hartford street dirt was 1,200 mug/g; levels were highest near the street and next to the buildings. The mean lead concentration of hand samples taken from the subject children was 2,400 mug/g; the mean weight of hand samples was 11 mg. The concentration of lead in dirt and househould dust was high enough to theoretically result in excessive lead accumulation in young children who are putting their dusty, dirty hands in their mouths during play. While we believe that lead emitted from automobiles contributes significantly to air, dirt and dust lead levels the environmental impact of reducing or eliminating lead from gasoline is not yet completely understood. (+info)
Longitudinal changes in blood lead level in children and their relationship to season, age, and exposure to paint or plaster.
(67/90)
Children screened for lead poisoning in the Brownsville district of New York City in either summer or winter were followed with blood lead tests for approximately six months to one year from screening to measure longitudinal changes in blood lead level and to identify some determinants of the changes. Only minimal evidence was found of the hypothesized summer rise in blood lead level, while the predominant trend seemed to be for blood lead levels to display statistical regression to the mean. In children found to have low to intermediate blood lead levels (less than 55 microgram/100ml) at screening, variables which were found to predict a rise in blood lead level of 10 microgram/100ml or greater from winter to summer were under age three and/or exposure to paint or plaster. (+info)
Effect of a screening program on changing patterns of lead poisoning.
(68/90)
A biphase program of screening and treating high-risk children for lead poisoning resulted in a 30% fall in mean lead values in the target areas over a 5-year period. The mean and median for subjects under 6 years was 4-10 mug/100 ml higher than for those over 6. Median for a high incidence area was 42 mug/100 ml in 1967 and 30.0 in 1971; for a low incidence area, 33 and 20 mug/100 ml in the equivalent years. Ingestion of lead paint was observed or demonstrated by x-ray in 90% of 2200 patients treated in the Lead Clinic. Gross neurologic sequelae were limited to two cases of mild, persistent ataxia. Impaired intellectual performance was observed subsequently in several asymptomatic patients with initial blood lead levels (PbB) >/= 100 mug/100 ml. (+info)
Significance of high soil lead concentrations for childhood lead burdens.
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The lead exposure of children and their mothers has been studied in two towns with mean soil lead contents of 900 and 400 ppm. No significant difference in blood or fecal lead contents was demonstrated between the two populations, but a small difference in hair lead content was shown. The blood lead content of children was greater than that of their mothers and was higher in the summer than in the spring samples. Children with pica for soil in the control area had increased lead content of blood and hair. Preliminary data for children and mothers from villages with mean soil lead contents of 500 ppm and 10,000 ppm are reported which show significant differences in blood and hair lead content within the normal range. The data suggest that soil lead content of 10,000 ppm may result in increased absorption of lead in children, but to a degree which is unlikely to be of biological significance. (+info)
New information on lead in dirt and dust as related to the childhood lead problem.
(70/90)
It has been known for many years that the eating of leaded paint is the prime cause of lead poisoning and elevated blood leads of children living in deteriorated housing. Recently, there has been speculation that children may eat dirt and dust contaminated with lead exhausted from cars and that this amount of ingested lead is sufficient to contribute significantly to the childhood lead problem. This paper reports on a twopart study conducted to evaluate the validity of the dirt-and-dust hypotheses. The first part of the study was made to determine the source of lead in dirt to which children are normally exposed. Dirt samples were taken in old urban areas around 18 painted frame houses and 18 houses of brick construction. Samples also were taken around seven old frame farmhouses remote from traffic. Based on the fact that lead concentrations in the dirt were similar in city and rural yards at corresponding distances from the houses, it is clear that nearly all of the lead in dirt around these houses is due to paint from the houses. Lead antiknock additives are therefore not a significant contributor to the lead content of dirt around houses where children usually play. The second part of the study used a naturally occurring radioactive tracer (210)Pb to determine the relative amounts of dust and other lead-containing materials (e.g., paint) eaten by young children. This tracer is present in very low concentrations in paint and in significantly higher concentrations in fallout dust. Stable lead and (210)Pb were analyzed in fecal material from eight children suspected of having elevated body burdens of lead and ten children living in good housing where lead poisoning is not a problem. The normal children averaged 4 mug Pb/g dry feces, with a range of 2 to 7. Of the eight children suspected of having elevated lead body burdens, two had fecal lead values within the normal range. However, the remaining six were 4 to 400 times as high. Despite these differences in fecal lead between the two groups, the groups were essentially identified in the (210)Pb content of their feces. The "elevated" children averaged 0.040 pCi of (210)Pb dry feces, while the normal group averaged 0.044 pCi/g. The results provide sound evidence that these children suspected of elevated lead body burden were not ingesting dust or air-suspended particulate. (+info)
Geophagia in rural Mississippi: environmental and cultural contexts and nutritional implications.
(71/90)
We investigated geophagia in the black population of rural Holmes County, Mississippi. Twenty-five sources of geophagical clays were located and most of the sources are associated with rural settlements throughout the county. Clays are taken from subsurface soil horizons, and all but one of the sources come from the upland portion of the county. Geophagia occurs among 57% of women and 16% of children of both sexes, but it is not found among adult males or adolescents. Average daily comsumption of clay is 50 g. Our data indicate geophagia is not correlated with hunger, anemia, or helminthic problems, but it may contribute to the common problem of hypertension. Geophagia has been suggested as one of the factors leading to hyperkalemia, but our data do not support this notion. (+info)
Motion sickness-induced pica in the rat.
(72/90)
Two experiments investigating the effects of motion sickness on pica (the consumption of non-nutritive substances) are reported. In the first experiment rats subject to rotational stimulation subsequently engaged in geophagia (clay consumption). In the second experiment use of a conditioned aversion paradigm confirmed that the method of rotational stimulation used in the first experiment causes motion sickness in rats. The results of these experiments indicate that simple gastrointestinal malaise in the absence of a deficiency state or acute toxemia will elicit pica. It is suggested that gastrointestinal distress may be a significant factor in the etiology of pica and its relationship to other causes of pica is discussed. (+info)