Soil pica

According to US-EPA (1997), data on soil ingestion rates for children who deliberately ingest soil (pica) are limited however, it does not appear to be a very common behavior. This conclusion is based on the seven key smdies used by US-EPA to estimate the daily soil intake in children, where only a single child, out of more than 600 examined, exhibited pica behavior directed toward sod. The results for this child are shown in Table 7.5. 

At hazardous waste sites, radiostrontium that is found in excess of natural background levels is most likely to be in soil and presents a special hazard for young children. Hand-to-mouth activity resulting in inadvertent soil consumption or intentional consumption of soil (pica behavior) will result in oral exposure to radiostrontium. Young children often play close to the ground and frequently play in dirt, which increases their dermal exposure to radiostrontium in dust and soil. The degree of hazard in each case depends on the form of strontium present at the waste site. 

Coposa soil V Salar Huasco soil Pica soil O Matilla Lama soil -----Nonpreference... 

Calabrese, E.J., Stanek, EJ., Gilbert, C.E., 1991. Evidence of soil—pica behavior and quantification of soil ingested. Hum. Exp. ToxicoL 10, 245—249. 

By predicting PbB levels, a determination can be made about what health impacts may be occurring at a given site. This will assist health assessment personnel in deciding whether further action is needed. A site-specific evaluation must be made before reaching any conclusions (e.g., pica children, ground cover over contaminated soil, nutritional status and age of the population, etc.). Issues relevant to children are explicitly discussed in Sections 2.6, Children s Susceptibility, and 5.6, Exposures of Children. 

Soil, street and home dust may contain increased lead levels. Children may have an additional exposure through repeated hand-to-mouth activities (Thornton et al. 1990), or through the pica behavior. The peak intake in children is when they are... 

Barltrop D (1966) The prevalence of pica. Am J Dis Child 112 116-123 Barltxop D, Strehlow CD, Thorton I, Webb JS (1974) Significance of high soil lead concentrations for childhood lead burden. Environ Health Perspect 7 75-82 Beloian A (1982) Use of a food consumption model to estimate human contaminant intake. Environ Monitor Assess (in press)... 

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