Pica behavior

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. 

For pica behavior, an ingestion rate of 10 g/day is considered by US-EPA as a reasonable value for use in acute exposure assessments, based on the available information. It should be noted, however, that this value is based on only one pica child observed in the Calabrese et al. (1989 - cited in US-EPA 1997) study, see 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. 

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... 

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. 

A mean Stanford-Binet IQ decrement of 5 points, fine motor dysfunction, and altered behavioral profiles were found in 70 preschool children exhibiting pica for paint and plaster and elevated PbB levels (>40 pg/dL, mean of 58 pg/dL), when compared with results for matched control subjects not engaged in... 

These instruments have the advantage of being congruent with different behavioral structures observed in MR. They also contain behaviors ordinarily not seen in typically developing children (e.g., pica, stereotypies, and self-injury), and many of them have the added advantage of normative data for young people who are mentally retarded. Hence, the choice of an appropriate assessment tool assumes some specialist knowledge of the field. 

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