Ingested dirt

Chimpanzees daily eat termite mound clay. The habit may have started by ingesting dirt along with termites. Rats, after rotation that causes motion sickness (stomach upset and diarrhea), eat more clay than normal (Mitchell et al, 1977). Geophagy may be instrumental in the success of rats in habitats with unpredictable diets and the resistance of the species to poisoning by humans. Clay can be eaten prophylactically but also in response to toxic food already in the gastrointestinal tract. 

For the majority of persons beyond the age of 5-6, the daily uptake of dirt due to intentional ingestion should be quite low. One route by which adults ingest dirt is presumably fruits and vegetables and nearly all of it is due to leafy vegetables... 

Acute-Duration Exposure. There are few data available for acute exposures in humans. This may be a function of the time required for the expression of effects (decreased heme synthesis, neurobehavioral changes, increased blood pressure, and interference with vitamin D metabolism) and the usual modes of exposure in humans, which are repeated ingestion of lead-containing dirt or lead-based paint chips in... 

Lanphear et al. (1996a, 1996b, 1997, 1998b) studied factors affecting PbB levels in urban children and found the following independent predictors of children s PbB levels dust lead loading in homes, African-American race/ethnicity, soil lead levels, ingestion of soil or dirt, lead content and condition of painted... 

Bames RM. 1990. Childhood soil ingestion How much dirt do kids eat Anal Chem 62 1023-1033. 

Children sometimes put dirt in their mouths. Because the adsorption of 3,3 -dichlorobenzidine to soils and sediments may not be readily reversible (Boyd et al. 1984 Chimg and Boyd 1987 Sikka et al. 1978), the bioavailability of the compound is limited. A child who ingested contaminated dirt would be expected to incur less exposure as compared to that from other, more direct routes. 

The exposure assessment may be performed for a single situation, i.e., a single subgroup of humans exposed for a certain period of time via a particular route. An example of this could be an exposure estimate for children with respect to exposure to a contaminant via ingestion of playground dirt on a single incident. 

Additional exposure to PCBs could occur for children who live near hazardous waste sites. Since children spend a lot of time playing on the ground, both indoors and out, they come into more contact with contaminants found on dust and dirt particles. They may be exposed to PCBs by dermal contact with PCB-contaminated soil and by ingesting contaminated soil from their unwashed hands and other hand-to-mouth behavior. The determination of PCBs in dust and dirt can therefore be important for predicting children s exposure. However, quantitative information regarding the bioavailability and amount of PCBs that children are exposed to through contact with contaminated soils are unavailable. 

An important subtlety that is often lost in the scientific literature is that mouthing tendencies and the ingestion of very small quantities of dirt associated with poor hygiene should not be called pica. Children who intentionally eat dirt, plaster or paint chips and, as a consequence, have developed chronic health problems can be said to suffer from the disease known as pica... 

Duggan and Williams (13) have summarized the literature on the amount of lead ingested through dust and dirt. In their opinion, a quantity of 50 fjtg of lead was the best estimate for... 

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