• Need for and prevalence of separate guidelines

• List of substances: Ba, Cu, CN-, F-, Ni, Phenol, V (cadmium evaluated, default SCTL protective of acute tox too)

• Ingestion rate: 10 grams one event (50x default)

• Review of tox values to be used

• Bioavailability: Assumed 100%

Acute Toxicity SCTL Issues

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Need / Prevalence• Pica behavior recognized, but acute exposure harm?

• FL sites can be driven by acute tox values (e.g., Ba)

• Other states/federal/international guidance– CA (HHSLs don’t include acute exposure)– MA (CN- only)– MN (Ba, Cu, CN-, F-, Phenol)– NY (As, Ba, Cd, Cu, CN-, Ni, Naph, Penta, Phenol); cites FL as basis– USEPA (RSLs do not address acute exposure)– Canada (CN- only)

• Regulation of other media (GW, SW) does not single out extreme outlier population Draft Copy

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List of Chemicals

• CN- and phenol have reasonable basis in tox

• Tox of Ba, Cu, F-, Ni, V lacks good foundation

• Endpoints for some are ambiguous, transient, reversible; should have real hazard potential

• Same substances present in dietary, commercial products at higher levels

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Ingestion Rate

• 10 gram, single event existing assumption– Historical support as infrequent acute exposure– More indicative of extreme pica or geophagy

• Frequency of events (e.g., 33% may ingest 10g 1-2 times per

year), often cited but weakly supported

• Calabrese et al. (1997) cites 200 mg/day protects 95% of children

• 1 to 5 gram range for pica recommendation (2011 EFH, 2008 Child EFH, CalEPA 2012, literature)

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Toxicological Guidance

• RfDacute values developed from human studies

• RfDacute for some substances set very close to acceptable dietary recommendations

• Large soil bolus alone may cause adverse effects• Existing dose/response from nonsoil exposures• Majority of effects gastrointestinal, transient

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Bioavailability

• Chemical-specific, but defaults to 100%

• Limited or no literature for most chemicals

• Other default recommendations (e.g., 50% MADEP)

• Single acute exposures beg question: Are there no reports of effect because toxins unavailable

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