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i I relevant soil criteria for the soil ingestion exposure pathway is provided in Table B-2. The average and maximum concentrations of 4,4'- DDE, 4,4'-DDD and 4,4'-DDT exceed the criteria for carcinogens. The maximum concentration of 4,4'-DDT exceeds the criteria for systematic toxicants. The average concentration of the pesticides in soil was used to calcu- late the hazard index. The results of the HI calculations are: Systematic Toxicants: Liver HIT = 0 022 Kidney HIT = 0.022 Carcinogens• HIC = 6 9 The HI calculated for carcinogens is considerably greater than one. While the concentrations of 4,4'-DDE and 4,4'-DDD contribute significantly to this hazard index, the greatest contribution can be attributed to the high concentrations of 4,4'-DDT in the soil . Inhalation of Airborne Dust The calculated airborne concentration of pesticides and the available RCRA RSDs and criteria for systematic toxicants are provided in Table B-3. The airborne chemical concentra- tions were calculated by multiplying the average concentrations in site soil by the State annual average dust (PM10 standard) concentration. The airborne concentrations calculated for the site were below the applicable RCRA criteria for all pesticides detected. Hazard indices were calculated for carcinogens and systematic toxicants using the assumptions described above. The calculated HIs are. Systematic Toxicants HIT = 2.7x10"5 Carcinogens HIC = 2.6x10-2 The systematic toxicants and carcinogens present in surface soil do not exceed EPA-established criteria for the inhalation exposure route. To determine the concentrations of pesticides that could remain in surface soil without posing an unacceptable risk due to ingestion after remediation, the HI calculations for soil ingestion were computed using only those surface soil samples that had 4,4'-DDT concentrations less than 1,000 ug/Kg. This value was selected because high concentrations of 4,4'-DDT had the greatest contribution to the previously calculated HI. Table B-4 lists the sample numbers and pesticide concentrations used for this calculation. Eking the average concentrations of pesticides shown in Table B-4, the following hazard index was calculated. Carcinogens: HIC = 0.90 Tie hazard index of less than 1 .0 indicates an excess cancer risk of less than one-in-a-million {10-6) . Based on these results, areas at the WPI13 B-4 882526.01