HEALTH RISK ANALYSIS CARRIED OUT IN AN OIL STORAGE AND DISTRIBUTION STATION IN EASTERN CENTRAL MEXICO TO DETERMINE REQUIRED CLEANING LEVELS

Subsoil of an oil storage and distribution station (ODSS) located in Eastern Central Mexico was characterized in terms of total petroleum hydrocarbons (TPHs), the 16 polynuclear aromatic hydrocarbons (PAHs) suggested by USEPA as priority contaminants, benzene, ethyl benzene, toluene, and xylenes (BTEX), methyl tert butyl ether (MTBE) tertamyl methyl ether (TAME), and four metals i.e, Fe, V, Pb, Ni and Zn. ODSS resulted contaminated mainly by TPHs in a concentration higher than that legislated in Mexico (NOM-EM-138-ECOL-2002). It was detected the presence of BTEX and 11 of the 16 PAHs suggested by USEPA as prioritary pollutants. MTBE was found in only one sampling point, but TAME was not found anywhere. Metals were under the suggested limits, so they do not need to be reduced. The health risk assessment carried out indicated that only dibenzo(a,h)anthracene is in a concentration that exceeds the previously fixed maximum acceptable risk of 1x10-5. Hence, dibenzo(a,h)anthracene must be reduced from 2.36 mg/kg to 2.0 mg/kg. Soil must be treated to reduce the TPHs actual concentration up to a value of 2,000 mg/kg, as suggested by the Mexican Norm