Proposição de valores de background para solos e depósitos sedimentares da zona não saturada do Polo Industrial de Camaçari.I

Abstract

This study establishes Background Threshold Values (BTV) for inorganic parameters in soils and sedimentary deposits of the unsaturated zone of the Camaçari Industrial Complex (CIC), Brazil. A geological conceptual model of the region was developed to design the sampling plan, which included soil and sediment samples from each lithological layer of the unsaturated zone within the Marizal and Barreiras formations. Samples were collected from reference areas selected to represent natural conditions. Following chemical and statistical analyses, parameters were categorized into three groups: (1) parameters with at least five detections, for which BTVs were calculated using the UTL95-95 method; (2) parameters with one to five detections, where BTVs were defined as the maximum values detected; and (3) undetected parameters, for which BTVs were set as below the detection limit. The BTVs for Group 1 are as follows: Al: 7308 mg/kg, As: 31.57 mg/kg, Ba: 2.47 mg/kg, Ca: 91 mg/kg, Cr: 10.9 mg/kg, Cu: 14 mg/kg, Fe: 78194 mg/kg, Hg: 0.11 mg/kg, Mg: 181 mg/kg, Mn: 26.76 mg/kg, Mo: 9.12 mg/kg, Na: 31.83 mg/kg, Ti: 178.4 mg/kg, V: 67.38 mg/kg, Zn: 21.11 mg/kg, Bromide: 2.47 mg/kg, Sulfate: 18.83 mg/kg, Sulfite: 70 mg/kg. These BTVs provide a foundation for environmental monitoring, industrial impact assessment, human health risk evaluation, and remediation planning in CIC’s contaminated areas. They also serve as critical tools for environmental licensing, regulatory enforcement, and policymaking in the CIC. The methodological framework developed is adaptable to other industrial regions, advancing scientific approaches to BTV definition and improving contaminated site management in Brazil and worldwide.