Atualização dos fatores de exposição e sua influencia nos valores de intervenção para solo do estado de São Paulo / Exposition factors update and their influence in intervention values for soil in São Paulo State

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

The Risk Assessment methodology is a management toei which allows the finding of a sustainable solution considering human health and remediation of contaminated areas. The Risk Assessment methodology was developed by the Environment Protection Agency (EPA) of USA and has been the base for application in many other countries. This methodology is based on adverse effect occurrence probability s determination, given the scenario the that the receptor is exposed. It establishes a logical sequence of steps to be followed, among those, the potential risk quantification associated to the exposed population characteristics, called Exposure Factors. CETESB has used the Risk Assessment methodology to determine Intervention Values for soils, which are reference values to classify an area as contaminated. CETESB, faced a lack of data for São Paulo s and also Brazilian population characteristics, therefore used Exposure Factors of known international sources. Taking into account the mentioned considerations, this project was developed having 3 mains goals: (a) to make a broad revision of recent information in national geographic studies and international data, aiming to consolidate data for São Paulo s population, and secondarily for brazilian population; (b) to analyze these new factors sensibility to Intervention Values consolidated by CETESB in 2001, to Benzene, Endrin and Nickel, considering agricultura!, residential and industrial scenarios, and (c) to propose Exposure Factors to be used in the new Orientation Values in the State of São Paulo as well as in the human health Risk Assessment process applied in contaminated areas. The Exposure Factors were updated through research in databases and literature sources, and were estimated based on specific mathematic equations, when appropriate. The sensibility analysis was carried out calculating intake doses and Risk values for the selected substances, using the CSOIL model and the same procedures used by CETESB to derivate Intervention Values. The results show that among the assessed parameters, body weight, air intake rate, and water and soil intake rate have the greater influence at the values of the calculated final risk. The magnitude of each factor depends on physical-chemical characteristics and contaminant s target compartment. The impact assessment of these Exposure Factors shows that there would not be changes for Benzene and Nickel in residential scenarios. The greater impact would be in the Industrial scenario, which concentrations would raise around 50%, caused mainly by the exclusion of children as receptors. In the agricultural scenario, there would be a raise of approximately 10%, related to the current intervention values. This study shows that, despite there is no numeric impact on the calculated risk values, the Exposure Factors variation may affect in a significant way the Intervention Values, that was the example used in this study, and also in studies of specific cases and in other reference values used in the management of contamínated areas in the State of São Paulo. A constant reassessment for the exposure factors is needed, whenever new data are published, and more specific, for São Paulo s population, which has different characteristics and behaviors from the rest of Brazil

ASSUNTO(S)

solos - poluição exposure factors avaliação de riscos ambientais aguas subterraneas - contaminação risk assessment riscos ambientais intervention values saude publica

ACESSO AO ARTIGO

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