Industrial deinking paper sludge waste: toxicity risk and health effects assessment of heavy metals by USEtox model

Abstract

Disposal of waste sludges produced in large amounts in the paper industry could generate significant environmental and health issues. One strategy to address them involves revalorization of deinking paper sludge (DPS) by reusing it as fertilizer. However, the possible human health risks associated with the use of DPS are still not well explored. The main objective of this report was to estimate DPS impacts on human toxicity. To achieve this goal, heavy metals analysis of the DPS waste (Cadmium; Cd, Copper; Cu; Molybdenum; Mo, Manganese; Mn; Lead; Pb; Cobalt; Co) was conducted. The assessment of human toxicity was performed by applying the UNEP/SETAC toxicity model USEtox 2.0 to establish indicators that reflect the potential health damage of these chemicals when released into the environment. Laboratory analysis, revealed a very low concentration of the DPS by the metallic contaminants (Cd, Cu, Mo, Mn, Pb, Co). According to the USEtox model results, these quantities will not lead to either carcinogenic or non-carcinogenic risks on human health even if there is a use of very high quantities of DPS. Indeed, the number of cases /t DPS emitted in agricultural soils didn’t exceed 950.10-7 for the non-carcinogenic effect and 3.71.10-7 for the carcinogenic effect for Pb. For Mn and Co, we noticed no toxic effects (0 cases /t DPS emitted). Furthermore, we observed that Mo and Cu had very weak non-carcinogenic effects and led respectively to 445.10-7 and 56.10-7 cases /t DPS emitted. Regarding the effect of Cd toxicity, in order to have one case of this metal toxicity from DPS waste in our study, we had to use a very important quantity of DPS (≈ 2 821 680t). All these data emphasized on the absence of heath human toxicity risk after DPS waste industrial disposal, by ingestion or inhalation.