Avaliação de riscos de infecção associados a helmintos em função do consumo de hortaliças cultivadas em solo com aplicação de biossólidos

Abstract

With the increase in population and in the use of water in domestic and industrial activities, it’s remarkable the growth in the generation of effluents throughout the world. Due to the increasingly restrictive requirements for the treatment of these effluents, the generation of sewage sludge also increases, which, after the proper treatment (dehydration, stabilization and hygienization), is transformed into a new type of material, biosolids. These soil determinants have become the target of great interest, as they offer a viable and sustainable alternative for the final disposal of waste generated in effluent treatment plants. However, just as they offer several benefits due to their application in agricultural soils, improving the soil's ability to retain moisture and supplying the nutritional needs of plants, biosolids are also a matter of concern, as they pose potential risks to human health and can eventually cause contamination and infections by pathogenic agents. The laws that regulate the applications and restrictions on the use of these materials, both nationally and internationally, present, on several occasions, inaccessible quality standards, measured only by epidemiological studies, without taking into account a risk assessment approach. Thus, through a bibliometric analysis, carried out to verify the evolution of research on the topics covered in this work, the relevance and trend in the increase of studies on such subjects can be observed. Given this context, the objective of this work was to carry out the application of the Quantitative Microbiological Risk Assessment tool (QMRA) associated with helminth eggs (Ascaris lumbricoides), as a function of the application of biosolids in the soil, to ingested raw crops (lettuce and carrots), based on secondary data from sewage sludge characterized by Santos et al. (2017). The use of the QMRA provided an estimate of the risk of infection by Ascaris lumbricoides for the population aged up to 15 years, due to the consumption of lettuce and carrots, based on probabilistic dose-response models for these microorganisms, applied to different scenarios. The results indicated that the annual risk of infection for the population group evaluated ranged from 2,99x10-2 to 9,48x10-7 pppy (per person per year) for lettuce consumption and from 1,24x10-1 to 4,19x10-6 pppy for carrot consumption. The variations in calculated risks were attributed to different sanitary barriers, such as the use of sludge in natura or after drying for 90 days, in addition to different levels of food hygienization before consumption.