Análise de metais potencialmente tóxicos (MPT) derivados de produtos agroquímicos em comunidade agrícola de Manaus

Abstract

Levels of potentially toxic metals (PTM) Cd, Co, Cu, Fe, Mn, Ni, Pb and Zn, in irrigation water, soil and vegetables (Lactuca sativa - lettuce, Allium schoenoprasum – chives e Coriandrum sativum – coriander) of the Nova Esperança Agricultural Community (Manaus – AM), as well as, bacteriological contamination rates (total and fecal coliforms) in water and physicochemical properties of soil and water were evaluated during the dry and rainy periods, within one year, with the objective of verifying the environmental contamination, promoted by the intense use of agrochemicals and urban waste. The PTM were analyzed by Flame Atomic Absortion Spectrometry, bacteriological contamination and physicochemical properties, in water by APHA metodology and soil by EMBRAPA metodology. The results showed levels of the PTM overpassing legislations limits, in water, CONAMA 357/2005, in soil, CONAMA 420/2009 and FAO/2012 in the vegetables. High levels of total and fecal coliforms, in water samples collected from the three bodies of water: the artesian well, cacimbas and stream in the area of study showed contamination above the limits established by MS. The PTM contamination has contributed to modify physicochemical properties in water and soil. Statistical tests showed influence of the seasonal period in the average concentrations of PTM in water, but without influence in soil. The calculation of ARS >1 for Cd, reveled poisoning in the consumption of these vegetables, within 20 years period.