Avaliação da qualidade da água em balneários de Itacoatiara - AM

Abstract

Freshwater beaches and resorts are places that attract tourists and assist in the development of local and regional economies in the State of Amazonas. Due to its importance, it is necessary to carry out a good management that allows the safe use for the population health. Considering the possibility of degradation of the natural environments and the risk of diseases by water transmission, a CONAMA Resolution 274/2000 was created as an instrument to verify parameters that determine criteria to evaluate if the beach’s or resort’s water is proper or improper for primary contact recreation. Despite the existence of this instrument for more than 16 years, a few numbers of papers have been found for this region in this area of study. In order to obtain information on the physical-chemical and microbiological quality of water and to carry out a study of the water conditions for recreational purposes, three freshwater beaches were defined in Itacoatiara, being used as a selection criterion their proximity to the urban area. The determination of the Most Probable Number (MPN) of total and thermotolerant coliforms in water was performed by the multiple tube fermentation method (MTF) and parameters pH, water temperature and dissolved oxygen with portable multiparameter equipment. Weekly sample collections were carried out in two hydrological periods on the days of greater frequency of bathers. The results of the microbiological analyzes persented values below 1000 MPN fecal coliforms (thermotolerant) per 100 mL of sample. The pH ranged from 5,75 to 8,23, water temperature from 28,7°C to 35,5°C and dissolved oxygen from 4,61 mgL-1 to 18,06 mgL-1. The physical and aesthetic conditions of the baths and waters were adequate, we did not find galleries of rainwater, algae flowering, sewage disposal, waste, oils and greases or other substances that may pose a health risk or make recreation unpleasant. Considering the CONAMA Resolution 274/2000, despite the presence of thermotolerant coliforms in the water and the pH variation, all places presented PROPER conditions for bathing, being categorized as EXCELLENT and VERY GOOD for recreation.