Qualidade microbiológica da água da bacia do Ribeirão São Bartolomeu, Viçosa - MG: análise epidemiológica, ambiental e espacial

• Autor(a) principal: Dias, Graziele Menezes Ferreira
• Data de Publicação: 2007
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5218
• topic: Manancial de abastecimento; Qualidade da água; Protozoários; Water supply; Water quality; Protozoa; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA::MEDICINA VETERINARIA PREVENTIVA::SANEAMENTO APLICADO A SAUDE DO HOMEM

This project aims at studying the dynamics of Giardia cysts Cryptosporidium oocysts. in São Bartolomeu stream (SB) watershed, Viçosa, Minas Gerais. In this sense, three studies were carried out: Study 1 - the impact caused by animal populations on the parasitological quality of SB water. Study 2 - enteroparasites prevalence among children residing in the SB watershed area. Study 3 - evaluation of SB microbiological and parasitological water quality parameters. In Study 1, from January 2003 to January 2004, water samples were collected every three months from the eight sampling points allocated within SB watershed, along with samples of animal feces from 40 farms, from two swinebreeding farms wastewaters, and from the final effluent of Romão dos Reis neighborhood sewage treatment plant (STP). The occurrence of enteroparasites in humans was surveyed in two communities living within SB watershed, focusing at the infant population, from zero to ten years old, from July 2004 to June 2005. In the same period Romão dos Reis STP effluent and SB water sample was monitored for protozoa. From January to June 2007, as part of the Study 3, water samples form the eight above mentioned sampling points, Romão dos Reis STP effluent, and a swine-breeding wastewater were also monitored for protozoa. The water quality was monthly evaluated for anaerobic and aerobic bacteria spores, and biweekly for streptococcus, enterococcus, E. coli, total coliforms and Giardia and Cryptosporidium (oo)cysts. In addition, the water flow and turbidity was also measured. High concentrations of protozoa were found in water samples all over the study period In Study 1, the arithmetic means of Giardia and Cryptosporidium were respectively, 20.2 and 15.3 (oo)cysts/L. The average prevalence of Giardia and Cryptosporidium in cattle farms was, respectively, 36.4 18.0%., being the difference statistically significant (p = 0.0002). The results of children feces exams, showed an absence of Cryptosporidium, but Giardia as the enteroparasite of highest prevalence (6.1%). High concentrations of both protozoa were found in Romão dos Reis STP final effluent (cysts of. in the order of around 104 Giardia cysts per liter and 102 Cryptosporidium oocysts per liter), in swine-breeding wastewaters (up to 103 Giardia cysts per liter and 102 Cryptosporidium oocysts per liter). In Study 3 the occurrence of protozoa in water samples was found to be correlated with rain and water turbidity (p < 0.01). The occurrence of Giardia and Cryptosporidium was also associated to the presence of anaerobic spores and Clostridium perfringens (p < 0.05). Also, a negative correlation was found between the occurrence of Giardia spp. and Cryptosporidium spp. and wooded areas, though not statistically significant (p < 0.05). The results indicate that animal breeding and human settlements in São Bartolomeu stream watershed contribute to its water contamination, regarding the presence of protozoa oocysts. The lack of protection measures of this drinking-water source may pose risks of disease transmission.