Giardia and Cryptosporidium in source waters of Sao Paulo State, Brazil

被引:30
作者
Hachich, EM
Sato, MIZ
Galvani, AT
Menegon, JRN
Mucci, JLN
机构
[1] Sao Paulo State Co Sanitat & Technol, CETESB, BR-05459900 Sao Paulo, Brazil
[2] Univ Sao Paulo, Coll Publ Hlth, BR-01246904 Sao Paulo, Brazil
关键词
Cryptosporidium; Giardia; microbiological analysis; parasitological analysis; source water;
D O I
10.2166/wst.2004.0061
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
Giardia lamblia and Cryptosporidium parvum are two protozoan intestinal parasites responsible for many drinking-water-related disease outbreaks in recent years, They are very resistant to conventional water treatment processes, can persist for long times in the environment and are, therefore, of great concern for public health. This work aimed to evaluate the presence of Giardia and Cryptosporidium in water sources from Sao Paulo State, Brazil, as part of the "Evaluation of Inland Waters from Sao Paulo State" project from CETESB. Over a period of 19 months, 278 water samples from 28 sites located in 10 watersheds were analysed. The immunofluorescence assay was used after concentration of the samples by the calcium carbonate flocculation technique. Thermotolerant (faecal) coliforms, faecal streptococci and Clostridium pertringens were also determined in order to verify the existence of correlation between these bacterial indicators and the protozoa. Giardia and Cryptosporidium were detected in 27% and 2.5% of the samples, respectively, a lower figure compared with the results reported by other authors, especially for Cryptosporidium. A Spearman rank correlation test demonstrated a significant correlation between Giardia and faecal indicator concentrations. According to the American Regulation of Monitoring (ICR), treated water from 16 of these 28 collection sites should also be analysed to evaluate whether the treatment process could remove the parasites. Some technical deficiencies of these methods still limit the utilisation of the monitoring results for public health decisions, but the data here reported will help to improve the quality of drinking water in Sao Paulo State.
引用
收藏
页码:239 / 245
页数:7
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