Aspects of health-related microbiology of the Subin, an urban river in Kumasi, Ghana

Abstract

The aim of this study was to assess the influence of urban waste, sewage and other human centred activities on the microbiological quality of the river Subin, which flows through the metropolis of Kumasi, Ghana, and serves as drinking water for communities downstream. Three sites, Racecourse, Asafo and Asago, on the Subin were monitored over a year for total coliforms, faecal coliforms, enterococci and biochemical oxygen demand. Bacterial indicator numbers (geometric mean 100 ml(-1)) varied from 1.61 x 10(9) to 4.06 x 10(13) for total coliforms, 9.75 x 10(8) to 8.98 x 10(12) for faecal coliforms and 1.01 x 10(2) to 6.57 x 10(6) for enterococci. There was a consistent increase in bacterial loading as the river flows from the source (Racecourse) through Kumasi. Bacterial numbers were significantly (p < or = 0.05) higher during the rainy season compared with the dry (harmattan) season. The biochemical oxygen demand ranged from 8 mg l(-1) at the source of the river to 419 mg l(-1) at Asago; none of the sites achieved internationally accepted standards for water quality. The River Subin becomes grossly polluted as it flows through Kumasi and at Asago, a rural community downstream of Kumasi that abstracts water from the river for drinking, this probably contributes to the observed high levels of diarrhoeal disease.

Chemical and biological characteristics of streams in the Owabi watershed

“…The high BOD levels suggest that the pollution of the stream is more of organic origin. Compared to average concentrations in urban streams in Ghana, the mean BOD values obtained for these streams were similar to those reported from samples from the Korle Lagoon (153.02 mg/L) in Accra and the Subin River (161.029 mg/L) in Kumasi (Obiri-Danso et al 2005).…”

Spatial dependency of cholera prevalence on potential cholera reservoirs in an urban area, Kumasi, Ghana

“…For instance, a microbial water quality analysis of an urban river, also delineated as a potential cholera reservoir, has been shown to be polluted with fecal material with total califorms varying from 1.61 × 10 9 to 4.06 × 10 13 per 100 ml. Bacterial counts are also reported to be significantly higher during the rainy season compared with the dry season (Obiri-Danso et al, 2005). Use of these water bodies for bathing, washing, cooking and other household activities is assumed to be greater for people who live closer to them (Ali et al, 2002a), and thus, will have higher cholera prevalence than those who live farther.…”

“…Where two 1st order streams meet, a 2nd order stream is created; where two 2nd order streams or 1st and 2nd order steams meet, a 3rd order stream is created; and so on. Although the water quality characteristics of these delineated stream segments have not been measured in this study, they are thought to be potential cholera reservoirs (Obiri-Danso et al, 2005). Hereafter, we refer to the potential cholera reservoirs as reservoirs.…”

Beyond access to water

“…The accumulation of dirt in tankers, due to irregular and improper cleaning, and their corrosion, contaminate the water which is mainly consumed by the poor. The rest, whose supplies come from the estimated 45 per cent of the total amount of drinking water which is produced from groundwater (Buamah et al 2008), face a similar problem because those sources too contain significant levels of contamination (Labite et al 2010;Obeng-Odoom 2011;Obiri-Danso et al 2005).…”