Microbial quality and suitability of roof-harvested rainwater in rural villages for crop irrigation and domestic use

Abstract

The study aimed at assessing the microbiological quality and suitability of roof-harvested rainwater (RHRW) for crop irrigation and domestic use. In total, 80 rain water tanks (246 samples) across three rural villages (Ga-Molepane, Jericho and Luthngele) were visited. Culture based techniques were used to isolate bacterial microbes and identities were confirmed using matrix assisted laser desorption/ ionization time of flight (MALDITOF MS). Uncultured fungal populations were also identified using pyrosequencing. Salmonella spp. (3%), L. monocytogenes (22%), total coliforms (57.7%), Escherichia coli (E. coli) (30.5%), Enterococcus spp. (48.8%), Pseudomonas spp. (21.5%) were detected in RHRW samples after rainfall. Fungal sequences belonging to species known to cause fever, coughing and shortness of breath in humans (Cryptococcus spp.) were identified. This study indicates that RHRW quality can be affected by external factors such as faecal material and debris on the rooftops. The use of untreated RHRW could pose a potential health risk if used for irrigation of crops or domestic use, especially in the case of a relative high population of immunocompromised individuals. This study does not dispute the fact that RHRW is an alternative irrigation water source but it recommends treatment before use for domestic purposes or for watering crops.

A global review of the microbiological quality and potential health risks associated with roof-harvested rainwater tanks

“…A recent study also used pyrosequencing of the ITS 1 and ITS 2 hypervariable regions of the 18S rRNA gene to investigate fungal community structure in five RHRW tank samples collected from rural villages in South Africa. 72 At phylum level, fungal sequences were classified into five phyla. These include Ascomycota, Basidiomycota, Chytridiomycota, Glomeromycota, and Zygomycota.…”

Roof-Harvested Rainwater Use in Household Agriculture: Contributions to the Sustainable Development Goals

“…While we have only discussed the positives here, there are some negatives and challenges. One particularly malignant issue that warrants serious consideration is the potentially increased risk of malaria due to mosquito breeding grounds associated with urban agriculture [67,78] and RSSsystems [79]. This will need to be mitigated by RSS design [80] and open containers are not generally recommended [81].…”

“…Another is diarrhea associated with using wastewater to irrigate and human waste as fertilizer [67]. Jongman and Korsten [79] investigated water quality in rural villages in South Africa in 80 rainwater tanks and concluded that the use of untreated rainwater in crop irrigation or domestic use poses a potential health risk, especially in areas with a high population of immunocompromised individuals, so they advocate treatment before use. A little consideration will also show that to fully realize the potential, there are a number of barriers.…”

Neonatal listeriosis during a countrywide epidemic in South Africa: A tertiary hospital’s experience

“…Other possible factors that may contribute to the comparatively high LM incidence in SA could include a more vulnerable population of pregnant women owing to high antenatal HIV prevalence, [13] and a higher prevalence of LM-contaminated food and water sources than in high-income countries. [31][32][33] Although HIV infection is not traditionally cited as a Although most of the babies acquire listeriosis from their mothers (transplacental transfer), research shows that it is possible for the organism, Listeria monocytogenes, to be transferred between neonates in healthcare. The transmission can already occur in the delivery room by means of respiratory equipment that is not cleaned properly after use, other contaminated instruments, multi-dose ointments or contaminated supplies.…”