The use in agriculture of excreta from urine-diversion toilets can be an alternative solution to the lack of sanitation and high costs of mineral fertilizers inherent to developing countries. The objective of this study was to evaluate the hygienic quality of urine used as fertilizer through an ecological sanitation system in Ouagadougou peri-urban areas. Chemical and microbiological analyses were performed in urine samples taken before and after thirty (30) days of storage in jerry cans exposed to sunlight. The concentrations of 7.0 g/l; 3.5 and 9.6 g/l of ammonia nitrogen for mean, minimum and maximum respectively, are obtained in unstored urine samples. These concentrations did not practically vary with the storage. On average, values of other chemical parameters analyzed in stored urine were as follows: pH, 8.8; phosphorus (P), 0.3 g/l; potassium (K), 1.9 g/l; total dissolved solids (TDS), 21.0 g/l; cadmium (Cd), 154.3 µg/l; copper (Cu), 5.2 µg/l; lead (Pb), 15.2 µg/l; chromium (Cr), 6.1 µg/l; nickel (Ni), 154.0 µg/l. Escherichia coli, staphylococci, enterococci, Salmonella and spores of Clostridium perfringens were detected in unstored urine samples, with 26% of fecal contamination rate. The time of storage (30 days) under sunlight was enough for almost all bacteria removal in urine samples. Although the fertilizing value of urine was confirmed, it would be important to take account of the best practices on applying in soils, because of the high TDS contents. Also, the risk linked to micropollutants in urine-based fertilizers could be negligible in view of low quantities. The results obtained in this study prove that after 30 days of exposure to sunlight urine collected via eco-toilet becomes bacteriologically sanitized, and can therefore be J. M. Makaya et al. 468 used to fertilize soils. However, it is necessary to demonstrate the inactivation of other groups of enteric microorganisms in human urine during storage.

Urine from urine-diversion toilets (UDTs) is routinely used as fertilizer for urban agriculture in Ouagadougou, Burkina Faso. Because urine from UDTs can be accidentally spoiled by feces, we determined whether virulent enteric viruses could persist in urine that is used for agricultural purposes and pose a threat to human health. Urine samples (N = 60) were first collected from 42 UDTs during the months of January and February 2012 in Ouagadougou and screened negative for the presence of norovirus (NoV) and group A rotavirus (RV). Composite urine from five collection sites was used to determine whether spiked murine norovirus (MNV) and group A bovine rotavirus (boRVA) could remain infectious at 15, 25, and 42 °C over an incubation period of 42 days in phosphate buffered saline (control) and urine. For both viruses, infectivity was determined by plaque assay and the presence of viral genome was evaluated by real-time RT-PCR. A decrease in the infectious titer was observed in composite urines that were experimentally seeded with MNV and boRVA. The decrease in the infectious titer was greater for MNV than for boRVA. Given that MNV was more labile to urine than boRVA was, MNV and boRVA genomes were still detectable after the 42 and 49 days incubation period for MNV and boRVA, respectively. Our data using substitutes of human NoV and RV suggested that there is a virucidal activity of urine against RVs and NoVs, given that the effect was lesser for RV. In spite of disappointing results for boRVA, the use of urine as fertilizer is still promising provided that future safety studies are extended to other enteric viruses.

The great challenge for the sustainable use of excreta (urine, faeces) in agriculture is to increase the benefits of these products as resources and decrease the negative effects on human health. The risk of gastrointestinal diseases associated with the use of human excreta as natural fertilisers is well established, while information on skin problems remains largely anecdotal. The objective of this study was to evaluate the prevalence of skin problems among people involved in the handling of the urine used as fertiliser along a productive sanitation system in Ouagadougou periurban areas. A questionnaire was used for each targeted worker to collect data on sociodemographic characteristics, conditions of work and reported health symptoms such as skin burning, itching, eye irritation and paronychia. The exposure measurements were essentially based on field observations. A total of 435 people were interviewed, including 45 workers in urine storage sites, 209 farmers using urine-based fertiliser and 181 control farmers. More than 35% of site workers reported skin symptoms. For farmers using urine-based fertiliser and their controls, 17.2% and 26.0% reported skin symptoms, respectively. Overall, the associations between skin symptoms and the handling of urine used as fertiliser were almost significant (P ˂ 0.06). Also, the study showed that these skin symptoms reported by the urine handlers are associated with conditions

To promote the use of eco-toilets is an alternative to the lack of sanitation and high cost of artificial fertilisers in developing countries. Human urine is the fraction of excreta containing most nitrogen, phosphorus and potassium which are essential nutrients for plant growth. The major concern related to the use of the urine as fertiliser is the possible presence of enteric pathogens. The reduction in the numbers of Escherichia coli, Enterococcus faecalis, Salmonella sp., Staphylococcus aureus, Clostridium perfringens spores during urine storage was studied in diluted and undiluted urine samples. These experimental samples were stored in ambient air and at temperatures of 25, 35 and 42°C. The initial concentration of ammoniacal nitrogen reduced from 8260 to 1070 mg/L in quarterdiluted urine (1:3), while the pH values remained stable at 8.6 (± 0.2). E. faecalis survived for 35 days in the quarter-diluted urine at 25°C. Survival times of the tested bacteria were more shortened in ammonia concentrated samples, on storage at 35, 42°C. Except C. perfringens spores, E. faecalis was the least sensitive to storage conditions as compared to S. aureus and the two Gram-negative bacteria tested. Therefore, temperature and ammonia acted synergistically to remove bacteria in the stored urine. Likewise, C. perfringens spores were the most persistent bacteria, with only 1-log 10 reduction within 100 days storage at ambient temperature. This study shows that a period of at least 30 days of undiluted urine storage at temperatures ≥ 25°C is sufficient to sanitize urine, considering only vegetative bacteria. Since urine from eco-toilets may contain other enteric organisms (viruses, protozoa, etc) appearing more persistent in external media, storage time must be lengthened for a satisfactory sanitation.