Nitrate in groundwater and agricultural products: intake and risk assessment in northeastern Iran.

The suitability of groundwater and agricultural products for human consumption requires determining levels and assessing the health risks associated with potential pollutants. Here, particularly pollution with nitrate still remains a challenge, especially for those urban areas suffering from insufficient sewage collection systems, resulting in contaminating soil, endangering food safety, and deteriorating drinking water quality. In the present study, nitrate concentrations in the commonly consumed fruit and vegetable species were determined, and the results, together with the groundwater nitrate levels, were used to assess the associated health risks for Mashhad city residents. For this assessment, 261 water samples and 16 produce types were used to compute the daily intake of nitrate. Nitrate in groundwater was analyzed using a spectrophotometer, and produce species were examined using High-Performance Liquid Chromatography. Ward's hierarchical cluster analysis was applied for categorizing produce samples with regard to their nitrate content. Additionally, to account for the sanitation hazards associated with groundwater quality for drinking purposes, total coliform and turbidity were also assessed using the membrane filter (MF) technique and a nephelometer, respectively. Nitrate concentrations exceeded the prescribed permissible limits in 42% of the groundwater wells. The outcomes also exhibit significantly higher nitrate accumulation levels in root-tuber vegetables and leafy vegetables compared to fruit vegetables and fruits. Using cluster analysis, the accumulation of nitrate in vegetables and fruits was categorized into four clusters, specifying that radish contributes to 65.8% of the total content of nitrate in all samples. The Estimated Daily Intake (EDI) of nitrate and Health Risk Index (HRI) associated with consumption of groundwater exceeded the prescribed limit for the children's target group in Mashhad's south and central parts. Likewise, EDI and HRI values for produce consumption, in most samples, were found to be in the tolerable range, except for radish, lettuce, and cabbage, potentially posing risks for both children and adult consumers. The total coliforms in groundwater were found to violate the prescribed limit at 78.93% of the sampling locations and were generally much higher over the city's central and southern areas. A relatively strong correlation (R2 = 0.6307) between total coliform and nitrate concentrations suggests the release of anthropogenic pollution (i.e., sewage and manure) in the central and southern Mashhad.

Hydrologic modelling for Lake Basaka: development and application of a conceptual water budget model.

Quantification of fluxes of water into and out of terminal lakes like Basaka has fundamental challenges. This is due to the fact that accurate measurement and quantification of most of the parameters of a lake's hydrologic cycle are difficult. Furthermore, quantitative understanding of the hydrologic systems and hence, the data-intensive modelling is difficult in developing countries like Ethiopia due to limitation of sufficient recorded data. Therefore, formulation of a conceptual water balance model is extremely important as it presents a convenient analytical tool with simplified assumptions to simulate the magnitude of unknown fluxes. In the current study, a conceptual lake water balance model was systematically formulated, solved, calibrated, and validated successfully. Then, the surface water and groundwater interaction was quantified, and a mathematical relationship developed. The overall agreement between the observed and simulated lake stage at monthly time step was confirmed based on the standard performance parameters (R(2), MAE, RMSE, E(f)). The result showed that hydrological water balance of the lake is dominated by the groundwater (GW) component. The net GW flux in recent period (post-2000s) accounts about 56% of the total water inflow. Hence, GW plays a leading role in the hydrodynamics and existence of Lake Basaka and is mostly responsible for the expansion of the lake. Thus, identification of the potential sources/causes for the GW flux plays a leading role in order to limit the further expansion of the lake. Measurement of GW movement and exchange in the area is a high priority for future research.

Safe-water shortages, gender perspectives, and related challenges in developing countries: the case of Uganda.

The need for water continues to become more acute with the changing requirements of an expanding world population. Using a logistical analysis of data from 301 respondents from households that harvest rainwater in Uganda, the relationship between dependent variables, such as water management performed as female-dominated practices, and independent variables, such as years of water harvesting, family size, tank operation and maintenance, and the presence of local associations, was investigated. The number of years of water harvesting, family size, tank operation and maintenance, and presence of local associations were statistically significantly related to adequate efficient water management. The number of years of water harvesting was linked to women's participation in household chores more than to the participation of men, the way of livelihoods lived for many years. Large families were concurrent with a reduction in water shortages, partially because of the availability of active labour. The findings also reveal important information regarding water-related operations and maintenance at the household level and the presence of local associations that could contribute some of the information necessary to minimise water-related health risks. Overall, this investigation revealed important observations about the water management carried out by women with respect to underlying safe-water shortages, gender perspectives, and related challenges in Uganda that can be of great importance to developing countries.

Knowledge of measures to safeguard harvested rainwater quality in rural domestic households.

Given the possibility of waterborne diseases caused by inappropriate rainwater harvesting systems, a survey was conducted in Uganda to assess existing knowledge of both physical and non-physical measures that safeguard harvested rainwater. Households who had received rainwater tanks were assessed on issues related to harvested rainwater quality. The study shows that 84% of respondents were aware of various sources of rainwater contamination, but only 5% were aware that they needed to adjust use of rainwater, depending on whether they cleaned the tank or not. Most of the respondents were not aware that gutter cleaning was necessary to improve water quality. Indeed, as the water from the collection surface is channelled through gutters, a number of measures need to be taken to control the entry of contaminations and subsequent growth of pathogens in the tank, e.g. first flush diverts, installation of filters, chemical use and mesh cleaning. The majority, however, did not take adequate care of the gutters and this impacts on health and social livelihood. Overall, the findings emphasize the need to provide more information to households when installing water harvesting tanks to ensure that the harvested rainwater is of high quality.