Supplementary file 1_Influence of storage practices, container type, and handling on overall safety of household drinking water quality.pdf

Household drinking-water storage is widespread in Koya, Iraq, due to intermittent supply, yet its short-term implications for water safety and quality are not well characterized. This study combined a household survey (n = 83) with laboratory testing of stored water from 10 representative homes to evaluate how storage practices and container choice relate to water quality. Stainless-steel, plastic and clay containers were assessed, and samples were analyzed for organic load, suspended solids, and key physicochemical indicators, including nutrient forms. The analytical focus of the study was limited to physicochemical parameters, which were used to evaluate short-term water-quality stability rather than microbiological safety. Most households stored treated water for less than 24 h, and measured parameters remained largely stable during this period; container material did not produce meaningful differences in nutrient indicators (TN p = 0.082; NH4+–N p = 0.727). However, 22.9% of participants reported recent gastrointestinal symptoms, while poor hygiene routines were common (e.g., infrequent cleaning of rooftop tanks). Although no microbiological analyses were performed, these self-reported symptoms highlight the potential relevance of household handling and maintenance practices beyond physicochemical stability alone. Overall, no detectable physicochemical differences were observed across container materials under short-term storage conditions, suggesting that water quality at the point of use is more closely linked to storage duration, handling, and hygiene practices than to container material itself. Improving household maintenance and hygiene practices should therefore be prioritized as a precautionary measure to reduce potential health risks.