Review Article

Evaluating the Effectiveness and Public Health Implications of Household Reverse Osmosis Water Filtration Systems: A Narrative Review

Abstract

Safe drinking water remains inaccessible to a substantial proportion of the global population, a circumstance that has contributed to the widespread adoption of household reverse osmosis (RO) as one of the most common point-of-use (POU) treatment technologies. This narrative review draws on 45 peer-reviewed studies, identified through a non-systematic search of Google Scholar, PubMed, and Scopus (the search terms and approach are detailed in Section 1), to assess the contaminant removal efficiency, water quality outcomes, public health benefits, and documented risks associated with domestic RO units. Thin-film composite (TFC) polyamide membranes, now standard in contemporary household systems, consistently achieve rejection rates exceeding 90% for most dissolved solids, heavy metals, and inorganic contaminants (Greenlee et al., 2009; Kucera, 2015); removal efficiencies for lead, arsenic, and cadmium typically surpass 95%, whereas nitrate rejection is comparatively lower, ranging between 85% and 93% depending on membrane condition and feedwater chemistry (Greenlee et al., 2009; Kucera, 2015). This performance, however, is not without cost. The substantial depletion of essential minerals such as calcium, magnesium, and bicarbonate reduces permeate pH to acidic levels, often below 6.5, raising legitimate questions regarding the long-term nutritional and cardiovascular consequences of consuming demineralized water (Kozisek, 2005; WHO, 2005). Household RO adoption in the Arab region and Iraq specifically is widely reported to have increased substantially over the past two decades, a trend attributed to elevated groundwater salinity and inconsistent municipal infrastructure (Al-Ansari et al., 2014); rigorous, published adoption-rate data at the household level nonetheless remain scarce. Maintenance compliance constitutes a documented concern more broadly, and field studies conducted outside the region have identified microbial re-contamination in poorly maintained systems (Payment, 1989; Payment et al., 1991); comparable Iraq-specific evidence could not be located in the course of this review, a gap identified here as a priority for future work. The review further addresses the environmental burden of brine discharge, cost-effectiveness across income levels, regulatory gaps in developing countries, and the near-total absence of standardized post-treatment remineralization protocols. It concludes by identifying critical gaps in the existing evidence base and proposing directions for future research, with particular attention to settings in which RO systems function as the primary or sole barrier against waterborne disease. 

Author Affiliation:

Talib Kamil Abed (ORCID): Environmental Research Center, University of Technology, Baghdad, Iraq.
Abdulazeez Ahmed Hamad (ORCID): Environmental Research Center, University of Technology, Baghdad, Iraq.
Ameer Mohammed Alwan: Environmental Research Center, University of Technology, Baghdad, Iraq.

How To Cite: T.K. Abed, A.H. Abdulazeez and A.M. Alwan. Evaluating the Effectiveness and Public Health Implications of Household Reverse Osmosis Water Filtration Systems: A Narrative Review. Interdisciplinary Studies on Applied Science, 3(2):34–47, 2026. https://doi.org/10.58613/isas325