Health status of residents of an urban dual reticulation system.

BACKGROUND Households in dual reticulation developments are supplied with recycled water from sewage effluent for some non-potable purposes, and conventional tap water for other uses. Adverse health effects from recycled water exposure are considered unlikely; however, no epidemiological studies have been undertaken to assess the public health impact of such exposures. METHODS We compared the health status of residents of a dual reticulation housing development with residents of an adjacent conventional water supply area by assessing consultation rates with primary-care physicians for three conditions considered plausibly related to recycled water exposure (gastroenteritis, respiratory complaints and dermal complaints), and two conditions considered unrelated to water exposures (urinary tract infections and musculoskeletal complaints). RESULTS We found little difference in the overall number of medical consultations per person, or in consultation rates for specific disease conditions between residents of the two water supply areas, after adjustment for demographic differences. Slight elevations in odds ratios (ORs) for dermal and respiratory consultations were observed, but seasonal patterns were not consistent with recycled water exposures. CONCLUSIONS This retrospective assessment of medical records indicates that residents of the dual reticulation water supply area are not likely to be experiencing elevated rates of adverse health outcomes as a result of their exposure to recycled water. This finding provides added assurance that appropriately operated and managed dual reticulation residential developments are a safe option for future urban water supplies.