These lag times are consistent with the incubation periods of common waterborne bacterial and protozoal gastroenteritis-causing organisms, or multiples of these incubation periods, and support the findings of related endemic and epidemic waterborne disease research. Additional research focussing on pathogen-specific outcomes is needed to confirm the etiologic nature of the observed associations. Given the potential public-health implications of the relationships identified, attempts were made to estimate the relative and absolute gastrointestinal health impacts attributable to GVRD drinking water. Given inherent limitations in both the data sources and the available analytic methodologies, the estimates provided above must be interpreted cautiously. The true health impact estimates may have been substantially less , or greater than those calculated.
Efforts continue to assess the variability and to refine the above estimates.
Although additional research is warranted to more accurately estimate the health impacts associated with GVRD drinking water, to validate the associations observed, and to clarify the roles of specific waterborne pathogens, this study provides evidence to support the hypothesis that during the study period, enteric waterborne pathogens present in each of GVRD s three drinking water supplies contributed to endemic gastroenteritis among Greater Vancouver residents. Aramini J, McLean, Wilson J et al. Drinking water quality and health care utilization for gastrointestinal illness in Greater Vancouver . In July 2000, a new ozone primary disinfection facility began treating the Coquitlam source water.