Statistically significant turbidity-gastroenteritis relationships were found among multiple age groups, among all three administrative health care data sets, and among the three water source distribution populations. Additional research focussing on pathogen-specific outcomes is needed to confirm the etiological 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 Greater Vancouver 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 Greater Vancouver 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 Greater Vancouver's three drinking water supplies contributed to endemic gastroenteritis among Greater Vancouver residents.