4.2.2. Risk

We found partial support for our hypothesis that tap water drinkers would have decreased risk perceptions, in terms of cognitive safety, affect safety, cognitive severity, affect severity, and comparative risk, compared to other clusters. Cognitive safety and severity were more useful at distinguishing between other clusters than affect safety and severity, and comparative risk most useful. Similar to previous studies, all risk items reliably and substantively differentiated between tap and bottled water e.g., [36,37].

Given the stronger risk perceptions of bottled water users, we were not surprised that comparative risk demonstrated strong differences between clusters but were surprised that those differences did not reflect patterns in the cognitive safety variable. The comparative risk variable introduced by Saylor (2011) asks respondents to contrast the cognitive safety of tap water relative to bottled water [21]. As a result, we expected perceptions to be similar across groups with these two variables. However, the strongest difference in comparative risk was found between tap water and bottled water groups, while the strongest difference in cognitive safety was between tap water and sink filter and mixed groups. Additionally, the comparative risk variable distinguished between tap water and all other clusters except for appliance filter drinkers, while cognitive safety only differentiated tap water from bottled water and sink filter and mixed groups. Future research might benefit from expanding avenues of relative risk to compare other water sources besides just bottled and tap or comparing water sources using other measures besides cognitive safety.
