Risk perceptions of drinking bottled vs. tap water in a low-income community on the US-Mexico Border

Background: Previous studies have shown that low-income Latinos generally drink bottled water over tap water and might be at increased risks for cavities from unfluoridated bottled water. In order to better design interventions, it is important to understand the risk perceptions of this unique high-risk yet historically marginalized group. Methods: : We interviewed low-income Latino households (n=90) from Nogales, Arizona who primarily drink bottled water and asked them to evaluate potential health risks of drinking tap water compared to 16 other voluntary activities. Unpaired t-tests were used to determine if statistically significant (α=0.05) differences occurred in perceived risk by drinking-water source and differences among demographic groups in their level of (dis)agreement with statements regarding tap or bottled water safety. To assess significant differences (α=0.05) in perceived risks and voluntariness to engage in a number of activities, including drinking local tap water and drinking water in different geographic regions, a one-way analysis of variance (ANOVA) followed by Scheffe’s post-hoc test with adjustment for the number of pairwise comparisons was used. Results: : Bottled water was perceived as significantly safer for consumption than tap water (p<0.001). A mean score of 4.7 was measured for “drinking tap water in Nogales, Arizona” on a Likert scale from 1 (low risk) to 5 (high risk). This was significantly higher than that of drinking tap water in San Francisco, California (µ=3.4, p<0.001) or smoking (µ=3.5, p<0.001). Ninety-eight percent of participants feared that drinking local tap water could result in illness, 79% did not drink their water because of fear of microbial and chemical contamination and 73% would drink their water if they knew it was safe regardless of taste. Conclusions: : These results suggest that fear of illness from tap-water consumption is an important contributing factor to increased bottled water use. Future efforts should focus on the development of educational and outreach efforts to assess the safety and risks associated with tap-water consumption and emphasize the importance of fluoride supplementation if not consuming tap water.