Determinants of tap water mistrust among Phoenix, Arizona Latinx adults

Underhydration, dehydration, and low water intake have been linked to various adverse health outcomes, including cardiovascular dysfunction, chronic diseases, and death (National Academy of Medicine 2005). Latino and Hispanic (herein Latinx) adults have significantly lower total water intake (Drewnowski et al. 2013; Brooks et al. 2017; Rosinger et al. 2018) and are 1.42 times more likely to be inadequately hydrated (Brooks et al. 2017) compared to non-Hispanic (NH) White adults. Moreover, Latinx adults tend to consume significantly higher proportions of sugar-sweetened beverages (Rosinger et al. 2017), which can increase the risk for obesity, type 2 diabetes, and cardiovascular diseases (Huang et al. 2014).

The Centers for Disease Control and Prevention (CDC) recommend individuals to ‘Rethink Your Drink’ by replacing sugar-sweetened beverages with water. Some tips to accomplish this include improving the flavor of water by adding berries, lime, lemon, or cucumber, storing water in the fridge, and using a reusable water bottle that can be refilled while on the go (Centers for Disease Control and Prevention 2019). These strategies may not be effective in Latinx adults as they are significantly more likely to perceive their tap water as unsafe compared to NH White adults (Onufrak et al. 2012; Pierce & Gonzalez 2017; Javidi & Pierce 2018) and bottled water serves as a costly alternative (Javidi & Pierce 2018).

Water insecurity is prevalent across the United States (US). Perceptions of unsafe tap water are likely valid for some populations and individuals. Minority and low-income communities are at a greater risk of water insecurity due to factors such as historical planning processes, redlining and under bounding, reduced enforcement of water regulations and standards, and repeat water violations (Balazs & Ray 2014; Meehan et al. 2020a). Yet mistrust in tap water also occurs when tap water is designated safe by federal agency standards (Wilson et al. 2022).

As an alternative to tap water, bottled water is not necessarily safer to consume. US Government Accountability Office testimony concluded that while the Environmental Protection Agency (which regulates tap water) and the US Food and Drug Administration (FDA, which regulates bottled water) have similar regulations for drinking water, the FDA is less capable of enforcing them for bottled water (United States Government Accountability Office 2009). In particular, the FDA cannot require bottled water to be tested in certified laboratories or test results (e.g., violations of water quality standards) to be reported (United States Government Accountability Office 2009). There also are no requirements for bottled water labels to include information regarding regulation compliance, the presence of contaminants, or potential health risks associated with contaminants (United States Government Accountability Office 2009).

Tap water safety perceptions generally appear to be influenced by geography, household and neighborhood characteristics, demographics, prior experiences with tap water, organoleptic (sensory) perceptions, and availability and sources of information about water (Colburn & Kavouras 2021). However, recent investigations have not consistently or comprehensively evaluated the same factors. Additionally, only one investigation (Park et al. 2019) included a sample comprised entirely of Latinx adults, and many factors in the remaining investigations were not evaluated for differences by race or ethnicity. Therefore, the factors that have previously been identified to influence tap water safety perceptions may not all be relevant to Latinx adults, specifically.

A greater understanding of tap water aversion could enhance efforts to improve water intake and reduce sugar-sweetened beverage intake in Latinx adults with access to safe tap water. Therefore, the purpose of this investigation was to evaluate perceptions, knowledge, behaviors, and experiences related to drinking water in Latinx adults residing in Phoenix, Arizona. We aimed to characterize the degree to which various factors predict the perception that tap water is not safe. Education level, annual income, and nativity status were explored as potential moderators.

English- and Spanish-speaking adults (18–65 years) who self-identify as Hispanic or Latinx (question: ‘What is your ethnicity?’; response options: ‘Hispanic or Latinx’, ‘Not Hispanic or Latinx’) in Phoenix, AZ (evaluated via self-reported zip code) were recruited for participation. The sample was selected using non-probability methods and recruited through Facebook ads, printed flyers, a university research participant registry, university banner ads, and word of mouth. Eligibility was evaluated via an online survey (Qualtrics, Provo, UT, USA). Participants were excluded if they satisfied at least one of the following criteria: pregnant, use diuretics, do not have access to a desktop, laptop, tablet, or smartphone, or do not have internet access. Potential participants were informed of participation risks and benefits and their rights as a participant. Free and informed consent was obtained electronically, and the study protocol was approved by the Institutional Review Board of Arizona State University, Arizona, USA (protocol no. STUDY00014055; approval date: June 1, 2021). This study was registered at clinicaltrials.gov (NCT04997031) and was conducted in compliance with the Helsinki Declaration as revised in 1983. Data collection occurred from September 2021 to February 2022 in Phoenix, Arizona, USA.

Ultimately, 1,029 individuals consented to voluntary participation, enrolled, and completed the study online. Data from 537 participants were excluded due to multiple submissions by the same person (n = 63), straight-lined data (n = 471), or missing data (n = 3), resulting in n = 492 for the analysis. Multiple submissions by the same person were identified by the use of the same email address and/or name, similar email addresses, and/or variations of similar first and last names. Participants were contacted to verify the completion of multiple surveys. Several survey questions were utilized to identify straight-lined data. For example, participants were asked to rank 11 items based on their level of importance. In many instances, items were ranked 1–11 in the order in which they were presented to the participant. Additionally, some questions asked participants to select ‘yes’ or ‘no’ to a list of items, some of which were contradictory statements. Specifically, one question asked: ‘Select ‘yes’ if you agree or ‘no’ if you disagree with each of the following statements about your home drinking water system’. Some individuals selected ‘yes’ for all eight items, which included: ‘I often use bottled water for drinking purposes’, ‘I never buy bottled water’, ‘I am satisfied with my current drinking water (piped in house)’, and ‘I am not satisfied with my current drinking water (piped in house)’. Finally, participants were excluded from analysis if pertinent data was missing (i.e., nativity status [n = 1] and age [n = 2]).

Enrolled participants completed an online survey (Qualtrics, Provo, UT, USA), which took an average of 37.14 minutes to finish. All responses were coded in Qualtrics before any participants completed the survey, which allowed researchers to download a coded version of the dataset. Participants completed an Adapted Survey of Water Issues in Arizona (Supplementary material, Figure 1), which was adapted from previous national water survey needs assessments from the US Department of Agriculture-Cooperative State Research, Education, and Extension Service Southwest States and Pacific Islands Regional Water Quality Program (Castro et al. 2011). This survey evaluates participant awareness, aptitudes, attitudes, and actions toward water quality (specifically, feelings about the environment, environmental perspective, water safety and quality perceptions, water quality education, governance, and demographics). Adaptations to the survey were minimal. One question previously utilized in literature was added to evaluate prior experiences with tap water: ‘What is your level of agreement with the following statement: I had a bad experience with tap water’ (Gorelick et al. 2011). The question ‘What is your gender?’ was updated to ‘What is your biological sex?’ due to differences in gender and biological sex. Two questions were added to evaluate participant nativity status (born in the US vs. born outside of the US) and race. Participants also completed household water security experience-based scales developed for low-income peri-urban and rural communities on the US-Mexico border (Jepson 2014).

Survey items used to measure all variables are outlined in Table 1. The outcome variable was the perception of tap water safety. Responses were classified as a safe (agree and strongly agree) or an unsafe (disagree and strongly disagree) perception of tap water. Covariate variables included sex, age, race, education level, annual income, and US nativity. Mutually exclusive categories were created for the race (Caucasian, African American/African/Black/Caribbean, Native American, and other), education levels (high school graduate or less, some college, and college graduate or more), and annual income (<$25,000, $25,000–$69,999, and ≥$70,000).

Exposure variables measured prior experience with poor water quality, organoleptic perceptions, sources of information about water, and the home drinking water system. Responses for experience with poor water quality were classified as bad experience (agree and strongly agree) or no bad experience (neither agree nor disagree, disagree, and strongly disagree) with tap water. Both questions measuring organoleptic perceptions were utilized to create continuous, composite variables. ‘Favorable perceptions of bottled water compared to tap water’ (0–3, mean ± standard deviation [SD] = 2.18 ± 1.14) was created with each ‘yes’ response scored as 1 and each ‘no’ response scored as 0 for organoleptic perceptions question one. Reliability was good (Cronbach's α = 0.81). ‘Negative home tap water experiences’ (0–6, mean ± SD = 3.02 ± 2.12) was created with each ‘yes’ response scored as 1, and each ‘no’ response scored as 0 for organoleptic perceptions question two. Reliability was good (Cronbach's α = 0.82). Items for the sources of information about the water question were reduced to clusters in meaningful ways: media (newspaper and television), government sources (environmental agencies, consumer confidence reports, and extension service), non-government sources (environmental groups, universities, and schools), friends/family, and healthcare provider. Finally, participants’ home drinking water systems were evaluated by the three Idealized Guttman scales (Jepson 2014) in addition to four questions listed in Table 1. The Idealized Guttman water scales evaluated water access, water quality and acceptability, and water distress. Water access was scored 0–7 (mean ± SD = 3.11 ± 2.43), had good reliability (Cronbach's α = 0.83), and was classified as adequate (0), marginal (1–3), low (4–5), and very low (6 –7). Water quality and acceptability were scored 0–6 (mean ± SD = 2.96 ± 2.09), had good reliability (Cronbach's α = 0.79), and were classified as acceptable (0), marginal (1–2), low (3–4), and very low (5–6). Water distress was scored 0–6 (mean ± SD = 2.89 ± 2.26), had good reliability (Cronbach's α = 0.85), and was classified as low (0), marginal (1–2), high (3–4), and very high (5–6). Responses for home drinking water systems questions one and two were classified as good quality (good or excellent, good and improving, good but deteriorating, fair, and no opinions/don't know) or bad quality (poor but improving and poor) of water. A continuous, composite variable, ‘Use of alternatives and/or modifications to home tap water’ (0–6), was created with each ‘yes’ response scored as 1 and each ‘no’ response scored as 0 for home drinking water systems question four. Reliability was acceptable (Cronbach's α = 0.68). ‘I am not satisfied with my current drinking water (piped in house)’ was excluded from the composite variable to improve reliability (Cronbach's α = 0.71, mean ± SD = 3.48 ± 1.55). Finally, descriptive variables measured influential sources of information, water quality responsibility, and learning opportunities.

Data analyses were completed using commercial software (IBM SPSS Statistics Version 27.0.0). Data are presented as odds ratio (OR), 95% confidence interval (95% CI) unless otherwise specified. A P < 0.05 was considered statistically significant for all analyses. Multicollinearity was assessed for predictor variables and interaction terms via bivariate correlation.

Binary logistic regression was utilized with tap water safety perceptions as the outcome variable (0 = safe, 1 = unsafe). All covariate variables were included in the model. Exposure variables were included as predictors based on relevance in the literature. Interactions between various predictors and nativity (i.e., prior bad experience with water, government information sources, and non-government sources), annual income (i.e., the past year home tap water composite variable, home drinking water system composite variable, water access score, water quality and acceptability score, and water distress score), and education level (i.e., media information sources, government information sources, non-government information sources, friends and family information source, and health care provider information source) were explored based on previous literature. Variables were centered before evaluating interactions to account for multicollinearity. Interactions were individually added to the model and evaluated for statistically significant effects via the likelihood ratio test. Predictors that did not have a statistically significant effect were removed from the model (Hosmer & Lemeshow 2000).

Participants were 28 ± 7 years and mostly male, educated (>90% have at least some college education), and born in the US (Table 2). 51.2% mistrusted their tap water safety. Household water insecurity was prevalent as <20% of participants had adequate water access, ∼30% had acceptable water quality, and ∼25% had low water distress. Contrarily, >80% of the sample perceived groundwater and surface water in their area positively. Tap water safety perceptions were only significantly different among education levels, with the highest prevalence of mistrust observed in adults with some college education (χ² test, P < 0.05).

Tap water safety perceptions significantly varied among many survey items (Table 3). Over half of individuals previously had a bad experience with tap water. However, about half of the individuals with and without prior bad experiences mistrusted their tap water (χ² test, P > 0.05). Most of the sample perceive bottled water to taste and smell better, have higher quality, and be safer than tap water, and >60% of individuals with each of these perceptions mistrusted their tap water (χ² tests, P < 0.001). Additionally, hard water/mineral deposits and unpleasant taste in home tap water were the most common experiences in the previous year, while the presence of other contaminants was the least common experience. Tap water mistrust was more prevalent for those experiencing hard water and mineral deposits, unpleasant taste, unpleasant smell, and other contaminants (χ² tests, P < 0.05).

Individuals change their minds about an environmental issue most commonly as a result of news coverage and least commonly as a result of financial considerations. Moreover, water quality information was most commonly received via television and least commonly received via consumer confidence reports. Overall, sources of information did not differ widely between tap water perceptions. The only difference observed was that a higher proportion of individuals with unsafe perceptions received water quality information from their healthcare provider (χ² test, P < 0.05).

Half of the participants purchased bottled water as their primary source of drinking water. Tap water mistrust was less prevalent among those using public supplies (municipal and rural) and more prevalent among those using private supplies or purchasing bottled water for primary sources of drinking water (χ² tests, P = 0.005). Several differences were observed regarding home drinking water systems. Tap water mistrust was more prevalent among those purchasing ≥1-gallon containers for drinking water, those who often used bottled water for drinking purposes, dissatisfaction with home drinking water infrastructure, and obtaining drinking water separately from the home water supply system (χ² tests, P < 0.05). The Idealized Guttman scale for water access revealed that tap water mistrust was more prevalent among those with adequate or low water access but less prevalent among those with very low water access (χ² test, P < 0.001).

Overall, the top three water quality learning opportunities of interest were to read a newspaper article or series or watch TV coverage, to read printed fact sheets, bulletins, or brochures, and to watch a video of information (Table 3). However, greater proportions of individuals who trusted their tap water comprised those who selected reading printed fact sheets, bulletins or brochures, reading a newspaper article or series or watching TV coverage, visiting a website, or attending a fair or festival (χ² test, P < 0.05). Contrarily, greater proportions of individuals who mistrusted their tap water (>60%) comprised those who selected wanting to take part in a onetime volunteer activity or to get trained for a regular volunteer position (χ² test, P < 0.01).

Beliefs about whether the environment receives the right amount of emphasis from local government and elected officials in Arizona (χ² test, P = 0.002) and about who should be most responsible for protecting water quality in the community (χ² test, P < 0.001) varied significantly by tap water safety perception. While 42.3% of individuals believed the environment receives the right amount of emphasis, 34.6% believed it does not. Moreover, 62.9% of individuals who believed the environment does not receive the right amount of emphasis also believed their tap water is unsafe. The remaining individuals believed the environment receives too much emphasis (17.9%) or did not have an opinion/did not know (5.3%). The majority of the sample believed the county, city, or town (34.1%) or individual citizens (29.7%) should be most responsible for protecting water quality in their community. Interestingly, 63.1% of those who believed the county, city, or town were responsible, and 38.4% of those who believed individual citizens are responsible mistrusted their tap water. The rest of the sample believed the state government (21.5%), the federal government (12.8%), or ‘other’ (0.6%) should be responsible. A small proportion (1.2%) did not know who should be responsible.

The binary logistic regression model is presented in Table 4. The odds of perceiving tap water to be unsafe were significantly greater for African American, African, Black, and Caribbean individuals compared to Caucasian individuals (P < 0.05). Perceptions were not influenced by education, sex, age, annual income, or nativity. The odds of mistrust were also significantly greater for each additional score for favorable perceptions of bottled water compared to tap water, negative home tap water experiences, use of alternatives and/or modifications to home tap water, and water quality and acceptability (P < 0.05). Conversely, the odds of mistrust were significantly lower for individuals whose primary source of drinking water is the public supply (municipal) as well as for each additional score for water access (P < 0.05). No sources of information had an influence on tap water safety perceptions. Finally, no significant interactions were observed between predictors and education level, annual income, or nativity status.

Tap water mistrust in Latinx adults appears to be related to organoleptic perceptions and behavioral changes to the home drinking water system. Overall, 51.2% of Latinx adults in this Phoenix, Arizona sample perceived their tap water to be unsafe. Previous studies observed the prevalence of mistrust from 14.7 to 33.8% in Latinx individuals (Onufrak et al. 2012; Pierce & Gonzalez 2017; Javidi & Pierce 2018; Park et al. 2019). It is not clear why the prevalence of mistrust was greater in the current sample, but it is unlikely that over half of the sample has access to unsafe water. Most drinking water in Phoenix, AZ is sourced from the Salt, Verde, and Colorado Rivers and regulated across five water treatment plants. Only ∼2% of drinking water in Phoenix is sourced from groundwater wells, which are operated by the city (City of Phoenix Water Services Department 2021). The City of Phoenix utilizes chlorine to disinfect all drinking water, which can generate disinfection byproducts in water. As of 2021, levels of chlorine, disinfection byproducts, and other substances were all below the maximum contaminant levels set by the EPA. Therefore, municipal tap water available to individuals in this sample was likely safe for consumption according to these regulatory standards. Participants appeared to agree with this as 88.2 and 83.5% had positive perceptions about the quality of local groundwater and surface waters. However, while the EPA monitors contaminants of emerging concern, there is currently no framework to regulate or act on these contaminants (Centers For Disease Control and Prevention). Accordingly, water that is deemed safe by federal agency standards may not be safe if contaminants of emerging concern are present (Post et al. 2017). Additionally, tap water quality can be affected by home infrastructure (e.g., premise plumbing). While water quality was not tested in participants’ residences, the City of Phoenix tested for lead and copper in a small sample (n = 71) of residential water taps and the federal standards set by the EPA were met (City of Phoenix Water Services Department 2021).

Mistrust in the present sample did not follow the patterns previously observed across education or income levels. The prevalence of mistrust was lowest in both the lowest and highest levels of education. While education level was a significant predictor of tap water mistrust, the odds of mistrust were not significantly different between having a college education or more and having some college education or having a high school education or less. In comparison, the prevalence of mistrust was lowest in the higher levels of education in previous investigations (Onufrak et al. 2012; Park et al. 2019). Moreover, the odds of trusting tap water safety were greater in US adults with at least a high school degree who completed the American Housing Survey in 2013 (OR = 1.448 (Pierce & Gonzalez 2017)) and 2015 (OR = 1.15 (Javidi & Pierce 2018)). The difference in our findings compared to previous findings is likely related to our sample being highly educated (>90% have at least some college education). In comparison, 30.6% of the total Phoenix, AZ population (≥25 years) have a bachelor's degree or higher. Therefore, this sample likely does not represent the general Latinx population in Phoenix, AZ (United States Census Bureau 2021). Additionally, the prevalence of mistrust has typically declined with increased income (Onufrak et al. 2012; Park et al. 2019). A clear relationship between income and tap water mistrust was not observed in the present investigation. Furthermore, education level and income level were not observed to moderate any relationships between predictors and tap water mistrust.

The prevalence of tap water mistrust was not different across race categories in the present sample. However, racial categories as defined by survey makers may not align with self-identification in Latinx adults (Allen et al. 2011). Specifically, some Latinx individuals may conceptualize race as an identity that is determined by more factors than physical characteristics and ancestry, such as experiences with discrimination, personal connection with family and culture, and level of identification with White Americans (Allen et al. 2011). Lack of identification with defined racial categories can lead to a greater prevalence of Latinx adults selecting ‘other race’ (Allen et al. 2011), which was observed in the present investigation. While tap water mistrust is commonly least prevalent among NH Caucasian individuals (5.1–10.8%), the prevalence was greater in Caucasian adults in the present sample (39.8%) (Onufrak et al. 2012; Pierce & Gonzalez 2017; Javidi & Pierce 2018). In addition to potential non-identification with racial categories, differences in prevalence may be related to ethnicity as previous investigations only recruited Caucasian individuals who were NH, while the present investigation only recruited Caucasian individuals of Latinx descent. Moreover, after controlling for all other predictors in the model, Latinx African American, African, Black, and Caribbean adults were over three times more likely to mistrust their tap water compared to Latinx Caucasian adults, which may reflect this group's disproportionate exposure to racial discrimination in water and housing policy in the US (Meehan et al. 2020b; Wilson et al. 2022).

US nativity did not influence tap water perceptions, despite findings from previous investigations in which the prevalence and odds of mistrusting tap water were greater in foreign-born individuals (Pierce & Gonzalez 2017; Javidi & Pierce 2018). The current findings could be related to a relatively small percentage of foreign-born participants (8.1%). In comparison, 19.2% of the total Phoenix, AZ population is foreign-born (United States Census Bureau 2021). Tap water mistrust in foreign-born Latinx adults was hypothesized to be related to experiences with poor water quality in their home countries (Pierce & Gonzalez 2017). A significant interaction between nativity and prior experiences with tap water was not observed in the present investigation. However, the country of origin was not reported by foreign-born participants in the present study. Differences in various factors such as tap water regulations, trust, and violations across all Latinx countries could impact comparisons made between US-born and foreign-born participants. For example, foreign-born Latino mothers from Central American countries have reported a greater prevalence of trust in tap water in their home countries than in the US (Colón-Ramos et al. 2017; McCarley et al. 2021).

Organoleptic characteristics of water have commonly been associated with safety perceptions. This is supported by our findings in which the odds of tap water mistrust increased with each additional negative home tap water experience. Mistrust was more common among Latinx adults who had experienced hard water/mineral deposits, unpleasant taste, unpleasant smell, and other contaminants in their home tap water in the previous year. The prevalence of mistrust was not different among adults with and without sediment or rusty color in their home tap water. Additionally, the odds of mistrust were significantly greater for each additional water quality acceptability score, where a higher score indicates worse water quality and acceptability. While organoleptic characteristics of water are not dependable indicators of health risk (Napier & Kodner 2008), it appears Latinx adults may associate undesirable perceptions with a lack of safety. The present findings are supported by previous focus groups and interviews in which Latinx adults reported believing their tap water was not safe due to unpleasant taste, discoloration, unpleasant smell, and presence of chlorine or other minerals that cause tap water to taste unpleasant (Scherzer et al. 2010; Hess et al. 2019).

Bottled water was purchased by about half of this sample as their primary source of drinking water. The prevalence of tap water mistrust was greater in those purchasing bottled water but lower in those using the public supply (municipal and rural) as their primary source. Accordingly, the odds of mistrust were significantly lower in those who rely on the public supply (municipal). Those who mistrust their tap water appear to rely on alternatives or modifications to the home drinking water system. Specifically, there was significantly greater prevalence of mistrust among those who are not satisfied with their current drinking water (piped in house) and the odds of mistrust increased with each additional alternative and/or modification employed. Mistrust was significantly more prevalent in those who purchase ≥1-gallon containers for drinking water, who often use bottled water for drinking water purposes, and whose drinking water is separate from their water supply system. Thus, Latinx adults who mistrust their tap water are most likely to rely on alternatives to their home drinking water system rather than modifications (i.e., water softener or water treatment system).

Hispanic households have been observed to be significantly less likely to rely on tap water (unfiltered and filtered) over bottled water compared to NH White households (Javidi & Pierce 2018). Additionally, the use of home water treatment devices was significantly less prevalent among Hispanic adults compared to NH White adults (Rosinger et al. 2018). It is possible that filtered or treated water may not be perceived as safe, even if it is perceived more favorably than unfiltered or untreated water. Florida residents who consumed municipal water believed that water filters could combat organoleptic concerns, such as unpleasant-tasting water. However, they still preferred bottled water for what they considered to be more serious concerns (i.e., safety, contamination, and health risk) (Triplett et al. 2019). Additionally, among Latinx parents participating in a water filter intervention, tap water consumption increased despite mixed perceptions of filtered water. Specifically, some perceived their water to be safer when using a water filter pitcher, while others maintained their distrust and still preferred bottled water (Reese et al. 2022; Santillán-Vázquez et al. 2022). Similarly, tap water mistrust in the present sample was prevalent among those with perceptions that bottled water tastes and smells better (62.2%), is of higher quality (60.9%), and is safer (61.7%) than tap water. Moreover, the odds of mistrusting tap water were significantly greater with each favorable perception of bottled water compared to tap water. In comparison, previous investigations have observed 34.1% (Onufrak et al. 2012) and 64.7% (Park et al. 2019) of Hispanic adults to perceive bottled water to be safer than tap water. Adults who believe bottled water is safer than tap water are significantly less likely to primarily consume tap water (van Erp et al. 2014). Similarly, beliefs that bottled water is cleaner and tastes better than tap have been associated with significantly greater odds of primarily consuming bottled water (Gorelick et al. 2011).

While participants have changed their minds about environmental issues in response to various sources of information, differences in the prevalence of mistrust were not observed for any source. However, newspapers, television, and friends and family were the most common sources of water quality information. The news, advertising, and friends have previously been identified as prevalent information sources, with family being a significantly more common source for Latinx parents compared to NH White parents (Gorelick et al. 2011). Additionally, 70.3% of participants received information from health care providers and the prevalence of mistrust was greater for those who receive water quality information from a health care provider (54.6%) compared to those who do not (43.2%). Previously, only ∼35% of participants were observed to receive information from their physicians (Gorelick et al. 2011). However, receiving information from health professionals is believed to have minimal to no influence on perceptions (Doria 2009), as supported by the present data (OR = 0.97, 95%CI = 0.50,1.89, P = 0.93).

Unsurprisingly, consumer confidence reports were the least common source of water quality information. While the EPA utilizes these reports to communicate with citizens about the quality of their local water, they do not meet national readability standards and are considered difficult to understand (Roy et al. 2015). The low prevalence of these reports as a source of information in the present study may also have been impacted by terminology used in the survey question. While participants were asked about consumer confidence reports in the survey, the reports in Phoenix, AZ are marketed as a water quality report. Therefore, it is possible that some participants were not aware that their water quality reports qualified as consumer confidence reports. Latinx mistrust in tap water safety has also been hypothesized to be related to distrust in the government (Scherzer et al. 2010). However, receiving water quality information from government sources and non-government sources was not a significant predictor of tap water mistrust in this investigation. Additionally, 68.4% of adults believe some level of government (federal, state, or local) should be responsible for protecting water quality in the community. Mistrust was greatest in those who believe local government should be responsible and lowest in those who believe individual citizens should be responsible. Ultimately, education about water quality does not appear to be an effective way to address tap water mistrust in Latinx adults. Contrarily, favorable perceptions of and reliance on bottled water in this sample support previous beliefs that water-related perceptions and behaviors are influenced by bottled water advertisements and marketing (Doria 2006; Pierce & Gonzalez 2017). In particular, bottled water marketing campaigns appear to capitalize on perceived associations between organoleptic perceptions, health, and risk through utilizing labels such as pure, pristine, natural, and healthy (Doria 2006; Wilk 2006). Bottled water marketing and advertising campaigns also have a history of targeting minorities (Javidi & Pierce 2018). Unfortunately, few promotional campaigns for tap water currently exist.

A high prevalence of survey responses included straight-lined data and were excluded from data analysis. This may have been influenced by various aspects of the online survey design, including the use of matrix questions, presenting more than one question per page, and the overall length of the survey. The statistical analysis utilized could have introduced type one error due to multiple comparisons. The sample was highly educated, with 92.9% of participants having completed at least some college, and was not evenly distributed across sexes (62.6% male). Participants were only recruited from Phoenix, AZ, so these results are not generalizable to other geographical areas. While participants with a wide range of ages (18–75 years) were recruited, 93.5% of the sample was <40 years (median age of 26 years). As mentioned previously, participants’ residential tap water quality was not tested. Accordingly, it is possible that some perceptions of mistrust in tap water safety are valid. The Adapted Survey of Water Issues in Arizona did not include bottled water marketing or advertising as a source of information about water. Future investigations should evaluate these sources of information as potential predictors of tap water perceptions. Finally, there is unmeasured error associated with all forms of public opinion research. As is commonly the case with self-reported data, we were not able to verify the accuracy of responses. Specifically, we could not verify whether individuals were Latinx or residents of the greater Phoenix, AZ area.

Overall, Latinx mistrust in tap water safety is very prevalent in Phoenix, AZ, and appears to be related to organoleptic perceptions of home tap water and reliance on alternatives to their home drinking water system, such as purchasing bottled water and ≥1-gallon containers for drinking water. The majority of this sample perceives local sources of water positively and appears to trust their government to regulate municipal water. Accordingly, public policy and/or interventions differentiating quality and sensory characteristics (e.g., taste and smell) from safety seem warranted. Onetime or regular volunteer activities related to water may be effective means for reaching this population.

Financial support for the conduct of the research was provided by the Arizona State University Graduate College and the Arizona State University Graduate and Professional Student Association. A.W.’s writing time was funded under NSF GCR-2021147. These funding sources had no involvement in the study design, in the collection, analysis, and interpretation of data, in the writing of the report, or in the decision to submit the article for publication.

All relevant data are included in the paper or its Supplementary Information.

S.A.K. is a scientific consultant for Hyduro Inc. and has served as a scientific consultant for Danone Research. He also has active grants with Danone Research and Standard Process.