Sources of and solutions to mistrust of tap water originating between treatment and the tap: Lessons from Los Angeles County

Urinary fluoride levels and metal co-exposures among pregnant women in Los Angeles, California

BACKGROUND

Fluoride is ubiquitous in the United States (US); however, data on biomarkers and patterns of fluoride exposure among US pregnant women are scarce. We examined specific gravity adjusted maternal urinary fluoride (MUFsg) in relation to sociodemographic variables and metal co-exposures among pregnant women in Los Angeles, California.

METHODS

Participants were from the Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) cohort. There were 293 and 490 women with MUFsg measured during first and third trimesters, respectively. An intra-class correlation coefficient examined consistency of MUFsg between trimesters. Kruskal-Wallis and Mann-Whitney U tests examined associations of MUFsg with sociodemographic variables. Covariate adjusted linear regression examined associations of MUFsg with blood metals and specific gravity adjusted urine metals among a subsample of participants within and between trimesters. A False Discovery Rate (FDR) correction accounted for multiple comparisons.

RESULTS

Median (IQR) MUFsg was 0.65 (0.5) mg/L and 0.8 (0.59) mg/L, during trimesters one and three respectively. During both trimesters, MUFsg was higher among older participants, those with higher income, and White, non-Hispanic participants than Hispanic participants. MUFsg was also higher for White, non-Hispanic participants than for Black, non-Hispanic participants in trimester three, and for those with graduate training in trimester one. MUFsg was negatively associated with blood mercury in trimester one and positively associated with blood lead in trimester three. MUFsg was positively associated with various urinary metals, including antimony, barium, cadmium, cobalt, copper, lead, nickel, tin, and zinc in trimesters one and/or three.

CONCLUSIONS

MUFsg levels observed were comparable to those found in pregnant women in Mexico and Canada that have been associated with poorer neurodevelopmental outcomes. Lower urinary fluoride levels among Hispanic and non-Hispanic Black participants in MADRES compared to non-Hispanic White participants may reflect lower tap water consumption or lower fluoride exposure from other sources. Additional research is needed to examine whether MUFsg levels observed among pregnant women in the US are associated with neurodevelopmental outcomes.

School Nutrition Environment and Services: Policies and Practices That Promote Healthy Eating Among K-12 Students

BACKGROUND

Changes to policies at the federal, state, and local levels over the last decade have influenced the school nutrition environment and services.

METHODS

This systematic review includes an analysis of individual research articles and government reports published from 2010 to 2021 that examine interventions to improve the school nutrition environment and services and increase the availability, selection, and consumption of healthier foods and beverages in K-12 schools in the United States.

RESULTS

Nutrition standards for school meals and food outside of meals improved access to healthier options in school. Providing school nutrition professionals with professional development, improving the palatability of school meals, offering taste tests, pre-slicing fruit, providing recess before lunch, offering incentives for trying healthier options, and providing access to drinking water resulted in increased selection and consumption of healthier items. There were inconclusive or mixed findings for some intervention strategies including adequate seat time for meals.

CONCLUSIONS

Despite demonstrated improvements to school meal programs and competitive foods, more work is needed to change the selection and consumption of healthier options among K-12 students. Schools can use multiple interventions to improve the school nutrition environment and services and help students adopt food and beverage choices that support health.

Management of biogenic taste and odour: From source water, through treatment processes and distribution systems, to consumers

Biogenic taste and odour (T&O) have become a global concern for water utilities, due to the increasing frequency of algal blooms and other microbial events arising from the combined effects of climate change and eutrophication. Microbially-produced T&O compounds impact source waters, drinking water treatment plants, and drinking water distribution systems. It is important to manage across the entire biogenic T&O pathway to identify key risk factors and devise strategies that will safeguard the quality of drinking water in a changing world, since the presence of T&O impacts consumer confidence in drinking water safety. This study provides a critical review of current knowledge on T&O-causing microbes and compounds for proactive management, including the identification of abiotic risk factors in source waters, a discussion on the effectiveness of existing T&O barriers in drinking water treatment plants, an analysis of risk factors for biofilm growth in water distribution systems, and an assessment of the impacts of T&O on consumers. The fate of biogenic T&O in drinking water systems is tracked from microbial production pathways, through the release of intracellular T&O by cell lysis, to the treatment of microbial cells and dissolved T&O. Based on current knowledge, five impactful research and management directions across the T&O pathway are recommended.

Health impacts of water and sanitation insecurity in the Global North: a scoping literature review for U.S. colonias on the Mexico border

U.S. border colonias are peri-urban settlements along the U.S.-Mexico border. Residents often face substandard housing, inadequate septic and sewer systems, and unsafe or inadequate household water. As of 2015, an estimated 30% of over 5 million U.S. colonia residents lacked access to clean drinking water, suggesting health complications. This scoping review identifies a very limited existing set of research on water and sanitation insecurity in U.S.-Mexico border colonias, and suggests value in additional focused research in this specific context to address health challenges. Preliminary health data indicates that due to water insecurity, colonia residents are more likely to contract gastrointestinal diseases, be exposed to carcinogenic compounds from contaminated water, and experience psychosocial distress. These widespread health issues in colonias are exacerbated by historical and ongoing socioenvironmental injustices in the U.S.-Mexico border region and their relation to the poor health outcomes.

Meeting the Water and Sanitation Challenges of Underbounded Communities in the U.S

Water and sanitation (wastewater) infrastructure in the United States is aging and deteriorating, with massive underinvestment over the past several decades. For many years, lack of attention to water and sanitation infrastructure has combined with racial segregation and discrimination to produce uneven access to water and wastewater services resulting in growing threats to human and environmental health. In many metropolitan areas in the U.S., those that often suffer disproportionately are residents of low-income, minority communities located in urban disadvantaged unincorporated areas on the margins of major cities. Through the process of underbounding (the selective expansion of city boundaries to exclude certain neighborhoods often based on racial demographics or economics), residents of these communities are disallowed municipal citizenship and live without piped water, sewage lines, and adequate drainage or flood control. This Perspective identifies the range of water and sanitation challenges faced by residents in these communities. We argue that future investment in water and sanitation should prioritize these communities and that interventions need to be culturally context sensitive. As such, approaches to address these problems must not only be technical but also social and give attention to the unique geographic and political setting of local infrastructures.

Associations between Household Water Fluoridation Status and Plain Tap or Bottled Water Consumption

INTRODUCTION

The benefits of community water fluoridation for preventing dental caries are attenuated if people do not consume tap water.

OBJECTIVES

We examined associations between household water fluoride content and consuming plain tap or bottled water among US youth.

METHODS

We used National Health and Nutrition Examination Survey data for 2013 to 2016 for 5,193 youth aged 2 to 19 y. Fluoride content in youth's household tap water samples was measured electrometrically with ion-specific electrodes and designated low (<0.6 mg/L) or about optimal (0.6 to 1.2 mg/L). Plain tap and bottled water consumption was obtained from one 24-h dietary recall. We used binomial regression models to estimate adjusted prevalence ratios (APRs) and 95% CIs for consuming plain tap water (including tap only or both tap and bottled) and consuming only bottled water as related to household water fluoride content (low or about optimal) and sociodemographic characteristics.

RESULTS

On a given day, 52.6% of youth consumed plain tap water (43.8% exclusively and 8.8% both tap and bottled) and 28%, only bottled water. Neither tap water (APR, 0.96; 95% CI, 0.84 to 1.10) nor only bottled water (APR, 1.03; 95% CI, 0.86 to 1.22) consumption was associated with household water fluoride content. Non-Hispanic Black youth and Hispanic youth were about 30% relatively less likely to consume tap water and 60% to 80% relatively more likely to consume only bottled water than non-Hispanic Whites. Low income, low parental education, and no past-year dental visit were associated with not consuming tap water.

CONCLUSION

Half of youth consumed plain tap water on a given day. Consuming plain tap water was not associated with community water fluoridation status. This study is the first to find that up to 50% of the population served by fluoridated water may not receive its full caries-preventive benefits due to not consuming plain tap water.

KNOWLEDGE TRANSFER STATEMENT

Half of US youth consumed plain tap water on a given day. Consuming plain tap water was not associated with community water fluoridation status. This finding suggests that up to 50% of the population served by fluoridated water systems may not receive its full caries-preventive benefits due to not consuming plain tap water. Our findings add support for the need to identify and address barriers to tap water consumption and promote health benefits of fluoridation.