The interactive effects of the seawater intrusion-affected zones and types of waterways on the surface water quality from the coastal Tien Giang Province, Vietnam.

Although inland surface water bodies have been studied intensively, few studies have looked at the interactive effects of seawater intrusion and waterway types on the water quality. The current study aimed to (1) assess the inland water quality as affected by waterway types and seawater intrusion-affected zones, (2) examine the longitudinal dynamics of the water quality, and (3) quantify the contributive percentage of pollution sources in the coastal Tien Giang Province, Vietnam. A total of 680 surface-water samples were taken from 34 sites distributed over the Tien River and its tributary canals from 2015 to 2019. The water samples were analyzed for 16 physical, chemical, and biological parameters, which were used for water quality index (WQI) estimation and subjected to two-way ANOVA and principal component analysis/factor analysis (PCA/FA). The WQI in both waterway types tended to get better from the downstream to the upstream zone with an improving rate of WQI faster in the River (from 79 to 88) than in the canals (from 82 to 85). The PCA/FA showed that water from the two waterway types could be polluted by six main pollution sources, one of which was derived from the seawater intrusion, one from aquaculture, and the others from agricultural, residential, and industrial activities. In brief, the inland surface water quality of a coastal area was interactively influenced by spatial distance and waterway types, transferring various pollutants in and out of the inland area.

Early Childhood Caries, Mouth Pain, and Nutritional Threats in Vietnam.

OBJECTIVES: We investigated the relationships among early childhood caries (ECC), mouth pain, and nutritional status in children aged 1 to 6 years in Southern and Central Vietnam. METHODS: A total of 593 parent-child pairs were recruited from 5 kindergartens or preschools in Ho-Chi Minh City and Da Nang. Parents completed surveys about dietary habits, oral health practices, and children's mouth pain experience; children received anthropometric assessment and dental examinations. RESULTS: There was a high prevalence of dental caries (74.4%), mostly untreated, and mouth pain (47.1%). Moderate correlations were found between parents' and children's consumption of soda (ρ = 0.361; P < .001) and salty snacks (ρ = 0.292; P < .001). Severity of ECC was associated with decreased weight- and body mass index-for-age z-scores. Presence of pulp-involved caries was associated with strikingly lower height-for-age (mean difference = 0.66; P = .001), weight-for-age (mean difference = 1.17; P < .001), and body mass index-for-age (mean difference = 1.18; P < .001) z-scores. Mouth pain was associated with lower body mass index-for-age z-scores (mean difference = 0.29; P = .013). CONCLUSIONS: ECC might negatively affect children's nutritional status, which might be mediated by the depth of decay, chronic inflammation, and mouth pain. Family-based and prevention-oriented nutrition and oral health programs are needed and should start during pregnancy and infancy.