Dietary Predictors of Urinary Biomarkers of Pyrethroids in the General Population - A Scoping Review.

BACKGROUND: Pyrethroid pesticides are ubiquitous environmental contaminants, contributing to chronic and potentially harmful exposure among the general population. Although studies have measured pesticide residues on agricultural products, the link between food intake and concentrations of pyrethroid biomarkers in urine remains unclear. OBJECTIVE: This scoping review aims to analyze peer-reviewed publications investigating dietary predictors of pyrethroid exposure through urinary biomarkers. We assess existing evidence, identify research gaps, and highlight current limitations. METHODS: We conducted a comprehensive search using PubMed and Google Scholar. Eligible studies examined associations between diets, food items or dietary components, and measured urinary pyrethroid biomarkers. No geographical restriction was applied to our search. Results were summarized in themes referring to study characteristics, relevant outcomes, biomarker measurement, dietary assessment and statistical analyses. RESULTS: We identified 20 relevant articles. Most studies presented evidence on associations between the consumption of organic diets or food items and reduced concentrations of 3-phenobenzoic acid metabolites in urine. There was less evidence for diet affecting other pyrethroid-specific biomarkers. Dietary assessment methodologies and recall periods varied, as did the number and timing of urine collections. Many studies did not control for potential alternative pyrethroid sources, exposure to other pesticides, or demographic and socioeconomic characteristics. CONCLUSION: Researchers should consider standardized dietary assessment, chemical analyses of foods consumed, adequate recall time, and food preparation methods. Consistency in biomarker measurement, including urine collection time and corrections for specific gravity or creatinine, is needed. Ensuring the validity of such studies also requires larger samples and appropriate control for confounders.

Heavy Metal Remediation by Dry Mycelium Membranes: Approaches to Sustainable Lead Remediation in Water.

Lead contamination poses significant and lasting health risks, particularly in children. This study explores the efficacy of dried mycelium membranes, distinct from live fungal biomass, for the remediation of lead (Pb(II)) in water. Dried mycelium offers unique advantages, including environmental resilience, ease of handling, biodegradability, and mechanical reliability. The study explores Pb(II) removal mechanisms through sorption and mineralization by dried mycelium hyphae in aqueous solutions. The sorption isotherm studies reveal a high Pb(II) removal efficiency, exceeding 95% for concentrations below 1000 ppm and ∼63% above 1500 ppm, primarily driven by electrostatic interactions. The measured infrared peak shifts and the pseudo-second-order kinetics for sorption suggests a correlation between sorption capacity and the density of interacting functional groups. The study also explores novel surface functionalization of the mycelium network with phosphate to enhance Pb(II) removal, which enables remediation efficiencies >95% for concentrations above 1500 ppm. Scanning electron microscopy images show a pH-dependent formation of Pb-based crystals uniformly deposited throughout the entire mycelium network. Continuous cross-flow filtration tests employing a dried mycelium membrane demonstrate its efficacy as a microporous membrane for Pb(II) removal, reaching remediation efficiency of 85-90% at the highest Pb(II) concentrations. These findings suggest that dried mycelium membranes can be a viable alternative to synthetic membranes in heavy metal remediation, with potential environmental and water treatment applications.

Blood lead levels and math learning in first year of school: An association for concern.

Lead is a well-known neurotoxicant that continues to affect children's cognition and behavior. With the aim to examine the associations of lead exposure with math performance in children at the beginning of formal schooling, we conducted a cross-sectional study of first-grade students from 11 schools in Montevideo, Uruguay. Math abilities were assessed with tests from the Batería III Woodcock-Muñoz (Calculation, Math Facts Fluency, Applied Problems, Math Calculation Skills and Broad Maths). Separate generalized linear models (GLM) tested the association of blood lead level (BLL) and each math ability, adjusting for key covariates including age and sex, maternal education, household assets and Home Observation for Measurement of the Environment Inventory score. In a complete-case of 252 first-grade students (age 67-105 months, 45% girls), mean ± SD blood lead level was 4.0 ± 2.2 µg/dL. Covariate-adjusted logistic models were used to examine the association between childhood BLLs and the odds of low math performance. BLL was negatively associated with scores on the Calculation test (ß (95% CI): -0.18 (-0.33, -0.03)), Math Calculation Skills (-1.26 (-2.26, -0.25)), and Broad Maths cluster scores (-0.88 (-1.55, -0.21)). Similarly, performance on the Calculation test, as well as cluster scores for Broad Maths and Math Calculation Skills differed between children with BLLs <5 and ≥ 5 µg/dL (p < 0.01), being lower in children with higher BLLs. Finally, considering the likelihood of low test performance, each 1 µg/dL higher B-Pb was related to 27% higher likelihood for Maths Facts Fluency, 30% for Broad Math and Math Calculation Skills, and 31% for Calculation (p < 0.05). These results suggest that lead exposure is negatively associated with several basic skills that are key to math learning. These findings further suggest that the cognitive deficits related to lead exposure impact student achievement at very early stages of formal education.

Companion animals and child development outcomes: longitudinal and cross-sectional analysis of a UK birth cohort study.

BACKGROUND: Research into the impact of social relationships on childhood and adolescent health and wellbeing has been largely limited to children's relationships with other humans, while studies into the impact of pet ownership are sparse and have generally not adjusted for potential confounders. This study aimed to investigate the association between pet ownership and a range of developmental outcomes in childhood and adolescence. METHODS: Data were self-reports and direct assessments of approx. 14,000 children from the Avon Longitudinal Study of Parents and Children (ALSPAC). Multivariable regression models adjusting for confounding factors examined associations between developmental outcome measures (emotional health, behavioural development, cognitive development, language development, educational attainment) and concurrent pet ownership, including species, and also longitudinal pet ownership history and pet-interaction where possible. Analyses model numbers using multiple imputation varied from n = 393-8963. RESULTS: In cross-sectional analyses, owning a dog (b = 0.24, [0.06-0.41], p = .004) and owning other/miscellaneous pets (b = 0.18, [0.03-0.33], p = .021) at age 3 were associated with higher prosocial behaviour score. Owning a pet was associated with a higher non-verbal communication score at age 2 (cross-sectional, b = 0.18, [0.04-0.32], p = .014), and a higher language development score at age 5 (cross-sectional, b = 1.01, [0.18-1.83], p = .017). However, pet ownership was associated with lower educational attainment across a number of academic subjects and timepoints, in both cross-sectional and longitudinal analyses. It was also cross-sectionally linked to hyperactivity at age 3 and conduct problems at age 3 and 11. Furthermore, at age 8, cross-sectional analysis showed that children who owned any pets (OR [95% CI]: 0.85 [0.73-0.98], p= ·026) or cats (0.83, [0.73-0.95], p= ·006) had lower odds of high self-esteem (scholastic competence). CONCLUSIONS: Using a large, well-designed longitudinal study and adjusting for key confounders, we found little evidence of cross-sectional or longitudinal associations between pet ownership and emotional health or cognitive outcomes in children. There may, however, be some cross-sectional and longitudinal association with poorer educational attainment and a positive impact on social interactions as seen through associations with enhanced language development and prosocial behaviour. This study demonstrates the importance of adjustment for confounding variables and suggests that, contrary to popular belief, positive impacts of pet ownership on childhood development may be mainly limited to social behaviour and language development.

Dietary patterns and cognitive achievement among school children in socio-cultural context, a case of Montevideo, Uruguay.

PURPOSE: The benefits of a healthy diet on children´s cognition have been described in several studies. However, many previous studies have analyzed the effect on general cognitive domains (e.g. intelligence), used measures based almost exclusively on local examinations, and rarely consider social context. OBJECTIVE: The objective of the present study was to examine the relationship between two diet patterns and contextualized cognitive performance measures of children aged 6-8 years from low-average income neighborhoods in Montevideo, Uruguay. METHODS: 270 first-grade children with complete data participated in the study. Consumption of foods was determined via two averaged 24-h dietary recalls with the mother. Two dietary patterns were identified via principal component analysis: "processed (high calorie) foods" and "nutrient dense". Children´s cognitive performance, including general cognitive abilities, achievement in mathematics and reading, and discrepancy scores between predicted and actual achievement was assessed with the Woodcock-Muñoz Cognitive and Achievement scales. The association of dietary patterns and cognitive endpoints was analyzed in multilevel models, clustered by children´s school. Sociodemographic and biological variables were used as covariates. RESULTS: The nutrient dense foods pattern, characterized by higher consumption of dark leafy and red-orange vegetables, eggs, beans & peas, potatoes, was associated with better performance in reading, with beta coefficient 3.28 (95% CI 0.02, 6.54). There was also an association between the nutrient dense foods factor and the Discrepancy in reading, 2.52 (0.17, 4.87). Processed (high calorie) foods pattern, characterized by higher consumption of breads, processed meats, fats and oils, sweetened beverages, and sweetened yogurt/dairy products; reduced intake of milk, pastries and pizza dinners was not associated with cognitive performance. CONCLUSIONS: Nutrient dense food pattern was positively associated with children's reading achievement. A nutrient-rich diet may benefit written language acquisition at the beginning of schooling.

Associations of an industry-relevant metal mixture with verbal learning and memory in Italian adolescents: The modifying role of iron status.

BACKGROUND: Biomarker concentrations of metals are associated with neurodevelopment, and these associations may be modified by nutritional status (e.g., iron deficiency). No prior study on associations of metal mixtures with neurodevelopment has assessed effect modification by iron status. OBJECTIVES: We aimed to quantify associations of an industry-relevant metal mixture with verbal learning and memory among adolescents, and to investigate the modifying role of iron status on those associations. METHODS: We used cross-sectional data from 383 Italian adolescents (10-14 years) living in proximity to ferroalloy industry. Verbal learning and memory was assessed using the California Verbal Learning Test for Children (CVLT-C), and metals were quantified in hair (manganese, copper, chromium) or blood (lead) using inductively coupled plasma mass spectrometry. Serum ferritin, a proxy for iron status, was measured using immunoassays. Covariate-adjusted associations of the metal mixture with CVLT subtests were estimated using Bayesian Kernel Machine Regression, and modification of the mixture associations by ferritin was examined. RESULTS: Compared to the 50th percentile of the metal mixture, the 90th percentile was associated with a 0.12 standard deviation [SD] (95% CI = -0.27, 0.50), 0.16 SD (95% CI = -0.11, 0.44), and 0.11 SD (95% CI = -0.20, 0.43) increase in the number of words recalled for trial 5, long delay free, and long delay cued recall, respectively. For an increase from its 25th to 75th percentiles, copper was beneficially associated the recall trials when other metals were fixed at their 50th percentiles (for example, trial 5 recall: ß = 0.31, 95% CI = 0.14, 0.48). The association between copper and trial 5 recall was stronger at the 75th percentile of ferritin, compared to the 25th or 50th percentiles. CONCLUSIONS: In this metal mixture, copper was beneficially associated with neurodevelopment, which was more apparent at higher ferritin concentrations. These findings suggest that metal associations with neurodevelopment may depend on iron status, which has important public health implications.

Neighborhood disadvantage and adolescent behavior problems: how do inferences differ across definitions of disadvantage?

BACKGROUND: Various definitions of neighborhood disadvantage (ND) exist, yet evidence is lacking on how ND operationalization may impact scientific inference. METHODS: We used data from wave 6 of the Fragile Families study, excluding those without census tract or behavior problem data (n = 2363). Outcomes included five scales from the caregiver-reported Child Behavior Checklist (CBCL) and a self-reported delinquency scale. ND was defined in four ways: (1) a modified Sampson definition which included four neighborhood poverty variables; (2) a poverty-only definition which only included percent households below poverty; (3) an overextended definition which added a mediator between the ND-behavior relationship, and (4) an expanded definition which added six additional ND variables to the modified Sampson definition. Using effect estimates from generalized linear models, differences were calculated using percent change-in-estimate, with the modified Sampson as the referent. RESULTS: Effect estimates were similar for the modified Sampson and expanded definitions (< 5% difference). The poverty-only definition differed from the modified Sampson unsystematically. Estimates for the overextended definition were consistently larger compared to modified Sampson (10-37% greater). The expanded and modified Sampson definitions produced similar results. CONCLUSION: Poverty-only and overextended ND definitions should be interpreted with caution.

Dietary Exposure to Toxic Elements and the Health of Young Children: Methodological Considerations and Data Needs.

Concerns have been raised regarding toxic-element (arsenic, cadmium, lead, and mercury) contamination of commercially available infant foods around the world. Young children are vulnerable to the effects of toxic elements, based on higher absorption levels and potentially poorer detoxification capacities. Toxic-element exposures in early life exact high societal costs, but it is unclear how much dietary exposure to these elements contributes to adverse health outcomes. Well-designed epidemiological studies conducted in different geographical and socioeconomic contexts need to estimate dietary toxicant exposure in young children and to determine whether causal links exist between toxicants in children's diets and health outcomes. This commentary outlines the methodological considerations and data needs to advance such research.

Optimized workflow for unknown screening using gas chromatography high-resolution mass spectrometry expands identification of contaminants in silicone personal passive samplers.

RATIONALE: Silicone wristbands have emerged as valuable passive samplers for monitoring of personal exposure to environmental contaminants in the rapidly developing field of exposomics. Once deployed, silicone wristbands collect and hold a wealth of chemical information that can be interrogated using high-resolution mass spectrometry (HRMS) to provide a broad coverage of chemical mixtures. METHODS: Gas chromatography coupled to Orbitrap™ mass spectrometry (GC/Orbitrap™ MS) was used to simultaneously perform suspect screening (using in-house database) and unknown screening (using vendor databases) of extracts from wristbands worn by volunteers. The goal of this study was to optimize a workflow that allows detection of low levels of priority pollutants, with high reliability. In this regard, a data processing workflow for GC/Orbitrap™ MS was developed using a mixture of 123 environmentally relevant standards consisting of pesticides, flame retardants, organophosphate esters, and polycyclic aromatic hydrocarbons as test compounds. RESULTS: The optimized unknown screening workflow using a search index threshold of 750 resulted in positive identification of 70 analytes in validation samples, and a reduction in the number of false positives by over 50%. An average of 26 compounds with high confidence identification, 7 level 1 compounds and 19 level 2 compounds, were observed in worn wristbands. The data were further analyzed via suspect screening and retrospective suspect screening to identify an additional 36 compounds. CONCLUSIONS: This study provides three important findings: (1) a clear evidence of the importance of sample cleanup in addressing complex sample matrices for unknown analysis, (2) a valuable workflow for the identification of unknown contaminants in silicone wristband samplers using electron ionization HRMS data, and (3) a novel application of GC/Orbitrap™ MS for the unknown analysis of organic contaminants that can be used in exposomics studies.

Low-level exposure to lead, mercury, arsenic, and cadmium, and blood pressure among 8-17-year-old participants of the 2009-2016 National Health and Nutrition Examination Survey.

BACKGROUND: Dysregulation of systolic, diastolic blood pressure (SBP, DBP), and pulse pressure (PP) in children may predict elevated blood pressure (BP) in adulthood. Toxicant exposure is widely studied as a risk factor for high BP in adults, but not in children. We assessed the joint associations between lead (Pb), mercury (Hg), arsenic (As), and cadmium (Cd) exposure and SBP, DBP, and PP among 8-17 year-old participants (n = 1642) of the 2009-2016 National Health and Nutrition Examination Survey (NHANES). METHODS: Participants with at least two BP measures were included. Urinary As and Cd were adjusted for urinary creatinine concentrations. Blood Pb, Hg, and urinary As, Cd were natural log-transformed. Bayesian Kernel Machine Regression (BKMR) analyses were conducted to assess the associations between the toxicant mixture and BP measures. Multivariable regression models assessed the associations between individual toxicants, and the four toxicants simultaneously with each of the outcomes. Interactions with sodium intake were tested. RESULTS: Exposure to all toxicants was low, with median (5%, 95%) level: Pb, 0.57 (0.26, 1.60) µg/dL; Hg, 0.37 (0.19, 2.12) µg/L; As, 5.61 (1.37, 33.2) µg/g creatinine, Cd, 0.06 (0.03, 0.23) µg/g creatinine. Toxicant mixture showed a statistically significant, inverse association with DBP, but not other BP measures. Linear regressions revealed no association between toxicants, individually or together, and BP measures. No evidence of interaction of sodium intake with any of the toxicants was observed. CONCLUSIONS: In a nationally representative sample of 8-17 year-olds, we found suggestive inverse association of the mixture of low-level Pb, Hg, As, and Cd, with DBP. Longitudinal studies with multiple toxicants are needed to understand the interactive effects of toxicants on children's BP.

COVID-19 and children's health in the United States: Consideration of physical and social environments during the pandemic.

Public health measures necessary to counteract the coronavirus disease 2019 (COVID-19) pandemic have resulted in dramatic changes in the physical and social environments within which children grow and develop. As our understanding of the pathways for viral exposure and associated health outcomes in children evolves, it is critical to consider how changes in the social, cultural, economic, and physical environments resulting from the pandemic could affect the development of children. This review article considers the environments and settings that create the backdrop for children's health in the United States during the COVID-19 pandemic, including current threats to child development that stem from: A) change in exposures to environmental contaminants such as heavy metals, pesticides, disinfectants, air pollution and the built environment; B) changes in food environments resulting from adverse economic repercussion of the pandemic and limited reach of existing safety nets; C) limited access to children's educational and developmental resources; D) changes in the social environments at the individual and household levels, and their interplay with family stressors and mental health; E) social injustice and racism. The environmental changes due to COVID-19 are overlaid onto existing environmental and social disparities. This results in disproportionate effects among children in low-income settings and among populations experiencing the effects of structural racism. This article draws attention to many environments that should be considered in current and future policy responses to protect children's health amid pandemics.

Lead exposure and indices of height and weight in Uruguayan urban school children, considering co-exposure to cadmium and arsenic, sex, iron status and dairy intake.

Child growth depends on complex factors including diet, nutritional status, socioeconomic, and sanitary conditions, and exposure to environmental chemicals. Lead exposure is known to impair growth in young children but effects in school-age children are less clear. The effects of co-exposure to low-level lead and other toxic metals on child growth are not well understood. We examined cross-sectional associations of blood lead (BLL) with growth indices (Z scores of body mass index for age, BAZ, and height for age, HAZ) in Uruguayan urban school children (n = 259; ~7 y). Potential differences in these associations in children with lower vs. higher urinary inorganic arsenic metabolites (U-As), urinary cadmium (U-Cd), sex (42% girls), iron deficiency (ID, 39% children), or intake of dairy foods below recommended levels were examined. BLL was measured using AAS, U-As using HPLC-HGICP-MS, and U-Cd using ICP-MS. Dietary information was obtained by two 24-h recalls completed by caregivers. Children's linear growth was within age and sex-appropriate reference values. Overweight (BAZ > 1 2 SD) was found in 20.1%, and obesity (BAZ > 2 SD) in 18.5%, of children. Ranges (5th, 95th percentile) of biomarker concentrations were: BLL, 0.8-7.8 µg/dL; U-Cd, 0.01-0.2 µg/L, and U-As, 4.0-27.3 µg/L. BLL was inversely associated with HAZ ([95% CI]: 0.10 [-0.17, -0.03]) in covariate-adjusted models. Although this association was slightly more pronounced in girls, children without ID, and children with lower U-As, there was little evidence of effect modification due to overlapping CIs in stratified models. BLLs were not associated with BAZ, except for a suggestion of a negative relationship in girls (-0.10 [-0.23, 0.02]) but not boys [0.001 [-0.11, 0.12]). Our findings indicate that exposure to low levels of lead was associated with lower HAZ in apparently normally growing urban school children. Larger future studies should help elucidate if these associations persist over time and across populations.

Vitamin B-6 Intake Is Modestly Associated with Arsenic Methylation in Uruguayan Children with Low-Level Arsenic Exposure.

BACKGROUND: Detoxification of inorganic arsenic (iAs) occurs when it methylates to form monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA). Lower proportions of urinary iAs and MMA, and higher proportions of DMA indicate efficient methylation. The role of B-vitamins in iAs methylation in children with low-level arsenic exposure is understudied. OBJECTIVES: Our study objective was to assess the association between B-vitamin intake and iAs methylation in children with low-level arsenic exposure (<50 µg/L in water; urinary arsenic 5-50 µg/L). METHODS: We conducted a cross-sectional study in 290 ∼7-y-old children in Montevideo. Intake of thiamin, riboflavin, niacin, vitamin B-6, and vitamin B-12 was calculated by averaging 2 nonconsecutive 24-h recalls. Total urinary arsenic concentration was measured as the sum of urinary iAs, MMA, and DMA, and adjusted for urinary specific gravity; iAs methylation was measured as urinary percentage As, percentage MMA, and percentage DMA. Arsenic concentrations from household water sources were assessed. Linear regressions tested the relationships between individual energy-adjusted B-vitamins and iAs methylation. RESULTS: Median (range) arsenic concentrations in urine and water were 9.9 (2.2-48.7) and 0.45 (0.1-18.9) µg/L, respectively. The median (range) of urinary percentage iAs, percentage MMA, and percentage DMA was 10.6% (0.0-33.8), 9.7% (2.6-24.8), and 79.1% (58.5-95.4), respectively. The median (range) intake levels of thiamin, riboflavin, niacin, and vitamin B-6 were 0.81 (0.19-2.56), 1.0 (0.30-2.24), 8.6 (3.5-23.3), and 0.67 (0.25-1.73) mg/1000 kcal, respectively, whereas those of folate and vitamin B-12 were 216 (75-466) and 1.7 (0.34-8.3) µg/1000 kcal, respectively. Vitamin B-6 intake was inversely associated with urinary percentage MMA (ß = -1.60; 95% CI: -3.07, -0.15). No other statistically significant associations were observed. CONCLUSIONS: Although vitamin B-6 intake was inversely associated with urinary percentage MMA, our findings suggest limited support for a relation between B-vitamin intake and iAs methylation in children exposed to low-level arsenic.

Associations of dietary intakes and serum levels of folate and vitamin B-12 with methylation of inorganic arsenic in Uruguayan children: Comparison of findings and implications for future research.

BACKGROUND: In the human body, inorganic arsenic (iAs) is methylated via the one-carbon cycle to form monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA). Lower proportions of iAs and MMA, and higher proportions of DMA in urine indicate efficient methylation; formation of DMA is thought to detoxify iAs and MMA. Studies on folate, vitamin B-12 and iAs methylation yield mixed findings, depending on whether folate and vitamin B-12 were assessed from diet, supplements, or using a blood biomarker. OBJECTIVE: First, to compare the associations of serum concentrations and estimated intake of folate and vitamin B-12 with indicators of iAs methylation. Second, to highlight the implications of these different B-vitamin assessment techniques on the emerging evidence of the impact of dietary modifications on iAs methylation. METHODS: The study was conducted among ~7-year-old children from Montevideo, Uruguay. Serum folate and vitamin B-12 levels were measured on the Horiba ABX Pentra 400 analyzer; urinary arsenic was measured using High-Performance Liquid Chromatography on-line with Inductively Coupled Plasma Mass Spectrometry. Dietary intakes were assessed using the average of two 24-h dietary recalls. Linear regressions assessed the associations of serum levels, and dietary intakes of folate (n = 237) and vitamin B-12 (n = 217) with indicators of iAs methylation. Models were adjusted for age, sex, body mass index, total urinary arsenic, and rice intake. RESULTS: Serum folate and vitamin B-12 levels were above the adequacy threshold for 99% of the participants. No associations were observed between serum folate, serum vitamin B-12, or vitamin B-12 intake and iAs methylation. Folate intake was inversely associated with urinary %MMA [ß (95% confidence interval): -1.04 (-1.89, -0.18)]. CONCLUSION: Additional studies on the role of B-vitamins in iAs methylation are needed to develop a deeper understanding of the implications of assessing folate and vitamin B-12 intake compared to the use of biomarkers. Where possible, both methods should be employed because they reflect different exposure windows and inherent measurement error, and if used individually, will likely continue to contribute to lack of consensus.

Specific domains of early parenting, their heritability and differential association with adolescent behavioural and emotional disorders and academic achievement.

Variations in parenting across large populations have rarely been described. It also remains unclear which specific domains of parenting are important for which specific offspring developmental outcomes. This study describes different domains of early parenting behaviours and their genetic heritability, then determines the extent to which specific domains of parenting are associated with later offspring outcomes. Parenting behaviours (birth to 3 years) were extracted from self-reported questionnaires administered to 12,358 mothers from the UK-based birth cohort study, the Avon Longitudinal Study of Parents and Children and modelled as a latent factor using Confirmatory Factor Analysis. Genetic heritability and correlations between parenting factors were estimated using genome-wide complex trait analysis. Three parenting factors were derived: parental enjoyment, conflictual relationships and stimulation; all showed low genetic heritability. There was no evidence of association between parental enjoyment and offspring behavioural disorders and depressed mood. Stimulation was associated with better English grades (standardised ß = 0.195, p < 0.001) and enjoyment was negatively associated with English grades (ß = - 0.244, p = < 0.001). Conflictual relationships were associated with higher risk of offspring behavioural disorders (ß = 0.228, p = 0.010) and depressed mood (ß = 0.077, p = 0.005). Higher enjoyment reduced the association between conflict and behavioural problems (interaction term ß = 0.113, p < 0.001). We found evidence for predictive specificity of early parenting domains for offspring outcomes in adolescence. Early stimulation, unlike enjoyment, promoted later educational achievement. Conflictual relationships were associated with greater risk of behavioural problems, buffered by increased enjoyment. These findings hold implications for parenting interventions, guiding their focus according to the specificity of parenting domains and their long-term outcomes in children.

Dietary Patterns Are Not Consistently Associated with Variability in Blood Lead Concentrations in Pregnant British Women.

BACKGROUND: During pregnancy lead crosses the placenta freely and can have adverse effects on the fetus, with the potential for lifelong impact on the child. Identification of dietary patterns and food groups in relation to measures of lead status could provide a more useful alternative to nutrient-specific advice to minimize fetal lead exposure. OBJECTIVES: The aim of this study was to evaluate whether dietary patterns and food groups are associated with blood lead concentration (B-Pb) in pregnancy. DESIGN: Whole blood samples were collected at a median of 11 wk gestation (IQR 9-13 wk) from women enrolled in the Avon Longitudinal Study of Parents and Children birth cohort study, and analyzed for lead. Dietary pattern scores were derived from principal components analysis of a food-frequency questionnaire (32 wk gestation). Associations of dietary pattern scores (quartiles), and of food groups (frequency of consumption), with the likelihood of B-Pb ≥5 µg/dL identified with adjusted logistic regression (n = 2167 complete cases). RESULTS: There was a negative association between the "confectionery" dietary pattern and the likelihood of B-Pb ≥5 µg/dL (OR: 0.62; 95% CI: 0.41, 0.94) in an adjusted model. There were no associations with other dietary patterns. There was a positive association between the food group "all leafy green and green vegetables" and the likelihood of B-Pb ≥5 µg/dL (OR 1.45; 95% CI: 1.04, 2.01). Conversely, the food group "cakes and biscuits" was negatively associated (OR 0.63; 95% CI: 0.43, 0.93). After multiple imputation, there was a positive association of the "healthy" diet pattern and no association of the "confectionery" pattern. CONCLUSIONS: We found limited evidence of an association between women's typical diet and B-Pb during pregnancy. Our findings do not indicate need to revise dietary guidance for pregnant women, who are advised to adopt a healthy diet in pregnancy, with a variety of foods consumed in moderation.

Effects of ALAD genotype on the relationship between lead exposure and anthropometry in a Cohort of Mexican children.

OBJECTIVES: Lead exposure is associated with children's growth, but this relationship may depend on the presence of susceptibility factors, including genetic variation. Blood lead levels (BLL) differ by ALAD (aminolevulinic acid dehydratase) genotype. We investigated the association between BLL and growth in Mexican first-graders with different ALAD genotypes. METHODS: Children between the ages of 6-8 years (n = 602) attending first grade in schools within the vicinity of a metal foundry in Torreón, Mexico were enrolled into a randomized controlled trial (RCT) testing the efficacy of iron and/or zinc supplementation on blood lead levels (BLL) and cognition. BLL and anthropometry were assessed at baseline (height, height-for-age z-score (HAZ), knee height, head circumference), after 6 (head circumference) and 12 months (height, HAZ, knee height). Children with ALAD1-1 and ALAD1-2/2-2 were compared. The study sample included 538 and 470 participants who had complete data at baseline and follow-up, respectively. Separate multivariable linear regression models adjusted for covariates were used to test the association between BLL at baseline and each anthropometric measure. Covariates included age, sex, hemoglobin, crowding, and maternal education. BLL x ALAD genotype interaction term was tested. RESULTS: Median BLL (10.1 µg/dL) did not differ by ALAD genotype. After covariate adjustment, baseline BLL was inversely associated with baseline height, HAZ, and knee height. The association (ß [95% CI]) between BLL and baseline height (-0.38[-0.68, -0.09]), HAZ (-0.07[-0.12, -0.02]) and knee height (-0.14[-0.25, -0.02]), was somewhat stronger in children with ALAD1-2/2-2 than ALAD1-1 (-0.09[-0.16, -0.02], -0.02[-0.03, -0.004] and -0.04[-0.06, -0.01], respectively). No associations between BLL and growth at 6 or 12 months were detected irrespective of ALAD genotype. CONCLUSIONS: BLL was adversely associated with anthropometric measures among Mexican children. ALAD genotype may be a susceptibility factor for the effects of lead on child growth.

Socio-demographic factors associated with pet ownership amongst adolescents from a UK birth cohort.

BACKGROUND: In developed nations, pet ownership is common within families. Both physical and psychological health benefits may result from owning a pet during childhood and adolescence. However, it is difficult to determine whether these benefits are due to pet ownership directly or to factors linked to both pet ownership and health. Previous research found associations between a range of socio-demographic factors and pet ownership in seven-year-old children from a UK cohort. The current study extends this research to adolescence, considering that these factors may be important to consider in future Human-Animal Interaction (HAI) research across childhood. RESULTS: The Avon Longitudinal Study of Parents and Children (ALSPAC) collected pet ownership data prospectively via maternal reports from gestation up to age 10 years old and via self-report retrospectively at age 18 for ages 11 (n = 3063) to 18 years old (n = 3098) on cats, dogs, rabbits, rodents, birds, fish, tortoise/turtles and horses. The dataset also contains a wide range of potential confounders, including demographic and socio-economic variables. The ownership of all pet types peaked at age 11 (80%) and then decreased during adolescence, with the exclusion of cats which remained constant (around 30%), and dogs which increased through 11-18 years (26-37%). Logistic regression was used to build multivariable models for ownership of each pet type at age 13 years, and the factors identified in these models were compared to previously published data for 7 year-olds in the same cohort. There was some consistency with predictors reported at age 7. Generally sex, birth order, maternal age, maternal education, number of people in the household, house type, and concurrent ownership of other pets were associated with pet ownership at both 7 and 13 years (the direction of association varied according to pet type). Factors that were no longer associated with adolescent pet ownership included child ethnicity, paternal education, and parental social class. CONCLUSIONS: A number of socio-demographic factors are associated with pet ownership in childhood and adolescence and they differ according to the type of pet, and age of child. These factors are potential confounders that must be considered in future HAI studies.

Effect of an equipment-behavior change intervention on handwashing behavior among primary school children in Kenya: the Povu Poa school pilot study.

BACKGROUND: Handwashing prevalence in schools in Kenya is low due to lack of access to water and soap and lack of drive for handwashing. Soapy water made from detergent powder is an inexpensive alternative to bar soap and disgust and social norms change can be powerful drivers of handwashing, but their effectiveness has not been assessed in school setting. In Kenyan public schools, we evaluated an equipment-behavior change intervention's effect on handwashing outcomes. We also monitored functionality of the Povu Poa prototypes to identify design improvements necessary for continued high usage in institutional settings. METHODS: The intervention included the "Povu Poa", a new type of handwashing station that dispensed foaming soap and rinse water, combined with school-wide behavior change promotion based on disgust and social norms. In this stepped-wedge cluster-randomized trial, we randomly selected 30 schools and divided them into 3 groups of 10. Following baseline data collection, we delivered the intervention sequentially (Group 1: 3-5 weeks after baseline; Group 2: 6-8 weeks; Group 3: 19-24 weeks). We observed outcomes [1] availability of handwashing materials at handwashing places, and; 2) observed handwashing behavior after toilet use among schoolchildren) at baseline and in three follow-up rounds. We compared the outcomes between schools that had received the intervention and schools that had not yet received the intervention. RESULTS: Water and soap/soapy water were available at 2% of school visits before intervention, and at 42% of school visits after intervention.. Before intervention, we observed handwashing with water after 11% of 461 toilet use events; no one was observed to wash hands with soap/soapy water. After intervention, we observed handwashing after 62% of 383 toilet use events (PR = 5.96, 95% CI = 3.02, 11.76) and handwashing with soap/soapy water after 26% of events (PR incalculable). Foaming soap dispenser caps were cracked in 31% of all observations, but were typically still functional. CONCLUSIONS: Our combined equipment-behavior intervention increased availability of handwashing materials and improved the compliance with handwashing after using the toilet, but handwashing with soap was still rare. Equipment durability must be improved for deployment in schools at scale. American Economic Association's Registry for Randomized Controlled Trials; Trial Registry Number (TRN): AEARCTR-0000662; Date of Registry: April 14, 2015.

Multiple-metal exposure, diet, and oxidative stress in Uruguayan school children.

Oxidative stress (OS) is an important consequence of exposure to toxic metals but it is unclear to what extent low-level metal exposures contribute to OS in children. We examined the cross-sectional association between urinary concentrations of arsenic (As), cadmium (Cd), and lead (Pb) and urinary markers of OS: F2-8α isoprostane and 8-hydroxy-2-deoxy-guanosine (8-OHdG). We also tested effect modification by dietary intakes. Of the 211 children aged 6-8 years living in Montevideo who were eligible for the study because they had at least one OS marker measured via ELISA, 143 were included in a complete-case analysis. Urinary metals were measured with inductively coupled plasma mass spectrometry (ICP-MS: Pb, Cd) and high-performance liquid chromatography online with hydride generation ICP-MS (As-metabolites); concentrations were log2-transformed. All urinary markers were adjusted for specific gravity of urine. Two 24-h dietary recalls were conducted to estimate children's dietary intakes, including total fruit and vegetable consumption and vitamin C, zinc and fiber intake. Ordinary least square (OLS) and weighted quantile sum (WQS) regressions were used to estimate the association between metals and each OS marker as outcome. Metal exposure was generally low: median urinary As, Cd, Pb 9.6 µg/L, 0.06 µg/L and 1.9 µg/L, respectively. Median 8-isoprostane concentration was 1.1 and 8-OHdG 39.6 ng/mL. Log2-transformed urinary As concentrations were positively associated with 8-OHdG concentrations (10.90 [3.82, 17.97]) in covariate-adjusted OLS models which also took account of exposure to Cd and Pb. In WQS, a mixture index was also associated with higher 8-OHdG (8.71 [1.12, 16.3] for each 25% increase in index value), mostly driven by As exposure. There was little evidence of effect modification by dietary antioxidants. In sum, even at low-level, As exposure is associated with detectable oxidative damage to the DNA.