Background: We previously reported associations between organochlorines and behaviors related to attention deficit hyperactivity disorder among boys and girls at 8 years of age using a teacher's ...rating scale for a birth cohort in New Bedford, Massachusetts (USA). Objectives: Our goal was to corroborate these findings using neuropsychological measures of inattentive and impulsive behaviors. Methods: We investigated the association between cord serum polychlorinated biphenyls (PCBs) and p,p'-dichlorodiphenyl dichloroethylene (p,p'-DDE) and attention and impulse control using a Continuous Performance Test (CPT) and components of the Wechsler Intelligence Scale for Children, 3rd edition (WISC-III). Participants came from a prospective cohort of children born during 1993–1998 to mothers residing near a PCB-contaminated harbor in New Bedford. Median (range) cord serum levels for the sum of four prevalent PCBs congeners 118, 138, 153, and 180 (ΣPCB₄) and p,p'-DDE were 0.19 (0.01–2.59) and 0.31 (0–14.93) ng/g serum, respectively. Results: We detected associations between PCBs and neuropsychological deficits for 578 and 584 children with CPT and WISC-III measures, respectively, but only among boys. For example, boys with higher exposure to ΣPCB₄ had a higher rate of CPT errors of omission rate ratio for the exposure interquartile range (IQR) = 1.12; 95% confidence interval (CI): 0.98, 1.27 and slower WISC-III Processing Speed (change in score for the IQR = –2.0; 95% CI: –3.5, –0.4). Weaker associations were found for p,p'-DDE. For girls, associations were in the opposite direction for the CPT and null for the WISC-III. Conclusions: These results support an association between organochlorines (mainly PCBs) and neuropsychological measures of attention among boys only. Sex-specific effects should be considered in studies of organochlorines and neurodevelopment.
Polybrominated diphenyl ethers (PBDEs), a major class of flame retardants, are ubiquitous environmental contaminants with particularly high concentrations in humans from the United States. This study ...is a first attempt to report and compare PBDE concentrations in blood drawn from a family. Serum samples from family members collected at two sampling occasions 90 days apart were analyzed for PBDE congeners. Concentrations of the lower-brominated PBDEs were similar at the two sampling times for each family member, with children's levels 2- to 5-fold higher than those of their parents. Concentrations of, for example, 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) varied from 32 ng/g lipid weight (lw) in the father to 60, 137, and 245 ng/g lw in the mother, child, and toddler, respectively. Decabromodiphenyl ether (BDE-209) concentrations differed significantly between the two samplings. September concentrations in the father, mother, child, and toddler were 23, 14, 143, and 233 ng/g lw, respectively. December concentrations (duplicate results from the laboratory) were 2 and 3, 4 and 4, 9 and 12, and 19 and 26 ng/g lw, respectively. Parents' ∑PBDE concentrations approached U.S. median concentrations, with children's concentrations near the maximum (top 5%) found in U.S. adults. The youngest child had the highest concentrations of all PBDE congeners, suggesting that younger children are more exposed to PBDEs than are adults. Our estimates indicate that house dust contributes to children's higher PBDE levels. BDE-209 levels for all family members were 10-fold lower at the second sampling. The short half-life of BDE-209 (15 days) indicates that BDE-209 levels can decrease rapidly in response to decreased exposures. This case study suggests that children are at higher risk for PBDE exposures and, accordingly, face higher risks of PBDE-related health effects than adults.
BACKGROUND: Perfluorooctanoic acid (PFOA) is a potential cause of adverse pregnancy outcomes, but previous studies have been limited by low exposures and small study size. OBJECTIVES: Using birth ...certificate information, we examined the relation between estimated PFOA exposure and birth outcomes in an area of West Virginia and Ohio whose drinking water was contaminated by a chemical plant. METHODS: Births in the study area from 1990 through 2004 were examined to generate case groups of stillbirth (n = 106), pregnancy-induced hypertension (n = 224), preterm birth (n = 3,613), term low birth weight (n = 918), term small-for-gestational-age (SGA) (n = 353), and a continuous measure of birth weight among a sample of term births (n = 4,534). A 10% sample of term births > 2,500 g were selected as a source of controls (n -3,616). Historical estimates of serum PFOA were derived from a previously developed fate and transport model. In a second study, we examined 4,547 area births linked to a survey with residential history data. RESULTS: In the analysis based only on birth records, we found no consistent evidence of an association between estimated PFOA exposure and stillbirth, pregnancy-induced hypertension, preterm birth, or indices of fetal growth. In the analysis of birth records linked to the survey, PFOA was unrelated to pregnancy-induced hypertension or preterm birth but showed some suggestion of an association with early preterm birth. Measures of growth restriction showed weak and inconsistent associations with PFOA. CONCLUSIONS: Based on the analysis using the health survey, these results provide little support for an effect of PFOA exposure on most pregnancy outcomes, except for early preterm birth and possibly fetal growth restriction.
Di-(2-ethylhexyl)phthalate (DEHP), the most commonly used plasticizer in flexible polyvinylchloride formulations, is a ubiquitous environmental contaminant. To date, no information exists on the ...potential health hazards from exposure to DEHP and/or its main metabolite, mono-(2-ethylhexyl)phthalate (MEHP), in high-risk conditions, such as pregnancy and during the neonatal period. The aim of this study was to evaluate prenatal exposure to DEHP and/or MEHP and its possible biologic effects. We measured serum DEHP and MEHP concentrations in the cord blood of 84 consecutive newborns by high-performance liquid chromatography. Relationships between DEHP/MEHP and infact characteristics were tested using Fisher's exact test, unpaired t-tests, and univariate linear regression analyses, and significant differences on univariate analysis were evaluated using multiple logistic regression analysis. We found detectable cord blood DEHP and/or MEHP concentrations in 88.1% of the samples. Either DEHP or MEHP was present in 65 of 84 (77.4%) of the examined samples. Mean concentrations of DEHP and MEHP were 1.19 ± 1.15 μg/mL 95% confidence interval (CI), 0.93-1.44, range = 0-4.71 and 0.52 ± 0.61 μg/mL (95% CI, 0.39-0.66, range = 0-2.94), respectively. MEHP-positive newborns showed a significantly lower gestational age compared with MEHP-negative infants (p = 0.033). Logistic regression analysis results indicated a positive correlation between absence of MEHP in cord blood and gestational age at delivery (odds ratio = 1.50, 95% CI, 1.013-2.21; p = 0.043). These findings confirm that human exposure to DEHP can begin in utero and suggest that phthalate exposure is significantly associated with a shorter pregnancy duration.
Lead, cadmium, mercury, and arsenic are common environmental pollutants in industrialized countries, but their combined impact on children's health is little known. We studied their effects on two ...main targets, the renal and dopaminergic systems, in > 800 children during a cross-sectional European survey. Control and exposed children were recruited from those living around historical nonferrous smelters in France, the Czech Republic, and Poland. Children provided blood and urine samples for the determination of the metals and sensitive renal or neurologic biomarkers. Serum concentrations of creatinine, cystatin C, and $\beta_2-microglobulin$ were negatively correlated with blood lead levels (PbB), suggesting an early renal hyperfiltration that averaged 7% in the upper quartile of PbB levels (> $55 \mu g/L$; mean, $78.4 \mu g/L$). The urinary excretion of retinol-binding protein, Clara cell protein, and $N-acetyl-\beta-D-glucosaminidase$ was associated mainly with cadmium levels in blood or urine and with urinary mercury. All four metals influenced the dopaminergic markers serum prolactin and urinary homovanillic acid, with complex interactions brought to light. Heavy metals polluting the environment can cause subtle effects on children's renal and dopaminergic systems without clear evidence of a threshold, which reinforces the need to control and regulate potential sources of contamination by heavy metals.
To test the hypotheses that children with autism spectrum disorder (ASD) have higher screen time than other children on a US nationally representative sample and that children with ASD are ...overrepresented among children who exceed the American Academy of Pediatrics (AAP) screen time recommendation (2 hours or less a day).
The National Survey of Children's Health 2011-2012, a nationally representative survey, asked parents to report their child's (aged 6-17 years) average daily media usage. The ASD subpopulation (n = 1393) was compared to children without ASD (non-ASD, n = 64,163). Differences were compared by design-corrected F tests. Regression models were estimated for both groups separately. Adjusted Wald tests were used to rigorously test the hypotheses.
More than half of US children exceed the AAP screen time recommendation. Compared to non-ASD, children with ASD had similar amounts of total screen time (3.21 hours per day vs 3.46 hours per day; P > .05), media (TV/video) time, and computer/mobile device leisure time. Children with ASD have a milder age gradient than the general population on computer/mobile device usage. Children with ASD were proportionally represented among high users (more than 2 hours per day). Data did not support hypotheses.
In a large, nationally representative US sample, there was no evidence that children with ASD differ in their screen time habits from other children. Both groups have high screen time use. Caution should be exercised before assuming that children with ASD are at higher risk of exceeding AAP screen time recommendations. Efforts to promote adherence to the recommendation are needed, but they should neither target nor exclude children with ASD.
Background: Prenatal exposure to mercury has been associated with adverse childhood neurologic outcomes in epidemiologic studies. Dose-response information for this relationship is useful for ...estimating benefits of reduced mercury exposure. Objectives: We estimated a dose-response relationship between maternal mercury body burden and subsequent childhood decrements in intelligence quotient (IQ), using a Bayesian hierarchical model to integrate data from three epidemiologic studies. Methods: Inputs to the model consist of dose-response coefficients from studies conducted in the Faroe Islands, New Zealand, and the Seychelles Islands. IQ coefficients were available from previous work for the latter two studies, and a coefficient for the Faroe Islands study was estimated from three IQ subtests. Other tests of cognition/achievement were included in the hierarchical model to obtain more accurate estimates of study-to-study and end point-to-end point variability. Results: We find a central estimate of-0.18 IQ points (95% confidence interval, -0.378 to -0.009) for each parts per million increase of maternal hair mercury, similar to the estimates for both the Faroe Islands and Seychelles studies, and lower in magnitude than the estimate for the New Zealand study. Sensitivity analyses produce similar results, with the IQ coefficient central estimate ranging from -0.13 to -0.25. Conclusions: IQ is a useful end point for estimating neurodevelopmental effects, but may not fully represent cognitive deficits associated with mercury exposure, and does not represent deficits related to attention and motor skills. Nevertheless, the integrated IQ coefficient provides a more robust description of the dose-response relationship for prenatal mercury exposure and cognitive functioning than results of any single study.
Background
The importance of a child's first 1000 days has now been widely accepted by the medical fraternity. Yet, we do not know much about caring practices in low‐resource settings.
Aim
This study ...aimed to investigate the caring capabilities of mothers in a low‐resource setting.
Method
In this study, in‐depth interviews were conducted with 18 mothers with children aged 30 months or younger to better understand the arrangements, means and ends that inform developmental health in a low‐resource setting in South Africa. The study was conducted in a low‐income area, the former black township of Mangaung in Bloemfontein. The mothers were recruited via pamphlets, and two interviews followed. Because of Covid‐19, interviews took place via mobile phones, in Sesotho, the local language in the area. Trained fieldworkers conducted, translated and transcribed the interviews. We used thematic analysis and the capabilities approach as the theoretical framework to analyse the responses from the mothers.
Findings
We used the following organizing themes: pregnancy and ante‐natal care, nutrition, cognitive and physical development, the home environment and access to health care. Although short‐term reactions to pregnancy were often negative, the longer‐term responses showed that the respondents have agency. Most of them could change their nutrition habits, breastfeed and receive adequate nutrition support from the public health system. Most experienced joy when their children reached milestones (cognitive and others), although they became anxious if milestones were not reached. They emphasized children's play and had dreams for their children's futures. Technology was often mentioned as playing a role in their children's development. A large proportion of the respondents had disrupted homes (because of absent or abusive fathers), but some had stable homes. Most of them showed substantial capability to overcome adverse home environments. The public health system helped them deal with their health problems and their children's health problems, although it also created anxiety in many cases. Our data show how they develop their capabilities and overcome obstacles organically in the face of resource limitations. Despite pregnancies being unexpected and unplanned and fathers being absent, the respondents accepted the pregnancy, adjusted their diets and social behaviour, showed agency by attending primary healthcare facilities and ensured that their children received the required vaccinations. Their extended families played an important role in providing care. Despite the sacrifices, the respondents expressed joy and helped their children function by eating, playing, socializing, learning and using their senses.
Conclusion
Our sample of mothers have the agency to adapt to the demands of parenthood and childcare and overcome adversity. Our data support the notion that mothers are held disproportionately and unfairly responsible for achieving the first 1000 days ideals. Despite considerable curtailment of their functionings and capabilities, they nevertheless showed agency to ensure their health and their children's health. A holistic approach should consider these findings in designing policy interventions for children's developmental health.
Patient and Public Contribution
We used paid fieldworkers to interact with the research participants.
ObjectiveThis study evaluated the relationship between physical literacy (PL) and muscular fitness (MF) as well as muscle-strengthening activities (MSA) in adolescents.MethodsA secondary ...cross-sectional study included 823 adolescents (45.1% boys) from the Eating Healthy and Daily Life Activities Study. The Spanish Perceived Physical Literacy Instrument for Adolescents (S-PPLI) assessed the participants’ perceived PL. The evaluation of MF in the young population was conducted using the Assessing the Levels of Physical Activity and Fitness (ALPHA-FIT) test battery. MSA were assessed by the following question: ‘In the past week, how many days did you exercise to strengthen or tone the muscle, such as through push-ups, sit-ups or lifting weights?’ To examine the associations between S-PPLI scores and handgrip strength, standing long jump and MSA days in adolescents, we employed generalised additive models.ResultsParticipants with high perceived physical literacty (PPL) had the highest handgrip strength (mean=25.1; PPL had the highest handgrip strength (mean=25.1; bias-corrected and accelerated (BCa) bootstrapped 95% CI 24.2 to 26.0) and standing long jump (mean=149.7; confidence interval (CI) 24.2 to 26.0) and standing long jump (mean=149.7; 24.2 to 26.0) and standing long jump (mean=149.7; BCa bootstrapped 95% CI 145.8 to 153.5). Conversely, those adolescents with low PPL had the lowest handgrip strength (mean=23.1; BCa bootstrapped 95% CI 22.3 to 23.8) and standing long jump (mean=137.3; BCa bootstrapped 95% CI 133.9 to 140.6). For MSA, adolescents with high PPL had the highest mean of MSA days (mean=3.0; BCa bootstrapped 95% CI 2.8 to 3.3), while the lowest mean was observed for those with low PPL (mean=2.0; BCa bootstrapped 95% CI 1.8 to 2.2).ConclusionA high level of PL was associated with higher levels of MF and MSA among Spanish adolescents.
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