Telomere tracking from birth to adulthood and residential traffic exposure

Background: Telomere attrition is extremely rapid during the first years of life, while lifestyle during adulthood exerts a minor impact. This suggests that early life is an important period in the determination of telomere length. We investigated the importance of the early-life environment on both telomere tracking and adult telomere length. Methods: Among 184 twins of the East Flanders Prospective Twin Survey, telomere length in placental tissue and in buccal cells in young adulthood was measured. Residential addresses at birth and in young adulthood were geocoded and residential traffic and greenness exposure was determined. Results: We investigated individual telomere tracking from birth over a 20 year period (mean age (SD), 22.6 (3.1) years) in association with residential exposure to traffic and greenness. Telomere length in placental tissue and in buccal cells in young adulthood correlated positively (r = 0.31, P < 0.0001). Persons with higher placental telomere length at birth were more likely to have a stronger downward shift in telomere ranking over life (P < 0.0001). Maternal residential traffic exposure correlated inversely with telomere length at birth. Independent of birth placental telomere length, telomere ranking between birth and young adulthood was negatively and significantly associated with residential traffic exposure at the birth address, while traffic exposure at the residential address at adult age was not associated with telomere length. Conclusions: Longitudinal evidence of telomere length tracking from birth to adulthood shows inverse associations of residential traffic exposure in association with telomere length at birth as well as accelerated telomere shortening in the first two decades of life

Small for gestational age and exposure to particulate air pollution in the early-life environment of twins

Several studies in singletons have shown that maternal exposure to ambient air pollutants is associated with restricted fetal growth. About half of twins have low birth weight compared with six percent in singletons. So far, no studies have investigated maternal air pollution exposure in association with birth weight and small for gestational age in twins. We examined 4760 twins of the East Flanders Prospective Twins Survey (2002-2013), to study the association between in utero exposure to air pollution with birth weight and small for gestational age. Maternal particulate air pollution (PM10) and nitric dioxide (NO2) exposure was estimated using a spatial temporal interpolation method over various time windows during pregnancy. In the total group of twins, we observed that higher PM10 and NO2 exposure during the third trimester was significantly associated with a lower birth weight and higher risk of small for gestational age. However, the association was driven by moderate to late preterm twins (32-36 weeks of gestation). In these twins born between 32 and 36 weeks of gestation, birth weight decreased by 40.2 g (95% CI: -69.0 to -11.3; p=0.006) and by 27.3 g (95% CI: -52.9 to -1.7; p=0.04) in association for each 10 mu g/m(3) increment in PM10 and NO2 concentration during the third trimester. The corresponding odds ratio for small for gestational age were 1.68 (95% CI: 1.27-2.33; p=0.0003) and 1.51 (95% CI: 1.18-1.95; p=0.001) for PM10 or NO2, respectively. No associations between air pollution and birth weight or small for gestational age were observed among term born twins. Finally, in all twins, we found that for each 10 mu g/m(3) increase in PM10 during the last month of pregnancy the within-pair birth weight difference increased by 19.6 g (95% CI: 3.7-35.4; p=0.02). Assuming causality, an achievement of a 10 mu g/m(3) decrease of particulate air pollution may account for a reduction by 40% in small for gestational age, in twins born moderate to late preterm

Residential landscape as a predictor of psychosocial stress in the life course from childhood to adolescence

Background: The effects of residential landscape, i.e., land use and traffic, on psychosocial stress in children are unknown, even though childhood stress might negatively affect normal development. In a longitudinal study, we investigate whether the residential landscape predicts childhood psychosocial stress and whether associations are independent of noise and air pollution. Methods: Belgian children aged 6.7-12.2 (N = 172, 50.9% boys) were followed for three years (2012-2015). Information on stress was obtained using standardized behavioral and emotional questionnaires and by a measure of hair cortisol. Residential landscape, including natural, agricultural, industrial, residential areas, and traffic, in a 100-m to 5-km radius around each child's home was characterized. Cross-sectional and longitudinal associations between psychosocial stress and the residential landscape were studied using linear regression and mixed models, while adjusting for age, sex, and parental socioeconomic status. Results: Natural landscapes were positively associated with better emotional status (increased happiness and lower sadness, anxiousness, and total negative emotions, beta = 0.14-0.17, 95% CI = 0.01-0.30). Similarly, we observed an inverse association between residential and traffic density with hyperactivity problems (beta = 0.13-0.18, 95% CI = 0.01-0.34). In longitudinal analyses, industrial area was a predictor of increases in negative emotions, while a natural landscape was for increases in happiness. Only the effect of natural landscape was partly explained by residential noise. Conclusion: Residential greenness in proximity to a child's residence might result in a better childhood emotional status, whereas poorer emotional status and behavioral problems (hyperactivity problems) were seen with residential and industrial areas and increased traffic density in proximity to a child's home

Ambient black carbon particles reach the fetal side of human placenta

Particle transfer across the placenta has been suggested but to date, no direct evidence in real-life, human context exists. Here we report the presence of black carbon (BC) particles as part of combustion-derived particulate matter in human placentae using white-light generation under femtosecond pulsed illumination. BC is identified in all screened placentae, with an average (SD) particle count of 0.95 × 104 (0.66 × 104) and 2.09 × 104 (0.9 × 104) particles per mm3 for low and high exposed mothers, respectively. Furthermore, the placental BC load is positively associated with mothers' residential BC exposure during pregnancy (0.63-2.42 µg per m3). Our finding that BC particles accumulate on the fetal side of the placenta suggests that ambient particulates could be transported towards the fetus and represents a potential mechanism explaining the detrimental health effects of pollution from early life onwards.status: publishe

Higher surrounding green space is associated with better attention in Flemish adolescents

Introduction: Previous studies suggested that green space is beneficial for the cognitive development in children. However, evidence in adolescents is limited. Therefore, we aim to investigate green space exposure in association with attention and behaviour in adolescents. Methods: This study includes 596 Flemish adolescents between 13 and 17 years old. Attention was assessed with Stroop Test (selective attention) and Continuous Performance Test (sustained and selective attention). Behaviour was determined based on the Strengths and Difficulties Questionnaire. Green space was estimated in several radius distances around their current residence and school based on high-resolution land cover data. Multilevel regression analyses were used adjusting for participant's age, sex, education level of the mother, and area deprivation index. Results: Surrounding green space in a 2000 m radius is associated with a faster reaction time in adolescents. An IQR (13%) increment in total green space within 2000 m of the residence and school combined, is associated with a 32.7 ms (95% CI: -58.9 to -6.5; p = 0.02) and a 7.28 ms (95% CI: -11.7 to -2.8; p = 0.001) shorter mean reaction time between the presentation of a stimulus and the response based on the Stroop Test and the Continuous Performance Test. Subdividing green space based on vegetation height, shows that green space higher than 3 m is associated with a faster reaction time of the Continuous Performance Test (-6.50 ms; 95% CI: -10.9 to -2.2; p = 0.004), while low green is not. We did not find an association between green space and behavioural development in adolescents. Conclusions: Our study shows that green space, especially trees, surrounding the residence and school combined is associated with better sustained and selected attention in adolescents. These findings indicate that the availability of green is important for adolescents that are growing up in a rapidly urbanizing world

Long-term residential exposure to air pollution is associated with hair cortisol concentration and differential leucocyte count in Flemish adolescent boys

Background: Exposure to air pollution and traffic noise are associated with adverse health outcomes in adolescents. Chronic endocrine stress and systemic inflammation have been hypothesized to underlie the adverse health effects. Simultaneous assessment of inflammation and chronic endocrine stress in epidemiological studies is lacking. The aim of the study was to investigate biomarkers of chronic endocrine stress and inflammation in relation to long-term residential exposure to air pollution and traffic noise in adolescents. Methods: In Flemish adolescents (14-15 years), we determined hair cortisol concentration (HCC) as a chronic stress biomarker in 3-cm scalp-near hair sections (n = 395), and leucocyte and leucocyte subtype counts (neutrophils, monocytes, lymphocytes) as inflammatory biomarkers in peripheral blood (n = 385). Daily particulate matter (PM2.5, PM10), nitrogen dioxide (NO2) and black carbon (BC) concentrations were modelled at the residential address and averaged over 3-month and 1-year periods prior to sampling. Residential traffic noise level was estimated and classified in 5 dB intervals. Sex-specific associations between residential exposures and effect biomarkers were studied using linear regression models, adjusted for a priori selected covariates. Results: In boys, HCC increased with a factor 1.30 (95% CI: 1.10, 1.54) for an increase in 1-year mean NO2 from the 25th to 75th percentile (p75/p25), after adjustment for age, BMI, personal and neighborhood socioeconomic status. The corresponding estimate for PM10 was 1.24 (95% CI: 1.02, 1.51). Total leucocyte count in boys, adjusted for the aforementioned covariates and recent health complaints, was positively associated with PM2.5, PM10, NO2 and BC. In particular, the neutrophil count increased with a factor 1.11 (95% CI: 1.03, 1.19) for a (p75/p25)-factor increase in 1-year mean BC, corresponding estimates for PM2.5, PM10 and NO2 were 1.10 (95% CI: 1.01, 1.19), 1.10 (95% CI: 1.01, 1.20) and 1.08 (95% CI: 1.00, 1.16). Lymphocyte count increased with a factor 1.05 (95% CI: 1.01, 1.10) for a (p75/p25)-factor increase in 1-year mean NO2. Similar results were observed for 3-month mean exposures. Results were robust to adjustment for recent air pollution exposure. In girls, air pollutants were not associated with HCC or differential leucocyte count. Residential traffic noise level was not associated with HCC or leucocyte counts in boys nor girls. Conclusions: Long-term residential exposure to air pollutants was positively associated with chronic endocrine stress and inflammation in adolescent boys, not in girls. This study may contribute to a better understanding of the early pathophysiological changes that may underlie adverse health effects of air pollution exposure in adolescents