Socioeconomic position, family context, and child cognitive development.

Socioeconomic position (SEP) may have different effects on cognitive development and family context could play a role in this association. This work aimed to analyse the role of socioeconomic positions, measured via various indicators collected longitudinally, in cognitive development at 7-11 years of age, evaluating the role of family context as a potential mediator. The study sample included 394 and 382 children from the INMA Gipuzkoa and Valencia cohorts, respectively. SEP indicators were assessed during pregnancy (family social class, parental education, employment, and disposable income) and at 7 (Gipuzkoa) and 11 (Valencia) years of age (At Risk of Poverty or Social Exclusion (AROPE)). Family context and cognitive development were measured with the Haezi-Etxadi Family Assessment Scale 7-11 (HEFAS 7-11) and Raven's Coloured Progressive Matrices (Raven's CPM), respectively. Linear regression models were developed to assess the relationships between (a) SEP-family context, (b) SEP-cognitive development, and (c) family context-cognitive development, adjusting for a priori-selected confounders. Simple and multiple mediation analyses were performed to explore the role of family context in the SEP-cognitive development relationship. Lower SEP was related with a lower cognitive score, this association being particularly robust for family social class. SEP indicators were related to subscales of family context, in particular those regarding cognitive stimulation, parental stress, and parenting. A relationship was also found between these three subscales and child cognitive development, mediating the effect of family social class on child cognition by 5.2, 5.5, and 10.8%, respectively, and 12.0% jointly.    Conclusion: Both family SEP and context contribute to a child's cognitive development. Equalising policies and positive parenting programmes could contribute to improving cognitive development in children. What is Known: • Parental social class, education, and employment status have been widely employed to measure socioeconomic position. What is New: • This work focuses on standard measurements of socioeconomic position but also other economic indicators such as the EHII and AROPE, and their effect on child cognitive development and family context. • Promotion of cognitive and linguistic development, parental stress and conflict, and parental profile fostering child development mediated the effect of family social class on cognitive development.

Associations of Maternal Educational Level, Proximity to Greenspace During Pregnancy, and Gestational Diabetes With Body Mass Index From Infancy to Early Adulthood: A Proof-of-Concept Federated Analysis in 18 Birth Cohorts.

International sharing of cohort data for research is important and challenging. We explored the feasibility of multi-cohort federated analyses by examining associations between three pregnancy exposures (maternal education, exposure to green vegetation and gestational diabetes) with offspring BMI from infancy to 17 years. We used data from 18 cohorts (n=206,180 mother-child pairs) from the EU Child Cohort Network and derived BMI at ages 0-1, 2-3, 4-7, 8-13 and 14-17 years. Associations were estimated using linear regression via one-stage IPD meta-analysis using DataSHIELD. Associations between lower maternal education and higher child BMI emerged from age 4 and increased with age (difference in BMI z-score comparing low with high education age 2-3 years = 0.03 [95% CI 0.00, 0.05], 4-7 years = 0.16 [95% CI 0.14, 0.17], 8-13 years = 0.24 [95% CI 0.22, 0.26]). Gestational diabetes was positively associated with BMI from 8 years (BMI z-score difference = 0.18 [CI 0.12, 0.25]) but not at younger ages; however associations attenuated towards the null when restricted to cohorts which measured GDM via universal screening. Exposure to green vegetation was weakly associated with higher BMI up to age one but not at older ages. Opportunities of cross-cohort federated analyses are discussed.

Susceptible windows of exposure to fine particulate matter and fetal growth trajectories in the Spanish INMA (INfancia y Medio Ambiente) birth cohort.

While prior studies report associations between fine particulate matter (PM2.5) exposure and fetal growth, few have explored temporally refined susceptible windows of exposure. We included 2328 women from the Spanish INMA Project from 2003 to 2008. Longitudinal growth curves were constructed for each fetus using ultrasounds from 12, 20, and 34 gestational weeks. Z-scores representing growth trajectories of biparietal diameter, femur length, abdominal circumference (AC), and estimated fetal weight (EFW) during early (0-12 weeks), mid- (12-20 weeks), and late (20-34 weeks) pregnancy were calculated. A spatio-temporal random forest model with back-extrapolation provided weekly PM2.5 exposure estimates for each woman during her pregnancy. Distributed lag non-linear models were implemented within the Bayesian hierarchical framework to identify susceptible windows of exposure for each outcome and cumulative effects [ßcum, 95% credible interval (CrI)] were aggregated across adjacent weeks. For comparison, general linear models evaluated associations between PM2.5 averaged across multi-week periods (i.e., weeks 1-11, 12-19, and 20-33) and fetal growth, mutually adjusted for exposure during each period. Results are presented as %change in z-scores per 5 µg/m3 in PM2.5, adjusted for covariates. Weeks 1-6 [ßcum = -0.77%, 95%CrI (-1.07%, -0.47%)] were identified as a susceptible window of exposure for reduced late pregnancy EFW while weeks 29-33 were positively associated with this outcome [ßcum = 0.42%, 95%CrI (0.20%, 0.64%)]. A similar pattern was observed for AC in late pregnancy. In linear regression models, PM2.5 exposure averaged across weeks 1-11 was associated with reduced late pregnancy EFW and AC; but, positive associations between PM2.5 and EFW or AC trajectories in late pregnancy were not observed. PM2.5 exposures during specific weeks may affect fetal growth differentially across pregnancy and such associations may be missed by averaging exposure across multi-week periods, highlighting the importance of temporally refined exposure estimates when studying the associations of air pollution with fetal growth.

Sleep problems at ages 8-9 and ADHD symptoms at ages 10-11: evidence in three cohorts from INMA study.

Sleep problems and attention deficit hyperactivity disorder (ADHD) are interrelated during childhood and preadolescence. The objective of this work is assessing if sleep problems at ages 8-9 represent an alarm sign for presenting ADHD problems at ages 10-11 in three cohorts from INMA Study. Participants were 1244 children from Gipuzkoa, Sabadell, and Valencia cohorts. Sleep problems were assessed (ages 8-9) with the sleep items of the Child's Behaviour Checklist (CBCL), and ADHD problems were collected through the Conner's Parent Rating Scales-Revised: Short Form (CPRS-R:S) (age 10-11). Minimally and fully adjusted negative binomial models were fitted for each CPRS-R:S scale. Linearity of the relationship was assessed with generalized additive models (cubic smoothing splines with 2, 3, and 4 knots). For sensitivity analyses, children with previous symptoms, those born preterm and small for gestational age, and cases with extreme values, were excluded. Sleep problems presented IRR (95% CI) of 1.14 (1.10-1.19), 1.20 (1.14-1.26), 1.18 (1.11-1.25), and 1.18 (1.13-1.23) for opposition, inattention, hyperactivity, and ADHD scales, respectively. Fully adjusted models slightly decreased the IRR, but the association remained similar and significant. Sensitivity analyses showed similar results to fully adjusted models with only hyperactivity shown a slight decrease on significance (p = 0.051) when ADHD cases at age 9 were excluded.   Conclusion: Sleep problems are an alarm sign for later neurodevelopment problems such as ADHD. Healthcare systems could take advantage implementing policies to pay special attention on the sleep habits and sleep hygiene. This could contribute to add evidence to public health programmes such as the Healthy Child Programme.

Poverty, social exclusion, and mental health: the role of the family context in children aged 7-11 years INMA mother-and-child cohort study.

Mental health problems are common in childhood and tend to be more frequent in populations at risk of poverty or social exclusion (AROPE). The family environment can play a role in reducing the impact of economic hardship on these problems. The aim of this study was to assess the effect of multidimensional poverty on the mental health of children aged 7-11 years and the role of the family environment in two areas of Spain. Participants were 395 and 382 children aged 7 and 11 from Gipuzkoa and Valencia, respectively. Internalizing and externalizing problem scales of the child behaviour checklist (CBCL) were used. AROPE indicators were obtained by questionnaire, and three dimensions of the family context (Organization of the Physical Environment and Social Context, Parental Stress and Conflict, and Parental Profile Fostering Development) were measured through subscales 3, 4 and 5 of the Haezi-Etxadi family assessment scale (7-11) (HEFAS 7-11), respectively. Data were analysed using negative binomial regression and Structural Equation Modelling. AROPE prevalence was 7.1 and 34.5% in Gipuzkoa and Valencia, respectively. In both cohorts, there was a significant increase in internalizing and externalizing problems among participants with a higher AROPE score. However, AROPE did not affect internalizing problems in children from families living in a better physical environment and with social support (Subscale 3). The AROPE effect was jointly mediated by subscales 4 and 5 in 42 and 62% of internalizing and externalizing problems, respectively. Preventing economic inequities by economic compensation policies, improving the neighbourhood and immediate environment around the school, and promoting positive parenting programmes can improve mental health in childhood.

Associations of early-life pet ownership with asthma and allergic sensitization: A meta-analysis of more than 77,000 children from the EU Child Cohort Network.

BACKGROUND: Studies examining associations of early-life cat and dog ownership with childhood asthma have reported inconsistent results. Several factors could explain these inconsistencies, including type of pet, timing, and degree of exposure. OBJECTIVE: Our aim was to study associations of early-life cat and dog ownership with asthma in school-aged children, including the role of type (cat vs dog), timing (never, prenatal, or early childhood), and degree of ownership (number of pets owned), and the role of allergic sensitization. METHODS: We used harmonized data from 77,434 mother-child dyads from 9 birth cohorts in the European Union Child Cohort Network when the child was 5 to 11 years old. Associations were examined through the DataSHIELD platform by using adjusted logistic regression models, which were fitted separately for each cohort and combined by using random effects meta-analysis. RESULTS: The prevalence of early-life cat and dog ownership ranged from 12% to 45% and 7% to 47%, respectively, and the prevalence of asthma ranged from 2% to 20%. There was no overall association between either cat or dog ownership and asthma (odds ratio [OR] = 0.97 [95% CI = 0.87-1.09] and 0.92 [95% CI = 0.85-1.01], respectively). Timing and degree of ownership did not strongly influence associations. Cat and dog ownership were also not associated with cat- and dog-specific allergic sensitization (OR = 0.92 [95% CI = 0.75-1.13] and 0.93 [95% CI = 0.57-1.54], respectively). However, cat- and dog-specific allergic sensitization was strongly associated with school-age asthma (OR = 6.69 [95% CI = 4.91-9.10] and 5.98 [95% CI = 3.14-11.36], respectively). There was also some indication of an interaction between ownership and sensitization, suggesting that ownership may exacerbate the risks associated with pet-specific sensitization but offer some protection against asthma in the absence of sensitization. CONCLUSION: Our findings do not support early-life cat and dog ownership in themselves increasing the risk of school-age asthma, but they do suggest that ownership may potentially exacerbate the risks associated with cat- and dog-specific allergic sensitization.

Radiofrequency electromagnetic fields from mobile communication: Description of modeled dose in brain regions and the body in European children and adolescents.

BACKGROUND: Little is known about radiofrequency electromagnetic fields (RF) from mobile technology and resulting dose in young people. We describe modeled integrated RF dose in European children and adolescents combining own mobile device use and surrounding sources. METHODS: Using an integrated RF model, we estimated the daily RF dose in the brain (whole-brain, cerebellum, frontal lobe, midbrain, occipital lobe, parietal lobe, temporal lobes) and the whole-body in 8358 children (ages 8-12) and adolescents (ages 14-18) from the Netherlands, Spain, and Switzerland during 2012-2016. The integrated model estimated RF dose from near-field sources (digital enhanced communication technology (DECT) phone, mobile phone, tablet, and laptop) and far-field sources (mobile phone base stations via 3D-radiowave modeling or RF measurements). RESULTS: Adolescents were more frequent mobile phone users and experienced higher modeled RF doses in the whole-brain (median 330.4 mJ/kg/day) compared to children (median 81.8 mJ/kg/day). Children spent more time using tablets or laptops compared to adolescents, resulting in higher RF doses in the whole-body (median whole-body dose of 81.8 mJ/kg/day) compared to adolescents (41.9 mJ/kg/day). Among brain regions, temporal lobes received the highest RF dose (medians of 274.9 and 1786.5 mJ/kg/day in children and adolescents, respectively) followed by the frontal lobe. In most children and adolescents, calling on 2G networks was the main contributor to RF dose in the whole-brain (medians of 31.1 and 273.7 mJ/kg/day, respectively). CONCLUSION: This first large study of RF dose to the brain and body of children and adolescents shows that mobile phone calls on 2G networks are the main determinants of brain dose, especially in temporal and frontal lobes, whereas whole-body doses were mostly determined by tablet and laptop use. The modeling of RF doses provides valuable input to epidemiological research and to potential risk management regarding RF exposure in young people.

Exposure to ultrafine particles in children until 18 years of age: A systematic review.

Airborne ultrafine particles (UFP) have been related to adverse health effects, but exposure in vulnerable population groups such as children is still not well understood. We aim to review the scientific literature regarding personal exposure to UFP in different microenvironments in populations until 18 years of age. The bibliographical search was carried out in July 2019 using the online database PubMed and was completed with references in articles found in the search. We selected the studies that used continuous counters and measured UFP levels in both specific microenvironment (houses, schools, transport, etc) and personal exposure. Finally, 32 studies fulfilled the criteria: of these, 10 analyzed personal exposure and 22 examined UFP levels in the microenvironment (especially in schools or nurseries (18/22)) and five in various microenvironments (including dwellings and means of transport, where exposure levels were higher). The characteristics of the microenvironments with the greatest levels of UFP were being close to heavy traffic or near cooking and cleaning activities. This review revealed the wide differences in exposure assessment methodologies that could lead to a lack of uniform and comparable information about the real UFP exposure in children.

Prenatal exposure to PM2.5 and NO2 and sex-dependent infant cognitive and motor development.

BACKGROUND: Prenatal exposure to air pollutants including particulate matter (<2.5 µm of diameter,PM2.5)and nitrogen dioxide (NO2) has been identified as a potential risk factor for neuropsychological developmental and mental health disorders. OBJECTIVE: This study aimed to analyze the associations between prenatal PM2.5 and NO2 exposure and cognitive functions in children at 4-6 years of age, including sex differences, and the modification effect of the duration predominant breastfeeding these associations. DESIGN: This study was conducted as part of the INMA project, a population-based birth cohort study in Spain (n = 1119). Each of the pregnant mothers was assigned a prenatal exposure to PM2.5 and NO2 for their whole pregnancy based on their place of residence. At the 4-6 year-old follow-up, infants' neuropsychological development was assessed using McCarthy scales: Verbal, Perceptive-Manipulative, Numeric, General Cognitive, Memory and Motor (gross and fine). Between 6 and 14 months of age, information concerning breastfeeding was gathered with a questionnaire. Regression analyses were performed to estimate the associations between exposure and outcomes, accounting for potential confounders. The analyses were stratified by child sex and breastfeeding duration. RESULTS: The majority of coefficients for the different cognitive domains were negative either for PM2.5 and NO2, though none was statistically significant. After stratifying by sex, the associations become even more negative for boys, with some of the associations becoming statistically significant (memory both for PM2.5 and NO2), and global cognition and verbal for NO2. Duration of predominant breastfeeding was not found to have a modifying effect. CONCLUSIONS: These findings suggest a sex-dependent effects on neuropsychological development at 4-6 years of age, with a greater vulnerability in boys, specifically in domains related to memory, verbal and general cognition. No modifying effect was observed for duration of predominant breastfeeding.

Air Pollution Exposure During Pregnancy and Symptoms of Attention Deficit and Hyperactivity Disorder in Children in Europe.

BACKGROUND: Exposure to air pollution during pregnancy may increase attention-deficit/hyperactivity disorder (ADHD) symptoms in children, but findings have been inconsistent. We aimed to study this association in a collaborative study of eight European population-based birth/child cohorts, including 29,127 mother-child pairs. METHODS: Air pollution concentrations (nitrogen dioxide [NO2] and particulate matter [PM]) were estimated at the birth address by land-use regression models based on monitoring campaigns performed between 2008 and 2011. We extrapolated concentrations back in time to exact pregnancy periods. Teachers or parents assessed ADHD symptoms at 3-10 years of age. We classified children as having ADHD symptoms within the borderline/clinical range and within the clinical range using validated cutoffs. We combined all adjusted area-specific effect estimates using random-effects meta-analysis and multiple imputations and applied inverse probability-weighting methods to correct for loss to follow-up. RESULTS: We classified a total of 2,801 children as having ADHD symptoms within the borderline/clinical range, and 1,590 within the clinical range. Exposure to air pollution during pregnancy was not associated with a higher odds of ADHD symptoms within the borderline/clinical range (e.g., adjusted odds ratio [OR] for ADHD symptoms of 0.95, 95% confidence interval [CI] = 0.89, 1.01 per 10 µg/m increase in NO2 and 0.98, 95% CI = 0.80, 1.19 per 5 µg/m increase in PM2.5). We observed similar associations for ADHD within the clinical range. CONCLUSIONS: There was no evidence for an increase in risk of ADHD symptoms with increasing prenatal air pollution levels in children aged 3-10 years. See video abstract at, http://links.lww.com/EDE/B379.

Comparison of urinary iodine levels in women of childbearing age during and after pregnancy.

PURPOSE: Median urinary iodine concentration (UIC) is used to describe the iodine status of a population. However, the link between UIC and iodine intake may vary during pregnancy. The aim of this study was to compare UIC during and after pregnancy, adjusting for factors that affect iodine intake. METHODS: Two repeated measures of UIC and data on maternal iodine intake estimated through questionnaires were collected during pregnancy and 1-4 years after pregnancy in a subsample of women (n = 598) from a mother and child cohort study in Spain. Random-effects interval regression was used to assess the changes in UIC according to pregnancy status. RESULTS: Median UIC was similar during (133 µg/L) and after pregnancy (139 µg/L). After adjusting for iodised salt, iodine supplement consumption, and socio-demographic related variables, UIC was 24.0% (95% CI 11.3, 38.2) higher after than during pregnancy. This difference was maintained in a subsample of women with exhaustive information on diet (n = 291): 26.2%, 95% CI 10.3, 44.4. CONCLUSIONS: In an iodine sufficient area for the general population, iodine excretion was lower during than after pregnancy when factors affecting iodine intake were controlled for. Current recommendations of median UIC during pregnancy are based on the equivalence between iodine intake and UIC estimated from studies in non-pregnant populations, which might lead to overestimation of iodine deficiency during gestation. Further studies should evaluate the equivalence between iodine intake and its urinary excretion during pregnancy.

Urban upbringing and childhood respiratory and allergic conditions: A multi-country holistic study.

OBJECTIVE: We integratively assessed the effect of different indoor and outdoor environmental exposures early in life on respiratory and allergic health conditions among children from (sub-) urban areas. METHODS: This study included children participating in four ongoing European birth cohorts located in three different geographical regions: INMA (Spain), LISAplus (Germany), GINIplus (Germany) and BAMSE (Sweden). Wheezing, bronchitis, asthma and allergic rhinitis throughout childhood were assessed using parental-completed questionnaires. We designed "environmental scores" corresponding to different indoor, green- and grey-related exposures (main analysis, a-priori-approach). Cohort-specific associations between these environmental scores and the respiratory health outcomes were assessed using random-effects meta-analyses. In addition, a factor analysis was performed based on the same exposure information used to develop the environmental scores (confirmatory analysis, data-driven-approach). RESULTS: A higher early exposure to the indoor environmental score increased the risk for wheezing and bronchitis within the first year of life (combined adjusted odds ratio: 1.20 [95% confidence interval: 1.13-1.27] and 1.28 [1.18-1.39], respectively). In contrast, there was an inverse association with allergic rhinitis between 6 and 8 years (0.85 [0.79-0.92]). There were no statistically significant associations for the outdoor related environmental scores in relation to any of the health outcomes tested. The factor analysis conducted confirmed these trends. CONCLUSION: Although a higher exposure to indoor related exposure through occupants was associated with an increased risk for wheezing and bronchitis within the 1st year, it might serve as a preventive mechanism against later childhood allergic respiratory outcomes in urbanized environments through enhanced shared contact with microbial agents.

Influence of paid maternity leave on return to work after childbirth.

BACKGROUND: Paid maternity leave (ML) has been associated with better health outcomes in mothers and newborns. However, its protective role in mothers' employment after childbirth remains unclear. OBJECTIVE: To assess the association between paid ML and being employed 1-year after childbirth. METHODS: As part of the INfancia y Medio Ambiente (INMA) cohort study, 507 Spanish women employed at 12th week of pregnancy, were asked about their employment status and job characteristics at 32nd week of pregnancy. One year after childbirth, they were re-interviewed about their employment status and if they had taken paid ML. Incidence of maternal employment 1-year after childbirth was estimated. Crude and adjusted associations with paid ML were assessed by logistic regression, and characterized by odds ratios (ORs) with associated 95% CIs. RESULTS: Information was obtained from 398 women. Of those, 290 (72.9%) were employed 1-year after childbirth. Incidence of maternal employment was lower for those who: i) didn't take paid ML, ii) were younger than 27 years; iii) had temporary contract, iv) had part-time jobs, v) reported less-favoured familiar social class, and vi) left the job before 32 weeks of pregnancy. Being employed 1-year after childbirth was more common in those who took paid ML (OR 2.7, 95%CI 1.6-4.5), also after adjusting for staying at work until advanced stages of pregnancy (OR 1.8, 95%CI 1.0-3.1). CONCLUSIONS: Taking paid ML seems to be associated with higher maternal employment rates 1-year after childbirth. Therefore, our findings suggest that protection of maternity might positively influence women's labour market participation after childbirth.

The Influence of Meteorological Factors and Atmospheric Pollutants on the Risk of Preterm Birth.

Atmospheric pollutants and meteorological conditions are suspected to be causes of preterm birth. We aimed to characterize their possible association with the risk of preterm birth (defined as birth occurring before 37 completed gestational weeks). We pooled individual data from 13 birth cohorts in 11 European countries (71,493 births from the period 1994-2011, European Study of Cohorts for Air Pollution Effects (ESCAPE)). City-specific meteorological data from routine monitors were averaged over time windows spanning from 1 week to the whole pregnancy. Atmospheric pollution measurements (nitrogen oxides and particulate matter) were combined with data from permanent monitors and land-use data into seasonally adjusted land-use regression models. Preterm birth risks associated with air pollution and meteorological factors were estimated using adjusted discrete-time Cox models. The frequency of preterm birth was 5.0%. Preterm birth risk tended to increase with first-trimester average atmospheric pressure (odds ratio per 5-mbar increase = 1.06, 95% confidence interval: 1.01, 1.11), which could not be distinguished from altitude. There was also some evidence of an increase in preterm birth risk with first-trimester average temperature in the -5°C to 15°C range, with a plateau afterwards (spline coding, P = 0.08). No evidence of adverse association with atmospheric pollutants was observed. Our study lends support for an increase in preterm birth risk with atmospheric pressure.

Urban green and grey space in relation to respiratory health in children.

We assessed the effect of three different indices of urban built environment on allergic and respiratory conditions.This study involved 2472 children participating in the ongoing INMA birth cohort located in two bio-geographic regions (Euro-Siberian and Mediterranean) in Spain. Residential surrounding built environment was characterised as 1) residential surrounding greenness based on satellite-derived normalised difference vegetation index (NDVI), 2) residential proximity to green spaces and 3) residential surrounding greyness based on urban land use patterns. Information on wheezing, bronchitis, asthma and allergic rhinitis up to age 4 years was obtained from parent-completed questionnaires. Logistic regression and generalised estimating equation modelling were performed.Among children from the Euro-Siberian region, higher residential surrounding greenness and higher proximity to green spaces were negatively associated with wheezing. In the Mediterranean region, higher residential proximity to green spaces was associated with a reduced risk for bronchitis. A higher amount of residential surrounding greyness was found to increase the risk for bronchitis in this region.Associations between indices of urban residential greenness and greyness with respiratory diseases differ by region. The pathways underlying these associations require further exploration.

Exposure to ambient air pollution during pregnancy and preterm birth: A Spanish multicenter birth cohort study.

BACKGROUND AND OBJECTIVE: Preterm birth is a major determinant of infant mortality and morbidity. Air pollution has been suggested as a risk factor for preterm delivery; however, the scientific evidence on this impact remains inconsistent. We assessed the association between residential exposure to air pollution during pregnancy and preterm birth (gestational age at delivery <37 weeks) in Spain. METHODS: This study was based on 2409 pregnant women participating in the INMA birth cohorts in Asturias, Gipuzkoa, Sabadell and Valencia. Ambient levels of nitrogen dioxide (NO2) and benzene were estimated for each woman's residence for each trimester and for the whole pregnancy, using temporally adjusted land-use regression models. The association between air pollution exposure and preterm birth was assessed for each cohort separately by means of logistic regression models controlling for potential confounders, under single- and two-pollutant models, for all the women in the study and for those spending more than 15h/day at home. Combined estimates of the association across cohorts were obtained through meta-analysis. RESULTS: Throughout the whole sample, suggestive but no statistically significant associations were found between exposure and preterm birth. For pregnant women spending more time at home significant associations were found for both pollutants, under single- and two-pollutant models. Under the last ones, NO2 exposure during the second trimester and the whole pregnancy was associated with a higher risk of preterm delivery (OR=1.58, (95%CI: 1.04-2.42) per 10µg/m(3) increase). Benzene exposure during the third trimester was also associated with preterm birth in that subsample (OR=1.45, (95%CI: 1.00-2.09) per 1µg/m(3) increase). CONCLUSION: We found suggestive associations between NO2 and benzene exposure during pregnancy and preterm birth. Estimates of the association were higher among women who spent more time at home, probably reflecting a better exposure assessment in this group.

Characterisation of exposure to non-ionising electromagnetic fields in the Spanish INMA birth cohort: study protocol.

BACKGROUND: Analysis of the association between exposure to electromagnetic fields of non-ionising radiation (EMF-NIR) and health in children and adolescents is hindered by the limited availability of data, mainly due to the difficulties on the exposure assessment. This study protocol describes the methodologies used for characterising exposure of children to EMF-NIR in the INMA (INfancia y Medio Ambiente- Environment and Childhood) Project, a prospective cohort study. METHODS/DESIGN: Indirect (proximity to emission sources, questionnaires on sources use and geospatial propagation models) and direct methods (spot and fixed longer-term measurements and personal measurements) were conducted in order to assess exposure levels of study participants aged between 7 and 18 years old. The methodology used varies depending on the frequency of the EMF-NIR and the environment (homes, schools and parks). Questionnaires assessed the use of sources contributing both to Extremely Low Frequency (ELF) and Radiofrequency (RF) exposure levels. Geospatial propagation models (NISMap) are implemented and validated for environmental outdoor sources of RFs using spot measurements. Spot and fixed longer-term ELF and RF measurements were done in the environments where children spend most of the time. Moreover, personal measurements were taken in order to assess individual exposure to RF. The exposure data are used to explore their relationships with proximity and/or use of EMF-NIR sources. DISCUSSION: Characterisation of the EMF-NIR exposure by this combination of methods is intended to overcome problems encountered in other research. The assessment of exposure of INMA cohort children and adolescents living in different regions of Spain to the full frequency range of EMF-NIR extends the characterisation of environmental exposures in this cohort. Together with other data obtained in the project, on socioeconomic and family characteristics and development of the children and adolescents, this will enable to evaluate the complex interaction between health outcomes in children and adolescents and the various environmental factors that surround them.

Health effects of the 2012 Valencia (Spain) wildfires on children in a cohort study.

In July 2012, two simultaneous wildfires burnt a big area in Valencia (Spain), where a birth cohort study (INMA) is being developed. The heavy smoke covered the whole INMA study area for several days. We aimed at evaluating the 2012 Valencia wildfire effects on the health of children enrolled in the INMA-Valencia cohort. Two weeks after the extinction of the wildfires, a phone survey was conducted and finally 460 individuals were enrolled. We considered a wildfire period (12-day interval when they were active) and a control period (12-day interval just before wildfires). Parents were asked about respiratory symptoms experienced during both periods, and during wildfires only about the preventive measures adopted and the perception of exposure, along with individual data collected through the different follow-up surveys of the cohort. Conditional logistic regression models were applied, and we included interaction terms for asthma/rhinitis and level of perception of exposure; 82.4 % perceived smoke smell outdoors, 40 % indoors and more than 90 % of the families observed the presence of ash. An adjusted odds ratio of 3.11 [95 % confidence interval 1.62-5.97] for itchy/watery eyes and 3.02 [1.41-6.44] for sore throat was obtained. Significant interaction terms for rhinitis and asthma in itchy/watery eyes and sneezing, and only asthma for sore throat were obtained. Exposure to wildfire smoke was associated with increased respiratory symptoms in this child population, particularly affecting susceptible individuals with asthma or rhinitis.

Systematic review of the association between climate and hip fractures.

This study aims to systematically review epidemiological studies that evaluate the relationship between meteorology and the incidence of hip fracture (HF). After a search in Scopus, PubMed, and Embase, two independent authors assessed the relevance of studies and extracted data for description. From each study, we extracted the geographic and temporal scope, design, study variables (meteorological and related to HF), statistical analysis, and estimated associations. Of a total of 134 works, 20 studies were selected. All use an ecological design but one case-crossover. Most studies have been conducted in northern latitudes. The analysis methodology did not take into account the temporal structure of the data in 10 studies (regression and linear correlations); the rest used Poisson regression (7) and ARIMA model (3). Most studies showed significant positive associations with rainfall, especially in the form of snow: HF relative risk (RR) on days with precipitation vs. days without precipitation that ranged from 1.14 (95 % confidence interval (CI)1.04 to 1.24) to 1.60 (95 % CI 1.06 to 2.41), the temperature, with RR by one degree Celsius decline from 1.012 (95 % CI 1.004 to 1.020) to 1.030 (95 % CI 1.023 to 1.037), and wind (3) RR FC windiest days vs. calm days: 1.32 (95 % CI 1.10 to 1.58) to 1.35 (95 % CI 0.88 to 2.08). This review shows that analytic methods are very heterogeneous and poorly adapted to the temporary nature of the data. Studies confirm a certain seasonality, with more fractures in winter and meaningful relationships with meteorological conditions typical of this season.

Nitrogen dioxide exposure, attentional function, and working memory in children from 4 to 8 years: Periods of susceptibility from pregnancy to childhood.

BACKGROUND: Air pollution exposure during pregnancy and childhood has been linked to executive function impairment in children, however, very few studies have assessed these two exposure periods jointly to identify susceptible periods of exposure. We sought to identify potential periods of susceptibility of nitrogen dioxide (NO2) exposure from conception to childhood on attentional function and working memory in school-aged children. METHODS: Within the Spanish INMA Project, we estimated residential daily NO2 exposures during pregnancy and up to 6 years of childhood using land use regression models (n = 1,703). We assessed attentional function at 4-6 years and 6-8 years, using the Conners Kiddie Continuous Performance Test and the Attention Network Test, respectively, and working memory at 6-8 years, using the N-back task. We used distributed lag non-linear models to assess the periods of susceptibility of each outcome, adjusting for potential confounders and correcting for multiple testing. We also stratified all models by sex. RESULTS: Higher exposure to NO2 between 1.3 and 1.6 years of age was associated with higher hit reaction time standard error (HRT-SE) (0.14 ms (95 % CI 0.05; 0.22) per 10 µg/m3 increase in NO2) and between 1.5 and 2.2 years of age with more omission errors (1.02 (95 % CI 1.01; 1.03) of the attentional function test at 4-6 years. Higher exposure to NO2 between 0.3 and 2.2 years was associated with higher HRT-SE (10.61 ms (95 % CI 3.46; 17.75) at 6-8 years only in boys. We found no associations between exposure to NO2 and working memory at 6-8 years. CONCLUSION: Our findings suggest that NO2 exposure during the first two years of life is associated with poorer attentional function in children from 4 to 8 years of age, especially in boys. These findings highlight the importance of exploring long-term effects of traffic-related air pollution exposure in older age groups.