Saharan dust episodes and pregnancy.

Desert dust is one of the natural contributors to atmospheric particulate matter worldwide. Although particulate pollution has been shown to adversely affect pregnancy, the available evidence on the impact of dust episodes on pregnancy is very scarce. The aim of this study was to evaluate the impact of Saharan dust episodes on pregnancy complications (preeclampsia and bacteriuria) and outcomes (birth weight and gestational age at delivery).

Green space, health inequality and pregnancy.

Green spaces have been suggested to improve physical and mental health and well-being by increasing physical activity, reducing air pollution, noise, and ambient temperature, increasing social contacts and relieving psychophysiological stress. Although these mechanisms also suggest potential beneficial effects of green spaces on pregnancy outcomes, to our knowledge there is no available epidemiological evidence on this impact. We investigated the effects of surrounding greenness and proximity to major green spaces on birth weight and gestational age at delivery and described the effect of socioeconomic position (SEP) on these relationships.

Exposure to trihalomethanes through different water uses and birth weight, small for gestational age, and preterm delivery in Spain.

Background: Evidence associating exposure to water disinfection by-products with reduced birth weight and altered duration of gestation remains inconclusive.

Objective: We assessed exposure to trihalomethanes (THMs) during pregnancy through different water uses and evaluated the association with birth weight, small for gestational age (SGA), low birth weight (LBW), and preterm delivery.

Methods: Mother-child cohorts set up in five Spanish areas during the years 2000-2008 contributed data on water ingestion, showering, bathing, and swimming in pools.

Climate extremes and the length of gestation.

Background: Although future climate is predicted to have more extreme heat conditions, the available evidence on the impact of these conditions on pregnancy length is very scarce and inconclusive.

Objectives: We investigated the impact of maternal short-term exposure to extreme ambient heat on the length of pregnancy.

Methods: This study was based on a cohort of births that occurred in a major university hospital in Barcelona during 2001-2005.

Spatial modeling of geographic inequalities in infant and child mortality across Nepal.

A survival regression model that allows for spatially correlated random effects is used to predict the hazard of dying among 12,714 children born between 1996 and 2006 in Nepal. The maps of fitted hazard rates show that even after accounting for individual and community-level covariates, a residual spatial pattern in infant mortality remains, with higher mortality concentrated in parts of Nepal's Far-Western and Mid-Western development regions. Results suggest a need to consider health policies and programs that reach children in spatially concentrated high-mortality areas.

Differences between marginal structural models and conventional models in their exposure effect estimates: a systematic review.

Background: Marginal structural models were developed to address time-varying confounding in nonrandomized exposure effect studies. It is unclear how estimates from marginal structural models and conventional models might differ in real settings.

Methods: We systematically reviewed the literature on marginal structural models since 2000.

Measurement errors in the assessment of exposure to solar ultraviolet radiation and its impact on risk estimates in epidemiological studies.

To date, many studies addressing long-term effects of ultraviolet radiation (UVR) exposure on human health have relied on a range of surrogates such as the latitude of the city of residence, ambient UVR levels, or time spent outdoors to estimate personal UVR exposure. This study aimed to differentiate the contributions of personal behaviour and ambient UVR levels on facial UVR exposure and to evaluate the impact of using UVR exposure surrogates on detecting exposure-outcome associations. Data on time-activity, holiday behaviour, and ambient UVR levels were obtained for adult (aged 25-55 years old) indoor workers in six European cities: Athens (37°N), Grenoble (45°N), Milan (45°N), Prague (50°N), Oxford (52°N), and Helsinki (60°N).

Investigating air pollution and atherosclerosis in humans: concepts and outlook.

Although ambient particulate matter contributes to atherosclerosis in animal models, its role in atherogenesis in humans needs to be established. This article discusses concepts, study design, and choice of health outcomes to efficiently investigate the atherogenic role of ambient air pollution, with an emphasis on early preclinical biomarkers of atherosclerosis that are unaffected by short-term exposure to air pollution (eg, carotid intima-media thickness [CIMT] and functional performance of the vessel). Air pollution studies using these end points are summarized.

Monitoring of heavy metal concentrations in home outdoor air using moss bags.

One monitoring station is insufficient to characterize the high spatial variation of traffic-related heavy metals within cities. We tested moss bags (Hylocomium splendens), deployed in a dense network, for the monitoring of metals in outdoor air and characterized metals' long-term spatial distribution and its determinants in Girona, Spain. Mosses were exposed outside 23 homes for two months; NO₂ was monitored for comparison.

Identification and prospective validation of clinically relevant chronic obstructive pulmonary disease (COPD) subtypes.

Background: Chronic obstructive pulmonary disease (COPD) is increasingly considered a heterogeneous condition. It was hypothesised that COPD, as currently defined, includes different clinically relevant subtypes.

Methods: To identify and validate COPD subtypes, 342 subjects hospitalised for the first time because of a COPD exacerbation were recruited.

Multiple correspondence discriminant analysis: an application to detect stratification in copy number variation.

We illustrate the use of multiple correspondence analysis (MCA) to correct for population stratification of copy number alteration data. In addition, we propose the use of multiple correspondence discriminant analysis (MCDA) to identify an optimal set of copy number variants (CNVs) that correctly infers the population stratification of a CNV map. Within MCDA, we highlight the novel use of correlation with class directions for variable ranking.

Local determinants of road traffic noise levels versus determinants of air pollution levels in a Mediterranean city.

Background: Both traffic-related noise and air pollution have been associated with cardiovascular disease (CVD). Spatial correlations between these environmental stressors may entail mutual confounding in epidemiological studies investigating their long-term effects. Few studies have investigated their correlation - none in Spain - and results differ among cities.

Power and sample size calculations for longitudinal studies estimating a main effect of a time-varying exposure.

Existing study design formulas for longitudinal studies assume that the exposure is time invariant or that it varies in a manner that is controlled by design. However, in observational studies, the investigator does not control how exposure varies within subjects over time. Typically, a large number of exposure patterns are observed, with differences in the number of exposed periods per participant and with changes in the cross-sectional mean of exposure over time.

Ambient air pollution and the progression of atherosclerosis in adults.

Background: Cross-sectional studies suggest an association between exposure to ambient air pollution and atherosclerosis. We investigated the association between outdoor air quality and progression of subclinical atherosclerosis (common carotid artery intima-media thickness, CIMT).

Methodology/principal Findings: We examined data from five double-blind randomized trials that assessed effects of various treatments on the change in CIMT.

Cognitive function and overweight in preschool children.

The authors assessed the association between cognitive function and incidence and maintenance of overweight in preschool children. A population-based birth cohort was established in Menorca, Spain, between 1997 and 1999 (n = 482). Body mass index (weight (kg)/height (m)(2)) was measured at ages 4 years and 6 years (n = 421).

Smoking habit, respiratory symptoms and lung function in young adults.

Background: Smoking is the primary cause of deterioration in forced expiratory volume (FEV(1)) and the development of chronic obstructive lung disease. This study assessed the independent association of smoking with respiratory symptoms and lung function in young adults who took part in the European Community Respiratory Health Survey (ECRHS-I).

Methods: Cross-sectional multi-centre survey of a general population of young adults aged 20(44 years in the ECRHS(I conducted in five Spanish centres.

Relations between respiratory symptoms and spirometric values in young adults: the European community respiratory health study.

We aim to assess whether respiratory symptoms are associated with lung function in young adults, and whether any such relation is similar in those with asthma, in men and women, and in different countries. Study participants (aged 20-44 years) were randomly selected from the general population in 35 centres in 15 countries as part of the European Community Respiratory Health Study. In all, 12,541 subjects (47%) completed a respiratory symptoms questionnaire and spirometry, metacholine challenge and immunoglobulin E tests.

Socioeconomic status and asthma prevalence in young adults: the European Community Respiratory Health Survey.

The authors assessed the association between asthma prevalence and socioeconomic status at both the individual and center levels simultaneously.by using data from 32 centers in 15 countries. Included were 10,971 subjects aged 20-44 years selected from the general population and interviewed in 1991-1992.

Smoking cessation and associated factors during pregnancy.

Objective: To examine smoking habits before and during pregnancy, as well as factors associated with smoking cessation, in three European settings.

Methods: Women seeking antenatal care in Ashford (UK), Minorca and Barcelona (Spain) were recruited to the Asthma Multicenter Infant Cohort Study (AMICS). Questionnaires inquiring into the smoking habits of each woman and her partner, demographic data, occupation, educational level, number of previous children, breast feeding, alcohol intake, and history of asthma and of other allergic diseases were completed during pregnancy and in the first year after delivery.

The role of age in cardiovascular risk factor clustering in non-diabetic population free of coronary heart disease.

Unlabelled: The objectives were to analyse whether cardiovascular risk factors appear simultaneously in the population and to determine whether it depends on age. The participants belong to a random sample of individuals 25-74 years of age, representative of the non-diabetic population free of coronary heart disease of the province of Gerona, Spain, studied during 1994-1996. Exploratory factor analysis was used to assess clustering of cardiovascular risk factors and confirmatory factor analysis to compare clustering among age groups (25-54 and 55-74).

Sources and concentrations of indoor nitrogen dioxide in Barcelona, Spain.

Sources and concentrations of indoor nitrogen dioxide (NO2) were examined in Barcelona, Spain, during 1996-1999. A total of 340 dwellings of infants participating in a hospital-based cohort study were selected from different areas of the city. Passive filter badges were used for indoor NO2 measurement over 7-30 days.

Serum organochlorines and urinary porphyrin pattern in a population highly exposed to hexachlorobenzene.

Background: Porphyria cutanea tarda (PCT) is caused by hexachlorobenzene (HCB) in several species of laboratory mammals, but the human evidence is contradictory. In a study among adults of a population highly exposed to HCB (Flix, Catalonia, Spain), the prevalence of PCT was not increased. We aimed at analysing the association of individual urinary porphyrins with the serum concentrations of HCB and other organochlorine compounds in this highly exposed population.

Domestic aeroallergen levels in Barcelona and Menorca (Spain).

Exposure to common indoor allergens is known to be associated with sensitization and triggers of asthma. Levels of allergens have been barely described in Mediterranean countries. This study reports domestic allergen levels among the general population of two regions of Spain.

Evaluation of urinary porphyrin excretion in neonates born to mothers exposed to airborne hexachlorobenzene.

The existence of a link between hexachlorobenzene (HCB) and porphyria cutanea tarda has been known for a long time. However, the epidemiologic data on effects on health caused by prenatal exposure have not provided convincing evidence that HCB alters porphyrin metabolism. Our objectives were to analyze urinary porphyrin excretion and HCB in maternal serum and fetal cord blood in neonates born in a village (Flix) near a chlorinated solvent factory, to detect possible adverse effects in urinary porphyrin excretion caused by prenatal exposure, and to assess their relationship with HCB blood levels.