Maternal short-term exposure to NO2 during pregnancy and its relationship with Doppler markers of placental function.

BACKGROUND: Maternal exposure to air pollution has been associated with poor obstetric outcomes. However, the available evidence on the impact of maternal exposure to air pollution on placental function is still scarce and is based on estimated ambient levels of air pollutants. OBJECTIVE: To evaluate the association between short-term maternal exposure to NO2 based on the objective personal measure of NO2 exposure and Doppler markers of placental function. METHODS: This study was based on a prospective cohort of 101 pregnant women, recruited at Hospital Sant Joan de Déu, Barcelona (Spain), between January 2017 and April 2018. NO2 diffusion tubes were worn by pregnant women to measure personal exposure to NO2 between weeks 28 and 32 of their pregnancy. Placental function was evaluated at the 32nd week of gestation by Doppler evaluation of mean uterine arteries pulsatility index (PI), umbilical artery PI, middle cerebral artery PI, cerebroplacental ratio (CPR) and ductus venosus PI. Linear regression models were applied to estimate the association of personal NO2 exposure and Doppler markers of placental function (one at a time), controlled for relevant covariates. RESULTS: Higher personal exposure to NO2 was significantly associated with lower mean uterine artery PI. Each one-interquartile range (IQR) increase in the exposure to NO 2 was associated with -0.07 (95% confidence intervals (CIs): -0.12, -0.02) decrease in uterine arteries PI. We also observed some suggestions for an inverse association between this exposure and CPR. A one-IQR increase in NO2 was associated with -0.18 (95% CIs: -0.37, 0.01) decrease in CPR. The findings for the rest of Doppler markers were not conclusive. CONCLUSIONS: Maternal exposure to NO2 could interfere with Doppler markers of placental function, potentially indicating a certain degree of cerebral vasodilatation with a decrease of mean uterine arteries PI.

Data set from large-scale citizen science provides high-resolution nitrogen dioxide values for enhancing community knowledge and collective action to related health issues.

Dataset from a large-scale air quality citizen science campaign is presented (xAire, 725 measurements, see Ref. [1]). A broad partnership with 1650 citizens from communities around 18 primary schools across Barcelona (Spain) provided the capacity to obtain unprecedented high-resolution NO2 levels which had in turn the capacity to provide an updated asthma Health Impact Assessment. Nitrogen dioxide levels being obtained in a 4-week period during February and March 2018 with Palmes' diffusion samplers are herein provided. Dataset includes NO2 levels from outdoor locations n=671, playgrounds n=31, and inside school buildings (mostly classrooms) n=23. Data was calibrated and annualized with concentration levels from automatic reference stations. It is shown that NO2 levels vary considerably with at some cases very high levels. Strong differences might also however be explained by the fact that ambient air pollution is reduced exponentially with distance from an emission source like traffic meaning that two samplers located about 100 m away can measure a tenfold difference concentration level.

Large-scale citizen science protocol provides high-resolution nitrogen dioxide values while enhancing community knowledge and collective action.

We present an already tested protocol from a large-scale air quality citizen science campaign (xAire, 725 measurements, see Ref. [1]). A broad partnership with 1,650 people from communities including 18 primary schools in Barcelona (Spain) provided the capacity to obtain unprecedented high-resolution NO2 levels. Communities followed the protocol to select measurement points and obtain NO2 levels from outdoor locations n=671, playgrounds n=31, and inside school buildings (primarily classrooms) n=23. Data was calibrated and annualized with concentration levels from the city´s automatic air quality monitoring reference stations [2].

Large-scale citizen science provides high-resolution nitrogen dioxide values and health impact while enhancing community knowledge and collective action.

We present outcomes from a large-scale air quality citizen science campaign (xAire, 725 measurements) to demonstrate its positive contribution in the interplay between advances in exposure assessment and developments in policy or collective action. A broad partnership with 1,650 people from communities around 18 primary schools across Barcelona provided the capacity to obtain unprecedented high-resolution NO2 levels and an updated asthma Health Impact Assessment. It is shown that NO2 levels vary considerably with at some cases very high levels. More than a 1,000 new cases of childhood asthma could be prevented each year by lowering NO2 levels. Representativity of site selection and the minimal number of samplers for land use regression modelling are considered. Enhancement of community knowledge and attitudes towards collective response were observed and identified as key drivers for successful large-scale monitoring campaigns. The results encourage strengthening collaboration with local communities when exploring environmental health issues.

Association between long-term exposure to traffic-related air pollution and subclinical atherosclerosis: the REGICOR study.

BACKGROUND: Epidemiological evidence of the effects of long-term exposure to air pollution on the chronic processes of atherogenesis is limited. OBJECTIVE: We investigated the association of long-term exposure to traffic-related air pollution with subclinical atherosclerosis, measured by carotid intima media thickness (IMT) and ankle-brachial index (ABI). METHODS: We performed a cross-sectional analysis using data collected during the reexamination (2007-2010) of 2,780 participants in the REGICOR (Registre Gironí del Cor: the Gerona Heart Register) study, a population-based prospective cohort in Girona, Spain. Long-term exposure across residences was calculated as the last 10 years' time-weighted average of residential nitrogen dioxide (NO2) estimates (based on a local-scale land-use regression model), traffic intensity in the nearest street, and traffic intensity in a 100 m buffer. Associations with IMT and ABI were estimated using linear regression and multinomial logistic regression, respectively, controlling for sex, age, smoking status, education, marital status, and several other potential confounders or intermediates. RESULTS: Exposure contrasts between the 5th and 95th percentiles for NO2 (25 µg/m3), traffic intensity in the nearest street (15,000 vehicles/day), and traffic load within 100 m (7,200,000 vehicle-m/day) were associated with differences of 0.56% (95% CI: -1.5, 2.6%), 2.32% (95% CI: 0.48, 4.17%), and 1.91% (95% CI: -0.24, 4.06) percent difference in IMT, respectively. Exposures were positively associated with an ABI of > 1.3, but not an ABI of < 0.9. Stronger associations were observed among those with a high level of education and in men ≥ 60 years of age. CONCLUSIONS: Long-term traffic-related exposures were associated with subclinical markers of atherosclerosis. Prospective studies are needed to confirm associations and further examine differences among population subgroups.

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. OBJECTIVES: We assessed the contribution of urban land-use and traffic variables to the noise-air pollution correlation in Girona town, where an investigation of the chronic effects of air pollution and noise on CVD takes place (REGICOR-AIR). METHODOLOGY: Outdoor annual mean concentrations of nitrogen dioxide (NO(2)) derived from monthly passive sampler measurements were obtained at 83 residential locations. Long-term average traffic-related noise levels from a validated model were assigned to each residence. Linear regression models were fitted both for NO(2) and noise. RESULTS: The correlation between NO(2) and noise (L(24h)) was 0.62. However, the correlation differed across the urban space, with lower correlations at sites with higher traffic density and in the modern downtown. Traffic density, distance from the location to the sidewalk and building density nearby explained 35.6% and 73.2% of the variability of NO(2) and noise levels, respectively. The correlation between the residuals of the two models suggested the presence of other unmeasured common variables. CONCLUSIONS: The substantial correlation between traffic-related noise and NO(2), endorsed by common determinants, and the dependence of this correlation on complex local characteristics call for careful evaluations of both factors to ultimately assess their cardiovascular effects.