Associations between heat wave during pregnancy and term birth weight outcomes: The PARIS birth cohort.

BACKGROUND: Climate change will make extreme weather events more frequent in the 21st century. Extreme ambient temperatures during the prenatal period have been associated with adverse pregnancy outcomes such as preterm birth. It is unclear, however, whether heat waves during pregnancy impact fetal growth in apparently healthy term newborns. OBJECTIVES: We aimed to investigate associations between heat wave during pregnancy and birth weight outcomes in term newborns from the PARIS birth cohort, and to explore meteorological conditions and air pollution as possible intermediate factors. METHODS: We examined data on 3,359 newborns born between 37 and 42 weeks in Paris, France, between 2003 and 2006. Associations of maternal exposure to heat wave (during whole pregnancy and each trimester) with birth weight and small for gestational age (SGA) at term were studied using linear and logistic regression models adjusted for potential confounders. Maternal characteristics were investigated as possible modifiers. We explored the mediating role of ambient temperature, relative humidity, and air pollution levels in the relationship between heat wave during the first trimester and term SGA. RESULTS: Mothers who were pregnant during the 2003 French heat wave (n = 506, 15 %) were more likely to have a term SGA baby (aOR = 2.70; 95 %CI: 1.38, 5.28) compared to mothers who did not experience heat wave during pregnancy. The association was stronger when heat wave occurred during the first trimester (aOR = 4.18; 95 %CI: 1.69, 10.35). Primiparous women were identified as more vulnerable than multiparous women. Average ambient temperature and air quality index explained about 36 % and 56 % of the association between heat wave during the first trimester and term SGA, respectively. CONCLUSIONS: This study suggests prenatal exposure to heat wave, especially during the first trimester, may adversely affect fetal growth of term newborns, which could be explained by both increasing ambient temperatures and worsening air quality.

Early exposure to sunlight and allergic morbidity: The PARIS birth cohort.

The relationship between sunlight and allergies in children has received limited attention from researchers. We sought to explore how early exposure to solar radiation is associated with allergic morbidity within the PARIS birth cohort study. Our research dealt with children who attended at least one of two health checkups: at 18 months (n = 2012) and at 8-9 years (n = 1080). Early exposure to solar radiation was assessed using meteorological data (e.g., solar radiation, temperature, and relative humidity). Children with similar meteorological exposure trajectories were grouped by a longitudinal and multidimensional cluster analysis. The association between solar radiation exposure and allergic morbidity (i.e., allergic sensitization at 18 months and 8-9 years; current asthma, rhinitis, and eczema at 8-9 years) was quantified by multivariable logistic regression models adjusted for potential confounders. The effect modification of maternal vitamin D supplementation during pregnancy was tested. Four meteorological exposure trajectories were found. The trajectory with the highest exposure to early solar radiation had a reduced risk of sensitization at 8-9 years compared to the trajectory with the lowest exposure (p = 0.06). The association was statistically significant in the vitamin D supplementation group. Solar radiation during prenatal and postnatal periods was significantly associated with a lower risk of sensitization at 8-9 years (for one interquartile range (IQR) increase, adjusted odds ratio (aOR): 0.47; 95 % confidence interval (CI): 0.25-0.87 and 0.84; 0.7-1.00, respectively). Increased prenatal exposure to solar radiation was significantly associated with a lower risk of asthma at 8-9 years (for one IQR increase, aOR: 0.32; 95 % CI: 0.1-0.96). Early sunlight exposure may reduce the risk of sensitization and asthma in school-aged children, especially in those prenatally exposed to vitamin D. These findings highlight the importance of vitamin D in preventing allergic diseases in children, either through supplementation or sunlight exposure.

Unsupervised identification of cardiometabolic profiles among adolescents: findings from the PARIS birth cohort study.

Metabolic syndrome (MetS) is known as a risk factor in cardiometabolic morbidity but there is no consensus on its definition for teenagers. We aimed to identify cardiometabolic health profiles and which parameters best discriminate them. K-means partitioning identified cardiometabolic profiles by sex using data on health measurements of 530 adolescents from the PARIS birth cohort. A discriminant analysis was performed. Cardiometabolic risk score and handgrip strength were also measured. Depending on definitions, MetS prevalence ranged from 0.2% to 1.3%. Two profiles were identified for the entire group and by sex: "healthy" and "at cardiometabolic risk." Weight and waist-to-height ratio or waist circumference explained more than 87% of the variance in the profile differentiation. The "at cardiometabolic risk" profiles included adolescents with overweight, a waist-to-height ratio over 0.5, and prehypertension. They had higher cardiometabolic risk scores and parents who were more likely to be overweight and have cardiometabolic diseases themselves. They also had higher birthweights, earlier adiposity-rebound and puberty ages, and lower relative handgrip strength.  Conclusion: The two profiles identified, based on cardiometabolic health, were associated with early indicators and handgrip strength. Results suggest that the waist-to-height ratio is a useful clinical tool for screening individuals at cardiometabolic risk and who therefore require clinical follow-up. What is Known: • Although there is a need for tools to assess cardiometabolic health during adolescence, there is no consensus on the definition of metabolic syndrome for this age group. What is Knew: • The findings suggest that waist-to-height ratio can serve as a simple and valuable clinical tool for screening individuals at cardiometabolic risk who may require clinical monitoring for early prevention of cardiovascular diseases.

The impact of COVID-19 lockdown restrictions on the short-term association between in-vehicle particulate pollutants and the respiratory health of Parisian taxi drivers.

OBJECTIVES: This study assessed the short-term associations between in-vehicle ultrafine particles (UFP) and black carbon (BC) concentrations and irritation symptoms and lung parameters of taxi drivers, pre- and post-lockdown. METHODS: As part of PUF-TAXI project, 33 taxi drivers were followed up during two typical working days. In-vehicle UFP and BC were continuously measured by monitoring instruments. Irritation symptoms during the working day were reported via an auto-questionnaire and lung function was assessed by a portable spirometer, pre- and post- work shift. Generalized estimating equations, adjusted for potential confounders, were used to study the association between air pollutants and health outcomes. Effect modification by measurement period (pre- and post-lockdown) was investigated. RESULTS: UFP and BC concentrations inside taxi vehicles decreased significantly post- compared to pre-lockdown. Incidence of nose irritation was positively associated with in-vehicle UFP and BC levels pre-lockdown, when pollutant levels were higher, whereas no significant association was found post-lockdown. The decrease in the FEF25-75% (forced expiratory flow at 25-75% of the forced vital capacity) during the working day was significantly associated with in-taxi UFP levels before but not after lockdown. No association was found with BC. By contrast, incidence of eye irritation was significantly inversely associated with in-vehicle humidity, regardless of pollutant concentrations and the measurement period. CONCLUSIONS: Our findings indicate that an upgrade in in-vehicle air quality could improve respiratory health. This study showed that the magnitude of the incidence of nasal irritation and decrease in lung function depends on UFP concentrations the commuters are exposed to.

Subgroups of perceptions and related behaviors during the COVID-19 lockdown: experience of adolescents in the PARIS birth cohort.

BACKGROUND: Adolescents may not all have reacted similarly to the COVID-19 lockdown. This study aimed to identify subgroups of perceptions in adolescents from the PARIS cohort during the first French lockdown, and to investigate whether adolescent behaviors differed according to these subgroups. METHODS: Online questionnaires were sent to 1,549 PARIS adolescents aged 13-17 years who reported on possible infection with SARS-CoV-2, their perceptions, and behaviors during lockdown. Ascending hierarchical clustering was performed on the perception variables. Associations of behaviors with perception clusters were analyzed using multivariable multinomial logistic regression. RESULTS: Three perception clusters were identified among 791 adolescents (response rate 51%). One cluster "happy" (39%) had good mental health and did not feel stressed during lockdown. Another cluster "unhappy" (19%) was mainly unhappy, felt stressed, suffered from overcrowded living conditions, and experienced deteriorating relationships with family members. A further cluster "intermediate" (42%) experienced moderate well-being and stress, felt more supported by family, and worried about the health of their relatives. Compared with the "happy" cluster, the unhappy adolescents were more affected by COVID-19, had difficulty doing school activities, spent more time on social networks and less time on video games, slept less, and reported a deterioration in their diet. Adolescents "intermediate" with moderate well-being were more often girls, spent more time on social networks, were more physically active, slept less, and more often reported eating fruit and vegetables and drinking alcohol. CONCLUSIONS: Not all adolescents experienced lockdown in the same way. This study highlighted subgroups that differed in terms of well-being and health-related behaviors. These results should motivate public authorities to consider the benefit/risk ratio of implementing strict lockdowns by taking into account family disparities and inequities among adolescents.

Staphylococcal Sensitization: A Correlate of Type 2-High Inflammation in Children With Severe Asthma.

BACKGROUND: Sensitization to Staphylococcus aureus enterotoxin (SE) has been identified to be a risk factor for asthma, but its determinants remain unclear. OBJECTIVE: To determine the significance of SE sensitization in children with moderate to severe asthma. METHODS: This was an observational cross-sectional analysis performed from 2011 to 2015 including children from the prospective Severe Asthma Molecular Phenotype cohort: school-age children with severe and moderate asthma or preschool-age children with severe and moderate recurrent wheeze. We evaluated sensitization to four SEs (Staphylococcus enterotoxin A, Staphylococcus enterotoxin B, Staphylococcus enterotoxin C, and toxic shock staphylococcic toxin). RESULTS: We analyzed data from 377 children: 233 of preschool age and 144 of school age. Among them, 26 (11.2%) and 59 (41.0%) children, respectively, had sensitization to at least one SE. The burden of sensitization was higher in older children in terms of both specific IgE levels and the number of sensitizations. In multivariable analysis, SE sensitization was associated with elevated total IgE in both populations (odds ratio [OR] = 9.35, P = .01; and OR = 8.06, P < .01), and with bronchoalveolar lavage eosinophilia in both preschool and school-age children (OR = 3.95, P = .03; and OR = 4.11, P = .03, respectively). Classification and regression trees showed an association of SE sensitization with age and with total IgE in the entire population, and with total IgE, bronchoalveolar lavage eosinophilia, and blood eosinophilia in school-age children. CONCLUSIONS: Staphylococcal enterotoxin sensitization was correlated with type 2-high inflammation (eosinophilic inflammation and elevated total IgE count) in this population of moderate to severe asthmatic children.

Innovative graph analysis method to assess gene expression modulation after fine particles exposures of 3D human airway epithelia.

Environmental particles have dramatic consequences for health, especially for the most vulnerable people, such as asthmatics. To better understand the impact on gene expression modulation of fine particles (PM2.5-0.3) from different emission sources, a 3D-airway model, a human bronchial epithelium (MucilAir-HF™) reconstructed from primary cells from healthy (EpiH) or asthmatic (EpiA) donors, was used. Repeated air-liquid exposures were performed, and epithelia were sacrificed to extract RNAs and assess gene expression. Data were analyzed according to the emission sources, physiological status, and exposure doses using a recent model consisting in a graph analysis on pairwise expression ratio. The results were compared with those from the classical ΔΔCt method. The graph analysis method proved to have better statistical properties than the classical ΔΔCt method and demonstrated that repeated PM2.5-0.3 exposures induced a dose-dependent up-regulation of the metabolic gene (CYP1B1) and a down-regulation of the inflammation gene (CXCL10). These modulations were greater for "industrial" than for "urban traffic" fine particles, and the effects were found to be greater after exposure of EpiA than EpiH, thus emphasizing the importance of the epithelium's physiological status in sensitivity to particles. Our study is original in terms of the experimental conditions and the graphical statistical analysis model established. The results highlight the importance of particle chemistry on the modulation of cellular and molecular responses, which may vary according to the individual's vulnerability.

Coronavirus Disease 2019 (COVID-19) Lockdown: Morbidity, Perception, Behaviors, and Attitudes in French Families From the PARIS Birth Cohort.

Background: Few studies have examined the overall experience of adolescents and their families during COVID-19 lockdowns. This study describes COVID-19-related morbidity in the PARIS birth cohort families during the first lockdown in France and identifies family profiles in terms of morbidity, perception, behaviors, and attitudes. Methods: Online questionnaires were sent to adolescents of the PARIS birth cohort and their parents. Possible COVID-19 was defined by symptoms using the ECDC definition. Household transmission was estimated by calculating the observed clinical secondary attack rates. Perception, behaviors and attitudes were assessed by levels of stress, degree of satisfaction regarding levels of information about COVID-19, degree of agreement with the lockdown and preventive measures. COVID-19 morbidity in adolescents and parents was compared using chi-squared or Student's t-tests. Within each family, perception, behaviors, and attitudes were compared between adolescents and parents using matched-pairs tests. To identify contrasting family profiles, a K-means cluster analysis was implemented. Results: Of 1,549 families contacted, 1,051 (68%) participated. Adolescents were less affected by possible COVID-19 than their parents (138.7 vs. 192.7 per 1,00,000 person-days). Household transmission of possible COVID-19 was higher when possible COVID-19 came from adults than from adolescents. Most families implemented preventive measures. Adolescents and parents generally shared the same attitudes, but adolescents were less compliant with restrictive measures. Four family profiles were identified which differed mainly regarding family stress, COVID-19 in the household, and compliance with preventive measures. Conclusion: Improving information dissemination to parents and adolescents, including dedicated adolescent messages, would increase adherence to preventive measures.

Changes in air quality in-taxis and in working conditions of taxi drivers pre- and post-lockdown, during the COVID-19 pandemic in the Paris area.

We evaluated the impact of the lockdown restriction measures in the Paris area on the variation of in-vehicle ultrafine particle (UFP) and black carbon (BC) concentrations between the pre- and post-lockdown period and professional drivers' working conditions and practices. The study was conducted with 33 taxi drivers. UFP and BC were measured inside their vehicles with DiSCmini® and microAeth® , respectively, on two typical working days pre- and post-lockdown. Job characteristics were self-reported. Our results showed that post-lockdown, both the number of clients and journey duration significantly decreased. Taxi drivers opened their windows significantly more and reduced the use of air recirculation. UFP decreased significantly by 32% and BC by 31% post-lockdown, with a weaker positive correlation compared to pre-lockdown. The reduction of in-vehicle UFP was due mainly to the reduction of traffic flow and ventilation settings, though the latter probably varied according to traffic conditions. The variation of in-vehicle BC also tended to be related to the decrease in traffic flow post-lockdown. We emphasize the role of traffic emissions on in-vehicle air pollution and that preventive measures such ventilation settings would help to minimize the exposure of professional drivers and passengers to air pollutants.

Early postnatal exposure to traffic-related air pollution and asthma in adolescents: vulnerability factors in the PARIS birth cohort.

BACKGROUND: Associations between early traffic-related air pollution (TRAP) exposure and respiratory and allergic morbidity in adolescents are inconsistent. However, sub-groups might be more vulnerable to the health effects of this exposure. OBJECTIVES: We investigated associations between early exposure to TRAP and respiratory and allergic morbidity at age 13 years in the PARIS birth cohort, and potential modifying effects of sex, parental allergy, stressful family event and lower respiratory tract infections (LRTI). METHODS: This study deals with data from 732 children of the PARIS birth cohort followed up using repeated questionnaires until 13 years of age. Prenatal TRAP exposure was assessed by measuring daily concentrations of nitrogen dioxide at the nearest station to mother's home. Early postnatal TRAP exposure was calculated for each child during the first year of life by a nitrogen oxides (NOx) air dispersion model taking into account both residence and daycare. Associations between TRAP exposures and asthma, rhinitis and related symptoms were assessed using multivariable logistic regression models adjusted for potential confounding factors. Effect modification was explored by testing multiplicative interactions. RESULTS: An increase in interquartile range (17.0 µg/m3) of early postnatal NOx exposure was positively related to current asthma (adjusted odds ratio aOR = 1.21; 95% confidence interval CI: 1.02, 1.43), severe wheeze (aOR = 1.23; 95% CI: 1.02, 1.47) and persistent asthma at 13 years old (aOR = 1.26; 95% CI: 1.03, 1.55) and tended to be associated with asthma ever. Parental history of allergy, asthma, early stressful family event and LRTI modified these associations with TRAP exposure. No relationship with rhinitis was found. Prenatal TRAP exposure did not show any association with respiratory and allergic morbidity. DISCUSSION: This study is one of the first to show several modifiers of the association between early postnatal TRAP exposure and asthma at adolescence. Not all adolescents seem equally affected by early postnatal TRAP exposure: those presenting parental history of allergy, especially asthma, those with early stressful family event or LRTI appear to be more vulnerable.

Mediterranean diet and lung function, sensitization, and asthma at school age: The PARIS cohort.

BACKGROUND: The Mediterranean diet (MD) has known health benefits, but its specific impact on allergy development is unclear. As part of the PARIS birth cohort follow-up, we aimed to investigate the adherence of 8-year-old children to the MD and its association with allergic/respiratory morbidity at school age. METHODS: Diet was assessed using a food frequency questionnaire completed by the parents. Adherence to the MD was assessed based on two scores: the KIDMED index and the Mediterranean Diet Score (MDS). Current allergic diseases (asthma, rhinitis, eczema), lung function indices (FEV1 and FVC), FeNO and specific IgE levels were determined during a health check-up at 8 years. Associations between levels of adherence to the MD and respiratory/allergic morbidity were studied using multivariable logistic and linear regression models adjusted for potential confounders. RESULTS: A total of 975 children were included in the present study, 35.6% with low adherence to the MD, 55.7% with moderate adherence and 8.7% with high adherence according to the KIDMED index. High family socioeconomic status, any breastfeeding at 6 months and consumption of organic food were associated with higher adherence to the MD. Compared with low adherence, high adherence was associated with lower risk of asthma and sensitization at 8 years, as well as higher FEV1 and FVC. CONCLUSION: This study suggests a protective effect of high adherence to the MD on allergic and respiratory morbidity at school age. These results need to be confirmed by further longitudinal analyses. A healthy diet may prevent allergic and respiratory morbidity in school-aged children.

Association between lung function of school age children and short-term exposure to air pollution and pollen: the PARIS cohort.

BACKGROUND: Daily levels of ambient air pollution and pollen may affect lung function but have rarely been studied together. We investigated short-term exposure to pollen and air pollution in relation to lung function in school-age children from a French population-based birth cohort. METHODS: This study included 1063 children from the PARIS (Pollution and Asthma Risk: an Infant Study) cohort whose lung function and FeNO measurements were performed at age 8 years old. Exposure data were collected up to 4 days before testing. We estimated daily total pollen concentration, daily allergenic risk indices for nine pollen taxa, as well as daily concentrations of three air pollutants (particulate matter less than 10 µm (PM10), nitrogen dioxide (NO2), ozone (O3)). Children with similar pollen and air pollution exposure were grouped using multidimensional longitudinal cluster analysis. Associations between clusters of pollen and air pollution exposure and respiratory indices (FEV1, FVC, FeNO) were studied using multivariable linear and logistic regression models adjusted for potential confounders. RESULTS: Four clusters of exposure were identified: no pollen and low air pollution (Cluster 1), grass pollen (Cluster 2), PM10 (Cluster 3) and birch/plane-tree pollen with high total pollen count (Cluster 4). Compared with children in Cluster 1, children in Cluster 2 had significantly lower FEV1 and FVC levels, and children from Cluster 3 had higher FeNO levels. For FEV1 and FVC, the associations appeared stronger in children with current asthma. Additional analysis suggested a joint effect of grass pollen and air pollution on lung function. CONCLUSION: Daily ambient chemical and biological air quality could adversely influence lung function in children.

Short-term association of in-vehicle ultrafine particles and black carbon concentrations with respiratory health in Parisian taxi drivers.

INTRODUCTION: Professional drivers are exposed inside their vehicles to high levels of air pollutants due to the considerable time they spend close to motor vehicle emissions. Little is known about ultrafine particles (UFP) or black carbon (BC) adverse respiratory health effects compared to the regulated pollutants. OBJECTIVES: We aimed to study the short-term associations between UFP and BC concentrations inside vehicles and (1) the onset of mucosal irritation and (2) the acute changes in lung function of Parisian taxi drivers during a working day. METHODS: An epidemiological study was carried out on 50 taxi drivers in Paris. UFP and BC were measured inside their vehicles with DiSCmini® and microAeth®, respectively. On the same day, the frequency and the severity of nose, eye, and throat irritations were self-reported by each participant and a spirometry test was performed before and after the work shift. Multivariate analysis was used to evaluate the associations between in-taxis UFP and BC concentrations and mucosal irritation and lung function, after adjustment for potential confounders. RESULTS: In-taxis UFP concentrations ranged from 17.9 to 37.9 × 103 particles/cm3 and BC concentrations from 2.2 to 3.9 µg/m3, during a mean of 9 ± 2 working hours. Significant dose-response relationships were observed between in-taxis UFP concentrations and both nasal irritation and lung function. The increase of in-taxis UFP (for an interquartile range of 20 × 103 particles/cm3) was associated to an increase in nasal irritation (adjusted OR = 6.27 [95% CI: 1.02 to 38.62]) and to a reduction in forced expiratory flow at 25-75% by -7.44% [95% CI: -12.63 to -2.24], forced expiratory volume in one second by -4.46% [95% CI: -6.99 to -1.93] and forced vital capacity by -3.31% [95% CI: -5.82 to -0.80]. Such associations were not found with BC. Incident throat and eye irritations were not related to in-vehicle particles exposure; however, they were associated with outdoor air quality (estimated by the Atmo index) and in-vehicle humidity, respectively. CONCLUSION: To our knowledge, our study is the first to show a significant association, within a short-period of time, between in and vehicle UFP exposure and acute respiratory effects in professional drivers.

Infant feeding clusters are associated with respiratory health and allergy at school age in the PARIS birth cohort.

BACKGROUND: As infant feeding may influence allergy development, we aimed to identify groups of infants based on feeding practices and to examine their associations with respiratory health/allergy at 8 years in the PARIS birth cohort. METHODS: Data on breastfeeding, consumption of infant formula (regular, pre-/probiotics, partially hydrolysed with hypoallergenic label [pHF-HA], extensively hydrolysed [eHF], soya) and solid food introduction were collected using repeated questionnaires at 1, 3, 6, 9 and 12 months. Infants with similar feeding practices over the first year of life were grouped using multidimensional longitudinal cluster analysis. Respiratory/allergic morbidity was studied at 8 years as symptoms, doctor's diagnoses (asthma, hay fever, eczema, food allergy), and measurement of lung function, FeNO and specific IgE. Associations between feeding-related clusters and respiratory/allergic morbidity were investigated using multivariable logistic and linear regression models adjusted for potential confounders including early respiratory/allergic outcomes and parental history of allergy. RESULTS: Five clusters were identified among 3446 infants: Cluster 1 (45%) mainly fed with regular formula, Cluster 2 (27%) exclusively breastfed during the first 3 months, and three other clusters consuming different types of formula (pre-/probiotics for Cluster 3 [17%], pHF-HA for Cluster 4 [7%], eHF/soya for Cluster 5 [4%]). Compared to Cluster 1, children from Cluster 2 tended to have a lower risk of asthma and children from Cluster 4 had a significant lower lung function (FEV1 , FVC), higher FeNO and higher risk of sensitization at 8 years. CONCLUSION: Early pHF-HA use was negatively associated with objective measures of respiratory/allergic morbidity at school age, while children breastfed for at least 3 months seem protected against asthma at 8 years old.

Determinants of ultrafine particles, black carbon, nitrogen dioxide, and carbon monoxide concentrations inside vehicles in the Paris area: PUF-TAXI study.

This study presents real-time concentrations of traffic-related air pollutants during 499 trips conducted by 50 Parisian taxi drivers from PUF-TAXI project. Ultrafine particles (UFP), black carbon (BC), and nitrogen dioxide (NO2 )/carbon monoxide (CO) were measured inside vehicles by Diffusion Size Classifier Miniature® , microAeth® , and Gas-Pro® , respectively, for nine hours. Vehicle/trip data characteristics were collected by questionnaires and on ambient conditions by monitoring stations. The associations between pollutant levels and their potential determinants were analyzed using generalized estimating equation model. Determinants of in-vehicle pollutants levels were identified: (1) ambient factors (meteorology and ambient pollution)-affecting BC, NO2, and CO; (2) vehicle characteristics-affecting all pollutants; and (3) trip-related driving habits-affecting UFP, BC, and CO. We highlight that commuters can, therefore, avoid high in-vehicle air pollutant concentrations mainly by (1) closing windows and activating air-conditioning under air recirculation mode in congested traffic; (2) smooth driving; and (3) maintaining cabin air filters.

Influence of the environmental relative humidity on the inflammatory response of skin model after exposure to various environmental pollutants.

The skin is an essential barrier, protecting the body against the environment and its numerous pollutants. Several environmental pollutants are known to affect the skin, inducing premature aging through mechanisms including oxidative stress, inflammation, and impairment of skin functions. Even climate conditions can impact the skin. Therefore, using a Reconstructed Human Epidermis (RHE), we tested the effect of two samples of fine particulate matters (PM0.3-2.5 - one metals-rich sample and the other organic compounds-rich), two Volatile Organic Compounds mixtures (VOCs - from a solvent-based paint and a water-based paint) and Tobacco Smoke (TS). All pollutants affected cellular functionality, but to a lesser extent for the water-based paint VOC. This effect was enhanced when RHE were preconditioned for 2 h by a semi-dry airflow (45% relative humidity) before pollutants application, compared to preconditioning by a humid airflow (90% relative humidity). In the absence of preconditioning, IL-1α, IL-6, IL-8, and RANTES were almost systematically induced by pollutants. When RHE were preconditioned by a semi-dry or humid airflow before being subjected to pollutants, the increase of IL-1α, IL-8, and RANTES falls into two groups. Similarly to RHE not treated with pollutants, RHE treated with VOCs after preconditioning by a semi-dry airflow showed increased IL-1α, IL-8, and RANTES release. On the contrary, RHE treated with PM or TS after preconditioning by a semi-dry airflow show a lower increase in IL-1α, IL-8, and RANTES compared to preconditioning by a humid airflow. The effect of real environmental relative humidity conditions of the air, combined with acute exposure to various environmental pollutants, seemed to relate mainly to structural changes of the skin, determining the outcome of the inflammatory response depending on the physicochemical characteristics of pollutants.

Cross-sectional study of in-vehicle exposure to ultrafine particles and black carbon inside Lebanese taxicabs.

Taxi drivers' exposure to traffic-related air pollutants inside their vehicles has been reported in different countries but not yet in Lebanon. Thus, we conducted a cross-sectional study on 20 Lebanese taxi drivers to (1) assess their exposure to ultrafine particles (UFP) and black carbon (BC) inside their vehicles and (2) identify determinants of this exposure. UFP and BC were measured using Diffusion Size Classifier Miniature® and microAeth® Model AE51, respectively, for 5 hours. Data on characteristics of vehicles and trips were collected by face-to-face interviews. Associations between pollutant levels and their determinants were analyzed by multiple linear regression. The mean of UFP count (35.2 ± 17.6 x 103 particles cm-3 ) and BC (5.2 ± 1.9 µg m-3 ) concentrations in-taxis was higher in the morning measurements compared with those in the afternoon measurements. UFP count increased in-taxis by 60% for every 10 minutes spent in blocked traffic and by 84% starting from two trips with smokers compared to trips without smokers. Conversely, UFP count decreased by 30% for every 10 minutes under both air-conditioning and air recirculation mode with windows closed. BC was not affected by any of these factors. Our findings suggest easy ways to reduce UFP exposure inside vehicles for all commuters.

Asthma and allergic rhinitis risk depends on house dust mite specific IgE levels in PARIS birth cohort children.

BACKGROUND: The natural history of allergic sensitization in childhood, and its impact on allergic disease development, needs to be clarified. This study aims to identify allergic sensitization and morbidity patterns during the first 8 years of life. METHODS: The study was conducted in the on-going population-based prospective Pollution and Asthma Risk: an Infant Study (PARIS) birth cohort. Sensitization profiles were identified by k-means clustering based upon allergen-specific IgE levels measured at 18 months and 8/9 years. Allergic morbidity profiles were identified by latent class analysis based on symptoms, symptom severity, treatments, and lifetime doctor-diagnoses of asthma, allergic rhinitis, and atopic dermatitis and on lower respiratory infections before 2 years. RESULTS: Five sensitization and 5 allergic morbidity patterns were established in 714 children. Children not sensitized or with isolated and low allergen-specific sensitization were grouped together (76.8%). A profile of early and transient sensitization to foods that increased the risk of asthma later in childhood was identified (4.9%). Children strongly sensitized (≥3.5 kUA/L) to house dust mite at 8/9 years (9.0%) had the highest risk of asthma and allergic rhinitis. Finally, timothy grass pollen at 8/9 years sensitization profile (5.3%) was related to respiratory allergic diseases, as was early onset and persistent sensitization profile (4.1%), this latter being also strongly associated with atopic dermatitis. CONCLUSIONS & CLINICAL RELEVANCE: We show that accurate assessment of the risk of allergic disease should rely on earliness and multiplicity of sensitization, involved allergens, and allergen-specific IgE levels, and not considering solely allergic sensitization as a dichotomous variable (allergen-specific IgE ≥0.35 kUA/L), as usually done. This is particularly striking for house dust mite. We are hopeful that, pending further confirmation in other populations, our findings will improve clinical practice as part of an approach to allergic disease prevention.

Exposure to traffic air pollutants in taxicabs and acute adverse respiratory effects: A systematic review.

INTRODUCTION: Taxi drivers could be at risk regarding their respiratory health due to their constant exposure to traffic related air pollutants (TRAP) inside their vehicles. Therefore, we aimed to review pollutants exposure inside taxi vehicles and its determinants as well as its acute adverse respiratory effects. METHODS: The literature search was done in Pubmed and in Embase. For additional resources we searched manually articles from the reference lists of the selected papers and from Google Scholar. We included only studies in French or in English language meeting the following eligibility criteria: design: observational and quasi-experimental; study population: taxi drivers or taxi commuters, outcome: pollutants levels in taxicabs and/or acute adverse respiratory effects. Data was extracted using tabulation according to the type of the study (exposure or epidemiological). RESULTS: Out of 1753 articles, 21 studies were included. Exposure studies underlined that TRAP concentrations inside taxicabs were higher than their urban background levels and even exceeded those recorded in buses, in trains and when commuting by active transport modes. Overall, their concentrations varied widely between studies depending on the characteristics of the urban environment and the vehicle fleet of each location. Meteorological parameters and ventilation settings appeared to influence pollutants concentrations inside each vehicle. Otherwise, deficiency in epidemiological studies and inconsistencies in their findings restrain our ability to determine the association between acute respiratory effects and exposure to TRAP inside taxicabs. CONCLUSION: Although studies are heterogeneous, results have shown a high but variable occupational exposure of taxi drivers to TRAP inside their vehicles. However, future researches are required to study short respiratory impact of taxi drivers' exposure to TRAP inside their vehicles.

Associations of black carbon with lung function and airway inflammation in schoolchildren.

BACKGROUND: Few studies have investigated the 24-hour respiratory health effects of personal black carbon (BC) and ultrafine particles (UFP) exposure in schoolchildren. The objective of this study was to investigate these associations with the lung function in children 10-years old with and without persistent respiratory symptoms. METHODS: We conducted a cross-sectional study in 305 children (147 and 158 with and without persistent respiratory symptoms, respectively) from three European birth-cohorts: PARIS (France) and INMA Sabadell and Valencia (Spain). Personal 24-hour measurements of exposure concentrations to BC and UFP were performed by portable devices, before lung function testing. Forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and the fraction of exhaled nitric oxide (FeNO) were determined. RESULTS: There was no association of UFP with lung function parameters or FeNO whereas the increase in 24-hour BC exposure concentrations was related to a statistically significant decrease in lung function parameters only among children with persistent respiratory symptoms [-96.8 mL (95% Confidence Interval CI: -184.4 to -9.1 mL) in FVC, and -107.2 mL (95% CI: -177.5 to -36.9 mL) in FEV1 for an inter-quartile range of 1160 ng/m3 exposure increase]. A significant positive association between BC and FeNO was observed only in children with persistent respiratory symptoms with current wheezing and/or medication to improve breathing [FeNO increases with +6.9 ppb (95% CI: 0.7 to 13.1 ppb) with an inter-quartile range BC exposure increase]. CONCLUSION: Children suffering from persistent respiratory symptoms appear to be more vulnerable to BC exposure.