Search results for "nitrogen dioxide"
showing 10 items of 57 documents
Optical Fibre NO2 Sensor Based on Lutetium Bisphthalocyanine in a Mesoporous Silica Matrix
2018
International audience; In this article, we describe a NO2 sensor consisting of a coating based on lutetium bisphthalocyanine (LuPc2) in mesoporous silica. The sensor exploits the absorption spectrum change of this material which strongly and reversibly decreases in contact with NO2. NO2 is measured by following the amplitude change in the reflected spectrum of the coating deposited on the tip of a silica fibre. As diffusion of NO2 in LuPc2 is slow, the response time could be slow. To reduce it, the active molecules are dispersed in a mesoporous silica matrix deposited by a sol-gel process (Evaporation Induced Self Assembly) avoiding the formation of large crystals. Doing so, the response i…
Selectivity improvement of semi-conducting gas sensors by selective filter for atmospheric pollutants detection
2006
International audience; The monitoring of atmospheric pollution using chemical gas sensors is a challenge due to the lack of selectivity of most existing devices. However, their performances can be improved using filtering films achieving the separation or the removal of some gases. This study is focused on the detection of carbon monoxide and of oxidant pollutants (nitrogen dioxide and ozone) by sensors constituted of SnO2, or phthalocyanine compounds. Two types of filters were investigated. Filters based on MnO2 powder are successful to remove ozone while preserving nitrogen dioxide in a large temperature range from ambient to 400 -C, but they partially convert carbon monoxide. The second…
Short term associations of ambient nitrogen dioxide with daily total, cardiovascular, and respiratory mortality: multilocation analysis in 398 cities
2021
Objective To evaluate the short term associations between nitrogen dioxide (NO2) and total, cardiovascular, and respiratory mortality across multiple countries/regions worldwide, using a uniform analytical protocol. Design Two stage, time series approach, with overdispersed generalised linear models and multilevel meta-analysis. Setting 398 cities in 22 low to high income countries/regions. Main outcome measures Daily deaths from total (62.8 million), cardiovascular (19.7 million), and respiratory (5.5 million) causes between 1973 and 2018. Results On average, a 10 μg/m3 increase in NO2 concentration on lag 1 day (previous day) was associated with 0.46% (95% confidence interval 0.36% to 0.5…
All-organic device with integrated chemical filter dedicated to the selective measurement of NO2 in air
2010
Abstract An original organic semiconductor gas sensor devoted to the selective monitoring of nitrogen dioxide in air has been successfully developed. This device combines the great sensitivity and the partial selectivity toward oxidizing gases of a molecular organic semiconductor, copper phthalocyanine, with the O3 filtering selectivity of an organic material, indigo. Experimental measurements highlight filtering yield of indigo close to 100% toward O3 and lower than 10% for NO2. Nanometric indigo layers were realized for the first time by thermal evaporation and characterized by FT-IR spectroscopy. Such all-organic device exhibits a high NO2 sensitivity for low concentrations, a resolution…
Air pollution, residential greenness and metabolic dysfunction during early pregnancy in the infancia y medio ambiente (Inma) cohort
2021
Despite extensive study, the role of air pollution in gestational diabetes remains unclear, and there is limited evidence of the beneficial impact of residential greenness on metabolic dysfunction during pregnancy. We used data from mothers in the Spanish INfancia y Medio Ambiente (INMA) Project from 2003–2008. We obtained spatiotemporally resolved estimates of fine particulate matter (PM2.5) and nitrogen dioxide (NO2) exposures in early pregnancy and estimated residential greenness using satellite-based Normal Difference Vegetation Index (NDVI) within 100, 300 and 500 m buffers surrounding the mother’s residence. We applied logistic regression models to evaluate associations between each o…
ENVIRONMENTAL EFFECTS ON FRACTIONAL EXHALED NITRIC OXIDE IN ALLERGIC CHILDREN
2011
Fractional exhaled nitric oxide (FeNO) is a non-invasive marker of airway inflammation in asthma and respiratory allergy. Environmental factors, especially indoor and outdoor air quality, may play an important role in triggering acute exacerbations of respiratory symptoms. The authors have reviewed the literature reporting effects of outdoor and indoor pollutants on FeNO in children. Although the findings are not consistent, urban and industrial pollution—mainly particles (PM2.5 and PM10), nitrogen dioxide (NO2), and sulfur dioxide (SO2)—as well as formaldehyde and electric baseboard heating have been shown to increase FeNO, whilst ozone (O3) tends to decrease it. Among children exposed to …
Outdoor, but not indoor, nitrogen dioxide exposure is associated with persistent cough during the first year of life
2011
Background and aims: Because their lungs and immune system are not completely developed, children are more susceptible to respiratory disease and more vulnerable to ambient pollution. We assessed the relation between prenatal and postnatal nitrogen dioxide (NO2) levels and the development of lower respiratory tract infections (LRTI), wheezing and persistent cough during the first year of life. Methods: The study population consisted of 352 children from a birth cohort in Valencia, Spain. Prenatal exposure to NO2, a marker of traffic related air pollution was measured at 93 sampling sites spread over the study area during four different sampling periods of 7 days each. It was modeled for eac…
Air Pollution Exposure During Pregnancy and Symptoms of Attention Deficit and Hyperactivity Disorder in Children in Europe
2018
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 …
Prenatal exposure to traffic-related air pollution and fetal growth in a cohort of pregnant women
2012
Objectives Scant evidence is available on effects of air pollution on longitudinally measured fetal biometry, and thus it remains unclear as to whether there are critical windows of exposure or specificity of effects. Our objective was to examine the association between exposure to nitrogen dioxide (NO2) during pregnancy and fetal and neonatal anthropometry in a cohort of Spanish women. Methods Temporally adjusted land-use regression was used to estimate exposure to NO2 at home addresses. Biparietal diameter (BPD), abdominal circumference (AC), femur length (FL) and estimated fetal weight (EFW) were evaluated in each trimester by ultrasound. As neonatal outcomes, weight, length and head cir…
Association of Exposure to Ambient Air Pollution With Thyroid Function During Pregnancy
2019
Key Points Question Is exposure to ambient air pollution in the first trimester associated with thyroid function throughout pregnancy? Findings Among 9931 pregnant women in 4 European cohorts and 1 US cohort, an increase of 5 μg/m3 in exposure to particulate matter with an aerodynamic diameter of 2.5 μm or less was associated with 20% higher odds of hypothyroxinemia. Meaning The findings of this study raise the possibility that exposure to particulate matter might disrupt thyroid function in pregnant women.