Ambient Levels Of Nitrogen Dioxide Research Articles

Childhood cancer and traffic-related air pollution in Switzerland: A nationwide census-based cohort study.

Motor vehicle exhaust is a major contributor to air pollution, and exposure to benzene or other carcinogenic components may increase cancer risks. We aimed to investigate the association between traffic-related air pollution and risk of childhood cancer in a nationwide cohort study in Switzerland. We identified incident cases from the Swiss Childhood Cancer Registry diagnosed<16years of age between 1990 and 2015 and linked them probabilistically with the census-based Swiss National Cohort study. We developed land use regression models to estimate annual mean ambient levels of nitrogen dioxide (NO2) and benzene outside 1.4 million children's homes. We used risk-set sampling to facilitate the analysis of time-varying exposure and fitted conditional logistic regression models adjusting for neighborhood socio-economic position, level of urbanization, and background ionizing radiation. We included 2,960 cancer cases in the analyses. The adjusted hazard ratios (HR) and 95% confidence intervals for exposure to NO2 per 10μg/m3 were 1.00 (95%-CI 0.88-1.13) for acute lymphoblastic leukemia (ALL) and 1.31 (95%-CI 1.00-1.71) for acute myeloid leukemia (AML). Using exposure lagged by 1 to 5years instead of current exposure attenuated the effect for AML. The adjusted HR for exposure to benzene per 1μg/m3 was 1.03 (95%-CI 0.86-1.23) for ALL and 1.29 (95%-CI 0.86-1.95) for AML. We also observed increased HRs for other diagnostic groups, notably non-Hodgkin lymphoma. Our study adds to the existing evidence that exposure to traffic-related air pollution is associated with an increased risk of childhood leukemia, particularly AML.

Ambient Air Pollution and Socioeconomic Status in China.

Background:Air pollution disparities by socioeconomic status (SES) are well documented for the United States, with most literature indicating an inverse relationship (i.e., higher concentrations for lower-SES populations). Few studies exist for China, a country accounting for 26% of global premature deaths from ambient air pollution.Objective:Our objective was to test the relationship between ambient air pollution exposures and SES in China.Methods:We combined estimated year 2015 annual-average ambient levels of nitrogen dioxide () and fine particulate matter [PM in aerodynamic diameter ()] with national demographic information. Pollution estimates were derived from a national empirical model for China at spatial resolution; demographic estimates were derived from national gridded gross national product (GDP) per capita at resolution, and (separately) a national representative sample of 21,095 individuals from the China Health and Retirement Longitudinal Study (CHARLS) 2015 cohort. Our use of global data on population density and cohort data on where people live helped avoid the spatial imprecision found in publicly available census data for China. We quantified air pollution disparities among individual’s rural-to-urban migration status; SES factors (education, occupation, and income); and minority status. We compared results using three approaches to SES measurement: individual SES score, community-averaged SES score, and gridded GDP per capita.Results:Ambient and levels were higher for higher-SES populations than for lower-SES population, higher for long-standing urban residents than for rural-to-urban migrant populations, and higher for the majority ethnic group (Han) than for the average across nine minority groups. For the three SES measurements (individual SES score, community-averaged SES score, gridded GDP per capita), a 1-interquartile range higher SES corresponded to higher concentrations of and ; average concentrations for the highest and lowest 20th percentile of SES differed by 41–89% for and 12–25% for . This pattern held in rural and urban locations, across geographic regions, across a wide range of spatial resolution, and for modeled vs. measured pollution concentrations.Conclusions:Multiple analyses here reveal that in China, ambient and concentrations are higher for high-SES than for low-SES individuals; these results are robust to multiple sensitivity analyses. Our findings are consistent with the idea that in China’s current industrialization and urbanization stage, economic development is correlated with both SES and air pollution. To our knowledge, our study provides the most comprehensive picture to date of ambient air pollution disparities in China; the results differ dramatically from results and from theories to explain conditions in the United States. https://doi.org/10.1289/EHP9872

Relationship between acute kidney injury, seasonal influenza, and environmental factors: A 14-year retrospective analysis

Despite high incidence of acute kidney injury (AKI) among patients hospitalised for influenza, no previous work has attempted to analyse and quantify the association between the two. Herein, we made use of Hong Kong's surveillance data to evaluate the time-varying relationship between seasonal influenza and risk of AKI with adjustment for potential environmental covariates. Generalized additive model was used in conjunction with distributed-lag non-linear model to estimate the association of interest with daily AKI admissions as outcome and daily influenza admissions as predictor, while controlling for environmental variables (i.e. temperature, relative humidity, total rainfall, nitrogen dioxide, and ozone). Results suggested a positive association between risk of AKI admission and number of influenza hospitalisation cases, with relative risk reaching 1.12 (95% confidence interval, 1.10–1.15) at the 95th percentile. Using median as reference, an almost U-shaped association between risk of AKI admission and temperature was observed; the risk increased significantly when the temperature was low. While ozone was not shown to be a risk factor for AKI, moderate-to-high levels of nitrogen dioxide (50–95th percentile) were significantly associated with increased risk of AKI admission. This study mentioned the possibility that AKI hospitalisations are subject to environmental influences and offered support for a positive association between seasonal influenza and AKI occurrence in Hong Kong. Authorities are urged to extend the influenza vaccination program to individuals with pre-existing renal conditions to safeguard the health of the vulnerable. Given that adverse health effects are evident at current ambient levels of nitrogen dioxide, the government is recommended to adopt clean-air policies at the earliest opportunity to protect the health of the community.

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

Background and objectivePreterm 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. MethodsThis 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. ResultsThroughout 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/m3 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/m3 increase). ConclusionWe 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.

Acute respiratory health effects of urban air pollutants in adults with different patterns of underlying respiratory disease

Whether underlying chronic respiratory diseases are susceptible factors for symptomatic episodes, which lead to primary-level care, in association with air pollutant exposures is unknown. We evaluated and compared association lag structures between daily ambient levels of nitrogen dioxide (NO(2)) and total suspended particulates (TSP) and respiratory symptom-related doctor visits in adults with different patterns of underlying chronic respiratory disease. In a time-stratified case-crossover analysis nested within a diary panel study, 459 Swiss adult participants with asthma, chronic bronchitis, chronic obstructive pulmonary disease (COPD) and healthy participants recorded occurrence of respiratory-symptom related doctor visits (n = 1,048) in one to six four-week intervals over two years. For each disease subgroup, odds ratios (ORs) for doctor visit were estimated as a function of NO(2) or TSP concentrations (per 10 micrograms per cubic meter [µg/m(3)]) lagged between 0-13 days in a polynomial distributed lag model. Higher ORs for NO(2) in participants with COPD (OR: 1.17, 95%CI: 1.02-1.35) and asthma (OR: 1.15, 95%CI: 1.02-1.30) occurred at exposure lags of two and five days, respectively. Doctor visits increased by 9.1% (95%CI: 3.2-15.4%) and 4.2% (95%CI: 1.2-7.2%) over the first week following a 10 µg/m(3) increase in NO(2) concentration in the COPD and chronic bronchitis subgroups, respectively. The percent increase in the COPD subgroup was significantly greater (p <0.05) when compared with the healthy subgroup. Observed findings were similar for TSP. Respiratory problems leading to a doctor visit, associated with an increase in exposure to NO(2) and TSP, may have a faster dynamic in individuals with COPD.

Modeling effects of traffic and landscape characteristics on ambient nitrogen dioxide levels in Connecticut.

An integrated exposure model was developed that estimates nitrogen dioxide (NO(2)) concentration at residences using geographic information systems (GIS) and variables derived within residential buffers representing traffic volume and landscape characteristics including land use, population density and elevation. Multiple measurements of NO(2) taken outside of 985 residences in Connecticut were used to develop the model. A second set of 120 outdoor NO(2) measurements as well as cross-validation were used to validate the model. The model suggests that approximately 67% of the variation in NO(2) levels can be explained by: traffic and land use primarily within 2 km of a residence; population density; elevation; and time of year. Potential benefits of this model for health effects research include improved spatial estimations of traffic-related pollutant exposure and reduced need for extensive pollutant measurements. The model, which could be calibrated and applied in areas other than Connecticut, has importance as a tool for exposure estimation in epidemiological studies of traffic-related air pollution.

Ambient levels of nitrogen dioxide (NO 2) may reduce pollen viability in Austrian pine ( Pinus nigra Arnold) trees — Correlative evidence from a field study

A fully randomized sampling design was adopted to test whether pollen viability of Austrian pine ( Pinus nigra Arnold) was impacted by NO 2 pollution. Spatial strata (500 ⁎ 500 m each) with high (41.9–44.6 µg m − 3 ) and low (15.4–21.0 µg m − 3 ) NO 2 were selected from a defined population in a small area (236.5 km 2, < 200 m range in elevation) in Northern Italy. Pollen viability was measured by means of the Tetrazolium (TTC) test. Analysis of variance by means of a generalised linear model showed that NO 2 was a significant factor ( P = 0.0425) affecting pollen viability. Within the treatment, no significant differences were detected among replicates. Within each replicate, sampling unit data were significantly different ( P = 0.000) and this suggested some improvement in the applied sampling design was needed. Pollen viability was significantly related to pollen germination ( P < 0.01) and tube length ( P < 0.01). This suggested a possible impact of NO 2 on the regeneration of Austrian pine in polluted environments.

Does Nitrogen Dioxide Affect Inflammatory Markers after Nasal Allergen Challenge?

Exposure to high ambient levels of nitrogen dioxide (NO2) enhances the bronchial inflammatory reaction to allergen in humans. We tested whether this NO2 effect occurs also in the upper airways. Sixteen allergic subjects with rhinitis and mild asthma were exposed at rest to either purified air or 500 microg/m3 NO2 for 30 minutes, followed 4 hours later by a nasal allergen challenge. Nasal lavage was performed before air/NO2 exposure, before allergen challenge, and 1, 4 and 18 hours after allergen challenge. Symptoms were recorded. The percentage of eosinophils and neutrophils, eosinophil cationic protein, and myeloperoxidase were similar after exposure to air + allergen and to NO2 + allergen. We noticed a tendency to increased sneezing the day after exposure to NO2 + allergen. The priming effect of an ambient brief NO2 exposure on subsequent allergic response was not noticeable in activation of inflammatory cells and mediators in the upper airways.

Brief exposures to NO2 augment the allergic inflammation in asthmatics

Exposure to high ambient levels of nitrogen dioxide (NO2) enhances the airway reaction in humans to allergen, measured as decreased pulmonary function. We tested whether this NO2 effect is associated with an increased inflammatory response to allergen in the airways. To mimic real-life conditions, in which exposure to high ambient levels of NO2 occurs only during short periods of time but often several times a day, we used a repeated-exposure model. On day 1, 18 subjects with allergic asthma were exposed, in randomized order, to purified air or to 500μg/m3 NO2 for 15min, and on day 2 for 2×15min. Allergen was inhaled 3–4h after the NO2 exposures on both days. Symptoms, pulmonary function, and inflammatory response in sputum and blood were measured daily. Eosinophil cationic protein in both sputum and blood increased more from day 1 to day 3 after NO2+allergen than after air+allergen, whereas eosinophil counts did not differ. The change in myeloperoxidase was significantly greater after NO2+allergen than after air+allergen in blood but not in sputum. This finding was not accompanied by raised levels of neutrophils in sputum and blood. Symptoms and pulmonary function were equally affected by NO2+allergen and air+allergen. We conclude that two to three brief exposures to ambient levels of NO2 can prime circulating eosinophils and enhance the eosinophilic activity in sputum in response to inhaled allergen. This might be an important mechanism by which air pollutants amplify the inflammatory reactions in the airways.

Airborne Ns (NO2 and NH3) in the Rijeka Bay area (Croatia), 1980-1995.

The determination of ambient levels of nitrogen dioxide (NO2) and ammonia (NH3) in the Rijeka Bay area started in 1980, as a part of the air quality monitoring programme. The results of 15 years of surveying (1980/81–1994/95) on ambient levels of these pollutants at two sampling sites are given in this work. Site 1 is located in the city, opposite the old petroleum refinery facilities, while Site 2 is located in the settlement 25 km from the city, opposite the eastern industrial zone. Annual means of NO2 varied between 34 and 60 μg/m3 at Site 1 and between 14 and 26 μg/m3 at Site 2, but do not follow the 40% reduction in industrial emissions of this pollutant, probably due to the dominant impact of other minor sources, like traffic. Yearly averages of NH3 were in the range of 13 to 26 μg/m3 at Site 1 and 7 to 16 μg/m3 at Site 2, and are practically constant during the period studied.

Urban air pollution and emergency admissions for asthma in four European cities: the APHEA Project.

BACKGROUND: A study was undertaken to assess the combined association between urban air pollution and emergency admissions for asthma during the years 1986-92 in Barcelona, Helsinki, Paris and London. METHODS:...

Long pathlength differential optical absorption spectroscopy (D O A S) measurements of gaseous HONO, NO2 and HCNO in the California South Coast Air Basin

A differential optical absorption spectrometer (DOAS) system was operated at Long Beach, CA during the 1987 SCAQS Fall episodes to measure atmospheric concentrations of nitrous acid (HONO), as well as ambient levels of nitrogen dioxide (NO2) and formaldehyde (HCHO). The rapid scanning (-3000 spectra per min) spectrometer was interfaced to a 25 m basepath open, multiple reflection system operated routinely at a total optical path of 800 m. During several of the Fall episodes at Long Beach, levels of gaseous HONO were the highest (>15 ppb) reported to date by the DOAS technique. Although approximately half, to all, of the measured nighttime HONO concentrations could be accounted for by proposed heterogeneous formation pathways involving NO2, HONO concentrations correlated well with primary pollutants such as CO and NO, suggesting that elevated nighttime HONO concentrations in the western end of the Los Angeles basin may be influenced by emissions of HONO from combustion sources. This has significant implications for models which assume HONO arises only from secondary formation, rather than a combination of direct emissions and atmospheric reactions. Estimates of hydroxyl (OH) radical production show that photolysis of HONO shortly after sunrise on these episode days produces a large pulse of OH radicals at a time of the day when OH production from photolysis of O3 and HCHO is low. In terms of integrated OH radical production, HONO is of comparable importance to HCHO and much more important than O3 during these Fall periods.

Changes in T-lymphocyte subpopulations and natural killer cells following exposure to ambient levels of nitrogen dioxide.

The effects of ambient levels of NO2 on murine splenic T-lymphocyte subpopulations and natural killer cells were investigated. AKR/cum and C57BL/6J mice were exposed, in inhalation chambers, to 0.25 ppm NO2 for 7 wk and 0.35 ppm NO2 for 12 wk, respectively. Monoclonal antibody technology was used in conjunction with fluorescence-activated cell sorter (FACS) analysis to detect quantitative changes in total T-lymphocytes (Thy-1.2-positive), mature T-lymphocytes (Lyt-1-positive), T-helper/inducer lymphocytes (L3T4-positive), T-cytotoxic/suppressor lymphocytes (Lyt-2-positive), and natural killer cells (asialo GM1-positive). Percentages of all T-lymphocyte subpopulations tested and natural killer cells were lower in spleens of mice exposed to NO2 compared to filtered-air controls. This is the first report providing evidence linking alterations in T-lymphocyte subpopulations and natural killer cells to NO2 exposure at ambient levels. Changes in T-lymphocyte subpopulations detected by FACS and correlated to impaired immune function may provide an extremely sensitive means of demonstrating NO2-induced changes in the immune system.

Passive sampler for ambient levels of nitrogen dioxide

Description du dispositif d'echantillonnage utilisant la triethanolamine comme agent absorbant. Analyse spectrophotometrique par le procede de Saltzman

Air Pollutants and the Facilitation of Cancer Metastasis

Studies have been carried out to determine whether the inhalation of ambient levels of nitrogen dioxide (NO2), a common air pollutant, could influence the frequency of blood-borne cancer cell metastasis to the lungs. B16 mouse melanoma cells were used as an in vivo test model. the results have indicated that animals inhaling ambient levels of NO2 developed a significantly higher number of melanoma nodules in their lungs than the animals inhaling filtered air. Thus, a new concept for the action of air pollutants is proposed. The question is raised whether similar events are taking place in urban human populations.

Air pollutants and the facilitation of cancer metastasis.

Studies have been carried out to determine whether the inhalation of ambient levels of nitrogen dioxide (NO2), a common air pollutant, could influence the frequency of blood-borne cancer cell metastasis to the lungs. B16 mouse melanoma cells were used as an in vivo test model. the results have indicated that animals inhaling ambient levels of NO2 developed a significantly higher number of melanoma nodules in their lungs than the animals inhaling filtered air. Thus, a new concept for the action of air pollutants is proposed. The question is raised whether similar events are taking place in urban human populations.

Effect of low levels of nitrogen dioxide inhalation on endogenous retrovirus gene expression

Cellular RNA prepared from various tissues of mice exposed to ambient levels of nitrogen dioxide (NO 2) for 1 to 20 weeks was examined for evidence of changes in the level of expression of endogenous retrovirus genes. Two strains of mice were used: low retrovirus expressor (Swiss Webster strain) and high retrovirus expressor (AKR strain). Low expressor mice were exposed to 0.8 ± 0.05 ppm and the high expressor mice to 0.3 ± 0.05 ppm NO 2. Among the tissues examined (lung, kidney, thymus, and spleen) of the low expressor mice only the spleen showed a significant elevation of the level of endogenous viral RNA in response to the NO 2 exposure. The elevation did not persist throughout the study; it was detected during the 1st and 18th weeks of exposure, whereas the viral RNA levels were near normal at periods in between. Similarly, the high expressor mice appeared to react to NO 2 exposure with the spleen showing enhanced retrovirus gene expression during the 1st, 8th, 12th, and 15th weeks of exposure. Measurements at the end of the 2nd and 20th weeks of study, however, showed comparable levels in spleens of the exposed and control mice. Although the activity of the virus genes is naturally elevated in the thymic tissue of AKR mice, the levels of viral RNA or the incidence of thymic lymphoma were not significantly altered by exposure to 0.3 ppm NO 2. The observed alterations of genetic expression in the splenic tissue of two different strains of mice, together with the fact that the spleen is closely interrelated with circulating blood components, support the emerging notion that the spleen is a target organ for the effects of inhalation of ambient levels of NO 2.

Spleen changes in animals inhaling ambient levels of nitrogen dioxide.

The effects of ambient levels of NO2 on the spleens of adult and newborn Swiss Webster (S/W) mice were determined. Spleens were evaluated by the following criteria: (1) spleen weight, expressed as a percent of the body weight (% spleen weight), (2) size of the spleen lymphoid nodules as determined by computed image analysis, (3) spleen cell counts, and (4) histopathologic evaluation. Data for NO2-exposed animals were compared with data for control animals that inhaled filtered air. Totals of 217 control and 217 NO2-exposed animals were studied. After 6 wk of exposure to NO2 at ambient levels (0.35 +/- 0.05 ppm), the following significant changes were observed in the spleens of exposed mice: (1) increase in % spleen weight (p less than 0.0025), (2) increase in size of spleen lymphoid nodules (p less than 0.01), (3) smaller increase in spleen cell number per given weight increment of spleen as determined by correlation coefficients (p less than 0.0125) and linear regression analysis of spleen cell counts, and (4) an apparently greater predominance of red cells in the red pulp. It is concluded that inhalation of NO2 is associated with quantifiable spleen changes, which may prove to be useful indicators for assessing effects of inhaled NO2.

Effects of ambient levels of nitrogen dioxide (NO2) on navel oranges

Mature naval orange trees, enclosed in plastic-covered greenhouses, were exposed to ambient and 2 times ambient air levels of NO/sub 2/ for 8 months from blooming to picking time to find out whether this pollutant is causing injury to citrus. There was no visible evidence of injury. Leaf drop was greater and yield of fruit was less in ambient air containing photochemical smog than in trees which received carbon-filter air or carbon-filtered air to which ambient or 2 times ambient levels of NO/sub 2/ were added. The addition of either of the two levels of NO/sub 2/ had no statistical effect on leaf drop or yield. Ambient levels of NO/sub 2/ which occur in the Los Angeles Basin are probably without effect on citrus.