Ambient NO2 Research Articles

Ambient temperature NO2 removal by adsorption on transition metal ion-exchanged chabazite zeolites

NO2 as a toxic air pollutant causes serious health problems and contributes to environmental damages, which needs to be abated to a harmless level urgently. However, the abatement of low-concentration NO2 pollution under ambient temperature is challenging due to the ineffectiveness of the state-of-the-art deNOx technologies which are only efficient at elevated temperatures (>300 °C). Adsorption is herein studied as an alternative approach for ambient temperature NO2 removal, using transition metal (i.e., Ag+, Cu2+, Co2+, Ni2+, Zn2+, In3+, and Ce3+) ion-exchanged chabazite (CHA) zeolites with different Si/Al ratios (Si/Al = 2, 6, and 12). NO2 is dominantly physiosorbed on the as-prepared samples, which enables the reversible adsorption in cyclic adsorption process. Ni2+ and Co2+ as active adsorption sites showed elevated affinity to NO2 molecules, which was attributed to the formation of Pi-back bonding via the donation of the electrons in dz2 orbital of the metal ions to Pi × orbitals of NO2 molecule, as evidenced by the changes in the electron occupancies in the orbitals of both transition metal ions and NO2 molecule upon NO2 adsorption (DFT calculation). Co2+ ion-exchanged CHA with Si/Al ratio of 2 (Co2+-2-L) showed an outstanding NO2 capacity of 4.65 mmol/g, with a stable NO2 removal performance verified by the adsorption-desorption cycles. The NO release amount of our adsorbents (<14%) was lower than other reported materials and can be further reduced by our designed double-bed adsorber. This study provides new fundamental knowledge in developing zeolite-based Pi-back bonding adsorbents for NO2 removal, which not only is of timely significance for developing sought-after technologies for NO2 abatement, but also provides a model adsorbent for the adsorptive removal of other molecules with Pi bonds (e.g., CO, NO, etc.)

Impacts of COVID-19's restriction measures on personal exposure to VOCs and aldehydes in Taipei City

The Coronavirus Disease 2019 (COVID-19) pandemic provided an unprecedented natural experiment, that allowed us to investigate the impacts of different restrictive measures on personal exposure to specific volatile organic compounds (VOCs) and aldehydes and resulting health risks in the city. Ambient concentrations of the criteria air pollutants were also evaluated. Passive sampling for VOCs and aldehydes was conducted for graduate students and ambient air in Taipei, Taiwan, during the Level 3 warning (strict control measures) and Level 2 alert (loosened control measures) of the COVID-19 pandemic in 2021–2022. Information on the daily activities of participants and on-road vehicle counts nearby the stationary sampling site during the sampling campaigns were recorded. Generalized estimating equations (GEE) with adjusted meteorological and seasonal variables were used to estimate the effects of control measures on average personal exposures to the selected air pollutants. Our results showed that ambient CO and NO2 concentrations in relation to on-road transportation emissions were significantly reduced, which led to an increase in ambient O3 concentrations. Exposure to specific VOCs (benzene, methyl tert-butyl ether (MTBE), xylene, ethylbenzene, and 1,3-butadiene) associated with automobile emissions were remarkably decreased by ~40–80 % during the Level 3 warning, resulting in 42 % and 50 % reductions of total incremental lifetime cancer risk (ILCR) and hazard index (HI), respectively, compared with the Level 2 alert. In contrast, the exposure concentration and calculated health risks in the selected population for formaldehyde increased by ~25 % on average during the Level 3 warning. Our study improves knowledge of the influence of a series of anti-COVID-19 measures on personal exposure to specific VOCs and aldehydes and its mitigations.

Acute effects of ambient air pollution on daily neurology clinic visits for vertigo: a time-series study in Wuhan, China

This study aimed to disclose the relationship between ambient air pollution and neurology clinic visits (NCVs) for vertigo. A time-series study was conducted to examine relationships between six different criteria air pollutants (SO2, NO2, PM2.5, PM10, CO, and O3) and daily NCVs for vertigo in Wuhan, China, from January 1st, 2017 to November 30th, 2019. Stratified analyses were computed according to gender, age, and season. A total of 14,749 records of NCVs for vertigo were enrolled in this study. Data showed that the increase in daily NCVs for vertigo corresponding to 10μg/m3 increase of respective pollutants are: SO2 (- 7.60%; 95% CI: - 14.25 to - 0.44%), NO2 (3.14%; 95% CI: 0.23 to 6.13%), PM2.5 (0.53%; 95% CI: - 0.66 to 1.74%), PM10 (1.32%; 95% CI: - 0.36 to 3.06%), CO (0.00%; 95% CI: - 0.12 to 0.13%), and O3 (0.90%; 95% CI: - 0.01% to 1.83%). Males were more susceptible to acute exposure to SO2 and NO2, compared to females (SO2: - 11.91% vs. - 4.16%; NO2: 3.95% vs. 2.92%), whereas the acute effect of O3 exposure was more significantly obvious in females than males (0.94% vs. 0.87%). Moreover, correlations between daily NCVs for vertigo and acute exposure to SO2, NO2, and O3 were all stronger in individuals under 50years old (SO2: - 12.75% vs. - 4.41%; NO2: 4.55% vs. 2.75%; O3: 1.27% vs. 0.70%). Short-term exposure to PM2.5 was more significantly associated with daily NCVs for vertigo in cool seasons (1.62% vs. - 0.68%), while the correlation between CO exposure and daily NCVs for vertigo was stronger in warm seasons (0.21% vs. - 0.03%). Our study demonstrated acute exposure to ambient NO2 and O3 positively associated with daily NCVs for vertigo. Acute effects of air pollution on daily NCVs for vertigo varied according to gender, age, and season.

Ambient temperature NO2 removal by reversible NO2 adsorption on copper-based metal-organic frameworks (MOFs)-derived nanoporous adsorbents

Nitrogen dioxide (NO2) is a potent atmospheric pollutant generated from fossil fuel combustion at power plants, industrial plants, and vehicles, which raises serious health concerns (e.g., respiratory diseases) and contributes to severe environmental pollution issues (e.g., acid rain and ground-level ozone). Adsorption is an efficient approach for ambient temperature NO2 removal, whose efficiency highly depends on the design of the adsorbents. The widely reported activated carbon adsorbents suffer from low and typically irreversible NO2 capacity apart from co-generation of considerable amounts of polluting NO (up to 50% of adsorbed NO2), which is released back into the atmosphere. Herein we report copper-based metal–organic framework (MOF)-derived carbon materials (i.e., Cu@C(CuBTC) and Cu@C(CuBDC)) featuring high NO2 capacity coupled with minimal release of NO and outstanding reusability for NO2 removal under ambient temperature. Both Cu@C(CuBTC) and Cu@C(CuBDC) showed an impressive improvement (up to 13.5 times) in NO2 capacity over their pristine MOFs counterparts, with Cu@C(CuBTC) showing the highest NO2 capacity (4.97 mmol/g) and minimal (<20 % of adsorbed NO2) release of NO in this study. Such a massive improvement in the NO2 capacity of carbonized composites is attributed to highly active and homogenously dispersed Cu nanoclusters, which serve as adsorption sites and play the dominant role in NO2 removal. Further, for the first time, Cu@C(CuBTC) exhibited outstanding reusability for NO2 removal under humid conditions, reflected by stable NO2 capacity in the cyclic adsorption tests (5 cycles), suggesting a great potential for real-world applications. This study provides a general and facile strategy for designing highly dispersed, water-resistant, and stable copper nanoclusters on carbon support for efficient adsorptive removal of various toxic gases under ambient temperature.

Two Air Quality Regimes in Total Column NO2 Over the Gulf of Mexico in May 2019: Shipboard and Satellite Views

AbstractThe Satellite Coastal and Oceanic Atmospheric Pollution Experiment (SCOAPE) cruise in the Gulf of Mexico was conducted in May 2019 by NASA and the Bureau of Ocean Energy Management to determine the feasibility of using satellite data to measure air quality in a region of concentrated oil and natural gas (ONG) operations. SCOAPE addressed both technological and scientific issues related to measuring NO2 columns over the outer continental shelf. Featured were nitrogen dioxide (NO2) instruments (Pandora, Teledyne API analyzer) at Cocodrie, LA (29.26°, −90.66°), and on the Research Vessel Point Sur operating off the Louisiana coast with measurements of ozone, carbon monoxide, and volatile organic compounds (VOCs). The findings: (a) all NO2 observations revealed two atmospheric regimes over the Gulf, the first influenced by tropical air in 10–14 May, the second influenced by flow from urban areas on 15–17 May; (b) comparisons of OMI v4 and TROPOMI v1.3 TC (total column) NO2 data with shipboard Pandora NO2 column observations averaged 13% agreement with the largest difference during 15–17 May (∼20%). At Cocodrie, the satellite–Pandora agreement was ∼5%. (c) Three new‐model Pandora instruments displayed a TC NO2 precision of 0.01 Dobson Units (∼5%); (d) regions of smaller, older natural gas operations showed high methane readings from leakage; elevated VOCs were also detected. Neither satellite nor spectrometer captured the magnitude of ambient NO2 variability near ONG platforms. Given an absence of regular air quality monitoring over the Gulf of Mexico, SCOAPE data constitute a baseline against which future observations can be compared.

Nitrous oxide emissions from tea plantations: A review.

Tea plantations are an important N2O source. Fertilizer-induced N2O emission factors of tea plantations are much higher than other upland agricultural ecosystems. According to the basic information on characteristics and knowledge of N2O emissions from tea plantations around the world, we comprehensively reviewed N2O emission characteristics, production process, influencing factors, and reduction measures from tea plantations. The global means of ambient N2O emission and N2O emission stimulated by nitrogen fertilizer application from tea plantations were (2.68±2.92) kg N·hm-2 and (11.29±9.45) kg N·hm-2, respectively. The fertilizer-induced N2O emission factor in tea plantations (2.2%±2.1%) was much higher than the IPCC-estimated N2O emission factor for agricultural land (1%). N2O emission from tea plantation soil (a typical acid soil) were mainly produced during nitrification and denitrification, with denitrification being dominant. N2O emission from tea plantations were significantly related to the amount of fertilizer application. Other factors, such as fertilizer type, could also affect soil N2O emissions in tea plantations. The main reduction methods of N2O emission from tea plantations included optimizing the amount and type of fertilizer, amending biochar, and rationally using nitrification inhibitors. In future, we should strengthen in-situ observations of soil N2O emission from tea plantations at both temporal and spatial scales, combine lab incubation and field studies to elucidate the mechanisms underling tea plantation soil N2O emissions, and use a data-model fusion approach to reduce uncertainties in the estimation of global N2O emission. These would provide theoretical support and practical guidance for reasonable N2O emission reduction in tea plantations.

Health Risk Assessment of Gaseous Pollutants in the Ambient Environment of Rayong City, Thailand: The Initiative of the EEC Area

The Eastern Economic Corridor (EEC) project initiative has an adverse impact on the increasing problem of air pollution. This research aims to determine ambient NO2, O3, and SO2 levels in the industrial area (IT) and urban area (UB) in Rayong city as part of a health risk assessment from 2018 to 2020. The average NO2, O3, and SO2 concentrations at IT site were ranged from 23.5–24.7 μg/m3, 42.7–56.7 μg/m3, and 12.5–14.0 μg/m3, while those at UB site were 14.8–20.7 μg/m3, 42.5–68.3 μg/m3, and 3.2–4.7 μg/m3, respectively. Their concentrations in dry season were higher than those in wet season at both IT and UB sites. The days in the IT site exceeded the daily WHO guideline of NO2 was 34.8–44.0%, while those in the UB site were 10.8–34.5%. The hazard quotient (HQ) values for a non-carcinogenic risk to human health caused by NO2 exposure indicated a medium hazard (HQ = 1.1–10.0), whereas the HQ values for SO2 and O3 indicated a negligible risk (HQ &lt; 1.0). The total non-carcinogenic risk (HI) from air pollutants contamination being exposed concurrently, on the other hand, indicated risk levels that are likely to affect health, particularly children. Therefore, environmental management and protection in Rayong city are important for people who live in industrial and urban areas, especially during dry period.

Exposure to various ambient air pollutants and 9 cardiovascular conditions among individuals with diabetes: A prospective analysis of the UK Biobank

Background and aimsThe adverse effects of air pollutants on the risk of most cardiovascular diseases (CVDs) are well-established, but the risk of CVDs such as deep vein thrombosis, pulmonary embolism, or aortic valve stenosis have been underappreciated, especially in the diabetic population. This study aimed to evaluate associations between long-term air pollutants exposure and the risk of incident CVDs among participants with diabetes. MethodsThis study included 27,827 participants with baseline diabetes from the UK Biobank. We then estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for CVDs associated with chronic air pollutant exposure in the diabetic population by fitting the Cox proportional hazards model. Moreover, we investigated the cardiovascular effects of air pollutants at concentrations below WHO guideline limits. ResultsAfter multivariable adjustment, long-term NO2 and NOx exposures were positively associated with the development of 8 and 6 types of CVDs in participants with diabetes, respectively. In term of particulate matters, the effect estimates ranged from 1.51 (1.13, 2.03) (coronary artery disease) to 4.65 (2.73, 7.92) (peripheral arterial disease) per 10 μg/m3 increase in PM2.5. Whereas, the effect estimates ranged from 1.15 (1.04, 1.27) (arterial hypertension) to 2.28 (1.40, 3.69) (pulmonary embolism) per 10 μg/m3 increase in PM10. In addition, our study discovered that for most of the cardiovascular events (8 of 9), the deleterious effects of air pollutants persisted even when participants were exposed to air pollutants concentrations below WHO guideline limits. ConclusionsLong-term exposure to ambient NO2, NOx, PM2.5, and PM10, either at normal or low level, increased risk of various cardiovascular outcomes in the diabetic population.

Potential ambient NO2 abatement by applying photocatalytic materials in a Spanish city and analysis of short-term effect on human mortality

Road traffic is the main contributor to NO2 emissions in many European cities, causing that the current limit values for the protection of human health are exceeded. The use of photocatalytic compounds that incorporate titanium dioxide (TiO2) is frequently proposed as abatement technology but its depolluting effectiveness on a real scale is still being investigated.In this work, the potential removal capacity of NO2 that selected TiO2-based materials would have if they were implemented in a street in the municipality of Alcobendas (Community of Madrid, Spain) has been evaluated. The number of avoided NO2-related deaths over the locality across the period 2001–2019 have been inferred. Moreover, the saving associated with the estimated removal of ambient NO2 due to the use of photocatalytic materials and costs generated by their acquisition and implementation in the selected urban environment were briefly studied.Attributable mortality due to NO2 concentrations for Alcobendas has been estimated in 289 deaths, being 9241 the total deaths due to natural cause. This presents a monthly variation associated with the evolution of both mortality due to natural causes and the average concentrations of NO2.The reduction in mortality via the hypothetical implantation of photocatalytic materials throughout the municipality, assuming ideal conditions for their optimal performance, would be a maximum of 3%.In addition, a saving of €5708 yr−1 km−2 related to NOx damage costs of transport was obtained. A total cost of k€4750.5 km−2 was associated to the purchase of photocatalytic materials and their application to all surfaces in that area.This technology has a big elimination potential in controlled conditions but a low reduction of ambient NO2 is provided when implemented in real outdoor urban scenarios. Its use can be recommended incorporated into engineering designs and applications, complementing other abatement measures, to reduce NO2 mortality in urban areas.

Exposure to ultrafine particles and the incidence of asthma in children: A population-based cohort study in Montreal, Canada.

The cohort included all children born and residing in Montreal, Canada, between 2000 and 2015. Children were followed for asthma onset from birth until <13 years of age. Spatially resolved annual mean concentrations of ambient UFPs were estimated from a land use regression model. We assigned prenatal exposure according to the residential postal code at birth. We also considered current exposure during childhood accounting for time-varying residence location. We estimated hazard ratios (HRs) using Cox proportional hazards models adjusted for age, sex, neighborhood material and social deprivation, calendar year, and coexposure to ambient nitrogen dioxide (NO2) and fine particles (PM2.5). The cohort included 352,966 children, with 30,825 children developing asthma during follow-up. Mean prenatal and childhood UFP exposure were 24,706 particles/cm3 (interquartile range [IQR] = 3,785 particles/cm3) and 24,525 particles/cm3 (IQR = 3,427 particles/cm3), respectively. Both prenatal and childhood UFP exposure were not associated with childhood asthma onset in single pollutant models (HR per IQR increase of 0.99 [95% CI = 0.98, 1.00]). Estimates of association remained similar when adjusting for coexposure to ambient NO2 and PM2.5. In this population-based birth cohort, childhood asthma onset was not associated with prenatal or childhood exposure to low concentrations of UFPs.

Short-term air pollution exposure associated with death from kidney diseases: a nationwide time-stratified case-crossover study in China from 2015 to 2019

BackgroundLong-term exposure to air pollution has been associated with the onset and progression of kidney diseases, but the association between short-term exposure to air pollution and mortality of kidney diseases has not yet been reported.MethodsA nationally representative sample of 101,919 deaths from kidney diseases was collected from the Chinese Center for Disease Control and Prevention from 2015 to 2019. A time-stratified case-crossover study was applied to determine the associations. Satellite-based estimates of air pollution were assigned to each case and control day using a bilinear interpolation approach and geo-coded residential addresses. Conditional logistic regression models were constructed to estimate the associations adjusting for nonlinear splines of temperature and relative humidity.ResultsEach 10 µg/m3 increment in lag 0–1 mean concentrations of air pollutants was associated with a percent increase in death from kidney disease: 1.33% (95% confidence interval [CI]: 0.57% to 2.1%) for PM1, 0.49% (95% CI: 0.10% to 0.88%) for PM2.5, 0.32% (95% CI: 0.08% to 0.57%) for PM10, 1.26% (95% CI: 0.29% to 2.24%) for NO2, and 2.9% (95% CI: 1.68% to 4.15%) for SO2. ConclusionsOur study suggests that short-term exposure to ambient PM1, PM2.5, PM10, NO2, and SO2 might be important environmental risk factors for death due to kidney diseases in China.

Chronic exposure to ambient PM2.5/NO2 and respiratory health in school children: A prospective cohort study in Hong Kong

Despite increasing concerns about the detrimental effects of air pollution on respiratory health, limited evidence is available on these effects in the Hong Kong population, especially in children. In this prospective cohort study between 2012 and 2017, we aimed to investigate the associations between exposure to air pollution (concentrations of fine particulate matter [PM2.5] and nitrogen dioxide [NO2]) and respiratory health (lung function parameters and respiratory diseases and symptoms) in schoolchildren. We recruited 5612 schoolchildren aged 6–16 years in Hong Kong. We estimated the annual average concentrations of ambient PM2.5 and NO2 at each participant’s address using spatiotemporal models. We conducted spirometry tests on all participants to measure their lung function parameters and used a self-administered questionnaire to collect information on their respiratory diseases and symptoms and a wide range of covariates. Linear mixed models were used to investigate the associations between exposure to air pollution and lung function. Mixed-effects logistic regression models with random effects were used to investigate the associations of exposure to air pollution with respiratory diseases and symptoms. In all of the participants, every 5-μg/m3 increase in the ambient PM2.5 concentration was associated with changes of − 13.90 ml (95 % confidence interval [CI]: −23.65 ml, −4.10 ml), − 4.20 ml (−15.60 ml, 7.15 ml), 27.20 ml/s (−3.95 ml/s, 58.35 ml/s), and − 19.80 ml/s (−38.35 ml/s, −1.25 ml/s) in forced expiratory volume in 1 s, forced vital capacity, peak expiratory flow, and maximal mid-expiratory flow, respectively. The corresponding lung function estimates for every 5-μg/m3 increase in the ambient NO2 concentration were − 2.70 ml (−6.05 ml, 0.60 ml), − 1.40 ml (−5.40 ml, 2.60 ml), − 6.60 ml/s (−19.75 ml/s, 6.55 ml/s), and − 3.05 ml/s (−11.10 ml/s, 5.00 ml/s), respectively. We did not observe significant associations between PM2.5/NO2 exposure and most respiratory diseases and symptoms. Stratified analyses by sex and age showed that the associations between exposure to air pollution and lung function parameters were stronger in male participants and older participants (11–14 year old group) than in female participants and younger participants (6–10 year old group), respectively. Our results suggest that chronic exposure to air pollution is detrimental to the respiratory health of schoolchildren, especially that of older boys. Our findings reinforce the importance of air pollution mitigation to protect schoolchildren’s respiratory health.

Ambient NO2 exposure affects hepatic glycolipid metabolism in mice with a sex-dependent property

NO 2 is one of the major air pollutants. Exposure to NO 2 is associated with various metabolic diseases, such as non-alcoholic fatty liver disease (NAFLD), diabetes, cardiovascular disease, etc. Abnormal hepatic glycolipid metabolism is a key feature of metabolic diseases. However, few studies provide evidence for the effects of NO 2 inhalation on hepatic glycolipid metabolism. In this study, female and male C57BL/6 J mice were exposed to NO 2 (2.5 ppm, 5 h/day) for 4 weeks using a systemic inhalation exposure system. The results indicated that NO 2 exposure increased the levels of hepatic enzymes in serum and led to liver dysfunction in female mice, but not male ones. Especially, female mice developed glycolipid metabolic disorders, including increased blood glucose, decreased hepatic glycogen and glucose tolerance, and increased lipid level in liver and blood. Metabolomic analysis clarified 33 differential metabolites of glycolipids, which were mainly enriched through several pathways, including synthesis and degradation of ketone bodies, fat digestion and absorption, galactose metabolism, fatty acid degradation, and glycerophospholipid metabolism. The mRNA and protein expression implicated that the exposure disrupted glucose metabolism by reducing hepatic glycogen synthesis and increasing gluconeogenesis, and caused lipid deposition by increasing lipogenesis and uptake, thereby increasing lipid oxidation and secretion. The findings highlight the risk of metabolic diseases upon exposure to NO 2 in the air. • NO 2 exposure caused female-specific hepatic glycolipid metabolism disorders. • NO 2 inhalation altered glycogen synthesis and gluconeogenesis. • NO 2 inhalation affected lipogenesis and uptake, and induced lipid deposition.

Compact, Fast Cavity Ring-Down Spectroscopy Monitor for Simultaneous Measurement of Ozone and Nitrogen Dioxide in the Atmosphere

A sensitive, compact detector for the simultaneous measurement of O3 and NO2 is presented in this work. There are two channels in the detector, namely the Ox channel and the NO2 channel. In the presence of excess NO, ambient O3 is converted to NO2 in the Ox measurement channel. In both channels, NO2 is directly detected via cavity ring-down spectroscopy (CRDS) at 409 nm. At a 10 s integration time, the Ox and NO2 channels have a 1σ precision of 14.5 and 13.5 pptv, respectively. The Allan deviation plot shows that the optimal sensitivity of O3 and NO2 occurs at an integration time of ~60 s, with values of 10.2 and 8.5 pptv, respectively. The accuracy is 6% for the O3 channel and 5% for the NO2 channel, and the largest uncertainty comes from the effective NO2 absorption cross-section. Intercomparison of the NO2 detection between the NO2 and Ox channels shows good agreement within their uncertainties, with an absolute shift of 0.31 ppbv, a correlation coefficient of R2 = 0.99 and a slope of 0.98. Further intercomparison for ambient O3 measurement between the O3/NO2-CRDS developed in this work and a commercial UV O3 monitor also shows excellent agreement, with linear regression slopes close to unity and an R2 value of 0.99 for 1 min averaged data. The system was deployed to measure O3 and NO2 concentrations in Hefei, China, and the observation results show obvious diurnal variation characteristics. The successful deployment of the system has demonstrated that the instrument can provide a new method for retrieving fast variations in ambient O3 and NO2.

Acute effects of ambient nitrogen dioxide exposure on serum biomarkers of nervous system damage in healthy older adults

Ambient nitrogen dioxide (NO2)-induced adverse health effects have been studied, but documented evidence on neural systems is limited. This study aimed to determine the acute effect of NO2 exposure on nervous system damage biomarker levels in healthy older adults. Five rounds of follow-up among 34 healthy retired people were scheduled from December 2018 to April 2019 in Xinxiang, China. The real-time NO2 concentrations were measured using a fixed site monitor. Serum samples were acquired during each round to measure nervous system damage biomarker levels: brain-derived neurotrophic factor (BDNF), neurofilament light chain (NfL), neuron-specific enolase (NSE), protein gene product 9.5 (PGP9.5), and S100 calcium-binding protein B (S100B). A linear mixed-effect model was incorporated to analyze the association between short-term NO2 exposure and serum concentrations of the above-mentioned biomarkers. Stratification analysis based on sex, educational attainment, glutathione S-transferase theta 1 gene (GSTT1) polymorphism, and physical activity intensity was conducted to explore their potential modification effect. The NO2 concentration ranged from 34.7 to 59.0 µg/m3 during the study period. Acute exposure to ambient NO2 was significantly associated with elevated serum levels of NfL, PGP9.5, and BDNF. In response to a 10 µg/m3 increase in NO2 concentration, NfL and PGP9.5 levels increased by 76 % (95 % confidence interval [CI]: 12–140 %) and 54 % (95 % CI: 1–107 %) on the lag0 day, respectively, while BDNF levels increased by 49 % (95 % CI: 2–96 %) at lag4 day. The estimated effect of NO2 on NSE levels in GSTT1-sufficient participants was significantly higher than that in GSTT1-null participants. Intriguingly, the estimation of NO2 on PGP9.5 levels in females was significantly higher than that in males. Most two-pollutant models showed robust results, except for O3, which might have had confounding effects on NO2-induced BDNF stimulation. In summary, acute exposure to NO2 was associated with increased levels of serum nervous system damage biomarker levels including NFL, PGP9.5, and BDNF. The present study provided insights into NO2 exposure-induced adverse neural effects.

The Association between Air Pollutants Exposure with Pre- and Hypertension by Vitamin C Intakes in Korean Adults: A Cross-Sectional Study from the 2013-2016 Korea National Health and Nutrition Examination.

Oxidative stress and systemic inflammation are the main pathways by which air pollutants cause hypertension (HTN). Vitamin C intake may reduce the risk of HTN caused by air pollutants. This study aimed to investigate the association between air pollutants and pre-HTN and HTN in Korean adults and whether these associations were modified by vitamin C intake, using data from the 2013-2016 Korean National Health and Nutrition Examination Survey (KNHANES). Cross-sectional study. This study used data from the KNHANES VI (2013-2015) and VII (2016) along with the data from the annual air pollution report of the Ministry of Environment. We included 11,866 adults who had responded to a semi-food frequency questionnaire. We used survey logistic regression models to evaluate the association of ambient PM10, SO2, NO2, CO, and O3 with pre-HTN and HTN according to vitamin C intake. After adjusting for potential covariates, exposure to ambient PM10, SO2, NO2, and CO was significantly associated with a high prevalence of pre-HTN and HTN, whereas exposure to O3 was significantly associated with a low prevalence of pre-HTN and HTN. In particular, as the air pollutant scores increased (severe air pollution), the prevalence of pre-HTN and HTN increased in a dose-dependent manner (highest score vs. lowest score, OR=1.85, 95% CI=1.39-2.46, p for trend <.0001). However, these associations were found to be pronounced in adults with low vitamin C intake (highest score vs. lowest score, OR=2.30, 95% CI=1.50-3.54, p for trend <.0001), whereas the statistical significance disappeared for adults with high vitamin C intake (highest score vs. lowest score, OR=1.40, 95% CI=0.93-2.12, p for trend=0.007). Exposure to air pollutants such as PM10, SO2, NO2, and CO may increase the prevalence of pre-HTN and HTN among Korean adults. In addition, a high intake of vitamin C may help prevent pre-HTN and HTN caused by air pollutants.

Excess deaths associated with long-term exposure to ambient NO2 in China

World Health Organization updated the target of annual mean NO2 from 40 μg m−3 to 10 μg m−3 in 2021 based on new evidences that showed statistically independent effects of long-term exposure to ambient NO2 and mortality. We estimate the excess deaths associated with long-term exposure to ambient NO2 (DAAN) from non-accidental disease (NAD), cardiovascular disease (CVD) and respiratory disease (RD) in China in 2013–2020 using a counterfactual analytic framework adopted by Global Burden Disease. We use relative risk (RR) values based on a meta-analysis, and assume a linear concentration-response (C-R) function and a threshold value of 10 μg m−3. DAAN from NAD vary in 279 (95% Cl: 189–366) to 339 (95% Cl: 231–442) thousand in 2013–2020, comparable to excess deaths attributed to long-term exposure to ambient O3 in China. DAAN from NAD changes by −43%–+220% using different RR values, C-R function shapes, and threshold values. DAAN from RD reduces while those from CVD increases significantly in 2013–2020. DAAN from RD account for ∼10% of total DAAN. We found that the reduction of NO2 concentration and baseline mortality of NAD offsets the adverse effects of population growth and aging in 2013–2017. In 2017–2020, the contribution from air pollution reduction surpasses the adverse effects of population growth and aging in most regions. We suggest that continuing the reduction rate of NO2 emissions in 2013–2020 would offset the effects of population growth and aging in 2020–2030. Faster reduction of NO2 sources is required to reduce DAAN in Liaoning, Shanxi, Shanghai, and Anhui, where DAAN from NAD, CVD and RD increased in 2013–2020. Our results should be interpreted with caution because the causality support of long-term exposure to ambient NO2 on mortality from toxicological studies is not firm yet, and NO2 is possibly just a marker of traffic-related pollutants.

Polycyclic aromatic hydrocarbons in coarse particles (PM10) over the coastal urban region in Poland: Distribution, source analysis and human health risk implications

In this study, the results of PM10-bound PAH measurements were subjected to positive matrix factorization (PMF) approach and diagnostic ratios to investigate their levels, seasonal variability, impact of primary anthropogenic sources, and human health risk via the inhalation route. Daily ground-based observations were carried out at a representative coastal site in Gdynia (northern Poland), from April to December 2019. The concentrations of Σ13PAHs in PM10 varied between 0.45 ng m−3 and 54.02 ng m−3, with a mean of 5.22 ± 8.67 ng m−3. A clear seasonality and distribution profiles of PM10-bound PAHs were observed as a result of local/remote sources and meteorological conditions. The highest Σ13PAH concentration was found in December (18.56 ± 16.45 ng m−3) and the lowest values were observed between June and September (3.89 ± 0.52 ng m−3). The PMF-based analysis revealed five factors, suggesting the importance of primary anthropogenic sources of PAHs, i.e. coal combustion, biomass burning, gasoline/diesel vehicles, industrial and shipping activities as well as natural gas combustion. In summer, PAH levels were mostly controlled by local shipping emissions as well as traffic-related and non-combustion sources such as photochemical decomposition. The winter PAH maxima were attributed to a strong increase in residential coal combustion. A Spearman's rank correlation and multilinear regression analysis showed that ambient temperature and NO× had a significant impact on intra-annual variability in PM10-bound PAH transformation in this region. PAH congeners in coarse-size fraction were positively correlated with SO2, indicating their shared anthropogenic sources. The annual mean of epidemiologically based ILCR value was 6.6 × 10−5. This work indicates a potential carcinogenic risk for the local population and a significant difference in BaPeq levels between the individual seasons in this region.

One-year spatiotemporal variations of air pollutants in a major chemical-industry park in the Yangtze River Delta, China by 30 miniature air quality monitoring stations

Fine chemical industrial park (FCIP) is a major source of atmospheric pollutants in China. A long-term high spatial resolution monitoring campaign on air pollutants had been firstly conducted in a major FCIP in Yangtze River Delta (YRD) from December 2019 to November 2020. The grid-based monitoring platform consisting of 30 miniature air quality monitoring stations (AQMSs) provided comprehensive coverage of a FCIP, and long-term monitoring studies solved the problem of lack of clarity about pollution sources in industrial parks. Overall, NO2 pollution was particularly high in the pharmaceutical industry, while TVOCs and O3 pollution were most serious in the textile dyeing industry, with PM pollution much higher in the metal smelting industry than in other industries, and in the leather industry, O3 pollution was relatively severe. The spatial and temporal variations of air pollutants showed that higher PM, CO and NO2 concentrations were revealed in winter while lower in summer due to better meteorological diffusion conditions. TVOCs concentrations were higher with an average of 1954 ppb in summer possibly due to their increased volatilization from their sources at higher ambient temperatures. O3 concentrations were at their peaks in spring (88.8 μg m−3) and early fall (78.5 μg m−3). The daily trends of O3 precursors (TVOCs and NO2) were clearly negatively correlated with O3, and they showed bimodal peaks due to anthropogenic activities, plant emissions, lowering of the mixed boundary layer, etc. The O3 formed in FCIP was judged to be NO2-limited during the monitoring period based on the ratios of NO2 to TVOCs. Therefore, the effective strategy to reduce O3 formation in FCIP is to decrease the ambient NO2 concentration. Based on Pearson correlation coefficients, it appeared that WS promoted O3 formation through long-term transport and that high air temperatures also contributed to O3 formation in the environment. It was also stated in the study that the closer the residential area is to the industrial sources, the more significant the correlation. Thus, the results of this study will also be helpful for policymakers to design pollutant control strategies for different industries to mitigate the impact of pollutants on human health.

Association between short-term exposure to air pollutants and cause-specific daily mortality in Italy. A nationwide analysis

Background/aimDaily air pollution has been linked with mortality from urban studies. Associations in rural areas are still unclear and there is growing interest in testing the role that air pollution has on other causes of death. This study aims to evaluate the association between daily air pollution and cause-specific mortality in all 8092 Italian municipalities. MethodsNatural, cardiovascular, cardiac, ischemic, cerebrovascular, respiratory, metabolic, diabetes, nervous and psychiatric causes of death occurred in Italy were extracted during 2013–2015. Daily ambient PM10, PM2.5 and NO2 concentrations were estimated through machine learning algorithms. The associations between air pollutants and cause-specific mortality were estimated with a time-series approach using a two-stage analytic protocol where area-specific over-dispersed Poisson regression models where fit in the first stage, followed by a meta-analysis in the second. We tested for effect modification by sex, age class and the degree of urbanisation of the municipality. ResultsWe estimated a positive association between PM10 and PM2.5 and the mortality from natural, cardiovascular, cardiac, respiratory and nervous system causes, but not with metabolic or psychiatric causes of death. In particular, mortality from nervous diseases increased by 4.55% (95% CI: 2.51–6.63) and 9.64% (95% CI: 5.76–13.65) for increments of 10 μg/m3 in PM10 and PM2.5 (lag 0–5 days), respectively. NO2 was positively associated with respiratory (6.68% (95% CI: 1.04–12.62)) and metabolic (7.30% (95% CI: 1.03–13.95)) mortality for increments of 10 μg/m3 (lag 0–5). Higher associations with natural mortality were found among the elderly, while there were no differential effects between sex or between rural and urban areas. ConclusionsShort-term exposure to particulate matter was associated with mortality from nervous diseases. Mortality from metabolic diseases was associated with NO2 exposure. Other associations are confirmed and updated, including the contribution of lowly urbanised areas. Health effects were also found in suburban and rural areas.