Fixed-site Monitoring Stations Research Articles

Refining Children's exposure assessment to NO2, SO2, and O3: Incorporating indoor-to-outdoor concentration ratios and individual daily routine

Exposure to air pollutants like sulfur dioxide (SO2), nitrogen oxides (NOx), and ozone (O3) is associated with adverse health effects, particularly with exacerbations of asthma symptoms and new asthma cases in both children and adults. While fixed-site monitoring (FSM) stations are commonly used in air pollutant exposure studies, they may not fully capture personal exposures due to limitations such as inadequate consideration of daily routines and indoor/outdoor concentration variations. In this study, to enhance the accuracy of personal exposure calculated by using FSM data, individual's daily activity routine, encompassing both indoor and outdoor environments, were incorporated by using indoor-to-outdoor concentration ratios. Three methodologies were compared to assess the accuracy of exposure calculations: (i) direct exposure determination employing passive samplers (PS), (ii) personal exposure calculated using FSM data alone, and (iii) personal exposure calculated using FSM data refined by integrating local average individual daily activity routines and indoor-to-outdoor ratios. The results demonstrate that the refined method (iii) yields substantial improvements in estimated exposure levels, reducing the average error from 1.4% to 0.4% for NO2, from 72.1% to 12.7% for SO2, and from 323.4% to 24.9% for O3.

Effect of short-term exposure to ambient air pollutants on non-accidental mortality in emergency department visits: a time-series study.

Exposure to air pollution has been linked to an increased risk of premature mortality. However, the acute effects of air pollution on the risk of non-accidental mortality have not been extensively researched in developing countries, and the findings thus far have been inconsistent. Therefore, this study aimed to examine the association between short-term exposure to six pollutants (PM2.5, PM10, SO2, NO2, O3, and CO) and non-accidental mortality in Beijing, China. Daily data on non-accidental deaths were gathered from 1 January 2017 to 31 December 2018. Air pollution data for the same period were collected from 35 fixed-site air quality monitoring stations in Beijing. Generalized additive models (GAM) based on Poisson regression were used to investigate the association between non-accidental mortality in emergency department visits and the daily average levels of air pollutants. There were 8,676 non-accidental deaths recorded during 2017-2018. After sensitivity analysis, short-term exposure to air pollutants, particularly gaseous pollutants, was linked to non-accidental mortality. Specifically, for every 10 μg/m3 increase (5 μg/m3 in SO2, 0.5 mg/m3 in CO) of SO2 (lag 04), NO2 (lag 04), O3 (lag 05), and CO (lag 04), the relative risk (RR) values were 1.054 (95% CI: 1.009, 1.100), 1.038 (95% CI: 1.013, 1.063), 1.032 (95% CI: 1.011, 1.054), and 1.034 (95% CI: 1.004, 1.066), respectively. In terms of causes of death, short-term exposure to NO2, SO2, and O3 increased the risk of circulatory mortality. Further stratified analysis revealed that the stronger associations were presented in females for O3 while in males for CO. People aged 65 and over were strongly associated with ambient air pollution. Our study showed that ambient air pollutants were associated with non-accidental mortality. Our findings suggested that efforts to control gaseous pollution should be stepped up, and vulnerable groups should be the focus of health protection education.

Differentiating the effects of fine and coarse particulate air pollution on the onset of stable and unstable angina: a case-crossover study in 305 Chinese cities

Background and purpose: Associations between fine and coarse particulate matters (i.e., PM2.5 and PM2.5–10, respectively) and the onset of angina have rarely been investigated. We aimed to systematically explore the impacts of PM2.5 as well as PM2.5–10 on the onset of stable and unstable angina at the hourly timescale. Methods: We performed a time-stratified case-crossover study among 995,734 angina patients from 1,655 hospitals in 305 Chinese cities from January 2015 to December 2021. Concentrations of PM2.5 and PM2.5–10 were collected at the hourly timescale from nearby fixed-site monitoring stations. Hourly onset information of unstable and stable angina was obtained from the Chinese Cardiovascular Association Database-Chest Pain Center. We applied conditional logistic regressions combined with polynomial distributed lag models to explore the lagged exposure–response associations. Subgroup analyses were performed to explore potential effect modifiers including age, sex, season, and region. Results: Transient exposure to PM2.5 was significantly associated with elevated risk of unstable and stable angina onset. The associations occurred immediately in the concurrent hour of exposure, attenuated thereafter, and turned to null at approximately lag 12 h for unstable angina and 9 h for stable angina. Each interquartile range increase in the PM2.5 concentrations over 0 to 12 h was associated with 1.32% (95% confidence interval [95% CI]: 0.94%–1.70%) and 1.69% (95% CI: 0.99%–2.39%) increase in the onset risk of unstable and stable angina, respectively. The results remained similar after controlling for co-pollutants. Greater magnitudes of associations were found among females and during cold season. Null associations were observed between PM2.5–10 and any type of angina. Conclusion: Our study indicates that acute exposure to PM2.5, rather than PM2.5–10, was significantly associated with the onset of both unstable and stable angina, underscoring the need of continued efforts in controlling particulate matter air pollution.

Association of exposure to air pollutants with gestational diabetes mellitus in Chiayi City, Taiwan.

We investigated the associations of exposure to particulate matter with an aerodynamic diameter less than 2.5 μm (PM2.5) and several gaseous pollutants with risk of gestational diabetes mellitus (GDM) in Taiwan. We retrospectively identified pregnant women who underwent a two-step approach to screen for GDM between 2006 and 2014. Information on concentrations of air pollutants (including PM2.5, sulfur dioxide [SO2], nitrogen oxides [NOx], and ozone [O3]) were collected from a single fixed-site monitoring station. We conducted logistic regression analyses to determine the associations between exposure to air pollutants and risk of GDM. A total of 11210 women were analyzed, and 705 were diagnosed with GDM. Exposure to PM2.5 during the second trimester was associated with a nearly 50% higher risk of GDM (odds ratio [OR] 1.47, 95% CI 0.96 to 2.24, p=0.077). The associations were consistent in the two-pollutant model (PM2.5 + SO2 [OR 1.73, p=0.038], PM2.5 + NOx [OR 1.52, p=0.064], PM2.5 + O3 [OR 1.96, p=0.015]), and were more prominent in women with age <30 years and body mass index <25 kg/m2 (interaction p values <0.01). Exposure to PM2.5 was associated with risk of GDM, especially in women who were younger or had a normal body mass index.

Short-term exposure to ozone and asthma exacerbation in adults: A longitudinal study in China.

The relationships between short-term ozone exposure and the acute exacerbations of asthma in adults have not been fully studied. Existing studies commonly ignored the effects of ozone on mild or early asthma exacerbations. To investigate the associations between short-term ozone exposure and asthma exacerbations in Chinese adults. We administered health management for adult asthma patients through the Respiratory Home Platform and required them to monitor their lung function every morning and evening by themselves. Finally, a total of 4,467 patients in 18 Chinese cities were included in the current analyses, with 79,217 pairs of lung function records. The maximum daily 8-h average ozone concentrations were collected from fixed-site air quality monitoring stations. We calculated diurnal peak expiratory flow (PEF) variation using morning and evening measurements of PEF and then defined different severity of asthma exacerbations with diurnal PEF variations >10, 15, and 20%, respectively. A binomial distributed generalized additive mixture model combined with distribution non-linear models was applied to examine the association of ozone with asthma exacerbations. We further conducted stratified analyses by sex, age, season of lung function tests, and region. We found that short-term ozone exposure was independently associated with an elevated risk of asthma exacerbations defined by lung function and the effects could last for about 2 days. At lag 0-2 days, each 10 μg/m3 increment in ozone concentration was associated with odds ratios of 1.010 [95% confidence interval (CI): 1.003, 1.017], 1.014 (95% CI: 1.005, 1.023), and 1.017 (95% CI: 1.006, 1.028) for asthma exacerbations that were defined by diurnal PEF variation over 10, 15, and 20%, respectively. The associations remained significant after adjusting for other pollutants, and became unstable when using 24-h average ozone concentration. We also found that the associations were relatively stronger in males, those aged 45 years and older, and in the warm season. Our results suggest that short-term ozone exposure can increase the risk of asthma exacerbations, even in the early stage of exacerbation. Male and older asthma patients may be more vulnerable to ozone air pollution, especially in the warm season.

Using mobile air quality station data to identify critical areas in the city of Rio de Janeiro regarding pollutant concentrations

Recent studies have shown that tropospheric ozone, fine particulate matter and nitrogen dioxide are the urban air pollutants of major concern regarding human health effects. Monitoring air quality is a challenge in several cities, such as Rio de Janeiro, where the number of fixed-site air quality monitoring stations and their spatial distribution are insufficient to assess the extent of atmospheric pollutants. However, despite this lack of resources, the data obtained by mobile stations are a valuable means of determining which areas are experiencing critical air quality conditions, and provide key information for an air quality management program. The main purpose of this study was to conduct a critical analysis of data obtained by the Municipal Department of Environment and Climate (SMAC) mobile station in the period 2010–2018. Concentrations determined for particulate matter with a diameter ≤2.5 µm (PM2.5), O3, NO2, SO2 and CO showed that PM2.5 and O3 are the pollutants of major concern, and that the north of the city has higher air quality indices for these compounds. In addition, the south-west district had relatively high ozone levels, probably owing to low concentrations of NO2 in a volatile organic compound (VOC)-limited ozone formation regime. These factors should be considered by the municipal government in future discussions of control strategies for managing the city’s air quality. This study also shows the value of mobile stations in making a preliminary survey of pollutant concentrations, mainly in countries with limited financial investment in air quality management.

Utility of outdoor central site monitoring in assessing exposure of school children to ultrafine particles

Epidemiological studies investigating the association between daily particle exposure and health effects are frequently based on a single monitoring site located in an urban background. Using a central site in epidemiological time-series studies has been established based on the premises of low spatial variability of particles within the areas of interest and hence the adequacy of the central sites to monitor the exposure. This is true to a large extent in relation to larger particles (PM2.5, PM10) that are typically monitored and regulated. However, the distribution of ultrafine particles (UFP), which in cities predominantly originate from traffic, is heterogeneous. With increasing pressure to improve the epidemiology of UFP, an important question to ask is, whether central site monitoring is representative of community exposure to this size fraction of particulate matter; addressing this question is the aim of this paper. To achieve this aim, we measured personal exposure to UFP, expressed as particle number concentration (PNC), using Philips Aerasense Nanotracers (NT) carried by the participants of the study, and condensation particle counters (CPC) or scanning mobility particle sizers (SMPS) at central fixed-site monitoring stations. The measurements were conducted at three locations in Brisbane (Australia), Cassino (Italy) and Accra (Ghana). We then used paired t-tests to compare the average personal and average fixed-site PNC measured over the same 24-h, and hourly, periods. We found that, at all three locations, the 24-h average fixed-site PNC was no different to the personal PNC, when averaged over the study period and all the participants. However, the corresponding hourly averages were significantly different at certain times of the day. These were generally times spent commuting and during cooking and eating at home. Our analysis of the data obtained in Brisbane, showed that maximum personal exposure occurred in the home microenvironment during morning breakfast and evening dinner time. The main source of PNC for personal exposure was from the home-microenvironment. We conclude that the 24-h average PNC from the central-site can be used to estimate the 24-h average personal exposure for a community. However, the hourly average PNC from the central site cannot consistently be used to estimate hourly average personal exposure, mainly because they are affected by very different sources.

Assessment of air pollution in the informal settlements of the Western Cape, South Africa

&#x0D; &#x0D; &#x0D; &#x0D; Introduction: South Africa has the highest ambient air pollution exposure associated with morbidity in the Sub-Saharan region, accounting for a total number of 14356 confirmed cases of mortality on an annual basis. The study assessed air pollution exposure levels of Khayelitsha and Marconi-Beam neighbourhoods that are not monitored by the fixed-site monitoring station provided by the government.&#x0D; Materials and methods: Weekly ambient air pollution measurements of Particulate Matter less than 2.5 μm (PM2.5) and Nitrogen Dioxide (NO2) were collected at households in neighbourhoods of Khayelitsha and Marconi-Beam during the summer and winter seasons. PM2.5 measurements were collected using Mesa Labs GK2.05 (KTL) cyclone attached to a GilAir Plus air sampling pump. Gases of NO2 were measured using passive diffusive samplers. Data were recorded on a Microsoft Excel 2016 spreadsheet. Statistical analyses were performed using IBM SPSS Statistics 28.0. The outcome of the seasonal exposure levels will be compared with the South African ambient air quality standards to ascertain the risk of potential exposure to significant levels of PM2.5 and NO2 that are hazardous to human health.&#x0D; Results: The results suggest that summer NO2 concentrations in the Khayelitsha neighbourhood ranged between (0 and 28 μg/m3), while in winter NO2 concentrations nearly doubled. A similar trend was observed regarding PM2.5 behaviour with summer overall exposure level of 7 μg/m3 and 13 μg/m3 during winter.&#x0D; Conclusion: Whilst there are no legislative guidelines to compare the measured weekly average results, the concentrations were still lower than the World Health Organization (WHO), and South African air quality standards values for PM2.5 and NO2 pollutants.&#x0D; &#x0D; &#x0D; &#x0D;

Development of methods for citizen scientist mapping of residential woodsmoke in small communities

BackgroundResidential wood burning is a major source of fine particulate matter (PM2.5) during winter and a leading contributor to air pollution. Exposure to woodsmoke PM2.5 is associated with many health effects, so it is important to characterize the magnitude and spatial variability in exposures. However, high infrastructure and maintenance costs of regulatory monitoring stations limit their spatial resolution and make monitoring infeasible for many small communities where woodsmoke may be prevalent. MethodsMobile monitoring was conducted with a nephelometer and multi-wavelength aethalometer, capable of identifying woodsmoke PM2.5, to capture spatially resolved data. This Combined Aethalometer and Nephelometer for Assessment of Woodsmoke (CANAW) method was evaluated in three pairs of communities in British Columbia, Canada. Measurements were also taken at fixed-site monitoring stations. Light scattering measured by a nephelometer (Bsp) was compared with gravimetric filter-based and beta-attenuation measures of PM2.5. The difference in absorbance of 370 nm and 880 nm wavelengths as measured by an aethalometer (delta C), was compared with the chemical woodsmoke tracer levoglucosan. ResultsFixed site measurements of Bsp and delta C were comparable with established methods of monitoring PM2.5 and woodsmoke, respectively. Correlations in each tested relationship across all locations were high (r ≥ 0.93 in all cases). Mobile monitoring captured high spatial variation in woodsmoke PM2.5 and maps of average concentrations during monitoring were created to identify woodsmoke hotspots. ConclusionFollowing the successful implementation of the mobile CANAW method, training materials were created and tested with lay volunteers along with an online mapping application. Volunteers were able to effectively operate the equipment, collect valuable data on woodsmoke concentrations, and map spatial patterns across their communities using the application. The CANAW method is a valuable option for advancing cost-effective data collection for residential woodsmoke in otherwise unmonitored communities, and to add spatial context to existing monitoring networks.

Associations of Carbonaceous Compounds and Water-Soluble Inorganic Ions in Ambient PM2.5 with Renal Function in Older Individuals: The China BAPE Study.

Exposure to fine particulate matter (PM2.5) is proven to be associated with a decline in renal function. However, few studies have explored the acute renal damage from carbonaceous compounds and water-soluble inorganic ions (WSIIs), which constitute the bulk of total PM2.5 mass. We examined the acute effect of these constituents of ambient PM2.5 on renal function in older Chinese individuals. Seventy-one healthy people aged 60-69 years from Jinan, China, were enrolled and visited monthly and asked to complete survey questionnaires, undergo physical exams, and provide blood samples. The hourly concentrations of organic carbon, elemental carbon (EC), and WSIIs in ambient PM2.5 were collected from a fixed-site monitoring station. The association between PM2.5 constituents and estimated glomerular filtration rate (eGFR) was evaluated using linear mixed-effects models after controlling for a series of covariates. We observed that ambient carbonaceous compounds and WSIIs were associated with a significant decline in renal function. The interquartile range increased in the 24 h moving average of carbonaceous compounds, and WSIIs in ambient PM2.5 were associated with -13.11% [95% confidence interval (95% CI): -19.49, -6.21%] to -0.81% (95% CI: -4.17, 2.67%) changes in eGFR. We found significant associations between EC, chlorine (Cl-), sodium (Na+), and magnesium (Mg2+) and eGFR in single-pollutant, constituent-PM2.5, and residual-constituent models with a lag period of 0-24 h. This study demonstrated that carbonaceous compounds and WSIIs in PM2.5 were inversely associated with renal function.

Associations between difference in anemia-related blood cell parameters and short-term exposure to ambient fine particles in Beijing elderly residents

BACKGROUND AND AIM: Anemia is a highly prevalent disease among elderly population with multiple adverse health outcomes. Particle exposure was a potentially risk factor of anemia. However, few studies have investigated the associations of particle exposure with anemia-related outcomes in the elderly, and the underlying mechanism is unclear. METHODS: Based on a panel study conducted between July 2016 and September 2017, anemia-related blood cell parameters, including red blood cell count (RBC), hemoglobin (HGB), hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and tumor necrosis factor α (TNF α), a marker of systemic inflammation, in serum samples were measured from 135 elderly participants at up to four clinical visits. Particulate pollutants—including particulate matter with an aerodynamic diameter of ≤ 2.5μm (PM2.5), black carbon (BC), ultrafine particles (UFPs), and accumulated-mode particles (Acc)—were continuously monitored at a fixed-site monitoring station. Linear mixed-effects models were used to examine the associations between particle exposure and anemia-related blood cell parameters, and mediation models were used to evaluate the mediation effect of TNFα on the associations. RESULTS:In the elderly participants, exposure to all measured pollutants were significantly associated with differences in anemia-related blood cell parameters, such as the association between HGB difference and per interquartile range (IQR) increase in average Acc concentration 14 d before clinical visits was -2.2% (95% CI: -3.8%, -0.6%). The significant associations of UFPs and Acc exposure with difference in anemia-related blood cells kept robust after adjustment for other pollutants. In advanced analysis, 25.2 % (95% CI: 7.4 %, 64.8 %) of difference in MCHC associated with average UFPs concentration 14 d before clinical visits were mediated by the level of TNFα. CONCLUSIONS:Short-term exposure to fine particles, especially UFPs and Acc, contributed to damage of anemia-related blood cell in the elderly, and systemic inflammation is a potential internal mediator. KEYWORDS: anemia-related blood cell parameters, ambient fine particles, mean corpuscular hemoglobin concentration (MCHC), tumor necrosis factor α (TNF α), ultrafine particles (UFPs), accumulated-mode particles (Acc)

Use of a LASSO approach to Identify ambient volatile organic compounds associated with emergency admissions for lower respiratory tract infection

BACKGROUND AND AIM: Existing evidence suggests that ambient volatile organic compounds (VOCs) may be associated with adverse respiratory outcomes, but it is unclear whether specific components may be responsible for triggering respiratory diseases. We aimed to examined which VOCs are associated with emergency admissions for lower respiratory tract infection (LRTI) based on a LASSO approach. METHODS: We obtained daily concentrations for 98 types of VOCs from two fixed-site monitoring stations located in Beijing. People who resided in Beijing for half a year or more and were hospitalized in local hospitals for the diagnosis of LRTI during the period of 2015 to 2016 were included. We used a LASSO approach to estimate specific VOC effects: (1) including all types of VOCs and fitting generalized linear models with a LASSO penalty function in a time-series framework using quasi-Poisson regression to identify which VOCs may be triggering LRTI; (2) including a specific VOC and fitting classic generalized linear models to estimate the associations with LRTI. RESULTS:There were 184,865 emergency admissions for LRTI during 2015 to 2016 in Beijing. Total VOC concentration ranged from 12.79ppb to 258.95ppb, of which alkanes account for about 38%, followed by alkenes (14%), and alkynes (7%). For LRTI, acetylene (C2H2), acrolein (C3H4O), 2,3-dimethylbutane (C6H14) and bromodichloromethane (CHBrCl2) were selected by the LASSO penalty function. Per IQR increase, short-term exposure to same-day C2H2 and C6H14 were associated with 1.90% (95%CI: 0.75, 3.07) and 2.07% (95%CI: 0.47, 3.70) change in LRTI, while C3H4O and CHBrCl2 were associated with 1.01% (95%CI: -0.24, 2.28) and -0.03% (95%CI: -0.75, 0.70) change in LRTI, respectively. CONCLUSIONS:Our study suggests that short-term exposure to C2H2 and C6H14 is associated with increased risk of LRTI emergency admissions. These specific components may reflect the role of traffic emission. Additional research is necessary to examine whether C3H4O and CHBrCl2 may affect LRTI. KEYWORDS: air pollution, volatile organic compounds, LASSO, respiratory emergency admissions

Solid State Gas Sensor Systems: Deployment for an Extensive Air Quality Monitoring in Urban Environment

Introduction Air pollution is a global threat having huge impact on human health and ecosystems [1]. In urban areas, the air quality can be considered as resulting from the overlapping of three different pollution components: regional background, urban background and hot spot events. Therefore, the continuous monitoring of these components is of critical importance. Indeed, the ability to separate the three components is the key to define reduction actions of atmospheric pollution linked to the related sources and for this reason, really effective.This work demonstrates that it is possible to determine, with reliability, sensitivity and selectivity comparable to those of the analytical instruments, the pollutants’ concentration in the atmosphere using specific advanced thick film gas sensors. They are based on nanostructured metal oxides (MOX sensors) which modify their surface properties when interacting with reducing or oxidizing gases [2].Nowadays, monitoring is usually performed in few fixed stations and through mobile stations (where the conventional equipment is installed on vehicles) for temporary measurement campaigns or occasional environmental impact estimations. The equipment used in these stations is often complex, expensive and difficult to deploy, requiring controlled environmental conditions and frequent maintenance and calibrations [1].Differently, systems based on MOX gas sensors constitute an advantageous solution because of their low-cost fabrication, maintenance, and installation, low power consumption, small dimensions and of easy deployment for a wide range of situations for example along heavy traffic roads, or in historic centers where fixed monitoring stations cannot be used due to their large size. Experimental The thick film gas sensors were fabricated through screen-printing technology. The sensing layers are based on specific functional materials synthesized in form of crystalline nanometric powders via wet chemistry processes [2]. A careful coordination of all different processes involved in the gas sensors realization, such as functional material preparation, deposition of sensing layers, substrates and electronics were done to optimize the sensors’ precision and accuracy.The arrays of thick film gas sensors were assembled in small remotely controlled units and used for on-site tests. A monitoring unit (see figure A) consists in a small box to lodge the sensors, the electronic circuitry related to each sensor and a main electronic control unit provided with serial connection through which the data are transferred to a GSM module which sends them to an input data server, on request.With the aim to validate the values of gas concentrations obtained through the array of MOX sensors, few monitoring units have been exposed to the real atmosphere beside fixed-site monitoring stations for air quality control. The sensor responses were studied in comparison with the pollutant concentrations as measured by the analytical instruments. In particular, IR and UV spectrophotometers for carbon monoxide and ozone, chemiluminescence analyzer for NOx and gas chromatograph for BTEX. Results and Conclusions The developed monitoring units based on different advanced thick film gas sensors have been successfully prepared with optimal level of reliability, stability, reproducibility and used to detect gaseous pollutants in the atmosphere with the same trend observed by the conventional analytical techniques for long monitoring periods, in different seasons and areas.As example, a laboratory experiment devoted to test the stability and repeatability of sensors is reported in the figure B. In the image, the figure B refers to the alternate signal of two sensors, nominally identical, to 0.1 and 0.8 ppm of benzene. The responses, defined as ratio between the conductance in presence of benzene and the conductance in air, were 1.2 to 0.1 ppm and 2.1 to 0.8 ppm of benzene for both sensors. A second experiment is shown in figure C: the ozone concentration measured in real atmosphere through a WO3 sensor was compared with the measurements carried out by means of a conventional analyzer (UV spectrophotometer). The data are expressed in both cases as hourly average obtaining a quite good agreement. The graph is relating to one month of monitoring, while, in the inset, a zoom on few days is shown.The innovative system, based on a specific MOX sensors array, is able to detect and quantify atmospheric pollutants constituting an advantageous solution for a wide range of situations, as for example along the roads of city centers or along heavy traffic roads, or in historic centers where fixed monitoring stations cannot be used due to their large size.

Acute effects of fine particulate matter constituents on cardiopulmonary function in a panel of COPD patients

BackgroundExposure to fine particulate matter (PM2.5) has been linked with adverse cardiorespiratory health conditions. However, evidence for PM2.5 constituents is still scarce, especially among patients with chronic obstructive pulmonary disease (COPD). ObjectiveTo investigate the associations of short-term exposure to different chemical constituents of PM2.5 with measures of cardiac and lung function in COPD patients. MethodsWe conducted a retrospective panel study among 100 COPD patients who received repeated measures of left ventricular ejection fraction (LVEF), forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and peak expiratory flow (PEF) in Shanghai, China from August 2014 to September 2019. Daily PM2.5 and PM2.5 constituents were obtained from fixed-site monitoring station. Linear mixed-effects models were used to estimate the associations of PM2.5. ResultsWe found water-soluble ions of PM2.5, mainly NO3−, SO42−, and NH4+ were robustly associated with reduced LVEF, and the reductions in LVEF associated with an IQR increase of them ranged from 1.8% to 2.0% (lag 1 d). Metal constituents such as Cu and As were associated with FEV1, FVC and PEF. The corresponding reductions in lung function parameters for an IQR increase of them ranged from 1.4% to 2.3% (lag 0 or 1 d). These associations remained relatively robust after adjusting for total PM2.5 mass and gaseous pollutants. ConclusionsOur results suggest that water-soluble ions and several metal/metalloid elements might be important constituents in PM2.5 that were associated with reduced cardiorespiratory function among COPD patients.

Exposure to Fine Particulate Matter and Inflammatory Cytokines and DNA Methylation in Healthy Young Adults

Background/Aim: Protective benefits of indoor air filtration in areas with high pollution levels are not fully understood. This study aims to examine whether short-term air filtration intervention could attenuate the hazards from acute exposure to fine particulate matter (PM2.5), and investigate the potential impact of this exposure on inflammatory cytokines and DNA methylation. Methods: A randomized, double-blind crossover trial of true or sham indoor air filtration was conducted among 29 healthy young adults in Beijing, China. Each episode covered a typical air pollution smog event, and 38 cytokines and their corresponding DNA methylation in the study participants were measured at three time points: pre-smog, during smog, and post-smog. Indoor PM2.5 concentrations were measured using an aerosol spectrometer and outdoor PM2.5 concentrations were collected from fixed-site monitoring stations. Linear mixed-effect models were used to evaluate the associations between exposure and outcome variables. Results: The indoor PM2.5 concentration with true filtration was 67.8% lower than sham filtration (13.8 μg/m3 vs. 42.8 μg/m3). Air filtration was significantly associated with decreases of 6.61% to 35.46% in 13 cytokines. Time-weighted personal PM2.5 exposure was significantly associated with changes in 11 cytokines and methylation at 27 CpGs. Specifically, PM2.5 exposure was associated with increases in MCP-1, MCP-3 and sCD40L, but hypomethylation in corresponding genes. Conclusions: This trial suggests that indoor air filtration might attenuate the adverse effects of PM2.5 exposure through changing cytokines and DNA methylation.

Association of ambient particle pollution with gestational diabetes mellitus and fasting blood glucose levels in pregnant women from two Chinese birth cohorts

BackgroundFasting blood glucose may capture the adverse effects of air pollution on pregnant women better than the incidence of gestational diabetes mellitus (GDM), but evidence on the association between air pollution and maternal glucose concentrations is limited. ObjectiveTo investigate the associations between air pollutants, GDM and fasting blood glucose during pregnancy. MethodsWe recruited 2326 pregnant women from two birth cohorts located in Guangzhou and Heshan, the Pearl River Delta region (PRD), China. PM10, PM2.5 and black carbon (BC) exposure concentrations in the first and second trimesters of pregnancy were collected at fixed-site monitoring stations for each cohort. Multiple logistic regressions were employed to estimate the associations between particle pollution and GDM. Mixed-effects models were used to evaluate the associations of air pollutants with blood glucose levels. Restricted cubic spline functions were fitted to visualize the concentration-response relationships. Distributed lag non-linear models were used to estimate week-specific lag effects of particle pollution exposure on GDM and blood glucose. Unconstrained distributed lag models with lags of 0–3 weeks were used to examine potential cumulative effects. ResultsWe observed positive and significant associations of PM10, PM2.5 and BC exposure with fasting glucose, particularly in the second trimester. PM10, PM2.5 and BC were strongly correlated and displayed similar cumulative (lag 0–3 weeks) associations with fasting blood glucose. Exposure to particle pollution was not associated with 1-h or 2-h blood glucose. Models estimating the association between air pollutants and GDM were consistent with statistical insignificance. ConclusionsBased on the results of the present study, exposure to air pollution during pregnancy exerts cumulative, adverse effects on fasting glucose levels. This study provides preliminary support for the use of blood glucose levels to explore the potential health impact of air pollution on pregnant women.

Effects of long-term exposure to air pollution on all-cause mortality and cause-specific mortality in seven major cities of South Korea: Korean national health and nutritional examination surveys with mortality follow-up

Evidence from cohort studies on the effects of long-term exposure to air pollution on mortality is limited in South Korea, which has high concentration of particles compared to North America, Western Europe, and Japan, and low exposure compared to China. To reduce knowledge gaps between other countries and South Korea, we investigated the association between all-cause, cardiovascular, and respiratory mortality and long-term exposure to PM10 and, as a surrogate for fine particles from local emission sources, SO2 and NO2. Participants comprised 18,220 subjects (97,114.4 person-years) residing in 73 districts of seven major cities of South Korea who were assigned to measurements of fixed-site monitoring stations and followed up. We applied Cox proportional hazard models with time-varying exposure up to three years average of air pollutants. We adjusted for individual and district-level covariates measured at baseline such as age, sex, socioeconomic positions, and health behaviors. We found that hazard ratios of PM10 and SO2 for all-cause mortality leveled off over approximately 5 ppb of SO2 and 35–50 μg/m3 of PM10. Interquartile range increases of PM10 (5.05 μg/m3), SO2 (2.09 ppb), and NO2 (11.41 ppb) were associated with 14.4% (95% CI: −0.4, 31.4), 18.1% (−4.5, 46.0), and 18.9% (−8.7, 54.7) increases in cardiovascular mortality, respectively. We did not find positive associations for respiratory mortality. The increase in cardiovascular mortality varied by sex (for PM10, in females, 27.4% (5.8, 53.5) increase), smoking (in non-smokers, 35.9% (12.7, 64.0) increase), drinking (in drinkers, 24.5% (2.1, 51.8) increase), marital status (in those not married, 23.1% (1.1, 49.9)), employment status (for SO2, in those employed, 79.4% (16.1, 177.3) increase), body mass index (in those ≥23, 47.6% (10.4, 97.3) increase), and community deprivation (for PM10, in less deprived communities, 21.0% (1.3, 44.4) increase). In summary, long-term exposure to air pollution is associated with mortality risk in South Korea. Our results suggest that the health effect of long-term exposure to air pollution may not be equal by sex, health behaviors and socioeconomic positions.

Susceptibility of individuals with chronic obstructive pulmonary disease to respiratory inflammation associated with short-term exposure to ambient air pollution: A panel study in Beijing

BackgroundChronic obstructive pulmonary disease (COPD) is a leading cause of death worldwide. There is no clear evidence of whether COPD patients are more susceptible to respiratory inflammation associated with short-term exposure to air pollutants than those without COPD. ObjectivesThis study directly compared air pollutant-associated respiratory inflammation between COPD patients and healthy controls. MethodsThis study is based on the COPDB panel study (COPD in Beijing). Fractional exhaled nitric oxide (FeNO) was repeatedly measured in 53 COPD patients and 82 healthy controls at up to four clinical visits. Concentrations of carbon monoxide (CO), nitrogen monoxide, nitrogen dioxide (NO2), sulfur dioxide (SO2), fine particulate matter (PM2.5), black carbon (BC), ultrafine particles (UFPs), and accumulated-mode particles (Acc) were monitored continuously at a fixed-site monitoring station. Linear mixed-effects models were used to compare the associations between ln-transformed FeNO and average 1–23 h concentrations of air pollutants before the clinical visits. ResultsFeNO was positively associated with interquartile range (IQR) increases in average concentrations of CO, NO2, SO2, BC, UFPs, and Acc in all participants, with the strongest associations in different time-windows (range from 6.6% for average 1 h NO2 exposure to 32.1% for average 7 h SO2 exposure). Associations between FeNO and average 13–23 h PM2.5 exposure differed significantly according to COPD status. Increases in FeNO associated with average 1–2 h NO exposure were significant in COPD patients (range 8.9–10.2%), while the associations were nonsignificant in healthy controls. Associations between FeNO and average 1–23 h CO and SO2 exposure tended to be higher in COPD patients than in healthy controls, although the differences were not significant. UFPs-associated respiratory inflammation was robust in both subgroups. ConclusionsCOPD patients are more susceptible to respiratory inflammation following PM2.5, NO, CO, and SO2 exposure than individuals without COPD.

Short-term effects of outdoor air pollution on acute ischaemic stroke occurrence: a case-crossover study in Tianjin, China

ObjectiveAmbient air pollution is associated with ischaemic stroke incidence. However, most of the previous studies used stroke-related hospital admission rather than stroke onset itself. This study aimed to evaluate the...

A spatio-temporal land use regression model to assess street-level exposure to black carbon

Estimation of exposure to air pollution using land use regression (LUR) models often focuses on spatial variation in (annual) average concentration. However, temporal variability is known to be an important factor for exposure. To estimate the short-term street-level exposure to black carbon (BC), we build a spatio-temporal LUR model by including time-dependent variables as predictor variables. We developed and evaluated the model based on data from an opportunistic mobile monitoring campaign in which city employees measured black carbon (BC) during their surveillance tours. Exposure estimates based on the hourly LUR model are more accurate than those based on a fixed site monitoring station or on a spatial LUR model, and can be used to estimate exposure of cyclists or pedestrians to traffic-related pollution based on a GPS track. We demonstrate the potential of building a real-time dynamic pollution map based on unstructured opportunistic measurements to provide personalized exposure information.