Urban Fine Particulate Matter and Elements Associated with Subclinical Atherosclerosis in Adolescents and Young Adults.

The relationships between the elemental constituents of PM2.5 and atherosclerosis remain limited, especially in young populations. This study included 755 subjects aged 12-30 years in the Taipei metropolis. A land use regression model was used to estimate residential annual mean concentrations of PM2.5 and eight elemental constituents. We evaluated the percent differences in carotid intima-media thickness (CIMT) with PM2.5 and elemental constituent exposures by linear regressions. Interquartile range increments for PM2.5 (4.5 µg/m3), sulfur (108.6 ng/m3), manganese (2.0 ng/m3), iron (34.5 ng/m3), copper (3.6 ng/m3), and zinc (20.7 ng/m3) were found to associate with 0.92% (95% confidence interval (CI): 0.17-1.66), 0.51% (0.02-1.00), 0.36% (0.05-0.67), 0.98% (0.15-1.82), 0.74% (0.01-1.48), and 1.20% (0.33-2.08) higher CIMTs, respectively. Factor analysis identified four air pollution source-related factors, and the factors interpreted as traffic and industry sources were associated with higher CIMTs. Stratified analyses showed the estimates were more evident in subjects who were ≥18 years old, females, or who had lower household income. Our study results provide new insight into the impacts of source-specific air pollution, and future research on source-specific air pollution effects in young populations, especially in vulnerable subpopulations, is warranted.

Neuropathology changed by 3- and 6-months low-level PM2.5 inhalation exposure in spontaneously hypertensive rats.

BACKGROUND: Epidemiological evidence has linked fine particulate matter (PM2.5) to neurodegenerative diseases; however, the toxicological evidence remains unclear. The objective of this study was to investigate the effects of PM2.5 on neuropathophysiology in a hypertensive animal model. We examined behavioral alterations (Morris water maze), lipid peroxidation (malondialdehyde (MDA)), tau and autophagy expressions, neuron death, and caspase-3 levels after 3 and 6 months of whole-body exposure to urban PM2.5 in spontaneously hypertensive (SH) rats. RESULTS: SH rats were exposed to S-, K-, Si-, and Fe-dominated PM2.5 at 8.6 ± 2.5 and 10.8 ± 3.8 µg/m3 for 3 and 6 months, respectively. We observed no significant alterations in the escape latency, distance moved, mean area crossing, mean time spent, or mean swimming velocity after PM2.5 exposure. Notably, levels of MDA had significantly increased in the olfactory bulb, hippocampus, and cortex after 6 months of PM2.5 exposure (p < 0.05). We observed that 3 months of exposure to PM2.5 caused significantly higher expressions of t-tau and p-tau in the olfactory bulb (p < 0.05) but not in other brain regions. Beclin 1 was overexpressed in the hippocampus with 3 months of PM2.5 exposure, but significantly decreased in the cortex with 6 months exposure to PM2.5. Neuron numbers had decreased with caspase-3 activation in the cerebellum, hippocampus, and cortex after 6 months of PM2.5 exposure. CONCLUSIONS: Chronic exposure to low-level PM2.5 could accelerate the development of neurodegenerative pathologies in subjects with hypertension.

Trajectory-Assisted Source Apportionment of Winter-Time Aerosol Using Semi-continuous Measurements.

Receptor models, e.g., positive matrix factorization (PMF), are beneficial in designing effective control strategies to improve air quality. Additionally, integrating the trajectory analysis data into receptor modeling facilitates identifying the contributions from long-range transported aerosols. This study was conducted in Taipei City of Taiwan, a representative urban area with high population density, heavy traffic, and residential-commercial complexes. Hourly measurements were applied into an integrated trajectory-source apportionment approach. PMF was used to identify seven potential sources, including ammonium sulfate related, oil combustion, firework/firecracker, dust, vehicle, coal/marine, and industry/vehicle. Ammonium sulfate related source (33%) was characterized as the largest contributor, followed by coal/marine (18%) and industry/vehicle (16%). Through this integrated method, contribution estimates of the ammonium sulfate related factor from distant potential source regions were differentiated. Additionally, detailed distributions of source contributions to PM2.5 event periods were revealed by applying these highly time-resolved measurements.

[Relationship between long non-coding RNA MALAT1 and prostate cancer].

Prostate cancer (PCa), as a malignant tumor originating in the prostate glandular epithelium, has become a global "killer" that threatens the health of elderly men. PCa-related studies have been focusing on the progression mechanisms and treatment strategies of the malignancy, particularly on the role of long non-coding RNA (lncRNA) in recent years. The lncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) plays a key role in the progression and treatment of PCa, as well as in its metastasis and invasion and cell proliferation. lncRNA MALAT1 not only influences the biological characteristics of PCa, but also has a regulatory effect on the medicinal treatment of the disease, its action mechanisms involving ceRNA and AR signaling pathways. This review focuses on the relationship between lncRNA MALAT1 and PCa, aiming to provide a new research direction for the diagnosis and treatment of the malignancy.

Mortality risk attributable to high and low ambient temperature: a multicountry observational study.

BACKGROUND: Although studies have provided estimates of premature deaths attributable to either heat or cold in selected countries, none has so far offered a systematic assessment across the whole temperature range in populations exposed to different climates. We aimed to quantify the total mortality burden attributable to non-optimum ambient temperature, and the relative contributions from heat and cold and from moderate and extreme temperatures. METHODS: We collected data for 384 locations in Australia, Brazil, Canada, China, Italy, Japan, South Korea, Spain, Sweden, Taiwan, Thailand, UK, and USA. We fitted a standard time-series Poisson model for each location, controlling for trends and day of the week. We estimated temperature-mortality associations with a distributed lag non-linear model with 21 days of lag, and then pooled them in a multivariate metaregression that included country indicators and temperature average and range. We calculated attributable deaths for heat and cold, defined as temperatures above and below the optimum temperature, which corresponded to the point of minimum mortality, and for moderate and extreme temperatures, defined using cutoffs at the 2·5th and 97·5th temperature percentiles. FINDINGS: We analysed 74,225,200 deaths in various periods between 1985 and 2012. In total, 7·71% (95% empirical CI 7·43-7·91) of mortality was attributable to non-optimum temperature in the selected countries within the study period, with substantial differences between countries, ranging from 3·37% (3·06 to 3·63) in Thailand to 11·00% (9·29 to 12·47) in China. The temperature percentile of minimum mortality varied from roughly the 60th percentile in tropical areas to about the 80-90th percentile in temperate regions. More temperature-attributable deaths were caused by cold (7·29%, 7·02-7·49) than by heat (0·42%, 0·39-0·44). Extreme cold and hot temperatures were responsible for 0·86% (0·84-0·87) of total mortality. INTERPRETATION: Most of the temperature-related mortality burden was attributable to the contribution of cold. The effect of days of extreme temperature was substantially less than that attributable to milder but non-optimum weather. This evidence has important implications for the planning of public-health interventions to minimise the health consequences of adverse temperatures, and for predictions of future effect in climate-change scenarios. FUNDING: UK Medical Research Council.

Ambient air pollution and risk of tuberculosis: a cohort study.

OBJECTIVES: Several respirable hazards, including smoking and indoor air pollution from biomass, were suggested to increase the risk of tuberculosis. Few studies have been conducted on ambient air pollution and tuberculosis. We investigated the association between exposure to ambient air pollution and incidence of active tuberculosis. METHODS: We conducted a cohort study using 106,678 participants of a community-based screening service in Taiwan, 2005-2012. We estimated individual exposure to air pollution using data from the nearest air quality monitoring station and the road intensity within a 500 m buffer zone. The incidence of tuberculosis was ascertained from the national tuberculosis registry. RESULTS: After a median follow-up of 6.7 years, 418 cases of tuberculosis occurred. Exposure to fine particulate matter (PM2.5) was associated with increased risk of active tuberculosis (adjusted HR: 1.39/10 µg/m3 (95% CI 0.95 to 2.03)). In addition, traffic-related air pollution including nitrogen dioxide (adjusted HR: 1.33/10 ppb; 95% CI 1.04 to 1.70), nitrogen oxides (adjusted HR: 1.21/10 ppb; 95% CI 1.04 to 1.41) and carbon monoxide (adjusted HR: 1.89/ppm; 95% CI 0.78 to 4.58) was associated with tuberculosis risk. There was a non-significant trend between the length of major roads in the neighbourhood and culture-confirmed tuberculosis (adjusted HR: 1.04/km; 95% CI 0.995 to 1.09). CONCLUSIONS: Our study revealed a possible link between ambient air pollution and risk of active tuberculosis. Since people from developing countries continue to be exposed to high levels of ambient air pollution and to experience high rates of tuberculosis, the impact of worsening air pollution on global tuberculosis control warrants further investigation.

Age of asthma onset and vulnerability to ambient air pollution: an observational population-based study of adults from Southern Taiwan.

BACKGROUND: Late-onset asthma (onset > 12 years) is pathologically distinct from early-onset asthma. The mechanism of air pollution is not a classic allergic inflammation and could have differential effect on late-onset and early-onset asthma. However, there is little known about the association of onset-age phenotype and air pollution. In this population-based study, we aimed to determine the association of asthma severity outcomes and air pollution regarding age at onset of asthma. METHODS: In 2004, we conducted a cross-sectional questionnaire survey about respiratory health among schoolchildren's parents randomly selected from 94 of 816 elementary and middle schools in southern Taiwan. Participants ever having typical asthma symptoms were enrolled. We used kriging method to estimate individual exposure to ambient air pollution in the preceding year before the year of asthma severity survey. Ordered logistic regression was used to determine the association of exposure and asthma severity scores. Age at asthma onset of 12 years was used as a cut-off to define early- or late-onset asthma. RESULTS: The study surveyed 35,682 participants. Data from 23,551 participants remained satisfactory with a response rate of 66 %. Among 20,508 participants aged 26-50 years, 703 questionnaire-determined asthmatics were identified and included for analysis. Using the median of PM10 (66 µg/m(3)) as a cut-off, those exposed to higher PM10 were more likely to have higher severity scores (OR = 1.74; 95 % CI, 1.13 - 2.70) only for asthmatics with asthma onset at > 12 years. CONCLUSIONS: In adulthood, exposure to PM10 has a greater effect on late-onset asthma than early-onset asthma and deserves greater attention among ambient air pollutants.

A land use regression model for estimating the NO2 concentration in Shanghai, China.

Limited by data accessibility, few exposure assessment studies of air pollutants have been conducted in China. There is an urgent need to develop models for assessing the intra-urban concentration of key air pollutants in Chinese cities. In this study, a land use regression (LUR) model was established to estimate NO2 during 2008-2011 in Shanghai. Four predictor variables were left in the final LUR model: the length of major road within the 2-km buffer around monitoring sites, the number of industrial sources (excluding power plants) within a 10-km buffer, the agricultural land area within a 5-km buffer, and the population counts. The model R(2) and the leave-one-out-cross-validation (LOOCV) R(2) of the NO2 LUR models were 0.82 and 0.75, respectively. The prediction surface of the NO2 concentration based on the LUR model was of high spatial resolution. The 1-year predicted concentration based on the ratio and the difference methods fitted well with the measured NO2 concentration. The LUR model of NO2 outperformed the kriging and inverse distance weighed (IDW) interpolation methods in Shanghai. Our findings suggest that the LUR model may provide a cost-effective method of air pollution exposure assessment in a developing country.

Different Severity and Severity Predictors in Early-Onset and Late-Onset Asthma: A Taiwanese Population-Based Study.

BACKGROUND: Late-onset asthma has been shown to be more severe than early-onset asthma in clinic-based studies. However, population-based studies are scarce, and the predictors of severity have been less studied. OBJECTIVES: To determine asthma severity and severity predictors regarding age at onset. METHODS: A cross-sectional questionnaire survey was conducted among parents of children from 94 schools in Taiwan in 2004. Asthma severity was defined as short-acting ß2-agonist (SABA), inhaled corticosteroid (ICS) and health care use in the last year. Information on age at onset, demographics, heredity and home exposure was collected. Ordered logistic or logistic regression was used for determining the associations between risk factors and severity. RESULTS: Participants aged 26-50 years were included, resulting in 21,057 (67.8%) participants. Among them, 449 reported ever having had physician-diagnosed asthma, and 381 of those subjects answered the question on age at asthma onset. The risks of rescue SABA, ICS and health care use were generally higher among late-onset (13-50 years) than early-onset (0-12 years) asthmatics. Use of SABA and health care increased from childhood-onset, adolescent- or young adult-onset to adult-onset asthma. Allergic rhinitis was positively associated with SABA use (OR, 9.08; 95% CI, 1.06-77.99) and ICS use (OR, 5.08; 95% CI, 1.47-17.52) in early-onset asthma. Dehumidifier use was negatively associated with SABA use (OR, 0.50; 95% CI, 0.29-0.87) and ICS use (OR, 0.38; 95% CI, 0.19-0.78) in late-onset asthma. CONCLUSIONS: In adults, late-onset asthma was more severe than early-onset asthma. Severity, as indicated by SABA and ICS use, was positively associated with allergic rhinitis in early-onset asthma and negatively associated with dehumidifier use in late-onset asthma.

Global variation in the effects of ambient temperature on mortality: a systematic evaluation.

BACKGROUND: Studies have examined the effects of temperature on mortality in a single city, country, or region. However, less evidence is available on the variation in the associations between temperature and mortality in multiple countries, analyzed simultaneously. METHODS: We obtained daily data on temperature and mortality in 306 communities from 12 countries/regions (Australia, Brazil, Thailand, China, Taiwan, Korea, Japan, Italy, Spain, United Kingdom, United States, and Canada). Two-stage analyses were used to assess the nonlinear and delayed relation between temperature and mortality. In the first stage, a Poisson regression allowing overdispersion with distributed lag nonlinear model was used to estimate the community-specific temperature-mortality relation. In the second stage, a multivariate meta-analysis was used to pool the nonlinear and delayed effects of ambient temperature at the national level, in each country. RESULTS: The temperatures associated with the lowest mortality were around the 75th percentile of temperature in all the countries/regions, ranging from 66th (Taiwan) to 80th (UK) percentiles. The estimated effects of cold and hot temperatures on mortality varied by community and country. Meta-analysis results show that both cold and hot temperatures increased the risk of mortality in all the countries/regions. Cold effects were delayed and lasted for many days, whereas heat effects appeared quickly and did not last long. CONCLUSIONS: People have some ability to adapt to their local climate type, but both cold and hot temperatures are still associated with increased risk of mortality. Public health strategies to alleviate the impact of ambient temperatures are important, in particular in the context of climate change.

Asthma incidence, remission, relapse and persistence: a population-based study in southern Taiwan.

BACKGROUND: In western countries, late-onset asthmatics are more severe than early-onset asthmatics in clinic-based studies. However, whether asthma occurrence rates were higher in late ages than in younger ages was inconclusive. This information is essentially lacking in Asian population. METHODS: The participants were schoolchildren's parents recruited from 94 elementary and middle schools in 2004. A cross-sectional self-administered questionnaire was sent through the children to their parents to survey their respiratory health. We investigated typical asthma symptoms occurring at different ages and subsequent remission or relapse after the first asthma event. Person-years of the participants from birth to the time of survey were used as the denominator. RESULTS: Among the 25,377 participants consisting of 949,807 total person-years, 860 reported ever having asthma. Highest incidences occurred at ages 0-12 and 36-40 years. The incidence of asthma was higher in males before puberty, and higher in females after puberty, with overall incidences 1.00 and 0.77 per 1000 person-years for females and males, respectively. Participants with late-onset asthma (onset age >12 years) comprised a large portion of adult current asthmatics. More than 52% of persistence or relapse was observed in early-onset asthma (onset age ≤12 years). The younger birth cohort had a more prominent later peak of asthma incidence than the older one. CONCLUSIONS: In Asian population, asthma occurrence showed a U-shape age distribution with a prominent second peak in the thirties. A high proportion of early-onset asthma relapsed and most of late-onset asthma persisted or relapsed in adulthood.

Modeling horizontal and vertical variation in intraurban exposure to PM2.5 concentrations and compositions.

Land use regression (LUR) models are increasingly used to evaluate intraurban variability in population exposure to fine particulate matter (PM2.5). However, most of these models lack information on PM2.5 elemental compositions and vertically distributed samples. The purpose of this study was to evaluate intraurban exposure to PM2.5 concentrations and compositions for populations in an Asian city using LUR models, with special emphasis on examining the effects of having measurements on different building stories. PM2.5 samples were collected at 20 sampling sites below the third story (low-level sites). Additional vertically stratified sampling sites were set up on the fourth to sixth (mid-level sites, n=5) and seventh to ninth (high-level sites, n=5) stories. LUR models were built for PM2.5, copper (Cu), iron (Fe), potassium (K), manganese (Mn), nickel (Ni), sulfur (S), silicon (Si), and zinc (Zn). The explained concentration variance (R(2)) of the PM2.5 model was 65%. R(2) values were >69% in the Cu, Fe, Mn, Ni, Si, and Zn models and <44% in the K and S models. Sampling height from ground level was a significant predictor in the PM2.5 and Si models. This finding stresses the importance of collecting vertically stratified information on PM2.5 mass concentrations to reduce potential exposure misclassification in future health studies. In addition to traffic variables, some models identified gravel-plant, industrial, and port variables with large buffer zones as important predictors, indicating that PM from these sources had significant effects at distant places.

Vertical variation of source-apportioned PM2.5 and selected volatile organic compounds near an elevated expressway in an urban area.

Fine particulate matter (PM2.5) and volatile organic compounds (VOCs) are associated with adverse health effects and show spatial variation in three dimensions. The present study attempted to evaluate source contributions of PM2.5 and toxic VOCs in a metropolitan area focusing on the associated vertical variations. A special emphasis is put on the effects of the elevated expressway on the vertical variability of contribution estimates of the identified sources. Nine source factors, i.e., soil dust, sea salt/oil combustion, secondary nitrate, industrial emission, aged VOCs/secondary aerosol, traffic-related I, solvent use/industrial process, secondary sulfate, and traffic-related II, were identified using positive matrix factorization (PMF). The main contributors to PM2.5 were secondary sulfate (19.1%) and traffic-related emissions (traffic-related I and II, 16.1%), whereas the largest contributors to VOCs were traffic-related emissions (37.6%). The influence of the elevated expressway is suggested to be particularly critical on vertical variations of traffic-related emissions, including aging and secondary formation of locally accumulated air pollutants near roads. Increasing the building porosity under the viaduct could reduce the accumulation of air pollutants caused by the shelter effect. Additionally, in-street barriers would be beneficial in reducing population exposure to traffic-related emissions by altering the airflows near roads.

Associations of road traffic noise and its frequency spectrum with prevalent depression in Taichung, Taiwan.

Introduction: Exposure to road traffic noise has been reported to be associated with depression in many epidemiological studies, but the association between noise frequency spectrum and depression remains unclear. This community-based study investigated the associations between road traffic noise exposure and its frequency components with prevalent depression. Methods: A total of 3,191 residents living in Taichung who participated in the Taiwan Biobank between 2010 and 2017, were included as study participants. The land-use regression models were used to evaluate individual annual average values of A-weighted equivalent sound level over 24 h (Leq,24h) and particulate matter with an aerodynamic diameter <2.5 µm (PM2.5) using the geographic information system. Multiple logistic regression was applied to estimate the odds ratios (ORs) for depression after adjusting for potential risk factors and PM2.5. Results: An interquartile range increase in Leq,24h at full frequency (4.7 dBA), 1,000 Hz (5.2 dB), and 2,000 Hz (4.8 dB) was significantly associated with an elevated risk for depression with ORs of 1.62 (95% confidence interval [CI]: 1.03, 2.55), 1.58 (95% CI: 1.05, 2.37), and 1.58 (95% CI:1.03, 2.43), respectively, by controlling for PM2.5. The high-exposure group (≥3rd quartile median of noise levels) at full frequency, 1,000 Hz, and 2,000 Hz had an increased risk for depression with ORs of 2.65 (95% CI: 1.16-6.05), 2.47 (95% CI: 1.07-5.70), and 2.60 (95% CI: 1.10-6.12), respectively, compared with the reference group (<1st quartile of noise levels) after adjustment for PM2.5. Significant exposure-response trends were observed between the prevalent depression and noise exposure by quartiles at full frequency, 1,000 Hz, and 2,000 Hz (all p < 0.05). Conclusion: Exposure to road traffic noise may be associated with an increased prevalence of depression, particularly at 1,000 and 2,000 Hz.

Evaluating the performance of the horizontal radial plume mapping technique for locating multiple plumes.

This paper evaluated the feasibility of using the horizontal radial plume mapping (HRPM) technique to locate multiple emission sources via computational simulation. Seventy-two test maps, each having two Gaussian distributions, were generated in a two-dimensional domain. The HRPM technique with the non-negative least square (NNLS) algorithm was then applied to reconstruct the plumes, assuming a nine-beam scanning beam geometry. The NNLS algorithm successfully reconstructed the source locations of 68 of the 72 test maps. However, when one of the plumes was near the origin, the NNLS did not always identify the peak locations correctly. Furthermore, when the two plumes were spaced closely, the NNLS tended to reconstruct a wide plume covering both plumes instead of separating them due to the resolution limitation of the current nine-beam geometry. In the sensitivity analysis, five sets of random error (1%, 5%, 10%, 20%, and 30%) were added in the path-integrated concentration (PIC) from the 72 test maps, and thus, an additional 360 reconstructions were implemented. Robust results were obtained when the noise added was less than 20%. The results generally support the implementation of the NNLS algorithm in the HRPM technique as described in the US. Environmental Agency (EPA) Other Test Method 10 (OTM-10).

Locating pollutant emission sources with optical remote sensing measurements and an improved one-dimensional radial plume mapping technique.

Previous studies have shown that there was a relatively large amount of uncertainty along the major wind direction in the results of locating emission sources using the one-dimensional radial plume mapping (RPM(1D)) technique based on optical remote sensing measurements. This paper proposes setting up an additional monitoring line that is perpendicular to the original scanning beam geometry to reduce this uncertainty. We first conducted a computer simulation study using the Gaussian dispersion model to generate the downwind concentrations of plumes from 400 source locations in a 201 m × 201 m spatial domain under various wind directions (n = 181). The optical remote sensing instrument was assumed to be at (0, 0) with two perpendicular monitoring lines, each of which had three beam segments of equal length. Each pair of the reconstructed downwind concentration profiles was then used to trace back to the source locations. The results showed that the accuracy of the method and its uncertainty were improved by using the proposed two-line RPM(1D) approach rather than the original one-line RPM(1D) approach at most simulated source locations. In a follow-up field experiment, a tracer gas was released at the coordinate of (100, 100). The release location was covered within the 0.25- to 0.5-probability area of the estimated results, and the distance between the actual and estimated source locations was 18.4 m (9.2% of the longest beam path).

Identifying and quantifying PM2.5 pollution episodes with a fusion method of moving window technique and constrained Positive Matrix Factorization.

PM2.5 pollution episodes rapidly and significantly deteriorate the air quality and are a critical concern worldwide. This study developed a fusion method based on the moving window dataset technique and constrained Positive Matrix Factorization (PMF) to differentiate and characterize potential factors in a PM2.5 episode case assuming having one new contributor. The hourly PM2.5 compositions of elements, ions and carbonaceous components, were collected from September to December 2020 in Taipei, Taiwan. Constraint targets based on the bootstrap analysis result of a PMF model using a long-term input dataset were imposed on the modeling of each moving window to ensure similar features of the retrieved factors. The constituents of an additionally differentiated factor to the episode, which was identified as regional transport, were stable among each moving window that covered the occurrence of the episode as revealed by the profile matching index. The results showed that the largest contributor to the PM2.5 mass during the episode period of 12/12/2020 was regional transport (61%), whereas that of 12/13 was the regular pollution of industry/ammonium sulfate related (43%). According to our review of the literature, this study is the first to apply both the moving window technique and constrained PMF to characterize the episode. The findings provide valuable information that can be used to explore the causes of PM2.5 episodes and implement air pollution control strategies.

Urban Air Pollution and Subclinical Atherosclerosis in Adolescents and Young Adults.

PURPOSE: The contribution of air pollution to subclinical atherosclerosis in a young population remains limited. This study aimed to assess whether long-term exposure to urban air pollutants increases carotid intima-media thickness (CIMT) in adolescents and young adults. METHODS: This study included 789 subjects between the ages of 12 and 30 years who lived in the Taipei metropolis from a cohort of young Taiwanese individuals. Residential addresses were geocoded, and annual average concentrations of particulate matter (PM) of different diameters, e.g., PM10, PM2.5-10, PM2.5, and nitrogen oxides (NOX), were assessed using land use regression models. The generalized least squares strategy with error term to consider the cluster effect of living addresses between individuals was used to examine the associations between urban air pollution and CIMTs. RESULTS: After adjusting for potential confounders, we found that interquartile range increases in PM2.5 (8.2 µg/m3) and NOX (17.5 µg/m3) were associated with 0.46% (95% CI: 0.02-0.90) and 1.00% (95% CI: 0.10-1.91) higher CIMTs, respectively. Stratified analyses showed that the relationships between CIMT and PM2.5 and NOX were more evident in subjects who were 18 years or older, female, nonsmoking, nonhypertensive, and nonhyperglycemic than in their respective counterparts. DISCUSSION: Long-term exposure to PM2.5 and NOX is associated with subclinical atherosclerosis in a young population. Age, sex, and health status may influence the vulnerability of air pollution-associated subclinical atherosclerosis.

Identifying low-PM2.5 exposure commuting routes for cyclists through modeling with the random forest algorithm based on low-cost sensor measurements in three Asian cities.

Cyclists can be easily exposed to traffic-related pollutants due to riding on or close to the road during commuting in cities. PM2.5 has been identified as one of the major pollutants emitted by vehicles and associated with cardiopulmonary and respiratory diseases. As routing has been suggested to reduce the exposures for cyclists, in this study, PM2.5 was monitored with low-cost sensors during commuting periods to develop models for identifying low exposure routes in three Asian cities: Taipei, Osaka, and Seoul. The models for mapping the PM2.5 in the cities were developed by employing the random forest algorithm in a two-stage modeling approach. The land use features to explain spatial variation of PM2.5 were obtained from the open-source land use database, OpenStreetMap. The total length of the monitoring routes ranged from 101.36 to 148.22 km and the average PM2.5 ranged from 13.51 to 15.40 µg/m³ among the cities. The two-stage models had the standard k-fold cross-validation (CV) R2 of 0.93, 0.74, and 0.84 in Taipei, Osaka, and Seoul, respectively. To address spatial autocorrelation, a spatial cross-validation approach applying a distance restriction of 100 m between the model training and testing data was employed. The over-optimistic estimates on the predictions were thus prevented, showing model CV-R2 of 0.91, 0.67, and 0.78 respectively in Taipei, Osaka, and Seoul. The comparisons between the shortest-distance and lowest-exposure routes showed that the largest percentage of reduced averaged PM2.5 exposure could reach 32.1% with the distance increases by 37.8%. Given the findings in this study, routing behavior should be encouraged. With the daily commuting trips expanded, the cumulative effect may become significant on the chronic exposures over time. Therefore, a route planning tool for reducing the exposures shall be developed and promoted to the public.

Greenhouse gas emission reductions from domestic anaerobic digesters linked with sustainable sanitation in rural China.

Anaerobic digesters provide clean, renewable energy (biogas) by converting organic waste to methane, and are a key part of China's comprehensive rural energy plan. Here, experimental and modeling results are used to quantify the net greenhouse gas (GHG) reduction from substituting a household anaerobic digester for traditional energy sources in Sichuan, China. Tunable diode laser absorption spectroscopy and radial plume mapping were used to estimate the mass flux of fugitive methane emissions from active digesters. Using household energy budgets, the net improvement in GHG emissions associated with biogas installation was estimated using global warming commitment (GWC) as a consolidated measure of the warming effects of GHG emissions from cooking. In all scenarios biogas households had lower GWC than nonbiogas households, by as much as 54%. Even biogas households with methane leakage exhibited lower GWC than nonbiogas households, by as much as 48%. Based only on the averted GHG emissions over 10 years, the monetary value of a biogas installation was conservatively estimated at US$28.30 ($16.07 ton(-1) CO(2)-eq), which is available to partly offset construction costs. The interaction of biogas installation programs with policies supporting improved stoves, renewable harvesting of biomass, and energy interventions with substantial health cobenefits are discussed.