Psychometric properties of a novel instrument for evaluating indoor air pollution health literacy in adults.

This study aimed to develop and validate the psychometric properties of a novel instrument that measures Indoor Air Pollution Health Literacy (IAPHL). The qualitative phase was conducted to design questions based on the conceptual model of the European Health Literacy Survey Questionnaire. We developed a 38-item instrument covering 12 constructs, that is, four information competencies within three health domains to assess IAPHL. A cross-sectional online video survey of 647 adults aged 20 years and above in Taiwan was conducted. Various measures of validity and reliability coefficients were assessed to indicate the psychometric properties of the IAPHL instrument. The content validity indices for relevance, importance, and clarity of the 38 questions were 0.97, 0.96, and 0.89, respectively. The model fit indices obtained from the confirmatory factor analysis supported the acceptable structures of the theoretically hypothetical 12-factor model (standardized root mean square residual = 0.055; root mean square error of approximation = 0.065). Internal consistency for the instrument showed a Cronbach's alpha of 0.96. The IAPHL instrument developed in this study showed satisfactory validity and reliability and can be used in future fieldwork.

A national survey of ambient air pollution health literacy among adult residents of Taiwan.

OBJECTIVE: To investigate the level of and covariates associated with ambient air pollution health literacy (AAPHL) among adult residents of Taiwan. METHODS: With a cross-sectional study design, we conducted telephone interviews using a Chinese version AAPHL scale, which consisted of 24 items assessing 12 subdomains of AAPHL formed by 4 information processing competence matrices (i.e., access, understand, appraise, and apply) and 3 health contexts (i.e., healthcare, disease prevention, and health promotion). The AAPHL was with the lowest and highest score at 1 to 4, respectively. Between September and November 2020, a sample of 1017 and 280 adults was successfully interviewed via home phones and mobile phones, respectively. We employed multiple linear regression models to identify covariates significantly associated with overall and 4 matric-specific AAPHL scores. RESULTS: The mean and standard deviation (±SD) of overall AAPHL score was considered as moderate at 2.90 (±0.56), with the highest and lowest metric-specific score for "apply" (3.07 ± 0.59) and "appraise" (2.75 ± 0.66). Lower education was significantly associated with a lower overall score; and living with children < 12 years and single were both significantly associated with higher overall scores. We also noted a significant geographic variation in overall score in which people living in the east/remote islands had highest scores. CONCLUSIONS: People in Taiwan had only moderate level of AAPHL; and covariates including education, living arrangement, marital status, and area of living were significantly associated with AAPHL. These covariates should be considered in future educational interventions aiming to improve the AAPHL in the community.

Effect of Implementing Electronic Toll Collection in Reducing Highway Particulate Matter Pollution.

Highway vehicle emissions can result in adverse health problems to nearby residents and workers, especially during traffic congestion. In response, the policy to implement electronic toll collection (ETC) has helped alleviate traffic congestion, as compared to manual toll collection (MTC) and has led to reduced air pollution and improved public health. However, the effect of ETC in reducing particulate matter polluting the air is not well understood, especially in the ultrafine particle (UFP) range (particle diameter <100 nm). To the best of our knowledge, this is the first study to investigate how ETC affects the traffic pattern and air quality, especially UFP and PM2.5. We selected a site in Tainan, Taiwan, and measured UFP and PM2.5 concentrations before and after the construction of the ETC system. The computed traffic volumes during peak travel periods (7:00 AM to 9:00 AM and 4:00 PM to 6:00 PM) respectively, accounted for approximately 23-25% and 14-18% before and after the implementation of ETC, indicating that peak traffic volumes were more homogeneous after ETC. Moreover, the results indicate that the full implementation of ETC can help reduce UFP number concentrations and PM2.5 mass concentrations in the highway downwind area by 4 × 103 #/cm3 and 20.5 µg/m3, respectively. After the full implementation of the ETC, significant reductions in both the UFP number concentration and PM2.5 mass concentration were seen. Furthermore, excessive lifetime cancer risks (ELCR) from exposure to PM2.5 and UFP together were reduced 49.3% after the implementation of the ETC. Accordingly, ETC not only helps alleviate traffic congestion but also reduces traffic emissions and lifetime cancer risk for people living or working near highways.

The effects of leaf area density variation on the particle collection efficiency in the size range of ultrafine particles (UFP).

Carbonaceous particles were generated during a "sooting burn" experiment to explore how heterogeneity in horizontal leaf area density (LAD) within the canopy impacts the ultrafine particle (UFP) collection efficiency at the branch-scale. To address this goal, wind tunnel experiments and a particle-size resolving model, which couples the turbulent flow field within the vegetated volume and the collection efficiency, were presented. Three scenarios were examined in a wind-tunnel packed with Juniperus chinensis branches: An LAD that was uniformly distributed, linearly increasing and linearly decreasing along the longitudinal or mean wind direction. The concentration measurements were conducted at multiple locations within the vegetated volume to evaluate the performance of the proposed model needed in discerning the role of LAD heterogeneity on UFP collection. Differences not exceeding 20% were found between modeled and measured concentration for all particle sizes across a wide range of wind speeds. The overall particle collection efficiency was found to be primarily governed by the spatially integrated LAD when differences in aerodynamic attributes (e.g., foliage drag) were accounted for. When combined with earlier studies, the results suggest that one parameter linking the laminar boundary layer conductance to the Schmidt number depends on particle size.

Psychometric properties of novel instrument for evaluating ambient air pollution health literacy in adults.

We aimed to develop and validate a comprehensive ambient air pollution health literacy instrument. We developed items covering 12 constructs, four information competencies within three health domains. In this population-based telephone interview study, probability proportional to size sampling and random digit dialing were used to determine participants. We conducted confirmatory factor analysis to analyze model fits and used content validity indices and Cronbach's alpha to measure content validity and internal consistency reliability. Twenty-four items were generated, and a total of 1,297 participants were recruited. A theoretically conceived 12-factor model was supported (root mean square error of approximation [RMSEA] = 0.068, comparative fit index [CFI] = 0.039, standardized root mean square residual [SRMR] = 0.934, normed fit index [NFI] = 0.914, Tucker-Lewis index [TLI] = 0.902). Content validity indices for relevance, importance, and unambiguity were 0.97, 0.99, and 0.94, respectively. Internal consistency reliability assessed by Cronbach's alpha was 0.93. The ambient air pollution health literacy instrument is valid and reliable and can be used in community residents. The novel instrument can guide the stakeholders and the authority to tailor and implement effective and appropriate interventions and actions, empowering the public to manage hazardous exposure and improving AAPHL of the public.

Reduction of atmospheric fine particle level by restricting the idling vehicles around a sensitive area.

Atmospheric particles are a major problem that could lead to harmful effects on human health, especially in densely populated urban areas. Chiayi is a typical city with very high population and traffic density, as well as being located at the downwind side of several pollution sources. Multiple contributors for PM2.5 (particulate matter with an aerodynamic diameter ≥2.5 µm) and ultrafine particles cause complicated air quality problems. This study focused on the inhibition of local emission sources by restricting the idling vehicles around a school area and evaluating the changes in surrounding atmospheric PM conditions. Two stationary sites were monitored, including a background site on the upwind side of the school and a campus site inside the school, to monitor the exposure level, before and after the idling prohibition. In the base condition, the PM2.5 mass concentrations were found to increase 15% from the background, whereas the nitrate (NO3-) content had a significant increase at the campus site. The anthropogenic metal contents in PM2.5 were higher at the campus site than the background site. Mobile emissions were found to be the most likely contributor to the school hot spot area by chemical mass balance modeling (CMB8.2). On the other hand, the PM2.5 in the school campus fell to only 2% after idling vehicle control, when the mobile source contribution reduced from 42.8% to 36.7%. The mobile monitoring also showed significant reductions in atmospheric PM2.5, PM0.1, polycyclic aromatic hydrocarbons (PAHs), and black carbon (BC) levels by 16.5%, 33.3%, 48.0%, and 11.5%, respectively. Consequently, the restriction of local idling emission was proven to significantly reduce PM and harmful pollutants in the hot spots around the school environment. IMPLICATIONS: The emission of idling vehicles strongly affects the levels of particles and relative pollutants in near-ground air around a school area. The PM2.5 mass concentration at a campus site increased from the background site by 15%, whereas NO3- and anthropogenic metals also significantly increased. Meanwhile, the PM2.5 contribution from mobile source in the campus increased 6.6% from the upwind site. An idling prohibition took place and showed impressive results. Reductions of PM2.5, ionic component, and non-natural metal contents were found after the idling prohibition. The mobile monitoring also pointed out a significant improvement with the spatial analysis of PM2.5, PM0.1, PAH, and black carbon concentrations. These findings are very useful to effectively improve the local air quality of a densely city during the rush hour.

Development of an efficient viral aerosol collector for higher sampling flow rate.

Viral aerosol infection through cough generates large amounts of viral aerosol and can result in many adverse health effects such as influenza flu and severe acute respiratory syndrome (SARS). To characterize the coughed viral aerosol, the sampler needs to sample at higher flow rate and possess high physical collection efficiency as well as high viral preservation. However, most current inertia-based high flow bioaerosol samplers are not suited for viral aerosol sampling since the viability will be lost doing the sampling process. Current condensation growth methods only have good physical collection efficiency and viral preservation at low flow rate (< 10 LPM). In this study, we developed a viral aerosol sampling system using a cooler and steam-jet aerosol collector (SJAC) for bioaerosol collection for the first time. The system is based on mixing condensation growth method and has high viral preservation at a higher flow rate (12.5 LPM). We control the inlet aerosol flow temperature and the SJAC mixing reservoir temperature to improve the physical collection efficiency and viability preservation of the viral aerosol. Results indicate that the physical collection efficiency is 70-99% for aerosol 30-100 nm when the aerosol flow and mixing reservoir temperature was 19 and 50 °C, respectively. In addition, the system was 7 and 22 times more efficient for viability preservation of MS2 bacteriophage than the commonly used All Glass Impinger 30 (AGI-30) and BioSampler®, respectively. Finally, the system can be applied to sample at a lower concentration (105 PFU/m3), and results shows the system was 4.7 times more efficient for viability preservation than using AGI-30 alone. The developed viral collection system will improve our understanding of the characteristics of coughed aerosol and can be used for future evaluation of respiratory protective equipment and environmental sampling.

An instantaneous spatiotemporal model for predicting traffic-related ultrafine particle concentration through mobile noise measurements.

People living near roadways are exposed to high concentrations of ultrafine particles (UFP, diameter < 100 nm). This can result in adverse health effects such as respiratory illness and cardiovascular diseases. However, accurately characterizing the UFP number concentration requires expensive sets of instruments. The development of an UFP surrogate with cheap and convenient measures is needed. In this study, we used a mobile measurement platform with a Fast Mobility Particle Sizer (FMPS) and sound level meter to investigate the spatiotemporal relations of noise and UFP and identify the hotspots of UFP. UFP concentration levels were significantly influenced by temporal and spatial variations (p < 0.001). We proposed a Generalized Additive Models to predict UFP number concentration in the study area. The model uses noise and meteorological covariates to predict the UFP number concentrations at an industrial site in Taichung, Taiwan. During the one year sampling campaign from fall 2013 to summer 2014, mobile measurements were performed at least one week for each season, both on weekdays and weekends. The proposed model can explain 80% of deviance and has coefficient of determination (R2) of 0.77. Moreover, the developed UFP model was able to adequately predict UFP concentrations, and can provide people with a convenient way to determine UFP levels. Finally, the results from this study could help facilitate the future development of noise mobile measurement.

PM2.5 components and outpatient visits for asthma: A time-stratified case-crossover study in a suburban area.

The effects of fine particles (PM2.5) on asthma have been widely confirmed by epidemiological research studies. However, a limited number of studies have investigated the relationship between exposure to different PM2.5 components and asthma. We characterized the PM2.5 components in a suburban site of central Taiwan and conducted a time-stratified case-crossover study to elaborate the effects of daily concentration of each PM2.5 component on asthma outpatient visits. We retrieved asthma outpatient claims for individuals less than 20 years old with a residential address in the Shalu district, Taiwan, from the National Health Insurance Research Database during 2000-2010. Multiple linear regression models were used to back extrapolate the historic concentration of individual components of PM2.5 from 2000 through to 2010, including black carbon (BC) and eight ions, namely, sulfate, nitrate (NO3-), ammonium, chloride, potassium (K+), magnesium, calcium, sodium. The odds ratio (OR) with a 95% confidence interval (CI) of individual PM2.5 components on asthma was estimated by conditional logistic regression. A total of 887 asthma outpatient visits with individuals who have an average age of 7.96±3.88 years were selected. After adjusting for confounders, we found an interquartile range (IQR) increase in BC level, an IQR increase in NO3- level, and an IQR increase in K+ level that were all associated with the increased risk of asthma outpatient visits from the current day (OR = 1.18, 95% CI: 1.05-1.34; OR = 1.11, 95% CI: 1.01-1.21; and OR = 1.16, 95% CI: 1.04-1.30, respectively). The effects of these components on asthma were stronger in the cold season than in the warm season. However, we did not find any lagging effects. The results suggest that exposure to NO3-, BC, and K+ derived from industry-related combustion or motor vehicles emission sources may increase the risk of asthma outpatient visits, particularly during the cold season.

The effects of vegetation barriers on near-road ultrafine particle number and carbon monoxide concentrations.

Numerous studies have shown that people living in near-roadway communities (within 100 m of the road) are exposed to high ultrafine particle (UFP) number concentrations, which may be associated with adverse health effects. Vegetation barriers have been shown to affect pollutant transport via particle deposition to leaves and altering the dispersion of emission plumes, which in turn would modify the exposure of near-roadway communities to traffic-related UFPs. In this study, both stationary (equipped with a Scanning Mobility Particle Sizer, SMPS) and mobile (equipped with Fast Mobility Particle Sizer, FMPS) measurements were conducted to investigate the effects of vegetation barriers on downwind UFP (particle diameters ranging from 14 to 102 nm) concentrations at two sites in North Carolina, USA. One site had mainly deciduous vegetation while the other was primarily coniferous; both sites have a nearby open field without the vegetation barriers along the same stretch of limited access road, which served as a reference. During downwind conditions (traffic emissions transported towards the vegetation barrier) and when the wind speed was above or equal to 0.5m/s, field measurements indicated that vegetation barriers with full foliage reduced UFP and CO concentrations by 37.7-63.6% and 23.6-56.1%, respectively. When the test was repeated at the same sites during winter periods when deciduous foliage was reduced, the deciduous barrier during winter showed no significant change in UFP concentration before and after the barrier. Results from the stationary (using SMPS) and mobile (using FMPS) measurements for UFP total number concentrations generally agreed to within 20%.

Particulate Matter Exposure in a Police Station Located near a Highway.

People living or working near roadways have experienced an increase in cardiovascular or respiratory diseases due to vehicle emissions. Very few studies have focused on the PM exposure of highway police officers, particularly for the number concentration and size distribution of ultrafine particles (UFP). This study evaluated exposure concentrations of particulate matter (PM) in the Sinying police station near a highway located in Tainan, Taiwan, under different traffic volumes, traffic types, and shift times. We focused on periods when the wind blew from the highway toward the police station and when the wind speed was greater than or equal to 0.5 m/s. PM2.5, UFP, and PM-PAHs concentrations in the police station and an upwind reference station were measured. Results indicate that PM2.5, UFP, and PM-PAHs concentrations in the police station can be on average 1.13, 2.17, and 5.81 times more than the upwind reference station concentrations, respectively. The highest exposure level for PM2.5 and UFP was observed during the 12:00 PM-4:00 PM shift while the highest PAHs concentration was found in the 4:00 AM-8:00 AM shift. Thus, special attention needs to be given to protect police officers from exposure to high PM concentration.

An integrated approach to assess exposure and health-risk from polycyclic aromatic hydrocarbons (PAHs) in a fastener manufacturing industry.

An integrated approach was developed to assess exposure and health-risk from polycyclic aromatic hydrocarbons (PAHs) contained in oil mists in a fastener manufacturing industry. One previously developed model and one new model were adopted for predicting oil mist exposure concentrations emitted from metal work fluid (MWF) and PAHs contained in MWF by using the fastener production rate (Pr) and cumulative fastener production rate (CPr) as predictors, respectively. By applying the annual Pr and CPr records to the above two models, long-term workplace PAH exposure concentrations were predicted. In addition, true exposure data was also collected from the field. The predicted and measured concentrations respectively served as the prior and likelihood distributions in the Bayesian decision analysis (BDA), and the resultant posterior distributions were used to determine the long-term exposure and health-risks posed on workers. Results show that long term exposures to PAHs would result in a 3.1%, 96.7%, and 73.4% chance of exceeding the PEL-TWA (0.2 mg/m3), action level (0.1 mg/m3), and acceptable health risk (10-3), respectively. In conclusion, preventive measures should be taken immediately to reduce workers' PAH exposures.

Field investigation of roadside vegetative and structural barrier impact on near-road ultrafine particle concentrations under a variety of wind conditions.

Roadside barriers, such as tree stands or noise barriers, are prevalent in many populated areas and have been shown to affect the dispersion of traffic emissions. If roadside noise barriers or tree stands are found to consistently lower ground-level air pollution concentrations in the near-road environment, this may be a practical strategy for reducing exposures to air contaminants along populated traffic corridors. This study measured ultrafine particle (UFP) concentrations using an instrumented mobile measurement approach, collecting data on major roadways and in near-road locations for more than forty sampling sessions at three locations in central North Carolina, USA. Two of the sampling sites had relatively thin tree stands, one evergreen and one deciduous, along a portion of the roadway. The third sampling site had a brick noise wall along a portion of the road. At 10 m from the road, UFPs measured using a mobile sampling platform were lower by approximately 50% behind the brick noise wall relative to a nearby location without a barrier for multiple meteorological conditions. The UFP trends at the vegetative barrier sites were variable and the barrier effect is uncertain. In some cases, higher concentrations were observed behind the vegetative barrier, with respect to the clearing, which may be due to gaps in the thin tree stands allowing the transport of traffic-related air pollution to near-road areas behind the vegetation. On-road sampling revealed no consistent difference in UFP levels in on-road portions of the road with or without a roadside barrier present. These findings support the notion that solid roadside barriers may mitigate near-road impact. Given the co-benefits of vegetative barriers in the urban landscape, research regarding the mitigation potential of vegetative barriers of other configurations (e.g., greater density, wider buffer) is encouraged.