A review of personal exposure studies in selected Asian countries' public transport microenvironments: lessons learned and future directions

This comprehensive paper conducts an in-depth review of personal exposure and air pollutant levels within the microenvironments of Asian city transportation. Our methodology involved a systematic analysis of an extensive body of literature from diverse sources, encompassing a substantial quantity of studies conducted across multiple Asian cities. The investigation scrutinizes exposure to various pollutants, including particulate matters (PM10, PM2.5, and PM1), carbon dioxide (CO2), formaldehyde (CH2O), and total volatile organic compounds (TVOC), during transportation modes such as car travel, bus commuting, walking, and train rides. Notably, our review reveals a predominant focus on PM2.5, followed by PM10, PM1, CO2, and TVOC, with limited attention given to CH2O exposure. Across the spectrum of Asian cities and transportation modes, exposure concentrations exhibited considerable variability, a phenomenon attributed to a multitude of factors. Primary sources of exposure encompass motor vehicle emissions, traffic dynamics, road dust, and open bus doors. Furthermore, our findings illuminate the influence of external environments, particularly in proximity to train stations, on pollutant levels inside trains. Crucial factors affecting exposure encompass ventilation conditions, travel-specific variables, seat locations, vehicle types, and meteorological influences. The culmination of this rigorous review underscores the need for standardized measurements, enhanced ventilation systems, air filtration mechanisms, the adoption of clean energy sources, and comprehensive public education initiatives aimed at reducing pollutant exposure within city transportation microenvironments. Importantly, our study contributes to the growing body of knowledge surrounding this subject, offering valuable insights for policymakers and researchers dedicated to advancing air quality standards and safeguarding public health.

Systematic identification of heat events associated with emergency admissions to enhance the heat-health action plan in a subtropical city: a data-driven approach

According to the United Nations Office for Disaster Risk Reduction (UNDRR), a heat-health action plan should address various impacts of hazards at different levels, including an early warning system to monitor risks and behaviour enhancement to increase disaster preparedness. It is necessary to comply with guidelines regarding heat duration/intensity. In this study, we developed a data-driven approach to rapidly and systematically estimate the impacts of various heat events on emergency admissions among the adult population (n = 7,086,966) in Hong Kong in order to enhance the heat-health action plan. Immediate, short-term, and long-term impacts determined by 1-day, 4-day, and 8-day windows were estimated to identify specific heat events suitable for early warnings. In addition, underestimated risk, determined by a continuous increase in heat risk after days without significant emergency admissions, was estimated to evaluate potential maladaptive behaviours among a specific subpopulation. Based on age- and gender-specific analyses, 1D, 1D1N, and 2D2N were observed to have a stronger immediate impact on emergency admissions. 1D1N and 2D2N also showed notable short-term and long-term impacts. Based on heat vulnerability factors (age and gender), 2D2N was a higher-priority extreme heat event for early warning measures than 1D1N. Furthermore, men aged 19 to 64 had the highest underestimated risk. Specifically, they had IRR values of 1.113 [1.087, 1.140], 1.061 [1.035, 1.087], and 1.069 [1.043, 1.095] during lag days 3-5 of 3D2N, respectively, possibly due to a lack of adaptive behaviour. By adopting our approach, the duration of heat events with significant health impacts can be identified in order to further enhance relevant heat stress information. This framework can be applied to other cities with a similar background for rapid assessment.

The effectiveness of fixed speed cameras on Iranian taxi drivers: An evaluation of the influential factors

Background

The adherence to speed limits can reduce deaths associated with road traffic injuries (RTIs) by more than a quarter. This study aimed to evaluate the effective factors on the speeding behavior of Iranian taxi drivers around fixed speed cameras.

Method

Telematics devices used in this study collected the location and speed of the vehicles. The units of analysis in this study were trips per camera, including 2.5 km before and after each camera. Linear regression analysis was used to identify kangaroo driving (KD), defined as trips with a significant V-shape in speed distribution around the camera. In the clustered camera zones, cameras were placed at regular intervals of approximately 3.5 km.

Findings

A total of 93,160 trips were recorded from 13,857,443 data points. There was an inverse association between drivers' age and KD with an odds ratio (OR) of 0.98 (95% confidence interval: 0.98-0.98). The intercity trips had a substantially higher probability of KD than urban trips (OR: 4.94 [4.73-5.16]). The tendency of drivers toward KD during the daylight hours vs. nighttime was significant for both urban (OR: 1.15 [1.06-1.25]) and intercity (OR: 1.18 [1.14-1.22]) trips. The 4 -8 a.m. period had the highest chance of KD in both urban (10.71% [7.41-14.53]) and intercity (44.13% [41.18-47.09]) trips. There was a significant decrease in the odds of KD inside the clustered camera zones (OR: 0.22 [0.20-0.25]).

Conclusion

The heterogeneous occurrence of KD in different locations and times indicates the necessity of evidence-based decision-making in urban planning to improve safe driving behaviors. The lower occurrence of KD in clustered camera zones could be a practical key to the effective control of speeding behaviors by helping in the efficient placement of cameras through sustainable development of cities and roads.

How Socioeconomic, Health Seeking Behaviours, and Educational Factors Are Affecting the Knowledge and Use of Antibiotics in Four Different Cities in Asia

Antibiotic resistance is occurring widely throughout the world and is affecting people of all ages. Socioeconomic factors, education, use of antibiotics, knowledge of antibiotics, and antibiotic resistance were assessed in four cities in Asia, namely Hong Kong, Shanghai, Hangzhou, and Bangkok. A survey using cluster sampling was used in 2021 to collect data on 642 subjects. Hongkongers used less antibiotics and were knowledgeable about using antibiotics to treat diseases, while Shanghainese were knowledgeable about antibiotic resistance. The multi-linear regression model reported that respondents who lived in Hong Kong (β = 0.744 (95% CI: 0.36-1.128), Shanghai (β = 1.65 (95% CI: 1.267-2.032), and Hangzhou (β = 1.393 (95% CI: 0.011-1.775) (reference group: Bangkok), who had higher scores on antibiotics knowledge (β = 0.161 (95% CI: 0.112-0.21)), higher educational attainment (β = 0.46 (95% CI: 0.296-0.625)), and who were more likely to consult a doctor on using antibiotics (β = 1.102 (95% CI: 0.606-1.598)), were more likely to give correct answers about antibiotic resistance, p < 0.001. Older respondents were less likely to answer the items correctly (β = -0.194 (95% CI: -0.333--0.055), p < 0.01. When educating the public on the proper use of antibiotics and antibiotic resistance, multiple strategies could be considered for people from all walks of life, as well as target different age groups.

Evaluation of the CORDEX regional climate models (RCMs) for simulating climate extremes in the Asian cities

This study evaluates the ability of 21 Regional Climate Models (RCMs) from the Coordinated Regional Climate Downscaling Experiment (CORDEX) in simulating climate extremes in the fast growing Asian cities which are highly vulnerable to climate change. The three Asian cities have two different climate characteristics, namely Bangkok and its vicinity and Ho Chi Minh City in tropical climate region and Kathmandu in sub-tropical and temperate climate region. The RCMs were evaluated to simulate the six climate indices; Consecutive Dry Days (CDD), Simple Daily Intensity Index (SDII), Number of extremely heavy precipitation days (R50mm), Maximum 1-day precipitation amount (RX1day), Mean of daily maximum temperature (TX mean) and Mean of daily minimum temperature (TN mean). The performance indicators used were correlation coefficient, normalized root mean square deviation, absolute normalized root mean square deviation and average absolute relative deviation. The Entropy method was endorsed to acquire weights of these four indicators and weightage average techniques were used for ranking of 21 RCMs. The result demonstrated that the best model for one climate index is not the same best model for other climate indices. The 3 RCMs; WAS44_SMHI_RCA4_IPSL_CM5A_MR, WAS44_SMHI_RCA4_MIROC5, and WAS44_IITM_REGCM4-4_CSIRO_MK3-6-0 are the best performing RCMs for simulating future climate extremes in Bangkok and its vicinity, Ho Chi Minh city and Kathmandu valley, respectively. Therefore, they are recommended to use for climate change impact and adaptation studies in water resources management in the selected cities.

Gaining or losing ground? Tracking Asia's hunger for 'new' coastal land in the era of sea level rise

Many coastal cities are short of land for development and, coupled with the need to mitigate the impact of extreme events against a background of ongoing sea-level rise, coastal land reclamation (CLR) has emerged as a frequently applied solution, most especially in Asia. However, the sustainability of these newly reclaimed lands under the combined onslaught of increasing population pressure, SRL, greater frequency of extreme events, and land subsidence is largely unknown. In order to assess the spatial extent and temporal trends in recent CLR projects, we mapped and tabulated the annual magnitude of change in coastal land gain from 1988 to 2018 for eight major Asian coastal cities. Across these cities, both the spatial extent and rate of CLR is remarkable; some 700 km² has been reclaimed in just three decades. >35% of this new coastal land has been constructed in Shanghai alone (562 km²), while Singapore and Incheon have also experienced substantial land gains. These three cities alone account for almost 10% of all the land gained globally over the last three decades. An analysis of the spatio-temporal patterns reveals that, since recently reclaimed areas are predominantly characterized by construction, including ports, airports, commercial and residential uses, economic development is the most prominent driver. Shanghai, however, represents a significant departure from this trend, whereby >50% of the new coastal land gained during the recent past has not been devoted to construction projects and is vegetated, suggesting a different policy context. Commercial or otherwise, subsidence is widely reported as a major characteristic of recently reclaimed coastal land and is a major environmental challenge. Mapping recent rates of land subsidence over these newly reclaimed lands reveal that most are subject to significant levels of deformation, in the case of the international airport at Incheon, Republic of Korea, exceeding 25 cm annually.

Analyzing the heat island magnitude and characteristics in one hundred Asian and Australian cities and regions

Urban heat island is the more documented phenomenon of climate change. Information on the magnitude and the characteristics of the canopy layer urban heat island measured in 101 cities and regions of Asia and Australia and collected through 88 scientific articles, are compiled, evaluated and presented. Data are classified in several clusters according to the experimental protocol used and the type of statistical information reported regarding the magnitude of the urban heat island. Results and detailed analysis are given for each defined cluster. Very significant differences on the UHI intensity are found between the clusters and analyzed in detail. The detailed impact of the main weather parameters and conditions on the magnitude of the UHI is also investigated. The specific influence of anthropogenic thermal fluxes as well as of the urban morphological and construction characteristics to UHI is thoroughly examined. The relation between the UHI intensity and the city size is assessed and global relationships of UHI as a function of the urban population are proposed. The seasonal and diurnal variability of the UHI is analyzed and discussed while specific features and conditions like the urban heat island characteristics in coastal cities and the existence of daytime cool islands are explored. Finally, the impact of the selected reference station and its characteristics is considered.