The distribution and influential factors of PM_2.5 and CO₂ in urban rail carriages

Abstract

The promotion of 'Green Transport' has increased the importance of urban rail transit in China. Increased passenger flow and longer travel time have led to increased attention to in-carriage air quality in trains. In this study, CO 2 and PM 2.5 monitoring were conducted in subway train carriages in a city in northern China. The study accounts for a variety of factors both inside and outside of the train carriages, such as passenger volume and exterior environment. The results reveal that good air quality outside of the train, an above ground location and the use of platform screen doors could aid in the attainment of acceptable PM 2.5 concentrations. In addition, linear models of CO 2 and PM 2.5 concentrations were established based on passenger density. The nonlinear recursive models were constructed using time-series analysis to reflect the cumulative effects of the amounts of CO 2 and PM 2.5. The spatial and temporal distributions show that, given a constant passenger density, the PM 2.5 concentration is higher near the door area than in the seating area. CO 2 concentrations varied in three stages, consistent with the change of local passenger load. Finally, a real-time optimized control method for fresh air volume and some suggestions are proposed to improve the in-carriage air quality of subway trains.

Correlation of Climate Change Indicators with Health and Environmental Data in the Philippines

“…Indoor air quality (IAQ) is frequently measured through CO 2. 21 This study in the Philippines showed a negative correlation (-0.519) between household air pollution health risk exposure value and mean temperature anomaly, similar to studies in Korea and Turkey. The study in Korea investigated the relationship of carbon dioxide in kitchens, living rooms, and bedrooms against temperature among apartments in Seoul.…”

“…IAQ is frequently measured through CO 2 . 21 The negative correlation of CO 2 and household air pollution health risk exposure value prevalence may be confounded by temperature and ventilation, as seen in the study of Yun et al (2020) and Argunhan and Aci (2018). 22,23 The study results showed that global carbon dioxide measurements negatively correlated to malaria incidence and NTD in the Philippines.…”

“…22 They found that during cooling seasons with an outdoor temperature of above 32°C but less than 36°C, there was a negative correlation of CO 2 and temperature . 21 Meanwhile, the study in Turkey investigated the relationship of CO 2 and particulate matter to temperature and showed a negative correlation of indoor CO 2 (-0.409), PM 10 (-0.324), and PM 5.0 (-0.261) to indoor temperature during spring. 23 These relationships may be attributed to ventilation.…”

Realization of interactive animation creation based on artificial intelligence technology

“…Through the pre‐debugging program, the robot can walk and avoid obstacles. With the development of artificial intelligence and pattern recognition technology, the use of human motion control robots to achieve HCI has become a hot topic 27,28 . The research of human body motion recognition technology has set off an upsurge at home and abroad.…”

End-to-end SARS-CoV-2 transmission risks in sport: Current evidence and practical recommendations

“…This, however, consumes a considerable amount of energy, [131] with the result that manufacturers and operators tend to recirculate most of the air and minimise the amount of 'fresh' outdoor air that is supplied to the carriages. [132] CO2 concentrations >1 800 ppm [132][133][134] and as high as 5 525 ppm [135] have been recorded on urban railway carriages during peak periods (CO2 concentrations in well-ventilated spaces are generally <1 000 ppm). [19,31] This suggests that during periods of high occupancy, ventilation rates in passenger carriages are frequently inadequate to protect passengers from far-field SARS-CoV-2 transmission.…”