Health co-benefits from mitigating climate change through mass rapid transit system: A case study in Kuala Lumpur, Malaysia.

Abstract

Introduction The introduction of mass rapid transit (MRT) system could play an important role in establishing a sustainable transport system in Kuala Lumpur city. Multi-goal integration in the transport development plan of the city is necessary to leverage on the expensive infrastructure investment. This study models the potential carbon savings and public health co-benefits from air pollution, traffic injury and physical activity brought by the two upcoming MRT lines in Kuala Lumpur. Methods A transport survey was carried out to estimate the current travel patterns, and age and gender distribution of likely users of the scheme around the first MRT line in Kuala Lumpur. Changes in health from the MRT use was compared against a counterfactual scenario of no scheme using comparative risk assessment. Air pollution was modelled based on reduction in PM2.5. Injuries were modelled based on changes to distance and constant risks for all modes. Physical activity was modelled based on walking to access the MRT stops. Results A net total of 196,595 tCO2 equivalent could be removed from traffic emissions by the two MRT lines. At the same time, 0.19 µg/m3 of PM2.5 could be reduced in the atmosphere, bringing down 5 deaths and 112 DALYs among the population in the vicinity. Due to the less kilometres travelled on roads, 27 attributed traffic injury deaths with 1,984 DALYs could be avoided among the MRT users. Walking in the first and last miles of using MRT could further reduce 82 deaths with 2,525 DALYs from increased overall physical activity. Altogether, a total of 114 deaths with 4,621 DALYs could be avoided from the implementation of the two MRT lines. Conclusion The MRT infrastructure could entail a large carbon emission savings from the transport sector to be part of the climate change mitigation. Overall, the biggest health co-benefits brought by the two MRT lines is the reduction in burden of disease from the increased overall physical activity in the urban population.