Development of emission of factor, traffic emission inventory and risks of air pollution on respiratory and cardiovascular hospital admissions in Kuala Lumpur

Abstract

Transportation sector is the largest consumer of energy in the form of fossil fuel in Malaysia, resulting in air pollutant emissions into the atmosphere. Inadequate information on local vehicle emission factors will affect the quantification of cityspecific emission inventory. Despite the fact that the weight of evidence clearly shows that urban air pollution, primarily from traffic emissions, is linked to respiratory and cardiovascular diseases, only few studies have been conducted in Malaysia. The main objectives of this study are to determine the gaseous emission factor from gasolinefuelled cars, to quantify a traffic emission inventory and to assess the risks of exposure to air pollutants on respiratory and cardiovascular admissions in Kuala Lumpur. Eleven cars were tested and CO, CO2 and NOx emissions were measured using exhaust analyser. A traffic emission inventory over Kuala Lumpur is generated using EMISENS model. The combination of GLM and DLNM model was used to estimate the association between air pollutants and respiratory and cardiovascular admissions. The emission factors from cars were CO: 0.76 ± 0.15 g/km, CO2: 236.02 ± 14.98 g/km and NOx: 0.23 ± 0.03 g/km. The total CO, NOx, PM10, SO2 and NMVOC emissions calculated over Kuala Lumpur in 2018 were 640.79, 61.50, 20.24, 5.96, and 668.74 kt/yr, respectively. Motorcycles are the largest source of CO, whereas cars are the primary source of NMVOC and SO2. Two mitigation strategy scenarios can reduce the emissions within the range of 5.92% and 29.04%. This study indicated the highest association of respiratory admissions and PM10 at lag 05 (RR = 1.0549, 95% CI = 1.0131, 1.0984), CO at lag 07 (RR = 1.0011, 95% CI = 1.0001, 1.0022) and NO2 at lag 07 (RR = 1.1000, 95% CI = 1.0141, 1.1931) for an increase of each unit in air pollutant concentration. Adverse respiratory effects at the population level in Kuala Lumpur were observed at low levels of exposure to air pollutants where the air quality standards were being met. Translating the scientific evidence on the impacts of traffic emissions on air quality and linking short-term exposure with health risks is beneficial for sustainable transportation planning.