Abstract
With the increasing trend of development and industrialization in Malaysia, air pollution has become an inevitable part of the process, resulting from increased vehicular activities and industrial processes. Toll operators are potentially exposed to high levels of air pollutants from working in proximity to traffic pollution sources, thereby increasing their risk of health defects associated with air pollution exposure. This study assessed the levels of Nitrogen dioxide (NO2) toll operators are exposed to, considering the influences traffic density and meteorological factors. This is intended to serve as an indicator of the cumulative pollution emanating from the combustion process of vehicles at toll plazas. Using Passive diffusion samplers saturated with Triethanolamine (TEA), the weekly indoor and outdoor NO2 concentrations at tollbooth were measured at Sungai Besi (SB), Kajang (KJ) and Putra-Makhota (PM) toll Plazas, to capture the varying traffic densities of 138,000, 65,000 and 24,100 vehicles/day respectively. The results showed that NO2 concentrations increase with traffic densities, and indoor NO2 concentrations correlated highly with outdoor NO2 concentrations (R2: SB = 0.767, KJ = 0.689 and PM = 0.877). The indoor/outdoor NO2 ratio varied from 0.7 to 1.2 for all toll booths, suggesting pollution control in-efficiency, caused by technical and behavioural factors. Also, meteorological factors had no significant effect on nitrogen dioxide concentrations, contrary to previous studies, which is likely due to the far distance between tool plazas and meteorological stations. Furthermore, the NO2 concentrations reported in this study were higher in comparison to weekly standards adopted in Germany (0.032 ppm) and previous literature. Therefore, toll operators are potentially exposed to high levels of pollution, and we advise that toll operators to wear pollution protection gears to reduce the risk of exposure, and the ventilation systems and mitigation measure (air curtain) reviewed to assess its efficiency.
Highlights
Air pollution in Malaysia emanates mainly from three sources, i.e. open burning, stationary and mobile sources, with mobile sources regarded as the highest contributor to air pollution, and accounting for approximately 70% - 75% of total air pollution for the past five (5) decades [1]
Using Passive diffusion samplers saturated with Triethanolamine (TEA), the weekly indoor and outdoor NO2 concentrations at tollbooth were measured at Sungai Besi (SB), Kajang (KJ) and Putra-Makhota (PM) toll Plazas, to capture the varying traffic densities of 138,000, 65,000 and 24,100 vehicles/day respectively
Toll booths can be described as a worst-case scenario of air pollution exposure, as operators are exposed to a combination of pollutants including Volatile Organic Compounds (VOCs), BTEX (Benzene, toluene, ethylbenzene, and xylene), polycyclic aromatic hydrocarbons [4], ultrafine particles [5], Organic Carbon [6], and Carbon monoxide [7] and Nitrogen Dioxide [3]
Summary
Air pollution in Malaysia emanates mainly from three sources, i.e. open burning, stationary and mobile sources, with mobile sources regarded as the highest contributor to air pollution, and accounting for approximately 70% - 75% of total air pollution for the past five (5) decades [1]. Vehicular activities such as deceleration, idling and acceleration result in the accumulation of air pollutants during travel, and studies have shown significant concentrations of air pollutants at 50 m to 200 m away from traffic interception with high traffic densities are evident, and downstream of traffic interception [2] [3]. Bartin et al [9] revealed that electronic (automatic) tolls experience lesser pollution than manual tolls over a short-term period, due to reduced idle time and vehicular activities
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
