18 Feb Nanoparticle Pollution Worse At Red Lights
MedicalResearch.com Interview with:
Dr. Prashant Kumar PhD (Cantab), MTech, BEng, FHEA, FCPS, FCCT, CEng(IEI), MIEnvSc, MIAQM, MIAAPC
Senior Lecturer in Wind Engineering
Department of Civil and Environmental Engineering (C5)
Faculty of Engineering and Physical Sciences
University of Surrey, Guildford
Medical Research: What is the background for this study? What are the main findings?
Dr. Kumar: Pollution is disproportionately spread in urban areas due to scattered mobile and stationary sources. Exhaust emissions from vehicles are one of the major sources of air pollution in urban areas. When vehicles stop at red lights, they go through different driving cycles such as idling, acceleration and deceleration. At the same time, a number of other vehicles are also queuing at red lights, emitting further emissions – these emissions take more time to disperse, especially in built-up areas, and end up accumulating in the air at traffic lights. In our study, we found that because drivers were decelerating and stopping at lights, then revving up to move quickly when lights go green, peak particle concentration was 29 times higher than that during free flowing traffic conditions. We also found that while drivers spent just two per cent of their journey time passing through traffic intersections managed by lights, that short duration contributes to about 25 per cent of their total exposure to these harmful particles.
Medical Research: What should clinicians and patients take away from your report?
Dr. Kumar: Vehicles emit a number of gaseous pollutants, as well as particles in various sizes. All these pollutants are known to cause damage to human health, including cardiovascular and respiratory diseases. In this work, we studied nanoparticles, which are particles below 100 nm – these are known to cause more harm than particles of larger sizes. These particles have the potential for lung deposition and translocation to other parts of the body. At traffic lights, we found that when we closed the windows and switched off the fan, this gave us the lowest exposure. When the windows were closed but fan was on, the exposure was at its highest. This is due to the fact that the air outside the vehicle at red lights is generally much more polluted compared with the air inside the car. Switching on the fan sucks the dirty air from outside to the inside the vehicle, and the air inside takes some time to dilute or escape out of the vehicle, resulting in accumulation of pollutants inside. In light of this, if it is not always possible to change your route to avoid these intersections, the best ways to limit your exposure is to keep windows shut, fans off and try to increase the distance between you and the car in front where possible. If walking on foot, pedestrians could perhaps consider changing routes and see whether there might be other paths less dependent on traffic light crossings. As far as clinicians are concerned, if they could bring awareness to patients during their sessions, this will assist in understanding the issue of high pollution exposure and allow patients to consider simple changes to limit their exposure.
Medical Research: What recommendations do you have for future research as a result of this study?
Dr. Kumar: Our study presents new information about the effect of dynamic driving on nanoparticle concentrations and exposure at the traffic lights. This provides a sound basis for future studies which could cover a diverse range of traffic intersections in different geographical settings, so that a database of exposure profiles in different settings could be developed. This could assist in estimating the contribution of exposure at traffic lights towards the daily commuting exposure in diverse city environments. Furthermore, toxicological studies could provide information on the type of serious and less-serious health issues, while the better dispersion models to apportion these high pollution zones are needed to mitigate and control the exposure of city dwellers at hotspot locations.
Goel, A., Kumar, P., 2015. Characterisation of nanoparticle emissions and exposure at traffic intersections through fast-response mobile and sequential measurements. Atmospheric Environment, doi: 10.1016/j.atmosenv.2015.02.002. [Online Link] http://dx.doi.org/10.1016/j.atmosenv.2015.02.002
MedicalResearch.com Interview with Dr. Prashant Kumar PhD (Cantab), MTech (2015). Nanoparticle Pollution Worse At Red Lights MedicalResearch.com
Last Updated on February 18, 2015 by Marie Benz MD FAAD