Showing papers by "Prashant Kumar published in 2010"
TL;DR: In this article, a review of the existing knowledge of nanoparticles in the urban atmosphere, highlights recent advances in our understanding and discusses research priorities and emerging aspects of the subject, as well as the role of removal mechanisms of various kinds.
307 citations
TL;DR: A number of underlining technical issues are discussed by comparing the properties and behaviour of MNPs with anthropogenically produced ANPs, essential for the judicious treatment of the MNPs in any potential air quality regulatory framework for ANPs.
Abstract: Currently, there are no air quality regulations in force in any part of the world to control number concentrations of airborne atmospheric nanoparticles (ANPs). This is partly due to a lack of reliable information on measurement methods, dispersion characteristics, modelling, health and other environmental impacts. Because of the special characteristics of manufactured (also termed engineered or synthesised) nanomaterials or nanoparticles (MNPs), a substantial increase is forecast for their manufacture and use, despite understanding of safe design and use, and health and environmental implications being in its early stage. This article discusses a number of underlining technical issues by comparing the properties and behaviour of MNPs with anthropogenically produced ANPs. Such a comparison is essential for the judicious treatment of the MNPs in any potential air quality regulatory framework for ANPs.
67 citations
TL;DR: In this paper, the potential impact of particle number concentrations derived from biofuel vehicles on existing regulatory concerns over atmospheric nanoparticles was discussed, and the potential effect of the particle number concentration derived from fuel-powered vehicles on the regulatory concerns was discussed.
40 citations
01 Jan 2010
TL;DR: In this paper, the influence of street canyon geometries on the dispersion of nanoparticles was investigated in urban street canyons where dispersion is limited by surrounding built-up environment.
Abstract: The adverse impacts of atmospheric nanoparticles on public health, climate change and urban visibility have attracted substantial attention of the air quality management and regulation authorities. Health issues become even more critical when people living or travelling nearby its sources (mainly vehicles) are exposed to high concentrations. One such place is urban street canyons where dispersion is limited by surrounding built–up environment. Hence, it is important to control their emissions in the urban environment. Several street canyon studies have looked into factors affecting the flow and dispersion conditions of gaseous pollutants, but very few have considered the influence of street canyon geometries on the dispersion of nanoparticles. Such information is critical for nanoparticle dispersion models that are required for designing mitigating policies in future.
4 citations
01 Jan 2010
TL;DR: In this article, a modified box model (Kumar et al. 2009b) and an operational street pollution model (OSPM) are used for this purpose and modelled results are compared with the measured nanoparticle concentrations.
Abstract: Suitable dispersion models are required for the p rediction of nanoparticle number concentrations for adopting mitigation policies. The aim of this work is to model the dispersion of nanoparticle number concentrations in the 10-300 nm range at different heights in an urban street canyon. A modified Box model (Kumar et al . 2009b) and an operational street pollution model (OSPM) are used for this purpose and modelled results are compared with the measured nanoparticle concentrations. Further, the article discusses the role of particle dynamics in street-scale modelling and analyses the influenc e of the uncertainty in particle number emission fa ctors on modelled concentrations. Reasons for discrepancies in modelled results due t o particle number emission factors and street-level particle dynamics are given.