This thesis and the work to which it refers are the results of my own efforts. Any ideas, data, images or text resulting from the work of others (whether published or unpublished) are fully identified as such within the work and attributed to their originator in the text, bibliography or in footnotes. This thesis has not been submitted in whole or in part for any other academic degree or professional qualification. I agree that the University has the right to submit my work to the plagiarism detection service Turnitin UK for originality checks. Whether or not drafts have been so-assessed, the University reserves the right to require an electronic version of the final document (as submitted) for assessment as above. Abstract There is substantial evidence that airborne particulate matter (PM) contributes to haze, acid rain, global climate change, and decreased life expectancy. Many recent studies have reported that a large fraction of airborne PM could be attributed to fugitive PM (fPM). The developing arid and semi-arid regions, in particular, are facing the biggest brunt of fPM usually ascribed to the regionally transported dust. On the other hand, the rapid expansion of their metropolitan cities is contributing a considerable amount of locally induced fPM which makes it a prominent environmental and health stressor in these areas. Based on field measurements and dispersion modelling, this thesis aims to: (i) measure fPM from two common sources (loose soils and non-exhaust traffic) in areas with arid desert climates, (ii) derive representative emission models, and (iii) assess their overall environmental and health impacts. For this thesis, on site measurements and samples of PM (<10 µm diameter) were collected. Source apportionment was performed to determine the contributions of individual sources. Dispersion modelling and regression analysis were used to derive emission models for loose Calcisols (a prominent soil in the subject areas) and vehicle-induced fPM (VfPM). Finally, our derived models were used along with the state-of-the-art practices (i.e., regional emission models and the World Health Organization's (WHO) Environmental Burden of Disease (EBD) method) to determine the environmental and health impacts of local fPM. Several important findings were extracted from the above analysis: (i) fPM from different origins contribute more than 60% of the urban PM in arid areas, (ii) power law emission models with wind speed dependence were derived for loose Calcisols soil, (iii) emission factors were derived for VfPM using linear regression and were close to values reported in USA, (iv) EBD estimates found that fPM may lead to ~ 11.0 times higher short-term excess mortalities compared to constant database measurements. 4
This review assesses the current state of air pollution in the Middle East and North Africa (MENA) region. Emission types and sources in the region are identified and quantified to understand the monitoring, legislative and reduction need through a systematic review of available literature. It is found that both health (e.g., particulate matter, PM, and heavy metals) and climate change (e.g., carbon dioxide and methane) emissions are increasing with the time. Regarding health emissions, over 99% of the MENA population is exposed to PM levels that exceed the standards set by the World Health Organization (WHO). The dominant source of climate change emissions is the energy sector contributing ~38% of CO2 emissions, followed by the transport sector at ~25%. Numerous studies have been carried out on air pollution in the region, however, there is a lack of comprehensive regional studies that would provide a holistic assessment. Most countries have air quality monitoring systems in place, however, the data is not effectively evaluated to devise pollution reduction strategies. Moreover, comprehensive emission inventories for the individual countries in the region are also lacking. The legislative and regulatory systems in MENA region follow the standards set by international environmental entities such as the WHO and the U.S. Environmental Protection Agency but their effective reinforcement remains a concern. It is concluded that the opportunities for emission reduction and control could be best implemented in the road transportation sector using innovative technologies. One of the potential ways forward is to channel finance flows from fossil fuel subsidies to upgrade road transport with public transportation systems such as buses and trains, as suggested by a ‘high shift’ scenario for MENA region. Furthermore, emission control programs and technologies are more effective when sponsored and implemented by the private sector; the success of Saudi Aramco in supporting national emission monitoring is one such example. Finally, an energy-pollution-water nexus is assessed for the region as an integrated approach to address urban issues. The assessment of topic areas covered clearly suggest a need to control the main sources of air pollution to limit its relatively high impact on the human health in the MENA region.
This chapter discusses the emission, transformation, and fate of incidental airborne nanoparticles. It starts with the up-to-date summary of recent review articles covering various aspects of both the incidental nanoparticles and ENPs. Transformation processes play an important role in influencing the characteristics of nanoparticles both spatially and temporally. A common method to represent the atmospheric size distributions of atmospheric particles is through various modes. A typical size distribution in atmospheric environments shows the presence of the following modes:nucleation, Aitken, accumulation, and coarse. Nucleation mode particles are those generally formed by the gas-to-particle conversion after rapid cooling and dilution of exhaust emissions. Understanding the different transformation processes (i.e., nucleation, coagulation, condensation, evaporation, and dry deposition) is important in order to study the temporal and spatial changes occurring to nanoparticles in the atmospheric environment. The detection of ENP concentrations is necessary for determining human exposure in both the indoor factory environment and ambient non-workplace atmosphere.