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Background: Exposure to indoor air pollutants has been associated with poorer respiratory health in children. This study investigates the respiratory health of Malaysian schoolchildren in relation to indoor air pollution. Methods: This cross-sectional study was conducted among 2,164 schoolchildren aged 10-11 years in urban and semi-rural schools. Parents completed a questionnaire and concentrations of air pollutants were measured in schools. SHS exposure was assessed using salivary cotinine. Results: The WHO Air Quality Guideline for PM2.5 was exceeded for most of the semi-rural schools while almost all of the urban schools exceeded the annual exposure limit for NO2. The Geometric Mean salivary cotinine concentrations for non-smoking schoolchildren were 0.47 ng/ml. The 3 main predictors of nocturnal cough were the presence of a current smoker at home (OR 1.97; 95% CI: 1.31-2.96), the absence of exhaust system in the kitchen (OR 1.67; 95% CI: 1.03-2.68) and the use of air conditioning (OR 3.10; 95% CI: 1.37-5.71). Exposure to SHS of ≥4 hours per day (OR 2.53; 95% CI: 1.55-4.14) explained approximately 6.0% of the likelihood of reporting doctor-diagnosed asthma. For the measure of asthma severity, NO2 and log average family size were the 2 predictors of limited speech during wheeze; NO2 concentrations of >50 μg/m3 contributes an OR of 5.98 (95% CI: 1.02-34.9) and log average family size with an OR of 14.6 (95% CI: 1.70-126). Conclusion: This study has identified that many Malaysian schoolchildren experience exposure to air pollution indoors that exceeds WHO guidance limits for several pollutants. There was no clear relationship between traffic-generated air pollutants and children’s respiratory health but there was a strong relationship between the number of hours children were exposed to SHS and asthma. There is a need for increased enforcement of existing smoke-free legislation and policies to reduce children’s exposure to SHS.

The control of atmospheric pollution in the urban environment has, in recent years, taken on important local, national and international significance. Legislation has been introduced in many countries to improve air quality in urban areas. Monitoring air pollution is an important part of understanding and improving air quality. Current standard methods of measuring air pollution only monitor at a single point in space which can lead to ambiguities when assessing air quality over an extended region, such as a city centre or a road intersection. Optical remote sensing techniques, such as long path Fourier transform absorption spectroscopy, overcome the limitations of point measurements by integrating over long paths and thus measuring the average ambient pollutant concentrations. A commercially available Fourier transform infrared (FTIR) spectrometer, together with custom built external optics has been used to make measurements of air pollution in Oxford city centre. It has been shown that it is possible to measure the concentrations of several pollutants simultaneously and in short measurement times. Issues relating to the performance of the spectrometer have been studied, their effects quantified and solutions proposed. Optimal estimation techniques have been applied to the analysis of the single beam spectra recorded by the FTIR spectrometer. This technique has previously only been applied to radiance and transmission spectra and so extensions were necessary. High resolution laboratory measurements of the absorption cross-sections of benzene and 1,3-butadiene have been made and the potential for detecting them in ambient urban air determined.

Though nitrogen oxides (NOx ) emissions from aircraft make a relatively small contribution to the overall NOx emissions when compared to surface emissions, they constitute the only man-made pollutant at high altitude. Excessive NOx emissions might cause ozone depletion in the stratosphere and ozone increases in the troposphere, both topics of increasing environment concern in recent years. To tackle the problem of NOx emissions and their effects upon the environment, the spatial distribution of NOy (NOx + RN03) needs to be fully understood. The most significant source of NOx emissions is due to long range civil subsonic aircraft during their cruise phase. Detailed studies were performed for seven cases, including five single flight and two global scale scenarios, using the most widely used B747-400 aircraft which are powered by 4 three-shaft turbofan engines. Using models of aircraft performance, cruise phase NOx emissions are derived and employed as input to run a three-dimensional chemistry transport model. In order to achieve realistic results, all scenarios were carried out using a one-year period of simulation to study the transport and dispersion of NOy emitted from aircraft exhausts. For a better understanding of the atmospheric behaviour of NOy , two other cases were also carried out, a one-month simulation during both summer and winter situations. The results show that the upper troposphere may certainly be perturbed by aircraft NOx emissions at cruise altitude. The relative increase in NOx concentration is estimated to be of the order of 40% in the meridional average and up to 160% in regions covered with heavy air traffic such as Europe, the USA and the North Atlantic. This thesis investigates the quantity of long range civil subsonic aircraft NOx pollutants at cruise altitude and their subsequent implications for the upper troposphere. It discusses the concept of atmospheric NOy pollution chemistry, using computer programs developed for both total aircraft performance and 3-D chemistry transport modelling, and combinations thereof. Simulations have been conducted to predict the relationship between the NOx emissions and the environment. In addition, the thesis highlights the most important variables and derives a procedure to model the emissions from subsonic aircraft flight and to assess their impacts upon the atmosphere. Finally, some complicated problems which need further work are also mentioned.

The aim of this thesis is to evaluate the cost to prevent CO2 emissions in the Green Investment Scheme. The research grant program, funded through the sale of surplus emission of bills under the Kyoto Protocol, is briefly framed in the overall context of climate policy (funding sources, AAU units, rules of emission trading, etc.). The thesis analysis the specific projects and then comparing the results obtained with the assumption of the Ministry of Environment on the possible development of the program. The thesis deals with the reduciton of CO2 emissions over the life of action based on available data. The analysis seeks to quantify of the average cost of one ton reduction of CO2 emissions.

A research report submitted to the Faculty of Geosciences, University of the Witwatersrand for the degree of Master of Science Johannesburg, 2015 / Quantifying or estimating emission uncertainty for particulate matter from stationary sources in South Africa. The estimation of measurement uncertainty with regards to hazardous air pollution emissions from stationary sources is currently the most uncertain element associated with obtaining relevant, valid stack emission data in South Africa. This project is aimed at developing an appropriate method to evaluate the uncertainty associated with particulate matter measurements conducted for stationary source emissions in the South African context. A series of In-Stack measurements were taken in accordance with recognized international methodology (ISO 9096:1992, and 2003) on two different industrial processes, representing a best and worst case scenario. A comparison between the two scenarios was made in an attempt to establish what components of the sampling technique have the greatest error. The effect of cumulative errors in the sampling train as well as external factors that may influence the results were evaluated and included in the final estimate of uncertainty. Some of the factors used included the sampling location, industrial process and external environmental factors. The overarching goal of this project was to establish an estimate of the cumulative uncertainty on the final emission values obtained, inclusive of both analytical, field sampling and process related variables that may result in a cumulative error associated with quantifying stationary source particulate matter emission values. The results of the study found that the estimated combined expanded uncertainty for both sets of data was calculated to be between 62 – 72%. Upon closer analysis of the data it was ascertained that the data obtained were inadequate and the calculation of the uncertainty of the results both with the compliant and non-compliant sampling campaigns revealed that the variability of the results was too great for both scenarios to make any statistically valid observations or conclusions about the data. In lieu of this, and considering the significant costs, time and labour involved in order to obtain enough data to enable adequate quantification of an uncertainty budget for the results obtained, the author has developed an alternative tool for assessing the quality and reliability of reported emission figures. The author has developed what he has named a sampling suitability matrix, this tool although subjective in nature will add significant value (in the authors opinion) to the interpretation of the quality and reliability of the final emission results reported. The intention of this tool is to be incorporated as supplementary information into all emission reports in future. This will enable the plant operator and regulator to assess the quality of reported data and final emission results, thus assisting in establishing whether the plant is in compliance with their Air Emission License (AEL) requirements or not.

A thesis submitted to the Faculty of Science, University of the Witwatersrand, in fulfillment of the requirements for the degree of Master of Science. Johannesburg, 2017. / The Highveld is identified as an air pollution ‘hotspot’ area where pollutant concentrations are elevated due to the high density of industrial and non-industrial air pollution sources. To enhance air quality across the Highveld, it was declared a priority area to manage and monitor pollutants to reduce their negative impact on the environment and society. Hence, the aim of this study was to investigate ambient air pollution across the Highveld Priority Area (HPA), using ground-level SO2, NOx and surface O3 concentrations, meteorological parameters and Moderate resolution imaging spectroradiometer (MODIS) atmosphere products, for January to December 2011, to develop new modelling techniques to aid in the management of air pollution. Results show the annual mean trace gas concentrations of SO2, NOx and surface O3 were 12.14, 14.75 and 28.77 ppb, respectively. SO2 and NOx concentrations were highest during winter at an average of 17.56 and 20.96 ppb, where surface O3 concentrations were highest during spring at an average of 32.82 ppb. Diurnal patterns of SO2 and surface O3 were similar, where a midday peak occurred. NOx concentrations instead showed peaks during traffic hours. Ambient air temperature, solar radiation, relative humidity, wind speed and rainfall levels peaked during summer. Atmospheric pressure was relatively stable throughout the year. Winds typically ranged from N to E up to April and from S to NW from May. Very little variation in SO2 and NOx concentrations was explainable by meteorology, 4 to 29 % and 5 to 23 %, while the influence of meteorology on surface O3 concentrations was more significant, 23 to 53 %. Spatial multiple regression statistical models using a cross validation approach for model validation were made over a number of temporal scales. The model fitting and validation processes indicated that the models were not a good fit as only up to 69, 74 and 58 % of SO2, NOx and surface O3 concentrations with high root means square error (RMSE) values of up to 22.10, 15.56 and 18.59 ppb, respectively, could be explained by the models. This process revealed the potential to model pollutants across the HPA, and as a pilot study future work can be based on this study. It is clear that spatial modelling for pollution estimation and management is necessary as seen by the frequent exceedances of the national and international ambient air quality standards. / XL2017

ABSTRACT Indoor air pollution has been associated with acute lower respiratory infections amongst children less than five years old in developing countries. Very little is known about the potential role of behavioural change in reducing child indoor air pollution exposure. This thesis explores three questions: did people change their behaviours following exposure to an intervention that promoted the health benefits of behavioural change? Were changes in behaviour attributable to the intervention? What were the motivations and barriers to behavioural change? The evaluation included a quantitative and a qualitative study. The quantitative study utilised a quasiexperimental before-after design amongst an intervention village (n=98 households). Results were compared to a similar control village (n=121) that did not receive the intervention. Baseline data were collected during winter 2003 and follow-up data were collected during winter 2004 (12 months later). A qualitative evaluation, using two rounds of 4 focus group interviews each, was used to answer questions that emerged from the quantitative study. Indoor air quality - PM10, CO and CO (measured on the youngest child) - were measured over a 24 hour period in randomly selected households before and after the intervention in the intervention (n=36) and control (n=38) groups. After adjusting for confounding factors, there was no statistical association between having the received the intervention and the likelihood of burning outdoors at follow-up (OR=1.16; 95% CI 0.6-1.8). Indoor air quality data showed significant median reductions in PM10 (94-96%), CO (85-97%) and CO (child) (83- 95%) amongst households that burned outdoors compared to those that burned indoors. Results from the qualitative study suggest that motivations for outdoor burning included: health considerations, reaction to participating in the study, reduced drudgery and prestige. Barriers to outdoor burning included the need for space heating during winter, perceptions of low indoor air pollution risk and gender relations. This study highlights the potential for exposure reduction through behavioural change and is original for three reasons. It is the first behavioural intervention study designed to reduce indoor air pollution in a rural African setting. Secondly, it is the first intervention study in the indoor air pollution field to identify the factors that influenced behavioural change. Thirdly, it is one of the first studies to align debates about behavioural change in the field of indoor air pollution with those in the broader environmental health promotion literature.

University of Macau / Faculty of Science and Technology. / Department of Civil and Environmental Engineering