Historically, the New Zealand rationale behind air quality management has been to adopt an effects-based approach based on environmental impacts. Generally, this method has been efficient in that it permitted emitters to decide how to minimise and mitigate impacts. However, to address the inconsistencies in air quality management across New Zealand born of this approach, and to permit measures designed to improve the working of the Resource Management Act (RMA), National Environmental Standards for Ambient Air Quality have been developed and implemented to establish consistent regulation and protection for all New Zealanders. The standards were gazetted in September 2004, for full implementation by 2013. This thesis explores the implementation of the National Environmental Standards for Ambient Air Quality, examining the philosophy behind the standards and associated strategies for dealing with air pollution management in New Zealand, and the international context for the development of appropriate tools to address air quality concerns. The research also provides an independent dispersion modelling assessment of the application of the Ministry for the Environment's initiative regarding sulphur dioxide in the Marsden Point airshed, Northland, utilising The Air Pollution Model (TAPM) for a period when heightened concentration values had been recorded. The key outcomes of the thesis are: (i) 99.9th percentile and maximum values for the simulated two-day modelling case study are within those stipulated by the air quality standards for sulphur dioxide; (ii) modelled concentrations associated with shipping within the airshed of interest contribute significantly to total modelled values; (iii) the chief obstruction to increased use of the prognostic modelling approach is that of the unsatisfactory availability and integrity of emission inventories; (iv) performing long-term high-resolution simulations with multiple point sources is prohibitive due to computational demands; (v) good quality monitoring will always be required; (vi) the standards have broad and far-reaching implications for resource managers, resource users and possibly the economy of individual regions and the country as a whole; (vii) the successful implementation of the National Environmental Standards for Ambient Air Quality in New Zealand will integrate a thorough understanding of modelling, measurements, meteorology and emissions.

Historically, the New Zealand rationale behind air quality management has been to adopt an effects-based approach based on environmental impacts. Generally, this method has been efficient in that it permitted emitters to decide how to minimise and mitigate impacts. However, to address the inconsistencies in air quality management across New Zealand born of this approach, and to permit measures designed to improve the working of the Resource Management Act (RMA), National Environmental Standards for Ambient Air Quality have been developed and implemented to establish consistent regulation and protection for all New Zealanders. The standards were gazetted in September 2004, for full implementation by 2013. This thesis explores the implementation of the National Environmental Standards for Ambient Air Quality, examining the philosophy behind the standards and associated strategies for dealing with air pollution management in New Zealand, and the international context for the development of appropriate tools to address air quality concerns. The research also provides an independent dispersion modelling assessment of the application of the Ministry for the Environment's initiative regarding sulphur dioxide in the Marsden Point airshed, Northland, utilising The Air Pollution Model (TAPM) for a period when heightened concentration values had been recorded. The key outcomes of the thesis are: (i) 99.9th percentile and maximum values for the simulated two-day modelling case study are within those stipulated by the air quality standards for sulphur dioxide; (ii) modelled concentrations associated with shipping within the airshed of interest contribute significantly to total modelled values; (iii) the chief obstruction to increased use of the prognostic modelling approach is that of the unsatisfactory availability and integrity of emission inventories; (iv) performing long-term high-resolution simulations with multiple point sources is prohibitive due to computational demands; (v) good quality monitoring will always be required; (vi) the standards have broad and far-reaching implications for resource managers, resource users and possibly the economy of individual regions and the country as a whole; (vii) the successful implementation of the National Environmental Standards for Ambient Air Quality in New Zealand will integrate a thorough understanding of modelling, measurements, meteorology and emissions.

White Island and Ruapehu are currently the most active volcanoes in New Zealand. During non-eruptive periods, intense quiescent degassing through fumaroles can occur. The current project studies the quiescent degassing plumes, including aerosol sampling on White Island and dispersion modelling of SO₂ and PM₁₀ from White Island and Ruapehu volcanoes. Aerosol sampling from fumaroles at the crater floor on White Island volcano was carried out on 9 February and 6 April 2005. The exposed filters were analysed for various anions and cations and the particle mass concentration and molar concentration determined. Major elemental constituents were sodium and chlorine (Na⁺: 413 µg m⁻³, Cl⁻: 1520 µg m⁻³), which show best correlation at both sampling sessions. Other ions detected, with little correlation, are Ca²⁺, PO₄³⁻ and to a certain extent Mg²⁺. Other constituents found, which cannot correlate explicitly to other ions, are K⁺, NH₄⁺, NO₃⁻, and SO₄²⁻. SEM study of one exposed filter was performed and mainly NaCl particles could be distinguished due to their well-defined cubic shape. The Air Pollution Model (TAPM) was used for dispersion modelling of SO₂ (models 1-4) and PM₁₀ (models 5 and 6) from White Island and Ruapehu volcanoes. Annual modelling was performed using different parameters of emission rate, exit temperature and exit velocity. The resulting plume dispersions show relatively low concentrations at ground level ≤10 m), particularly for the models of PM₁₀ dispersion. TAPM calculated the highest SO₂ ground level concentrations with model 4, where the NES values of 350 and 570 µg m⁻³ were exceeded several times. The data was then used for detailed hazard assessment of urban population in the North Island. The meteorological data from annual modelling was used for model evaluation and compared with observation data from different weather stations by statistical calculations. Overall, TAPM performed well with most good and very good results. To evaluate SO₂ dispersion modelling, airborne plume measurements were carried out on 22 November 2006 by plume traverses at 3, 10 and 20 km. Although there is some variation, the calculated correlation coefficients indicate good model results for two plume traverses at 3 and 20 km and one plume traverse at 10 km. The meteorological data was also used for model evaluation, and the results indicate good model performance. TAPM is therefore suggested for future studies when more observation data are available to verify the calculated model data.

Air quality of the Kao-Ping airshed has been the worst of all airsheds which are divided into seven groups by districts in Taiwan. The percentage of annual bad air quality (Pollution Standard Index, PSI > 100) in the Kao-Ping airshed (6.65−13.56%) was twice than it in the Yun-Chia-Nan airshed (2.58−6.98%) during the past decade (1998−2007). Oil refineries, petrol/plastic industries, power plants, and iron/steel/metal plants are the major industries in the Kaohsiung metropolitan area. Due to intensive industrial and traffic activities, the Kao-Ping area has the poorest air quality in Taiwan − either increased ground-level concentrations of particulate matter (PM) or ozone (O3) associated with unfavorable meteorological conditions − particularly between late fall and mid-spring The temporal and spatial characterization of suspended particles in the Kao-Ping area was analyzed by using TAPM (air quality model) and CMB (receptor model) to understand the contributions of the major emission sources. Estimations using the TAPM model suggest that point-source emissions were the predominant contributors (about 49.1%) to PM10 concentrations at Hsiung-Kong industrial site in Kaohsiung City, followed by area sources (approximately 35.0%) and neighboring transport (7.8%). Because Ping-Tung City (urban) and Chao-Chou town (rural) are located downwind of Kaohsiung City when north or northeasterly winds prevail, the two sites also experience severe pollution events despite the lack of industrial sources; neighboring transport contributed roughly 39.1% to PM10 concentrations at Ping-Tung and 48.7% at Chao-Chou. Results of CMB (chemical mass balance) modeling show that the main contributors to PM2.5 mass are vehicle exhaust (gasoline vehicle emission: 43% and diesel vehicle emission: 17% at Hsiung-Kong; gasoline vehicle emission: 45% and diesel vehicle emission: 19% at Ping-Tung; gasoline vehicle emission: 12% and diesel vehicle emission: 29% at Chao-Chou). And the main contribution to PM2.5-10 mass is the paved road emission (Hsiung-Kong: 40%; Ping-Tung: 48%; Chao-Chou: 50%). It is recommended that air quality model is an appropriate tool to large area and receptor model is more suitable to specific point to identify emission sources by the results in this study.

White Island and Ruapehu are currently the most active volcanoes in New Zealand. During non-eruptive periods, intense quiescent degassing through fumaroles can occur. The current project studies the quiescent degassing plumes, including aerosol sampling on White Island and dispersion modelling of SO₂ and PM₁₀ from White Island and Ruapehu volcanoes. Aerosol sampling from fumaroles at the crater floor on White Island volcano was carried out on 9 February and 6 April 2005. The exposed filters were analysed for various anions and cations and the particle mass concentration and molar concentration determined. Major elemental constituents were sodium and chlorine (Na⁺: 413 µg m⁻³, Cl⁻: 1520 µg m⁻³), which show best correlation at both sampling sessions. Other ions detected, with little correlation, are Ca²⁺, PO₄³⁻ and to a certain extent Mg²⁺. Other constituents found, which cannot correlate explicitly to other ions, are K⁺, NH₄⁺, NO₃⁻, and SO₄²⁻. SEM study of one exposed filter was performed and mainly NaCl particles could be distinguished due to their well-defined cubic shape. The Air Pollution Model (TAPM) was used for dispersion modelling of SO₂ (models 1-4) and PM₁₀ (models 5 and 6) from White Island and Ruapehu volcanoes. Annual modelling was performed using different parameters of emission rate, exit temperature and exit velocity. The resulting plume dispersions show relatively low concentrations at ground level ≤10 m), particularly for the models of PM₁₀ dispersion. TAPM calculated the highest SO₂ ground level concentrations with model 4, where the NES values of 350 and 570 µg m⁻³ were exceeded several times. The data was then used for detailed hazard assessment of urban population in the North Island. The meteorological data from annual modelling was used for model evaluation and compared with observation data from different weather stations by statistical calculations. Overall, TAPM performed well with most good and very good results. To evaluate SO₂ dispersion modelling, airborne plume measurements were carried out on 22 November 2006 by plume traverses at 3, 10 and 20 km. Although there is some variation, the calculated correlation coefficients indicate good model results for two plume traverses at 3 and 20 km and one plume traverse at 10 km. The meteorological data was also used for model evaluation, and the results indicate good model performance. TAPM is therefore suggested for future studies when more observation data are available to verify the calculated model data.

One important component for successful air quality modelling is the utilisation of a reliable meteorological simulator. Evaluating the model with respect to its overall performance in predicting natural processes is no easy task. The problem is twofold, firstly there is the availability and suitability of field data with which to compare a model with and secondly there is the method of evaluation. The Air Pollution Model (TAPM), developed by the CSIRO was used to simulate the winds in Southeast Queensland (SEQ). The complex nature of the airshed makes it difficult to compare modelled data with observational data as the observational data may be influenced by local phenomena. Evaluation of the model through the use of standard statistics and monthly and seasonal statistics illustrated that overall the model predicted the annual average wind speeds and temperatures well. Through the use of synoptic clustering, more detail on model performance was gained and it was found that TAPM predicted sea breezes that occurred on high pollution days. The sensitivity of the model to the selection of input parameters such as soil type, land use, vegetation, and rain processes was also investigated.