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    Be nice to the air: Severe haze pollution and mutual fund risk
    (Elsevier Inc, 2023-11) Surva R; Nguyen H; Visaltanachoti N
    Motivated by the significant impacts of environmental risks on economic decisions and the increasing roles of mutual funds in financial markets in recent decades, this study examines the impact of ambient pollution on mutual funds’ risk outcomes. Using propriety data manually collected from several datasets, our fund fixed-effect regression estimates show that polluted air increases tracking errors and mutual fund return volatility. The adoption of different identification strategies, including instrumental variable estimations and difference-in-difference analyses based on two natural experiments, suggests the impact of air pollution on mutual funds’ risk is causal. Our findings suggest that air pollution harms fund managers’ cognitive abilities and impairs their investment efficiency, leading to an increase in mutual funds’ tracking errors and return volatility. Overall, our findings provide more insights into the impact of climate change on social behavior by shedding new light on the impact of air quality on asset managers’ behavior.
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    Volcanic air pollution and human health: recent advances and future directions
    (Springer Nature Switzerland AG on behalf of the International Association of Volcanology & Chemistry of the Earth's Interior, 2022-01) Stewart C; Damby DE; Horwell CJ; Elias T; Ilyinskaya E; Tomašek I; Longo BM; Schmidt A; Carlsen HK; Mason E; Baxter PJ; Cronin S; Witham C
    Volcanic air pollution from both explosive and effusive activity can affect large populations as far as thousands of kilometers away from the source, for days to decades or even centuries. Here, we summarize key advances and prospects in the assessment of health hazards, effects, risk, and management. Recent advances include standardized ash assessment methods to characterize the multiple physicochemical characteristics that might influence toxicity; the rise of community-based air quality monitoring networks using low-cost gas and particulate sensors; the development of forecasting methods for ground-level concentrations and associated public advisories; the development of risk and impact assessment methods to explore health consequences of future eruptions; and the development of evidence-based, locally specific measures for health protection. However, it remains problematic that the health effects of many major and sometimes long-duration eruptions near large populations have gone completely unmonitored. Similarly, effects of prolonged degassing on exposed populations have received very little attention relative to explosive eruptions. Furthermore, very few studies have longitudinally followed populations chronically exposed to volcanic emissions; thus, knowledge gaps remain about whether chronic exposures can trigger development of potentially fatal diseases. Instigating such studies will be facilitated by continued co-development of standardized protocols, supporting local study teams and procuring equipment, funding, and ethical permissions. Relationship building between visiting researchers and host country academic, observatory, and agency partners is vital and can, in turn, support the effective communication of health impacts of volcanic air pollution to populations, health practitioners, and emergency managers.
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    Banning Diesel Vehicles in London: Is 2040 Too Late?
    (MDPI, 2019) Shammut, Moayad; Cao, Mengqiu; Zhang, Yuerong; Papaix, Claire; Liu, Yuqi; Gao, Xing
    Air pollution contributes to 9400 deaths annually in London and diesel vehicles are considered a major source of lethal air pollutants. Consequently, the UK government announced its intention to ban diesel vehicles by 2040 to achieve a sustainable zero-carbon road transport system. Since no empirical studies have used a bottom-up approach to seek Londoners’ views, it is therefore worth investigating the public opinion regarding this forthcoming ban. This paper aims to fill this research gap by taking London as a case study. A survey was designed, and fieldwork was conducted to distribute questionnaires to Londoners. Completed questionnaires were analysed using both quantitative and qualitative methods. The findings revealed that the majority of Londoners would be in favour of the ban if they were sufficiently exposed to the appropriate sources of information and were favourably disposed towards environmental protection measures. The results also showed that Londoners were more likely to switch to electric vehicles (EVs) if they were offered generous incentives and encouraged to use scrappage schemes. The present study makes a strong case for enforcing the ban well before 2040. The significance of this research is to provide clearer signals regarding the future of diesel vehicles, which in turn will strengthen the EV policy and uptake.
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    Hydrogen sulphide in Rotorua, New Zealand : personal exposure assessment and health effects : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Earth Science at Massey University, Palmerston North, New Zealand
    (Massey University, 2011) Hinz, Ruth; Hinz, Ruth
    Long-term exposure to low level hydrogen sulphide (H2S) may be a health risk. However, research on this has been scarce. Rotorua offers a unique opportunity for such an investigation as its population is regularly exposed to geothermal H2S and few copollutants are present. To date, only ambient H2S concentrations have been investigated. The current study aimed to measure personal exposure levels and to assess potential health effects. In particular, the study involved: 1. Method development to measure exposure, including the adaption of a personal sampler 2. Analysis of personal exposure levels including personal and ambient air measurements 3. Identification of the main determinants of exposure 4. Assessment of the association between personal exposure and health effects involving the respiratory, the circulatory and the nervous systems. The Chemcassette® tape was found to be a suitable and cost effective personal sampler. More than 75% of participants had exposure levels below 5 parts per billion (ppb). The group of remaining participants had exposure levels between 5 and 90 ppb, which were five times higher than those measured in the other two groups (CI: 3.71-6.73). Those participants had frequented a 1-2 km wide north-south corridor in central Rotorua for longer than 2 hours. Previously, the corridor had been identified as an area of elevated H2S concentrations in geological and ambient air surveys. However personal exposure levels were considerably lower than air monitoring data in this area. Whether this is attributable to the mobility of participants or the sheltering effect of buildings is unclear. Personal samplers with readings above 90 ppb were associated with proximity to geothermal sources and/ or buildings with H2S intrusion. Personal exposure levels varied between trials in the central corridor, while western and eastern Rotorua consistently showed low levels (<5 ppb). Higher H2S concentrations (up to 3.5 times CI 2.07-5.76) in the central corridor were associated with north-north-easterly to easterly winds carrying additional H2S from the Sulphur Bay geothermal area on the eastern margin of the corridor (effect estimate coefficient: 3.5, CI 2.07-5.76). An indication of an increased asthma risk was found for the southern part of the corridor (OR: 2.9, CI: 1.17-7.18), but the association needs further investigation. In conclusion, this study found elevated personal H2S levels along a central corridor in Rotorua and the possibility of an association with asthma.
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    Source parameter estimation of atmospheric pollution from accidental releases of gas : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Mathematics at Massey University, Palmerston North, New Zealand
    (Massey University, 2003) Kathirgamanathan, Padmanathan
    This thesis presents the development of an inverse model that may be used to estimate the source term parameters for a polluting gas released into the atmosphere from a point above the ground. The model uses measured pollution concentrations at observation sites on the ground as well as meteorological data such as wind speed and cloud cover. The inverse model is formulated as a least- squares minimisation problem coupled with the solution of an advection-diffusion equation. The least-squares technique allows quantification of the uncertainty of the calculated estimates, which in turn allows estimation of the uncertainty of the simulation model predictions. The minimisation problem where the pollutants are released instantaneously is well-posed and the source term is calculated with reasonable accuracy. However, the problem with a non-steady extended release source is ill-posed; consequently, its solution is extremely sensitive to errors in the measurement data. Tikhonov's regularisation, which stabilises the solution process, is used to overcome the ill-posedness of this problem. The optimal value of the regularisation parameter in the problem is estimated using both the linear and non-linear L-curve criterion, and a generalised cross-validation approach. The accuracy of the model is examined by using simulated concentration data (generated by the forward model) to which normally-distributed relative noise has been added, as well as some real experimental data.