BITS Faculty Publications

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    Assessment of environmental and public health risk of on-site wastewater treatment systems
    (American Society of Agricultural and Biological Engineers, 2004) Goonetilleke, Ashantha
    On-site wastewater treatment systems are common throughout Australia, with most systems located in the urban fringe and rural regions. The number of on-site treatment systems is increasing rapidly as these areas undergo more intensive development. Consequently, there is a significant increase in environmental and public health risks associated with these systems. This has lead to the recognition of the need for the articulation of treatment standards and criteria which are flexible and robust to satisfy specific public health and environmental requirements. Currently, these concepts are not being widely applied in on-site treatment of wastewater. A research project was undertaken to identify and assess the environmental and public health risks associated with on-site wastewater treatment systems in an area within the Gold Coast region, Southeast Queensland, Australia. A detailed surface and groundwater investigation including nutrient and microbiological analysis and modeling studies were undertaken to identify and assess the risk of contamination from nutrients and pathogenic organisms discharged from on-site systems. This also included the assessment of the potential risks in relation to high densities of on-site systems. High levels of nutrients, in particular nitrate, has been found in an unconfined shallow aquifer within the study area, directly below high densities of systems. Similarly, high fecal coliforms have also been observed in various locations throughout the area. Therefore, it crucial that the impact of high densities of on-site systems on shallow groundwater is appropriately assessed in order to minimise the potential risks to the environment.
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    Human health risk assessment of heavy metals in urban stormwater
    (Elsevier, 2016-07) Goonetilleke, Ashantha
    Toxic chemical pollutants such as heavy metals (HMs) are commonly present in urban stormwater. These pollutants can pose a significant risk to human health and hence a significant barrier for urban stormwater reuse. The primary aim of this study was to develop an approach for quantitatively assessing the risk to human health due to the presence of HMs in stormwater. This approach will lead to informed decision making in relation to risk management of urban stormwater reuse, enabling efficient implementation of appropriate treatment strategies. In this study, risks to human health from heavy metals were assessed as hazard index (HI) and quantified as a function of traffic and land use related parameters. Traffic and land use are the primary factors influencing heavy metal loads in the urban environment. The risks posed by heavy metals associated with total solids and fine solids (< 150 μm) were considered to represent the maximum and minimum risk levels, respectively. The study outcomes confirmed that Cr, Mn and Pb pose the highest risks, although these elements are generally present in low concentrations. The study also found that even though the presence of a single heavy metal does not pose a significant risk, the presence of multiple heavy metals could be detrimental to human health. These findings suggest that stormwater guidelines should consider the combined risk from multiple heavy metals rather than the threshold concentration of an individual species. Furthermore, it was found that risk to human health from heavy metals in stormwater is significantly influenced by traffic volume and the risk associated with stormwater from industrial areas is generally higher than that from commercial and residential areas.
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    Assessment and management of human health risk from toxic metals and polycyclic aromatic hydrocarbons in urban stormwater arising from anthropogenic activities and traffic congestion
    (Elsevier, 2017-02) Goonetilleke, Ashantha
    Toxic metals (TMs) and polycyclic aromatic hydrocarbons (PAHs) in urban stormwater pose risk to human health, thereby constraining its reuse potential. Based on the hypothesis that stormwater quality is primarily influenced by anthropogenic activities and traffic congestion, the primary focus of the research study was to analyse the impacts on human health risk from TMs and PAHs in urban stormwater and thereby develop a quantitative risk assessment model. The study found that anthropogenic activities and traffic congestion exert influence on the risk posed by TMs and PAHs in stormwater from commercial and residential areas. Motor vehicle related businesses (FVS) and traffic congestion (TC) were identified as two parameters which need to be included as independent variables to improve the model. Based on the study outcomes, approaches for mitigating the risk associated with TMs and PAHs in urban stormwater are discussed. Additionally, a roadmap is presented for the assessment and management of the risk arising from these pollutants. The study outcomes are expected to contribute to reducing the human health risk associated urban stormwater pollution and thereby enhance its reuse potential.
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    Quantitative assessment of human health risk posed by polycyclic aromatic hydrocarbons in urban road dust
    (Elsevier, 2017-01) Goonetilleke, Ashantha
    Among the numerous pollutants present in urban road dust, polycyclic aromatic hydrocarbons (PAHs) are among the most toxic chemical pollutants and can pose cancer risk to humans. The primary aim of the study was to develop a quantitative model to assess the cancer risk from PAHs in urban road dust based on traffic and land use factors and thereby to characterise the risk posed by PAHs in fine (< 150 μm) and coarse (> 150 μm) particles. The risk posed by PAHs was quantified as incremental lifetime cancer risk (ILCR), which was modelled as a function of traffic volume and percentages of different urban land uses. The study outcomes highlighted the fact that cancer risk from PAHs in urban road dust is primarily influenced by PAHs associated with fine solids. Heavy PAHs with 5 to 6 benzene rings, especially dibenzo[a,h]anthracene (D[a]A) and benzo[a]pyrene (B[a]P) in the mixture contribute most to the risk. The quantitative model developed based on traffic and land use factors will contribute to informed decision making in relation to the management of risk posed by PAHs in urban road dust.
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    Catchment scale assessment of risk posed by traffic generated heavy metals and polycyclic aromatic hydrocarbons
    (Elsevier, 2017-10) Goonetilleke, Ashantha
    Heavy metals (HMs) and polycyclic aromatic hydrocarbons (PAHs) are among the most toxic chemical pollutants present in urban stormwater. Consequently, urban stormwater reuse is constrained due to the human health risk posed by these pollutants. This study developed a scientifically robust approach to assess the risk to human health posed by HMs and PAHs in urban stormwater in order to enhance its reuse. Accordingly, an innovative methodology was created consisting of four stages: quantification of traffic and land use parameters; estimation of pollutant concentrations for model development; risk assessment, and risk map presentation. This methodology will contribute to catchment scale assessment of the risk associated with urban stormwater and for risk mitigation. The risk map developed provides a simple and efficient approach to identify the critical areas within a large catchment. The study also found that heavy molecular weight PAHs (PAHs with 5–6 benzene rings) in urban stormwater pose higher risk to human health compared to light molecular PAHs (PAHs with 2–4 benzene rings). These outcomes will facilitate the development of practical approaches for applying appropriate mitigation measures for the safe management of urban stormwater pollution and for the identification of enhanced reuse opportunities.
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    Creating a hierarchy of hazard control for urban stormwater management
    (Elsiever, 2019-12) Goonetilleke, Ashantha
    Urban stormwater reuse is becoming increasingly prevalent to overcome the serious urban water scarcity being experienced around the world. Therefore, the adoption of reliable approaches to minimise the human health risk posed by pollutants commonly present in urban stormwater such as heavy metals and polycyclic aromatic hydrocarbons (PAHs) is critical for safe stormwater reuse. This study collected a total of 40 pollutant build-up samples and analysed the concentrations of nine heavy metals and 15 PAH species. Based on pollutant build-up data, pollutant concentrations in stormwater were estimated through modelling. Risk assessment was conducted using an existing model developed by previous studies. The study outcomes confirmed that simply evaluating the individual pollutant concentrations based on guideline threshold values cannot comprehensively estimate the overall human health risk posed by these pollutants. Accordingly, it is recommended that the assessment of the overall human health risk should be based on the pollutant mix present as provided by the models discussed in this paper. The study also demonstrated the practical application of a robust risk assessment model to derive the hierarchy of hazard control to provide a reliable underpinning to urban stormwater risk management. The outcomes suggest that decentralised hazard control methods such as the provision of custom designed Water Sensitive Urban Design (WSUD) measures can be implemented in priority areas with high risk from stormwater pollution based on the risk assessment undertaken. Distributed hazard control methods can be applied to reduce the generation of primary toxic pollutants, especially chromium (Cr) and heavy PAHs, through elimination and substitution measures. The percentage reduction in traffic volume required to mitigate the human health risk can be quantified through the risk models presented. The study outcomes will contribute to the development of efficient, targeted and reliable stormwater management strategies and to identify viable opportunities for stormwater reuse.
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    Source quantification and risk assessment as a foundation for risk management of metals in urban road deposited solids
    (Elsevier, 2021-04) Goonetilleke, Ashantha
    Urban road build-up solids contain toxic metals posing potential risks to human health. Management of human health risks arising from these metals is critical in urban areas. This study collected solids build-up data from 16 study sites with various land use and traffic characteristics. Source quantification was conducted using PCA/APCS receptor model. It was found that soil and asphalt wear are the largest contributors (69.43%) to risk and mainly contribute Al, Cr, Mn, Fe, Ni, Zn and Pb to build-up solids. Brake wear is the second largest contributor accounting for 17.20% and contributes Cd and Cu. Tyre wear is the third major contributor (11.38%) and it primarily contributes Ni, Zn and Cr. Mathematical equations were fitted to estimate the risk against daily traffic volume and land use fractions, and the uncertainty analysis highlighted that risk assessment should account for the variability in metal concentrations rather than a point value of concentrations at a given time and space. Based on source quantification and risk assessment, an integrated risk management model was developed to manage human health risks from toxic metals in build-up solids. This risk model provides guidance for urban planning and land use development to mitigate risk arising from urban road deposited solids.
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    Risk associated with microplastics in urban aquatic environments: a critical review
    (Elsevier, 2022-10) Goonetilleke, Ashantha
    The presence of microplastics (MPs) has been recognized as a significant environmental threat due to adverse effects spanning from molecular level, organism health, ecosystem services to human health and well-being. MPs are complex environmental contaminants as they bind to a wide range of other contaminants. MPs associated contaminants include toxic chemical substances that are used as additives during the plastic manufacturing process and adsorbed contaminants that co-exist with MPs in aquatic environments. With the transfer between the water column and sediments, and the migration within aquatic systems, such contaminants associated MPs potentially pose high risk to aquatic systems. However, only limited research has been undertaken currently to link the environmental risk associated with MPs occurrence and movement behaviour in aquatic systems. Given the significant environmental risk and current knowledge gaps, this review focuses on the role played by the abundance of different MP species in water and sediment compartments as well as provides the context for assessing and quantifying the multiple risks associated with the occurrence and movement behaviour of different MP types. Based on the review of past literature, it is found that the physicochemical properties of MPs influence the release/sorption of other contaminants and current MPs transport modelling studies have primarily focused on virgin plastics rather than aged plastics. Additionally, risk assessment of contaminants-associated MPs needs significantly more research. This paper consolidates the current state-of-the art knowledge on the source to sink movement behaviour of MPs and methodologies for assessing the risk of different MP species. Moreover, knowledge gaps and emerging trends in the field are also identified for future research endeavours.
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    Risk assessment of electric vehicle supply chain in India using fuzzy analytical hierarchical process
    (Elsevier, 2025) Digalwar, Abhijeet K.
    The shift to electric vehicles (EVs) in India is a key step toward sustainable mobility as the transportation sector greatly contributes to greenhouse gas emissions. However, this transition demands a revised supply chain associated with various EV components such as batteries, motors, etc. Despite the ongoing efforts in the electrification of the transportation sector, numerous complexities and uncertainties in the EV supply chain have a bearing impact on its efficiency. The authors have conducted the research work to find out and rank the risk factors associated with the EV supply chain specific to India. A detailed literature review has been done and feedback from the industry stakeholders and academicians has been taken to identify the risk factors. The fuzzy analytical hierarchy process which is a multicriteria decision-making technique has been used to study the multidimensional effects of various decisions. The fuzzy analytical hierarchy process, a combined approach of analytical hierarchy process and fuzzy logic theory is effective in conducting risk assessment of a complex system that involves multiple uncertainties similar to the Indian EV supply chain.
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    Development of an automobile industry risk index
    (Inder Science, 2019-11) Sharma, Satyendra Kumar
    The aim of this research is to construct a Bayesian belief network (BBN) model, which encompasses all the risk factors relevant to the Indian automotive sector that can give a fair, empirical idea as to how much the risk factors drive down the gross turnover of the industry. The BBN model is used to gauge business, economic and external risks and evaluate its impact on gross turnover of the industry. Empirical model draws a lot of implications to streamline the risk effects in the industry, but it clearly shows that the three factors - business risks, economic risks and external risks are not entirely independent and are positively correlated with each other. Bayesian networks provide a very useful risk assessment tool that takes into account the advantages of both quantitative and qualitative risk assessment methods. This is a novel, empirical effort to provide a generalised model to integrate all risks - domestic, global, economic, legal - relevant to the automotive industry.