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- Bolinius, Damien Johann, 1989-
(författare)
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Methods to measure mass transfer kinetics, partition ratios and atmospheric fluxes of organic chemicals in forest systems
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Vegetation plays an important role in the partitioning, transport and fate of hydrophobic organic contaminants (HOCs) in the environment. This thesis aimed at addressing two key knowledge gaps in our understanding of how plants exchange HOCs with the atmosphere: (1) To improve our understanding of the uptake of HOCs into, and transfer through, leaves of different plant species which can significantly influence the transport and fate of HOCs in the environment; and (2) To evaluate an experimental approach to measure fluxes of HOCs in the field. The methods presented in papers I, II and III contribute to increasing our understanding of the fate and transport of HOCs in leaves by offering straightforward ways of measuring mass transfer coefficients through leaves and partition ratios of HOCs between leaves, leaf lipids and lipid standards and reference materials like water, air and olive oil. The passive dosing study in paper III in particular investigated the role of the composition of the organic matter extracted from leaves in determining the capacity of the leaves to hold chemicals and found no large differences between 7 different plant species, even though literature data on leaf/air partition ratios (Kleaf/air) varies over 1-3 orders of magnitude. In paper IV we demonstrated that the modified Bowen ratio method can be extended to measure fluxes of persistent organic pollutants (POPs) if the fluxes do not change direction over the course of the sampling period and are large enough to be measured. This approach thus makes it possible to measure fluxes of POPs that usually require sampling times of days to weeks to exceed method detection limits. The experimental methods described in this thesis have the potential to support improved parameterization of multimedia models, which can then be evaluated against fluxes measured in the field using the modified Bowen ratio approach.
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| 2. |
- Cousins, Anna Palm, 1975-
(författare)
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Environmental fate of chemicals released from consumer products : Multimedia modelling strategies
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The objective of this thesis was to assess the environmental fate and transport of chemicals emitted from consumer products through the development and application of modelling tools. The following hypotheses were tested: i) Multimedia fate models can be applied in a multistage assessment process to emerging chemicals when limited knowledge exists to identify the likely environmental fate and to direct further research; ii) the indoor environment acts as a source of anthropogenic substances in consumer products to the outdoor environment; and iii) chemical removal pathways in the indoor environment are important for the fate of organic chemicals in densely populated areas.The thesis shows that a structured chemical fate assessment strategy can and should be applied at early stages of the evaluation of emerging chemicals to assess their fate and to direct further research. Multimedia fate models play a key role in this strategy. The three‐solubility approach is a simple, rapid method that can be used to estimate physical‐chemical properties for use in early stage evaluation (Paper I). Emissions in the indoor environment affect the urban fate of hydrophobic organic chemicals by providing additional removal pathways and prolonging urban chemical residence times compared to outdoor emissions (Paper III). Emissions of BDE 209, DINP and DEHP to Stockholm indoor air were estimated to be 0.1, 3.4 and 290 mg/capita year, respectively (Paper IV). The contribution of emissions indoors to outdoor air pollution varies between substances. For BDE 209, emissions in the indoor environment added 38 % to the mass entering Stockholm city with inflowing air. For Sweden, the indoor environment was estimated to account for 80 % of BDE 209 emissions to outdoor air (Papers II and IV). For the phthalates, outdoor emissions and/or background inflow are the dominant sources to outdoor air pollution in Stockholm and the influence of the indoor environment is limited (Paper IV).
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| 3. |
- Di Guardo, Antonio, et al.
(författare)
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Environmental fate and exposure models : advances and challenges in 21st century chemical risk assessment
- 2018
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Ingår i: Environmental Science. - : Royal Society of Chemistry (RSC). - 2050-7887 .- 2050-7895. ; 20:1, s. 58-71
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Forskningsöversikt (refereegranskat)abstract
- Environmental fate and exposure models are a powerful means to integrate information on chemicals, their partitioning and degradation behaviour, the environmental scenario and the emissions in order to compile a picture of chemical distribution and fluxes in the multimedia environment. A 1995 pioneering book, resulting from a series of workshops among model developers and users, reported the main advantages and identified needs for research in the field of multimedia fate models. Considerable efforts were devoted to their improvement in the past 25 years and many aspects were refined; notably the inclusion of nanomaterials among the modelled substances, the development of models at different spatial and temporal scales, the estimation of chemical properties and emission data, the incorporation of additional environmental media and processes, the integration of sensitivity and uncertainty analysis in the simulations. However, some challenging issues remain and require research efforts and attention: the need of methods to estimate partition coefficients for polar and ionizable chemical in the environment, a better description of bioavailability in different environments as well as the requirement of injecting more ecological realism in exposure predictions to account for the diversity of ecosystem structures and functions in risk assessment. Finally, to transfer new scientific developments into the realm of regulatory risk assessment, we propose the formation of expert groups that compare, discuss and recommend model modifications and updates and help develop practical tools for risk assessment. Environmental significance Multimedia environmental fate models are regularly employed in the risk assessment of chemicals. They historically evolved from simple approaches to more refined and integrated modeling tools, often provided as part of a tiered strategy. Much work has been devoted to improving various aspects at the process and environmental description levels, but some issues need further research and model development, such as the capability to properly simulate the behaviour of polar and ionizable chemicals in the environment, the biovailability of chemicals in aquatic and terrestrial environments, and variability in time and space to account for more ecological relevance. At the same time, it is important to avoid paralysis by analysis and develop practical tools for regulatory risk assessment that are fit for purpose. We propose the formation of expert groups to address this task.
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| 4. |
- Hader, John D., et al.
(författare)
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Enabling forecasts of environmental exposure to chemicals in European agriculture under global change
- 2022
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 840
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Forskningsöversikt (refereegranskat)abstract
- European agricultural development in the 21st century will be affected by a host of global changes, including climate change, changes in agricultural technologies and practices, and a shift towards a circular economy. The type and quantity of chemicals used, emitted, and cycled through agricultural systems in Europe will change, driven by shifts in the use patterns of pesticides, veterinary pharmaceuticals, reclaimed wastewater used for irrigation, and biosolids. Climate change will also impact the chemical persistence, fate, and transport processes that dictate environmental exposure. Here, we review the literature to identify research that will enable scenario-based forecasting of environmental exposures to organic chemicals in European agriculture under global change. Enabling exposure forecasts requires understanding current and possible future 1.) emissions, 2.) persistence and transformation, and 3.) fate and transport of agricultural chemicals. We discuss current knowledge in these three areas, the impact global change drivers may have on them, and we identify knowledge and data gaps that must be overcome to enable predictive scenario-based forecasts of environmental exposure under global change. Key research gaps identified are: improved understanding of relationships between global change and chemical emissions in agricultural settings; better understanding of environment-microbe interactions in the context of chemical degradation under future conditions; and better methods for downscaling climate change-driven intense precipitation events for chemical fate and transport modelling. We introduce a set of narrative Agricultural Chemical Exposure (ACE) scenarios — augmenting the IPCC's Shared Socio-economic Pathways (SSPs) — as a framework for forecasting chemical exposure in European agriculture. The proposed ACE scenarios cover a plausible range of optimistic to pessimistic 21st century development pathways. Filling the knowledge and data gaps identified within this study and using the ACE scenario approach for chemical exposure forecasting will support stakeholder planning and regulatory intervention strategies to ensure European agricultural practices develop in a sustainable manner.
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