Olwenn Martin | Brunel University (original) (raw)
Papers by Olwenn Martin
Environment International, 2015
Systematic review (SR) is a rigorous, protocol-driven approach designed to minimise error and bia... more Systematic review (SR) is a rigorous, protocol-driven approach designed to minimise error and bias when summarising the body of research evidence relevant to a specific scientific question. Taking as a comparator the use of SR in synthesising research in healthcare, we argue that SR methods could also pave the way for a "step change" in the transparency, objectivity and communication of chemical risk assessments (CRA) in Europe and elsewhere. We suggest that current controversies around the safety of certain chemicals are partly due to limitations in current CRA procedures which have contributed to ambiguity about the health risks posed by these substances. We present an overview of how SR methods can be applied to the assessment of risks from chemicals, and indicate how challenges in adapting SR methods from healthcare research to the CRA context might be overcome. Regarding the latter, we report the outcomes from a workshop exploring how to increase uptake of SR methods, attended by experts representing a wide range of fields related to chemical toxicology, risk analysis and SR. Priorities which were identified include: the conduct of CRA-focused prototype SRs; the development of a recognised standard of reporting and conduct for SRs in toxicology and CRA; and establishing a network to facilitate research, communication and training in SR methods. We see this paper as a milestone in the creation of a research climate that fosters communication between experts in CRA and SR and facilitates wider uptake of SR methods into CRA.
The Science of the total environment, Jan 10, 2015
Current chemicals regulation operates almost exclusively on a chemical-by-chemical basis, however... more Current chemicals regulation operates almost exclusively on a chemical-by-chemical basis, however there is concern that this approach may not be sufficiently protective if two or more chemicals have the same toxic effect. Humans are indisputably exposed to more than one chemical at a time, for example to the multiple chemicals found in food, air and drinking water, and in household and consumer products, and in cosmetics. Assessment of cumulative risk to human health and/or the environment from multiple chemicals and routes can be done in a mixture risk assessment (MRA). Whilst there is a broad consensus on the basic science of mixture toxicology, the path to regulatory implementation of MRA within chemical risk assessment is less clear. In this discussion piece we pose an open question: should the scope of human MRA cross legislative remits or 'silos'? We define silos as, for instance, legislation that defines risk assessment practice for a subset of chemicals, usually on t...
A Risk Based Approach, 2011
A Risk Based Approach, 2011
Critical Reviews in Environmental Science and Technology
Metals are of particular importance in relation to water quality, and concern regarding the impac... more Metals are of particular importance in relation to water quality, and concern regarding the impact of these contaminants on biodiversity is being encapsulated within the latest water-related legislation such as the Water Framework Directive in Europe and criteria revisions to the Clean Water Act in the United States. This review undertakes an evaluation of the potential of 2-stage wastewater treatment consisting of primary sedimentation and biological treatment in the form of activated sludge processes, to meet more stringent discharge consents that are likely to be introduced as a consequence. The legislation, sources of metals, and mechanisms responsible for their removal are discussed, to elucidate possible pathways by which the performance of conventional processes may be optimized or enhanced. Improvements in effluent quality, achievable by reducing concentrations of suspended solids or biochemical oxygen demand, may also reduce metal concentrations although meeting possible re...
Environmental health : a global access science source, 2013
Assessing the detrimental health effects of chemicals requires the extrapolation of experimental ... more Assessing the detrimental health effects of chemicals requires the extrapolation of experimental data in animals to human populations. This is achieved by applying a default uncertainty factor of 100 to doses not found to be associated with observable effects in laboratory animals. It is commonly assumed that the toxicokinetic and toxicodynamic sub-components of this default uncertainty factor represent worst-case scenarios and that the multiplication of those components yields conservative estimates of safe levels for humans. It is sometimes claimed that this conservatism also offers adequate protection from mixture effects. By analysing the evolution of uncertainty factors from a historical perspective, we expose that the default factor and its sub-components are intended to represent adequate rather than worst-case scenarios. The intention of using assessment factors for mixture effects was abandoned thirty years ago. It is also often ignored that the conservatism (or otherwise) ...
Toxicological sciences : an official journal of the Society of Toxicology, 2007
Endocrine disruption remains one of the most controversial contemporary environmental issues. Whi... more Endocrine disruption remains one of the most controversial contemporary environmental issues. While the desired level of protection is ultimately a societal choice, endocrine toxicity could result in a wide spectrum of adverse health effects. Although the application of the causal framework of weight-of-evidence approaches to complex toxicological issues has incited much interest, no international criteria or guidance have yet been developed. In this context, the evidence on end point-specific risks to human health contained in the International Program on Chemical Safety Global assessment of the State-of-Science on Endocrine Disruptors report was updated and assessed qualitatively using three simple criteria relevant to the practical application of the precautionary principle (PP): incidence trends, association, and consequence. The current degree of knowledge was then ranked according to ignorance, uncertainty, and risk. The main sources of scientific uncertainty in relation to in...
Ciência & Saúde Coletiva, 2008
Environmental Health Perspectives, 2008
Toxicological Sciences, 2007
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2009
Environmental Science & Technology, 2005
Environmental Pollution, 2010
Environmental Health Perspectives, 2007
Environment International, 2015
Systematic review (SR) is a rigorous, protocol-driven approach designed to minimise error and bia... more Systematic review (SR) is a rigorous, protocol-driven approach designed to minimise error and bias when summarising the body of research evidence relevant to a specific scientific question. Taking as a comparator the use of SR in synthesising research in healthcare, we argue that SR methods could also pave the way for a "step change" in the transparency, objectivity and communication of chemical risk assessments (CRA) in Europe and elsewhere. We suggest that current controversies around the safety of certain chemicals are partly due to limitations in current CRA procedures which have contributed to ambiguity about the health risks posed by these substances. We present an overview of how SR methods can be applied to the assessment of risks from chemicals, and indicate how challenges in adapting SR methods from healthcare research to the CRA context might be overcome. Regarding the latter, we report the outcomes from a workshop exploring how to increase uptake of SR methods, attended by experts representing a wide range of fields related to chemical toxicology, risk analysis and SR. Priorities which were identified include: the conduct of CRA-focused prototype SRs; the development of a recognised standard of reporting and conduct for SRs in toxicology and CRA; and establishing a network to facilitate research, communication and training in SR methods. We see this paper as a milestone in the creation of a research climate that fosters communication between experts in CRA and SR and facilitates wider uptake of SR methods into CRA.
The Science of the total environment, Jan 10, 2015
Current chemicals regulation operates almost exclusively on a chemical-by-chemical basis, however... more Current chemicals regulation operates almost exclusively on a chemical-by-chemical basis, however there is concern that this approach may not be sufficiently protective if two or more chemicals have the same toxic effect. Humans are indisputably exposed to more than one chemical at a time, for example to the multiple chemicals found in food, air and drinking water, and in household and consumer products, and in cosmetics. Assessment of cumulative risk to human health and/or the environment from multiple chemicals and routes can be done in a mixture risk assessment (MRA). Whilst there is a broad consensus on the basic science of mixture toxicology, the path to regulatory implementation of MRA within chemical risk assessment is less clear. In this discussion piece we pose an open question: should the scope of human MRA cross legislative remits or 'silos'? We define silos as, for instance, legislation that defines risk assessment practice for a subset of chemicals, usually on t...
A Risk Based Approach, 2011
A Risk Based Approach, 2011
Critical Reviews in Environmental Science and Technology
Metals are of particular importance in relation to water quality, and concern regarding the impac... more Metals are of particular importance in relation to water quality, and concern regarding the impact of these contaminants on biodiversity is being encapsulated within the latest water-related legislation such as the Water Framework Directive in Europe and criteria revisions to the Clean Water Act in the United States. This review undertakes an evaluation of the potential of 2-stage wastewater treatment consisting of primary sedimentation and biological treatment in the form of activated sludge processes, to meet more stringent discharge consents that are likely to be introduced as a consequence. The legislation, sources of metals, and mechanisms responsible for their removal are discussed, to elucidate possible pathways by which the performance of conventional processes may be optimized or enhanced. Improvements in effluent quality, achievable by reducing concentrations of suspended solids or biochemical oxygen demand, may also reduce metal concentrations although meeting possible re...
Environmental health : a global access science source, 2013
Assessing the detrimental health effects of chemicals requires the extrapolation of experimental ... more Assessing the detrimental health effects of chemicals requires the extrapolation of experimental data in animals to human populations. This is achieved by applying a default uncertainty factor of 100 to doses not found to be associated with observable effects in laboratory animals. It is commonly assumed that the toxicokinetic and toxicodynamic sub-components of this default uncertainty factor represent worst-case scenarios and that the multiplication of those components yields conservative estimates of safe levels for humans. It is sometimes claimed that this conservatism also offers adequate protection from mixture effects. By analysing the evolution of uncertainty factors from a historical perspective, we expose that the default factor and its sub-components are intended to represent adequate rather than worst-case scenarios. The intention of using assessment factors for mixture effects was abandoned thirty years ago. It is also often ignored that the conservatism (or otherwise) ...
Toxicological sciences : an official journal of the Society of Toxicology, 2007
Endocrine disruption remains one of the most controversial contemporary environmental issues. Whi... more Endocrine disruption remains one of the most controversial contemporary environmental issues. While the desired level of protection is ultimately a societal choice, endocrine toxicity could result in a wide spectrum of adverse health effects. Although the application of the causal framework of weight-of-evidence approaches to complex toxicological issues has incited much interest, no international criteria or guidance have yet been developed. In this context, the evidence on end point-specific risks to human health contained in the International Program on Chemical Safety Global assessment of the State-of-Science on Endocrine Disruptors report was updated and assessed qualitatively using three simple criteria relevant to the practical application of the precautionary principle (PP): incidence trends, association, and consequence. The current degree of knowledge was then ranked according to ignorance, uncertainty, and risk. The main sources of scientific uncertainty in relation to in...
Ciência & Saúde Coletiva, 2008
Environmental Health Perspectives, 2008
Toxicological Sciences, 2007
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 2009
Environmental Science & Technology, 2005
Environmental Pollution, 2010
Environmental Health Perspectives, 2007