| 1. |
- Diamond, Miriam, et al.
(author)
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Exploring the planetary boundary for chemical pollution
- 2015
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In: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 78, s. 8-15
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Research review (peer-reviewed)abstract
- Rockström et al. (2009a, 2009b) have warned that humanity must reduce anthropogenic impacts defined by nine planetary boundaries if “unacceptable global change” is to be avoided. Chemical pollution was identified as one of those boundaries for which continued impacts could erode the resilience of ecosystems and humanity. The central concept of the planetary boundary (or boundaries) for chemical pollution (PBCP or PBCPs) is that the Earth has a finite assimilative capacity for chemical pollution, which includes persistent, as well as readily degradable chemicals released at local to regional scales, which in aggregate threaten ecosystem and human viability. The PBCP allows humanity to explicitly address the increasingly global aspects of chemical pollution throughout a chemical's life cycle and the need for a global response of internationally coordinated control measures. We submit that sufficient evidence shows stresses on ecosystem and human health at local to global scales, suggesting that conditions are transgressing the safe operating space delimited by a PBCP. As such, current local to global pollution control measures are insufficient. However, while the PBCP is an important conceptual step forward, at this point single or multiple PBCPs are challenging to operationalize due to the extremely large number of commercial chemicals or mixtures of chemicals that cause myriad adverse effects to innumerable species and ecosystems, and the complex linkages between emissions, environmental concentrations, exposures and adverse effects. As well, the normative nature of a PBCP presents challenges of negotiating pollution limits amongst societal groups with differing viewpoints. Thus, a combination of approaches is recommended as follows: develop indicators of chemical pollution, for both control and response variables, that will aid in quantifying a PBCP(s) and gauging progress towards reducing chemical pollution; develop new technologies and technical and social approaches to mitigate global chemical pollution that emphasize a preventative approach; coordinate pollution control and sustainability efforts; and facilitate implementation of multiple (and potentially decentralized) control efforts involving scientists, civil society, government, non-governmental organizations and international bodies.
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| 2. |
- Backhaus, Thomas, 1967, et al.
(author)
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Joint algal toxicity of phenylurea herbicides is equally predictable by concentration addition and independent action.
- 2004
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In: Environmental toxicology and chemistry / SETAC. - 0730-7268. ; 23:2, s. 258-64
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Journal article (peer-reviewed)abstract
- Photosynthesis-inhibiting phenylurea derivatives, such as diuron, are widely used as herbicides. Diuron concentrations clearly exceeding the predicted-no-effect concentration have been regularly measured in European freshwater systems. The frequently observed exposure to mixtures of phenylureas additionally increases the hazard to aquatic primary producers. Fluctuating numbers and concentrations of individual toxicants make experimental testing of every potential mixture unfeasible. Thus, predictive approaches to the mixture hazard assessment are needed. For this purpose, two concepts are at hand, both of which make use of known toxicities of the individual components but are based on opposite mechanistic suppositions: Concentration addition is based on the idea of similar mechanisms of action, whereas independent action assumes dissimilarly acting mixture components. On the basis of pharmacological reasoning, it was therefore anticipated that the joint algal toxicity of phenylurea mixtures would be predictable by concentration addition. Indeed, we could demonstrate a high predictive power of concentration addition for these combinations. Surprisingly, however, the opposite concept of independent action proved to be equally valid, because both concepts predicted virtually identical mixture toxicities. This exceptional case has previously been derived from theoretical considerations. Now, the tested phenylurea mixtures serve as an example for the practical relevance of this situation for multicomponent mixtures.
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| 3. |
- Scheringer, Martin, et al.
(author)
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Planetary boundaries for chemical pollution
- 2012
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In: Dioxin 2012 - 32nd International Symposium on Halogenated Persistent Organic Compounds.
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Conference paper (peer-reviewed)abstract
- Based on the concept by Rockström et al the paper discusses the principles of the concept in relation to chemical pollution and the specific challenges associated to that. The paper conclude the chemical pollution is certainly a strong anthropogenic impact of global relevance. However, because of the local or regional nature of many exposures and effects caused by chemicals, there is probably not a single tipping point for the global system that would have to be reflected by a planetary boundary. Therefore, in order to assess and manage chemical pollution, it seems to be more promising to focus on certain classes of chemicals separately and to derive boundaries of different types for these classes of chemicals, as illustrated in the paper for CFCs, POPs and food contaminants.
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