Toxicant impact

M. H. Depledge, in Toxic Impacts of Wastes on the Aquatic Environment, ed. J. F. Tapp, S. M. Flunt... 

Tapp, J. et al. (ed.) (1996) Toxic Impact of Wastes on the Aquatic Environment, Royal Society of Chemistry, London. 

The comprehensive and detailed assessment of the risks required for a safety-case can only be satisfactorily carried out for major installations with the aid of computer software. Suites of programmes for quantitative risk analysis have been developed over the past decade by consulting firms specializing in safety and environmental protection. Typical of the software available is the SAFETI (Suite for Assessment of Flammability Explosion and Toxic Impact) suite of programs developed by DNV Technica Ltd. These programs were initially developed for the authorities in the Netherlands, as a response to the Seveso Directives of the EU (which requires the development of safety cases and hazard reviews). The programs have subsequently been developed further and extended, and are widely used in the preparation of safety cases see Pitblado el al. (1990). 

ETO and degradation product toxicity Impact on seal integrity... 

Fedorov L.A., Yablokov, A. V. Pestitsidy - toksicheskiy udar po biosfere i cheloveku (Pesticides The Toxic Impact on the Biosphere and Humans) Moscow Nauka, 1999. 462 pp. 

Anyway, one of the recent and most comprehensive LCA studies on printed matter [22, 24] focus on the importance of chemical emissions as compared to emissions related to energy, and actually include toxic impacts from chemical emissions like printing ink, of which some components may accumulate in recycled paper. 

Impact categories (model outputs) eco-toxicity impacts and/or human toxicity impact... 

USEtox calculates characterization factors for human toxicity and freshwater ecotoxicity. Assessing the toxicological effects of a chemical emitted into the environment implies a cause-effect chain that links emissions to impacts through three steps environmental fate, exposure, and effects. Linking these steps, a systematic framework for toxic impacts modeling based on matrix algebra was developed to some extent within the OMNIITOX project [10]. USEtox covers two spatial scales, the continental and the global scales. 

As is evident from Fig. 3, paper production contributes significantly (about 30% of total) to the impact profile but is not at all dominating like in former studies (60-80% of total) focusing on energy consumption and only including chemicals and potential toxic impacts to a limited degree. If the toxicity-related impact categories are excluded in this case study, the contribution from paper is increased to 67% of total, which is at the level of the former studies. 

Known emissions from the production stage, which are not covered by characterisation factors and which may contribute significantly to the toxicity impact categories, include emissions of components occurring in small quantities in the raw materials (typically well below 5%) like siccatives (organic metal compounds), softeners (phthalates), antioxidants (aromatics) and wetteners (surfactants). Due to lack of readily available knowledge of their exact identity and/or lack of readily available data on their inherent environmental properties, it has not been possible to include them in the case study. 

Fig. 5 Normalized human toxicity impact scores of the use of 1 m2 cushion vinyl floor covering, broken down into Life Cycle stages...

In the results the emissions of mercury appear to have a very substantial contribution for the human toxicity impact score. These emissions are caused by the coproduction of chlorine and sodium hydroxide by electrolysis using a mercury cell. However, this technique is phased out. Therefore, the process descriptions in the Ecoinvent database do not represent up to date technology. In the Ecoinvent database the process for PVC production, in which chlorine is used as one of the compounds, is an aggregated processes based on, seemingly outdated, data from PlasticsEurope. These outdated data also influence the impacts related to waste treatment by incineration because sodium hydroxide is necessary for the waste incineration process. 

In the LCIA community there is much discussion on the characterization of heavy metals for toxicity. Due to large residence times in the environment, the characterization factors for heavy metals tend to dominate the impact scores for toxicity impact categories. This might suppress the impacts of other relevant toxic substances, like DEHP. For this reason the results are calculated using the characterization factors derived by the Usetox model instead of the Uses model. Uses model is the original baseline characterization model that is recommended in the Dutch LCA Handbook [1]. 

So from the point of view of additives, it seems that they may indeed contribute significantly to life cycle impacts. The case study of PVC flooring shows that additives contribute significantly, not just to toxicity impact due to DEHP emissions but also to global warming due to GHG emissions along the Cradle-to-Grave chain of the compound DEHP. 

To identify the key toxicants impacting marine and freshwater ecosystems on a site and basin scale as a crucial basis for scientifically sound risk assessment and decision support on risk management, remedial action strategies and preventive policies for the mitigation of harmful effects. 

To provide a better understanding of toxic impacts on aquatic ecosystems, cause-effect relationships between changes in biodiversity and the impact of environmental pollution as causative factor as well as the underlying processes. This included the assessment of sub-lethal effects in vitro and in vivo as early warning strategies and of their strength to predict potential hazards to the ecosystem. 

Radhaiah, V. and S.V.K. Reddy. 1989. Toxic impact of fenvalerate on superoxide dismutase and catalase activity levels in liver, muscle and gill tissues of a freshwater fish, Tilapia mossambica (Peters). Biochem. Inter. 18 655-660. 

Reddy, P.M. and M. Bashamohideen. 1988. Toxic impact of fenvalerate on the protein metabolism in the branchial tissue of a fish, Cyprinus carpio. Current Sci. 57 211-212. 

ALLEVIATION OF TOXIC IMPACT OF CHEMICAL AGENTS ON HUMAN ORGANISM... 

Landis WG, Matthews RA (1993) Development of pattern recognition techniques for the evaluation of toxicant impacts to multispecies systems. Government Reports Announcements Index (GRA I) Issue 21 NTIS/AD-A267 197/2, p 255... 

Knowing the identity of the chemicals being handled and understanding their properties is imperative in the safe handling and siting of materials. Without knowing what the chemical is, the risks of fire, explosion, and toxic impact cannot be considered. 

Significant parameters to be considered in designing a treatment and disposal facility for pharmaceutical wastewater are given in Table 12. Biochemical oxygen demand measurements of the waste have been reported to increase greatly with dilution, indicating the presence of toxic or inhibitory substances in some pharmaceutical effluents. The toxicity impact upon various biological treatments by various antibiotics, bactericidal-type compounds, and other pharmaceuticals has been described in the literature [21-24]. 

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