Biodegradation aspects of Polycyclic Aromatic Hydrocarbons (PAHs): A review

 Many atmospheric chemicals occur in the gas phase as well as in liquid cloud droplets and aerosol particles Therefore, it is necessary to understand the distribution between the phases According to Henry's law, the equilibrium ratio between the abundances in the gas phase and in the aqueous phase is constant for a dilute solution Henry's law constants of trace gases of potential importance in environmental chemistry have been collected and converted into a uniform format The compilation contains 17 350 values of Henry's law constants for 4632 species, collected from 689 references It is also available at http://wwwhenrys-laworg 

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Compilation of Henry's law constants (version 4.0) for water as solvent

In 2005, a comprehensive comparison of life cycle impact assessment toxicity characterisation models was initiated by the United Nations Environment Program (UNEP)–Society for Environmental Toxicology and Chemistry (SETAC) Life Cycle Initiative, directly involving the model developers of CalTOX, IMPACT 2002, USES-LCA, BETR, EDIP, WATSON and EcoSense. In this paper, we describe this model comparison process and its results—in particular the scientific consensus model developed by the model developers. The main objectives of this effort were (1) to identify specific sources of differences between the models’ results and structure, (2) to detect the indispensable model components and (3) to build a scientific consensus model from them, representing recommended practice. A chemical test set of 45 organics covering a wide range of property combinations was selected for this purpose. All models used this set. In three workshops, the model comparison participants identified key fate, exposure and effect issues via comparison of the final characterisation factors and selected intermediate outputs for fate, human exposure and toxic effects for the test set applied to all models. Through this process, we were able to reduce inter-model variation from an initial range of up to 13 orders of magnitude down to no more than two orders of magnitude for any substance. This led to the development of USEtox, a scientific consensus model that contains only the most influential model elements. These were, for example, process formulations accounting for intermittent rain, defining a closed or open system environment or nesting an urban box in a continental box. The precision of the new characterisation factors (CFs) is within a factor of 100–1,000 for human health and 10–100 for freshwater ecotoxicity of all other models compared to 12 orders of magnitude variation between the CFs of each model, respectively. The achieved reduction of inter-model variability by up to 11 orders of magnitude is a significant improvement. USEtox provides a parsimonious and transparent tool for human health and ecosystem CF estimates. Based on a referenced database, it has now been used to calculate CFs for several thousand substances and forms the basis of the recommendations from UNEP-SETAC’s Life Cycle Initiative regarding characterisation of toxic impacts in life cycle assessment. We provide both recommended and interim (not recommended and to be used with caution) characterisation factors for human health and freshwater ecotoxicity impacts. After a process of consensus building among stakeholders on a broad scale as well as several improvements regarding a wider and easier applicability of the model, USEtox will become available to practitioners for the calculation of further CFs.

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USEtox—the UNEP-SETAC toxicity model: recommended characterisation factors for human toxicity and freshwater ecotoxicity in life cycle impact assessment

Persistent organic pollutants (POPs): state of the science.

Glyphosate-based weed control products are among the most widely used broad-spectrum herbicides in the world. The herbicidal properties of glyphosate were discovered in 1970, and commercial formulations for nonselective weed control were first introduced in 1974 (Franz et al. 1997). Formulations of glyphosate, including Roundup® Herbicide (RU)1 (Monsanto Company, St. Louis, MO), have been extensively investigated for their potential to produce adverse effects in nontarget organisms. Governmental regulatory agencies, international organizations, and others have reviewed and assessed the available scientific data for glyphosate formulations and independently judged their safety. Conclusions from three major organizations are publicly available and indicate RU can be used with minimal risk to the environment (Agriculture Canada 1991; USEPA 1993a; WHO 1994). Several review publications are available on the fate and effects of RU or glyphosate in the environment (Carlisle and Trevors 1988;Smith and Oehme 1992 ; Malik et al. 1989;Rueppel et al. 1977; Sullivan and Sullivan 1997;Forestry Canada, 1989). In addition, several books have been published about the environmental and human health considerations of glyphosate and its formulations (Grossbard and Atkinson 1985; Franz et al. 1997). In addition, RU and other glyphosate formulations have been selected for use in a number of weed control programs for state and local jurisdictions in the United States. Many of these uses require that ecological risk assessments be conducted in the form of Environmental Impact Statements or Environmental Assessments. These documents are comprehensive and specific to local use situations. Documents are available for risk assessments in Texas, Washington, Oregon, Pennsylvania, New York, Virginia, and other states (USDA 1989;USDA 1992;USDA 1996;USDA 1997;USDI 1989; Washington State DOT 1993).

Ecotoxicological Risk Assessment for Roundup ® Herbicide

Illustrated handbook of physical-chemical properties and environmental fate for organic chemicals

Polynuclear Aromatic Hydrocarbons (PAHs): Chlorinated Dibenzo-p-Dioxins: Chlorinated Dibenzofurans. List of Symbols and Abbreviations. Appendices.

Polynuclear aromatic hydrocarbons, polychlorinated dioxins, and dibenzofurans

Preface. INTRODUCTION. The Incentive. Physical-Chemical Properties. Quantitative Structure Property Relationships (QSPRs). Fate Models. Data Sources and Presentations. MONOAROMATIC HYDROCARBONS. List of Chemicals and Data Compilations. Summary Tables and QSPR Plots. Illustrative Fugacity Calculations: Level I, II, and III. Commentary on the Physical-Chemical Properties and Environmental Fate. CHLOROBENZENES. List of Chemicals and Data Compilations. Summary Tables and QSPR Plots. Illustrative Fugacity Calculations: Level I, II, and III. Commentary on the Physical-Chemical Properties and Environmental Fate. POLYCHLORINATED BIPHENYLS (PCBs). List of Chemicals and Data Compilations. Summary Tables and QSPR Plots. Illustrative Fugacity Calculations: Level I, II, and III. Commentary on the Physical-Chemical Properties and Environmental Fate. List of Symbols and Abbreviations. Appendices. List of BASIC Program for Fugacity Calculations. List of Spreadsheet Program for Lotus 123* Calculations.

Monoaromatic hydrocarbons, chlorobenzenes and PCBs

This comprehensive series focuses on environmental fate prediction and quantitative structure activity relationship analysis.

Mackay, Donald, Ph. D.

Papers

Illustrated handbook of physical-chemical properties and environmental fate for organic chemicals

Polynuclear aromatic hydrocarbons, polychlorinated dioxins, and dibenzofurans

Monoaromatic hydrocarbons, chlorobenzenes and PCBs

Volatile organic chemicals

Nitrogen and sulfur containing compounds and pesticides