Environmental effect reference information

Sulfur species are found in ambient air in most parts of North America and in most industrial countries. Their sources include natural emissions (biogenic and volcanic), smelting of ores and other industrial refining processes, and combustion of sulfurbearing fuels. This paper will focus on the combustion sources in the United States and some of the effects of their sulfur emissions. The environmental effects of sulfur in the environment have been of interest for many years and much of the information presented here has been drawn from the various conference proceedings and assessment documents that have been published in recent years (1-11). When specific references are not listed in the text, the information represents a consensus from these various sources. 

To allow for comparison of the environmental effects of pesticides, various tools have been developed to express these effect(s) in quantifiable terms. One example is the Environmental Impact Quotient (EIQ) developed by Kovach and co-workers [19]. The aim of the EIQ is to transform information on the toxicological and environmental impacts of pesticides into a usable format to facilitate the choice which pesticide to apply in practice. For each pesticide, the EIQ value is based on an equation which brings together mode of action, environmental behavior, and toxicity to humans, animals, and wildlife. To calculate the environmental impact of fee application of a certain pesticide, its EIQ is multiplied with the application dose (applied amount of active ingredient). To date, EIQs are available for more than 200 pesticides, including chemical and organic pesticides (see website under reference [19]). 

Principle 3 defines an applicability domain that refers to the response and chemical structure space in which the model makes predictions with a given reliability. Ideally the applicability domain should express the structural, physicochemical, and response space of the model. The chemical structure space can be expressed by information on physicochemical properties and/or structural fragments. The response can be any physicochemical, biological, or environmental effect that is being predicted. 

The goal of LCA is to compare the fiill range of environmental effects assignable to products and services by quantifying all inputs and outputs of material flows and assessing how these material flows impact the environment. This information is used to improve processes, support policy and provide a sound basis for informed decisions. The term life cycle refers to the notion that a fair, holistic assessment requires the assessment of raw-material production, manufacture, distribution, use and disposal including all intervening transportation steps necessary or caused by the productis existence. 

Optical sensors offer some advantages over electrochemical methods [10, 11]. First, no reference electrode is required however, reference intensity is necessary to minimize environmental effects on the system. Second, fiberoptic sensors are immune to electrical noise, but ambient light can be a problem. Finally optical sensors have the potential for higher information content than electrical sensors because there is a complete spectrum of information available. However, the linearity is usually limited to a very narrow range. 

The already mentioned recent overviews of Barone and co-workers [541, 544] also contain information about recent computations of vibrationaUy resolved absorption spectra including environmental effects. Recent developments and applications of TD-DFT in combination with Car-Parrinello dynamics for the description of photochemical processes in complex systems were described by Moret et al. [116, 847] and Buda [848]. We have also already mentioned recent works of Bearpark, Robb et al. [50, 134-136] and Martinez and co-worker [103,131,133]. For recent applications concerning biologically oriented questions we again refer to the excellent review of Seim and Thiel [60] and some other works [702-704]. 

Acute and Chronic Toxicity. Although chromium displays nine oxidation states, the low oxidation state compounds, -II to I, all require Special conditions for existence and have very short lifetimes in a normal environment. This is also tme for most organ ochromium compounds, ie, compounds containing Cr—C bonds. Chromium compounds that exhibit stabiUty under the usual ambient conditions are limited to oxidation states II, III, IV, V, and VI. Only Cr(III) and Cr(VI) compounds are produced in large quantities and are accessible to most of the population. Therefore, the toxicology of chromium compounds has been historically limited to these two states, and virtually all of the available information is about compounds of Cr(III) and/or Cr(VI) (59,104). However, there is some indication that Cr(V) may play a role in chromium toxicity (59,105—107). Reference 104 provides an overview and summary of the environmental, biological, and medical effects of chromium and chromium compounds as of the late 1980s. 

The more difficult thing is to develop models that can, with reasonable confidence, be used to predict ecological effects. A detailed discussion of ecological approaches to risk assessment lies outside the scope of the present text. For further information, readers are referred to Suter (1993) Landis, Moore, and Norton (1998) and Peakall and Fairbrother (1998). One important question, already touched upon in this account, is to what extent biomarker assays can contribute to the risk assessment of environmental chemicals. The possible use of biomarkers for the assessment of chronic pollution and in regulatory toxicology is discussed by Handy, Galloway, and Depledge (2003). 

Human research issues affect all programs in US-EPA. In its Office of Research and Development, US-EPA conducts research with human subjects to provide critical information on environmental risks, exposures, and effects in humans. This is referred to as first-party research. In both its Office of Research and Development and its program offices (including the Office of Air and Radiation, the Office of Water, the Office of Solid Waste and Emergency Response, and the Office of Prevention, Pesticides and Toxic Substances), US-EPA also supports research with human subjects conducted by others. This is referred to as second-party research. In aU this work US-EPA is committed to full compliance with the common rule. The US-EPA will continue to conduct and support such research, and to consider and rely on its results in US-EPA assessments and decisions. 

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