Potential environmental effects

The normal measures of acute toxicity which are used for classification and initial risk assessment are  

The 72 hour IC50 (concentration which inhibits growth or growth rate of an alga by 50% during 72 hours exposure). 

The 48 hour EC50 (concentration which immobilises 50% of Daphnia during 48 hours exposure). 

The 96 hour LC50 (concentration which kills 50% of fish during 96 hours exposure). 

If a substance biodegrades in an aquatic environment, further information is needed on whether the substance has degraded to innocuous molecules or to relatively persistent and toxic derivatives. 

---

Radium, thorium, and other radionuclides accumulate in uranium mill tailings. The potential environmental effects of these radionuclides has become of increasing concern to the public. In the future, it may be necessary to modify existing uranium recovery processes to accommodate removal of radium and perhaps other radioactive decay products of uranium. 

These large mass flows are, themselves, the source of environmental problems. To describe the plant simply in terms of its production capacity of 300,000 tons/day is an over simplification. In any such process there will be other process flows which, in some instances may amount to much more than the simple product flow. The amounts of trace materials, even at a few p.p.m. in concentration, which can accumulate or which may have to be released amount, in times of months or years, to large quantities. We are concerned about the potential environmental effects of these trace materials. In spite of this concern, however, we have little hard knowledge of these effects, in part because we know so little about the chemistry of small amounts of trace elements and compounds in large amounts of water or air. If we then are going to come to rational terms with the environment, knowing what can be safely released and what cannot, we have to know a lot more about chemistry or trace concentrations. 

Kleter, G.A., Harris, C.A., Stephenson, G.R. and Unsworth, J. (2008) Comparison of herbicide regimes and the associated potential environmental effects of glyphosate-resistant crops vs. what they replace in Europe. Pestic Manage Sci, 64, 479-488. 

Plume Behavior and Potential Environmental Effects of Large Dry Cooling Towers... 

The magnitude of the heat rejection of large modern power generating plants is so great that the problem of potential environmental effects due to dry cooling systems must be studied. The plumes from both natural-draft and mechanical-draft towers designed for 1000-MW plants of several representative types are examined with respect to... 

Names of toxicologically synergistic products Potential environmental effects... 

An analysis of potential environmental effects related to energy use and material resources and environmental releases... 

Under the agreements of the Montreal Protocol on Substances that Deplete the Ozone Layer, the production of chlorofluorocarbons (CFCs), halons and several other halocarbons has been prohibited [1,2]. Consequently, there is an interest in replacing these compounds [3]. As part of the development of such replacing compounds, it is necessary to consider and evaluate the potential environmental effects of their use, especially on stratospheric ozone [2],... 

Environmental and health effects of radionuclides are summarized by Siegel and Bryan, (see Chapter 9.06). Potential environmental effects of hydrocarbons and organic chemicals are addressed in other chapters, and will not be discussed here. Environmental and health effects of arsenic, selenium, and mercury are addressed in greater detail elsewhere in this volume, including Chapters 9.02 and 9.04. Further information on the environmental geochemistry of metals is presented by Callender (see Chapter 9.03). 

Calculated CGR versus ECP correlations for ECLs ranging from 0.1 to 50 cm and for a stress intensity factor of 27 MPa.m1/2 and for the other, constant conditions, as stated in the figure, are shown in Fig. 13. In the low potential limit, no ECP dependence of the CGR is noted, because crack extension occurs only because of creep. At higher potentials, environmental effects become dominant such that, at sufficiently high potentials, the CGR increases in a... 

Toxicity testing has been a contentious issue. Its opponents argue that toxicity tests are complex, expensive and imprecise. In spite of these arguments, as standardized toxicity tests are developed and their interpretation and regulatory applications are refined, it is clear that toxicity tests will become powerful instruments for pollution monitoring and control. They measure directly the potential environmental effects of complex mixtures and provide information that cannot be obtained by any other means. 

It seems reasonable then, when considering the potential environmental effects that engineered organisms could have when released into the air, water and soil, that environmental science and environmental protection be the paramount consideration in any regulatory scheme. But that is not the case with the present regulatory framework. 

Berkowitz JB, Goyer MM, Harris JC et al. (1978). Literature Review - Problem Definition Studies on Selected Chemicals. Final Report. Vol. II. Chemistry, Toxicology and Potential Environmental Effects of Selected Organic Pollutants. AD B052964. Fort Detrick, MD US Army Medical Bioengineering Research and Development Laboratory. 

The reaction to the presence of pesticides in groundwater is also influenced by a multiplicity of factors. In addition to the potential toxicity of the materials or their potential environmental effects, emotional factors seem to contribute to the negative response. 

Some people are also very concerned about the potential environmental effects of aquaculture operations. A USDA advisory committee on aquatic biotechnology and environmental safety recently drew up a set of performance standards and logic flowcharts for safely conducting research with genetically modified fish and shellfish (ABRAC). This effort was especially noteworthy because it enjoyed the collective support of the aquatic research community, private industry, environmental interest groups, and state natural resource officials. 

Tury et al. (2003) have investigated the atmospheric fate and potential environmental effects of TDI and diphenylmethane-4,4 -diisocyanate MDl. TDI degrades in the atmosphere by oxidation by -OH radicals with an estimated half-life of one day. The compound does not react with water in the gas phase at a significant rate. Typical emission losses are 25 g/t of TDI used in making slabstock foam. 

Tury, B., D. Pemberton, and R. E. Bailey. 2003. Fate and potential environmental effects of methylenediphenyl diisocyanate and toluene diisocyanate released into the atmosphere. J. Air Waste Manag. Assoc. 55(1) 61-66. 

Greene JC (1996) A protocol for testing the potential environmental effect of solutions eluted from highway construction and repair Materials. Interim Report, NCHRP Project 25-9, Department of Civil, Construction, and Environmental Engineering, Oregon State University, Corvallis, OR... 

During the stage of life cycle impact assessment, results generated in a life cyde inventory are condensed and assigned to potential environmental effects. The aim is... 

Provide the public with the information necessary to enable them to understand the potential environmental effects of the companies operations and be prepared to respond positively to expressions of public concern... 

Report on the Assessment of Potential Environmental Effects of Chemicals -The Effects on Organisms other than Man and on Ecosystems, Organisation for Economic Co-operation and Development, Paris, France, 1980. 

An LCA study completes with the interpretation phase, where the overall process is evaluated, the results obtained from previously completed phases (i.e., LCI and LCIA) are reported, and overall conclusions and recommendations are drawn and made, respectively. According to ISO 14040 (ISO, 2006a,b), the interpretation shall clarify that the results of the LCIA indicate potential environmental effects, but they do not predict actual impact on specific impact categories. 

---