Pesticides environmental problems

The above analysis is somewhat oversimplified and is considered an Incomplete assessment of the existing environmental problems caused by pesticides. Again, it must be emphasized that there is no completely satisfactory way to summarize all of the environmental and social costs in terms of dollars. For example, it is impossible, if not unethical to place a monetary value on human lives either lost, diseased, or disabled because of pesticide use. It is equally difficult to place a monetary value on total wildlife losses. Good health, and Indeed life itself have no price tag. 

Change the environment. We are used to solving environmental problems by relatively simple interventions adding fertilisers, pesticides and water. However, it is much more difficult to remove an excess than it is to supplement a deficiency. A technological solution to the salinity problem has many possibilities but all are costly. In the case of staple foods then either their market value (commercial) or the resources of their consumers (subsistence) precludes such a solution. 

Attempts have been made to apply the structure-activity concept (Hansch and Leo 1995) to environmental problems, and this has been successfully applied to the rates of hydrolysis of carbamate pesticides (Wolfe et al. 1978), and of esters of chlorinated carboxylic acids (Paris et al. 1984). This has been extended to correlating rates of biotransformation with the structure of the substrates and has been illustrated with a number of single-stage reactions. Clearly, this approach can be refined with the increased understanding of the structure and function of the relevant degradative enzymes. Some examples illustrate the application of this procedure ... 

The scientific community is indebted to Alexey Yablokov and Lev Fedorov for carefully examining the pesticide impact on public health and the environment. Their studies add to our knowledge and their results suggest ways that public health and environmental pesticide related problems could be avoided. Given the food security needs of the rapidly expanding world human population, a safe and a productive agriculture are vital for the future. 

The usual method for disposing of pesticides in the USSR was walling them into spent quarries and mine shafts. For example, more than 3000 tons of pesticides were walled into unfitted vertical boreholes in the Krasnodar Krai. The complete destruction of pesticides has become a large environmental problem, comparable in scale to the problem of destroying chemical weapons stocks. About 40,000 tons of unused pesticides (banned or too old to be used) had accumulated in the countries of the former Soviet Union, about half of which are located in Russia. 

The threat of pesticides impact on the environment in Russia and other CIS countries has not diminished because they were used less in the 1990s. The long-term influence of pesticides on the soil not only has not decreased, but has become more apparent. Until recently, OCP soil contamination, significantly exceeding MPC, has been observed in the Krasnodar Krai, in the Republics of Central Asia, Moldova, Kazakhstan, in Ukraine, and in other regions [35]. DDT and its metabolites cause the most significant environmental problems, especially where perennial and industrial crops are grown. 

The publication of Silent Spring (authored by Rachel Carson), which outlined many environmental problems associated with chlorinated pesticides, caused a ban on the use of DDT in 1972. 

Although this chapter concentrates on environmental problems associated with metals, the discharge of organic compounds is also subjected to stringent limits. The compounds that cause most concern are pesticides, herbicides, phenols, biphenyls, polychlorinated hydrocarbons (PCBs), and polyaromatic hydrocarbons (PAHs). 

In general most of the pesticide residues are immobilized on soil particles, although in some cases, such as alachlor, atra-zine, benomyl, diphenamid, EPTC, naptalam and propachlor, significant amounts were found in the liquid phase. This presence in the liquid phase, which is primarily aqueous, can cause environmental problems if the liquid contents are lost due to leakage. 

Partitioning in Pesticide Mode of Action and Environmental Problems... 

QSAR are useful In the design of pesticides and medicinal drugs, and In environmental problems such as the prediction of toxicity and blodegradablllty. An empirical relationship can be properly used only for Interpolation whereas one based solidly on well-established theory can be used at least to some extent for extrapolation as well. It seems of real Importance, then, to determine the nature and slgmiflcance of steric and bulk parameters In QSAR. 

Americans are often awakened to new environmental problems as a result of articles written or speeches given by prominent scientists or politicians who have become interested in the problem. Such was the case when Rachel Carson wrote about the dangers of pesticide pollution in her now-famous bookSilentSpring (1962). 

Plant diseases cause serious losses in crop production. Pesticide application is currently the primary way to control crop disease, but it has raised an array of environmental problems. Achieving sustainable agriculture will require avoiding a... 

Often, many simultaneously occurring pollutants or contaminants determine an environmental problem. In industry, agriculture, and households, products are often mixtures of many compounds. The process of production and consumption is accompanied by emissions and consequently by contamination. One example is the use of toxaphene in the past, a very complex mixture of polychlorinated camphenes, as a pesticide. Technical toxaphene consists of more than 175 individual compounds. A second example is industrial and domestic emissions resulting from the combustion of fossil fuels. The emissions contain both a mixture of gases (SO2, NOx, CO2, etc.) and airborne particulate matter which itself contains a broad range of heavy metals and also polycyclic aromatic hydrocarbons (PAH). 

Soon, L.G., Hock, O.S. (1987) Environmental problems of pesticide usage in Malaysian rice-fields. In Management of Pests and Pesticides. Tait, J., Napompeth, B., Editors, pp. 10-21, Westview, London, United Kingdom. 

In this volume of Issues we address the sources, environmental cycles, uptake, consequences and control of many of the more important chlorinated organic micropollutants. Under this heading we have included a range of semi-volatile persistent compounds, notably polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) as well as a number of chlorinated pesticides. We have not sought to include volatile species such as CFCs which cause environmental problems of an entirely different nature. The compounds included in this volume cause no threat to the stratospheric ozone layer, but have given widespread cause for concern in relation to their environmental persistence and high toxicity, and their potential for adverse effects on humans and wildlife. 

There are other advantages, too. With lower levels of insecticide, wildlife are not apt to be affected and environmental problems associated with pesticide use, e.g., groundwater contamination and pesticide translocation, will definitely be diminished or eliminated. 

Pesticides are crucial for maintanence of our modern food production. However, current patterns of use and misuse of chemical pesticides have resulted In some environmental problems. Ground water contamination by herbicides and other pesticides may threaten... 

Studies conducted by the Food and Agriculture Organisation (FAO) of the United Nations show that there are around 100 000 tonnes of obsolete pesticide stocks in developing countries. Africa alone probably accounts for up to 48 000 tonnes. Obsolete pesticides cannot only be found in developing countries in Africa, the Near East, Asia and Latin America, they are also an environmental problem in many Central and Eastern European countries. The main hazard, however, is the acute toxicity of these pesticides. They present an acute and potential risk both for the community and the environment. These obsolete pesticides are not only a barrier to sustainable development in emerging countries, they arc also a hazard for the global environment. The countries concerned are not in a position to solve the problems on their own. They have neither die technical expertise, the facilities nor the necessary financial means. For this reason, it is essential that the OECD countries provide support. 

Few studies have been carried out on the fate of pesticides in tropical ecosystems. If reported, they often lack an appropriate assessment of the processes that affect fate and factors influencing those processes imder specific conditions. Due to the complexity of the environmental problems, modeling is seen as an essential tool in resolving them. 

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