Pesticides benefits

FIGURE 8.1 The risk curve lines shown represent thresholds between different types of decisions (based on ECOFRAM 1999a and 1999b). These thresholds would be determined by decision makers and may move location subject to other factors that affect the decision (e.g., pesticide benefits). The bottom graph shows an example risk curve with uncertainty bounds. The curve clearly fits within the acceptable risk category however the upper uncertainty bound does not, indicating a need for risk mitigation or further refinement of the risk assessment. 

Many factors affect the mechanisms and kinetics of sorption and transport processes. For instance, differences in the chemical stmcture and properties, ie, ionizahility, solubiUty in water, vapor pressure, and polarity, between pesticides affect their behavior in the environment through effects on sorption and transport processes. Differences in soil properties, ie, pH and percentage of organic carbon and clay contents, and soil conditions, ie, moisture content and landscape position climatic conditions, ie, temperature, precipitation, and radiation and cultural practices, ie, crop and tillage, can all modify the behavior of the pesticide in soils. Persistence of a pesticide in soil is a consequence of a complex interaction of processes. Because the persistence of a pesticide can govern its availabiUty and efficacy for pest control, as weU as its potential for adverse environmental impacts, knowledge of the basic processes is necessary if the benefits of the pesticide ate to be maximized. 

Chemicals are ubiquitous as air, carbohydrates, enzymes, lipids, minerals, proteins, vitamins, water, and wood. Naturally occurring chemicals are supplemented by man-made substances. There are about 70000 chemicals in use with another 500-1000 added each year. Their properties have been harnessed to enhance the quality of life, e.g. cosmetics, detergents, energy fuels, explosives, fertilizers, foods and drinks, glass, metals, paints, paper, pesticides, pharmaceuticals, plastics, rubber, solvents, textiles thus chemicals are found in virtually all workplaces. Besides the benefits, chemicals also pose dangers to man and the environment. For example ... 

A pesticide manufacturing plant should prepare a hazard assessment and operability study and also prepare and implement an emergency preparedness and response plan that takes into account neighboring land use and the potential consequences of an emergency. Measures to avoid the release of harmful substances should be incorporated in the design, operation, maintenance, and management of the plant. Implementation of cleaner production processes and pollution prevention measures can yield both economic and environmental benefits. 

All decisions involve tradeoffs. Does the benefit of increased food product ion outweigh possible health risks of a pesticide Do the beneficial effects of a new drug outweigh a potentially dangerous side effect in a small fraction of users The answers are rarely obvious, but we should at least try to base our responses on facts. 

One reason for the rapid growth in the use of pesticides worldwide has been the "Green Revolution" (5), Although there have been some benefits from pesticide use in agriculture, they also cause significant environmental and public health problems. The same is true in public health where Insecticides have been used to control malaria. However, today Increased resistance to insecticides in mosquitoes and Increased resistance to drugs by the malarial parasite are resulting in an explosive increase of malaria worldwide (5). 

From this analysis it is clear that in addition to their benefits, the use of pesticides in food production not only causes serious public health problems but also considerable damage to vital agricultural and natural ecosystems in the United States and world. A conservative estimate suggests that the environmental and social costs of pesticide use in the United States total about 4 billion each year. Worldwide the yearly environmental and public health costs are probably at least 100 billion. This is several times the 18 bllllon/yr spent on pesticides in the world. 

This analysis has demonstrated that pesticide use in the world could be reduced by approximately 50% without any reduction in crop yields (in some cases increased yields) or the food supply. This effort would require applying pesticides only-when-necessary plus using various combinations of the nonchemical control alternatives currently available (34). Although food production costs might Increase slightly (0.5% to 1%), the added costs would be more than offset by the positive benefits to public health and the environment (15). 

Several aspects of the problem of herbicides being contaminated with nitrosamines, and the resulting inadvertent introduction of nitrosamines into the environment, will be discussed in other papers in this symposium. Unrecognized until less than five years ago, the situation has inspired intense debate and prompted several of the environmental chemistry studies mentioned in this paper. Like the presumed threat from the in vivo nitros-ation of pesticide residues, discussions sometimes lack the type of anticipated dose and effect calculations just mentioned. Unlike the active ingredients, whose benefits can justify residue tolerances and acceptable daily intakes, nitrosamine contaminents afford no known benefits, and the desirability of minimizing their levels is undisputed. 

The basic tenets of the proposed policy is to encourage the manufacturer to reduce or eliminate the N-nitroso contaminant level in his product, or failing this to establish that the level does not exceed an "acceptable risk to the user of the pesticide or the general public. This latter process of evaluation also requires that the Agency consider the benefits of this pesticide together with the risk in order to reach a final decision. Since there might be hundreds of products falling under this policy, the... 

S.L. Johnson and J.E. Bailey, Food Quality Protection Act of 1996, in Pesticides Managing Risks and Optimizing Benefits, N.N. Ragsdale and J. N. Seiber (eds), ACS Symposium Series 734, American Chemical Society, Washington, DC, pp. 8-15 (1999). 

Undertake an Intensive Educational Program. A program of information on health benefits derived from the wise use of pesticides and the health hazards associated with their misuse is greatly needed. The educational facilities of the American Medical Association, consisting of ten professional journals and the lay publication, Today s Health, will be available to the committee. In addition, the inquiry service which is conducted by the various departments, councils, and bureaus of the American Medical Association will be coordinated in order that letters of committee interest will receive their mutual attention. 

The growing concerns about the public health and environmental impacts of pesticides have led many in the general public and the government to question whether all the benefits of pesticides, such as the perfect red apple, are worth the associated costs of environmental pollution, human illness and loss of life, bird kills, and the destruction of other beneficial natural organisms. Indeed, some agriculturists have been viewed as primarily concerned with promoting commercial interests rather than protecting public health and the environment. 

Assure that pesticide tolerances are safe for vulnerable populations, in particular, infants, children and the elderly, based on a reasonable certainty of no harm health-based standard, instead of the previous cost-benefit balancing standard ... 

The district will benefit the most from a method for destruction of this toxic material called "Mobile plasma complex for recycling of unfit and unidentified pesticides", which has been designed by the "Colorit" Institute of Dnepropetrovsk. However the mentioned method still has to be ecologically and sanitary-epidemiologically evaluated by experts. 

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