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Question: Pesticides and Health: A Review of Evidence on Health Effects, Valuation of Risks, and Benefit-Cost Analysis

Answer: The use of chemicals in modern agriculture has significantly increased productivity. But it has also significantly increased the concentration of pesticides in food and in our environment, with associated negative effects on human health. Annually there are dozens of million cases of pesticide poisonings worldwide (Richter, 2002). Moreover, it is now better understood that pesticides have significant chronic health effects, including cancer, neurological effects, diabetes, respiratory diseases, fetal diseases, and genetic disorders. These health effects are different depending on the degree, and the type of exposure. Typically, the effects are different for farmers who are directly exposed to pesticides, compared to those for farmers’ relatives or people living in rural areas who are less directly exposed. There are also effects on consumers through pesticide residues in food.
Pesticides use and regulation have long been controversial. The publication in 1962 of the famous Silent Spring by the biologist Rachel Carson made popular the risks associated to DDT (dichlorodiphenyltrichloroethane) (Carson, 1962). This was followed by the cancelation of this pesticide for agricultural uses by US authorities. Other prominent examples of pesticide cancelation include EDB (ethylene dibromide) in 1983 and methyl bromide in 2005. It is well known now that a significant fraction of pesticides are carcinogenic; for instance, 18% of all insecticides and 90% of all fungicides were found to be carcinogenic (NAS, 1987). It is also well known that pesticide residues remain for long periods of time, and that they are especially toxic to the young. Also, pesticides kill domestic animals, fishes, and bees. Moreover, their use results in the development and evolution of pesticide resistance in insects, weeds, and plant pathogens. Nevertheless hundreds of pesticides are used worldwide, and some pesticides are used in some countries but not in others. For instance, the main pesticide which is used in corn production in the United States is atrazine, but this pesticide has been banned in the EU because of its toxicity since 2004 (Official Journal of the European Union 2004/248/CE).

Public decisions concerning pesticides have long been suspected of regulatory capture. One of the reasons for transferring in 1970 pesticides regulatory responsibility from the US Department of Agriculture to the Environmental Protection Agency (EPA) was to lessen the influence of farmers and pesticide producers. But this transfer of responsibility naturally increased the influence of consumers and environmentalists. Indeed, Cropper, Evans, Berardi, Ducla-Soares, and Portney (1992) showed that both grower and environmental groups’ participation played a major role in explaining the EPA decisions to cancel a pesticide in the 1970s and 1980s. Risk assessment practices also play a role in pesticides regulation. The zero-risk or “de minimis risk” target has long been the advanced objective of regulators. But this objective is overly ambitious, and often not implemented as a result. There is a lot of evidence for instance that a significant portion of food samples still exceeds the maximum residue limits set by regulators both in the United States and in Europe. Finally, risk perceptions may also influence pesticide regulation. Indeed, there is evidence that people underestimate the risks from natural carcinogens but that they nevertheless overestimate the risks from carcinogenic pesticides (Slovic, 2000).
These observations illustrate the challenge of regulating pesticides. At the root of this challenge there is the immense difficulty of producing more food with less pesticide, and the uncertainty about health effects of pesticides. Zilberman and Millock (1997) talk about a regulation nightmare. Given the growing health concerns of the population, some drastic actions to curb the use of pesticides have been decided in some countries. For instance, Denmark decided as early as in 1986 to reduce by two the pesticide treatment frequency in agriculture. More recently, France announced in 2008 a reduction by two of pesticide use by 2018 in its “Ecophyto 2018” plan (MAP, 2009). A major problem with such ambitious policy targets is that they need not reflect an appropriate balance of benefits and costs induced by pesticides use in our societies. Also, these policy targets are difficult, if not impossible, to implement in practice, in part because of the opposition of farmers. In this difficult political context, the US EPA has long noticed that producing sound comparisons of benefits and costs of proposed pesticides regulations might be helpful to policy makers in order to identify and design a coherent pesticide regulatory policy (EPA US, 1992). However, only few studies based on benefit-cost analysis (BCA) concerning pesticides have been produced so far (Pimentel, 2005).
The aim of this study is to contribute to the understanding of the health effects of pesticides exposure and of how pesticides have been and should be regulated. Our conceptual framework is BCA, namely, the most common economic method to evaluate a public policy. In the context of pesticide regulation, this framework requires evidence on health effects on those exposed directly and indirectly, valuation of risks, consideration of market and nonmarket failures, policy alternatives, and estimates of costs. As a first step we provide literature reviews on recent scientific findings on health effects. As a second step, we provide evidence on preference valuation of health risks related to pesticides use. Finally, we provide an overview and discussion of different policies and of difficulties of evaluating them using BCA. One objective of these reviews is to relate the findings from the different disciplines (health, economics, and public policy) to each other, and to identify gaps and needs for future research.

The chapter is organized as follows. First the review of the findings on the health effects related to pesticides use is presented. Then, after a brief introduction on preference elicitation, the findings from the literature on individual preferences and pesticides are summarized. Both sections end with some concluding remarks on each topic. A review and discussion on how pesticides use has been regulated and evaluated are then provided. We end the chapter with some concluding remarks. Moreover, the appendix contains a set of tables in which we briefly present the results of the scientific publications on health effects and valuation of risks selected in our sample.

(Source: , 23 Sep 2021)

Source Link: https://doi-org.onlinedatabase.librarynet.com.my/10.1108/S0731-219920140000024006