gies available and the current economic and commercial interests and that the limits allowed today may be different in the future and from what they were in the past, thus they are not established in relation to the harm they cause to health, but have more to do with the technological packages currently available and the companies involved.
     According to FAO (2000) sensory analysis studies have been performed to determine differences in the organoleptic properties of fruits and vegetables such as apples, tomatoes and carrots, in which the persons interviewed have recognized better flavor and color in organic as compared to conventional produce. In addition, it has been recognized that there are fewer losses due to fungi attacks during the storage of organic produce.
     It is recognized that many developing countries have deficient food safety systems due to weak public infrastructure and incomplete or obsolete legislation that is not in line with international standards; there are even shortcomings in the developed world, when primary production is not covered. In addition, the responsibilities related to food safety and food control tend to be dispersed among several institutions and the laboratories lack the equipment and basic supplies they need, all of which is aggravated by climatic conditions. The shortcomings of the food safety systems may result in an increase in food problems and food diseases. Diarrheal diseases, for example, provoked mainly by the consumption of unhealthy food and water, take the lives of 1.8 million children each year (FAO, 2007).
     Almost all chemical pesticides authorized in conventional food production are prohibited in organic production; therefore contamination may be very low in organic products. More than 500 additives are authorized in conventional foods, but only 30 additives are authorized in organic foods. It has been concluded that a predominantly organic diet reduces the amount of toxic chemicals ingested, avoids transgenics, reduces the quantity of food additives and coloring; increases the consumption of vitamins, minerals, essential fatty acids and beneficial antioxidants; and appears to have the potential to lower the incidence of cancer, coronary heart disease, allergies and hyperactivity in children (Cleeton, 2004).

      The Regional Conference of Consumers of Healthy Food, held in Bogotá, Colombia, in August 2004, organized by Consumers International, Office for Latin America and the Caribbean, recognized that the use of pesticides as well as the presence of pesticide residues in foods present in the market are a major concern for the consumers’ movement, since quality and safety include the primary stage of production and the processing of such products. Accordingly, emphasis was placed on the need for a comprehensive approach to ensuring safety, from production to final consumption, through sustainable agricultural production. It was emphasized that the cooperation and joint action of Consumers International with Latin American networks such as RAP-AL (Red de Acción en Plaguicidas y sus Alternativas en América Latina, Pesticide Action Network in Latin America) and MAELA (Latin American Agroecology Movement) play an essential role here. It is also crucial that strategic partnerships be strengthened with the women’s movement to work on issues of food security and food sovereignty, health promotion, promoting

 breastfeeding and safe foods (Consumers International, 2004).
     Although organic or agroecological foods are of significantly better quality than conventional ones, it cannot be said that they are totally safe. For example, one may find detectable levels of persistent organic pollutants (POPs) in organic or agroecological foods, such as DDT and other organochlorine insecticides that are no longer used because they accumulated in the soil for years.8 Agroecological produce may also contain residues of other chemical pesticides that reach it by drift, with rain, or with contaminated waters, but also less frequently and in lower concentrations than in conventional produce (FAO, 2000; Bordeleau, 2002).
     Animal manure and other organic waste such as biosolids or sludge from wastewater treatment plants, which may be used as fertilizer in ecological agriculture, may pose risks of contamination by pathogenic microorganisms that survive inadequate composting conditions (FAO, 2000).
     It might be thought that organic foods pose risks of contamination with aflatoxins, a by-product of the contamination of foods with certain fungi in conditions favorable for them, given that they occur without the use of chemical fungicides. Nonetheless, it has been shown that such is not the case. Aflatoxins, which may induce cancer of the liver at very low dosages if ingested over a prolonged period of time, may be avoided by good practices in farming, postharvest handling and storage. Studies have been reported that found that the level of aflatoxin in organic milk was lower than in conventional milk (FAO, 2000).
     With regard to post-harvest handling, the vitamin C content and the dry matter are, on average, greater in organic crops and the percentage of water less, therefore they keep better than products handled with chemicals, since they are more resistant to diseases and pests (Barg and Queirós, 2007).
1.7.4 Impacts of the production systems
1.7.4.1 Environmental impacts
Agriculture general impacts. There is widespread agreement that habitat destruction and fragmentation is the major driver of biodiversity loss worldwide. While habitat destruction and fragmentation have many causes, foremost among them in terms of the area affected is agriculture (Goudie, 1990; Heywood and Watson, 1995; McNeely and Scherr, 2003; MA, 2005b). Siltation of water bodies caused by the removal of natural vegetative cover can have similarly negative effects on aquatic and marine organisms. Agriculture directly impacts aquatic biodiversity when excessive water is removed for irrigation. Production practices, such as burning cleared vegetation, can cause additional loss of biodiversity. Livestock contributes enormous amounts of methane to the world’s atmosphere, which in turn contributes to climate change and impacts biodiversity (Clay, 2004). Some species introduced for agricultural purposes have become

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⁸ These persistent contaminants are called organic because they contain carbon in their molecule since they are manufactured from fossil fuels, but their use is prohibited in organic agriculture.