Arguments opposing organic food

Food safety
Conventional food does contain pesticide residues – often multiple residues. In contrast, a study published in 2002 showed that "Organically grown foods consistently had about one-third as many residues as conventionally grown foods."[36][37] Yet, the potential health effects of pesticide residues found in food are subject to debate. One could argue that modern analytical chemistry is capable of detecting such small quantities of a substance that the meaning of a positive result is difficult to interpret, and many scientists think that such residues are without effect.[38] Pesticides are subjected to a battery of tests before they can be approved by the EPA [2] and "residue tolerances" are established above which produce exceeding these tolerances cannot be sold.
Furthermore the professors Lois Swirsky Gold and Bruce Ames argue :"Whereas public perceptions tend to identify chemicals as being only synthetic and only synthetic chemicals as being toxic, every natural chemical is also toxic at some dose," and have shown that 50% of all natural chemicals in food gave a positive test as a carcinogen when tested in rodents, casting doubt on any link of food residues and cancer risk.[39]
Author Thomas DeGregori argues that at the heart of the organic food movement are feelings of anti-technology and anti-modern science[40] and points out that it is modern science, after all, that has increased the life expectancy of many people and helps to feed the world's growing population.

[edit] Sustainability
Newer non-organic practices, particularly no-till agriculture, which relies on herbicides to clear the land, offer considerable improvements in energy efficiency. Anthony Trewavas argues that the sustainability of organic agriculture is less than that of conventional agriculture (see Trewavas (2000)[41][42]).
Soil benefits: Trevavas also argues that many of the soil benefits of organic agriculture have been demonstrated to be due to crop rotation, which is not an exclusively organic strategy (see Trewavas (2000) cited above).
Land usage: Organic food growers lose a significantly larger portion of their crops to pests, mold, etc, and therefore require significantly higher land usage to generate the same amount of product. One study shows that a crop of organic tomatoes, for example, would use approximately 642% more land than one grown via conventional methods.[43]
Pesticide use: While organic agriculture aims to keep pesticide use to a minimum, it is a common misconception that organic agriculture does not use pesticides. Some pesticides used on organic farms contain the heavy metal copper, which can lead to copper accumulation in the soil. Other pesticides that are approved for use by organic producers include ryania, sabadilla, and rotenone.[44]The botanical pesticide sabadilla is toxic to honeybees, and according to the California Department of Environmental Protection its mammalian toxicology has not been fully studied.[45]
Toxicity of "organic pesticides": Conventional pesticides must be thoroughly studied before they can be placed on the market[citation needed]. However, such studies are not required for the pesticides used in organic agriculture[citation needed].
John Kent, Lecturer in Agricultural Protection, from the School of Agriculture at Charles Sturt University in Australia supports the idea that organically grown food is not as sustainable, arguing that while organically grown food certainly has its place in today's free market, the world population could not be fed with pesticide-free agriculture.[46]

[edit] Organic food is expensive
Critics claim that organic food is more expensive than conventional food and thus too highly priced to be affordable to persons on a lower income. Organic products typically cost 10 to 40% more than similar conventionally produced products.[47] Processed organic foods vary greatly in price compared when compared to their conventional counterparts. An Australian study by Choice magazine in 2004 found processed organic foods in supermarkets to be 65% more expensive, but noted this was not consistent. Some products were more than twice the price (such as chocolate), others were similarly priced (jam).[7]
Prices may be higher because organic produce is produced on a smaller scale, and may need to be milled or processed separately.

[edit] Organic food has become too commercial
Organic food began as a small movement with farmers rejecting the use of conventional farming practices. With the market share of Organic food outpacing much of the food industry many big companies have moved into this market. With these large companies, and with the creation of a legal certification framework (2002 in the US), there is worry that the very definition of organic food will change from what it used to be.[48]
Source : http://en.wikipedia.org/wiki/Organic_food ..