The use of soluble chemical fertilizers has resulted in high nitrate concentrations in many conventionally farmed foods, especially in fruits and vegetables. Leafy vegetables can have the highest concentrations. The leaching of these fertilizers has also resulted in high nitrate levels in some drinking water systems around the world.
High nitrate content in food and drinking water can be converted to carcinogenic nitrosamines. Nitrates can impair the ability of the blood to carry oxygen and may pose a risk of methemoglobinemia, a condition that can occur in infants and adults with a diminished capability to secrete gastric acid. A rise in the pH in their digestive system allows bacteria to proliferate, increasing the transformation of nitrate to nitrite. When this nitrite is absorbed into the bloodstream, it oxidizes iron in the hemoglobin of red blood cells to form methemoglobin, which lacks hemoglobin's oxygen-carrying ability. In severe cases this can be one of the causes of Blue Baby syndrome, however in most cases the symptoms would be tiredness, lethargy and a general feeling of being unwell.
The nitrate content of organically grown crops is usually significantly lower than that of conventionally grown products. The governments of Germany and France have encouraged conversion to organic farming in certain areas in a bid to improve water quality, particularly in relation to its nitrate content.
The FAO states the case very succinctly: "It has been demonstrated that organically produced foods have lower levels of pesticide and veterinary drug residues and, in many cases, lower nitrate contents. Animal feeding practices followed in organic livestock production also lead to a reduction in contamination of food products of animal origin."
The facts show that organic food has significant health benefits because it has negligible chemical residues and pathogens and higher nutritional values when compared to conventionally farmed food.
Andre Leu has been involved in the organic industry since 1972. He currently owns a certified organic farm in the lower section of the Daintree River valley in North Queensland, Australia. He grows organic tropical fruits from part of the farm, with the balance being retained as tropical rain forest. Andre is the Chair of the Organic Federation of Australia, the peak organisation for the organic industry in Australia He is also chairperson of the Far North Queensland Lychee Growers Association and Vice President of the Australian Lychee Growers Association, where he has the responsibility for developing export markets. Andre runs workshops on organic production in Australia and other countries and teaches horticulture and environment at Tropical North Queensland Institute of TAFE.