Nitrate biogeochemical provinces and cancer diseases

NITRATE BIOGEOCHEMICAL PROVINCES AND CANCER DISEASES IN THE ASIAN REGION 

Nitrogen species, like nitrate and nitrite, have been confirmed to be procarcinogenic. The excessive inpnt of these nitrogen componnds into food and drinking water in the presence of tertiary amines, for instance from medicines, can lead to the formation of carcinogenic N-nitrosoamines. 

The nitrate (N03 ) content in crops is one of the most important indicators of farm production quality. Nitrate content in food is strictly regulated because of its toxicity, especially to young children. The actual toxin is not the nitrate ion itself but rather the nitrite ion (N02 ), which is formed when nitrate is reduced by intestinal bacteria, notably Escherichia coli. In adults, nitrate is absorbed high in the digestive tract before reduction can take place. In infants, whose stomachs are less acidic, E. coli can colonize higher up the digestive tract and therefore reduce the NO3 to NO2 before it is absorbed. 

The problem of nitrate accumulation seems to be especially severe in leafy vegetables grown in greenhouses under winter conditions, owing to intensive application of nitrogen fertilizers and low light intensity, which retard nitrate metabolism in crops. 

0-5 mg/kg body weight. For KNO2 and NaN02 the ADI is 0 0.2 (temporary), while for KNO3 it is not specified. The value of ADI is zero for baby food. The WHO sets the ADI at 220 mg an adult. 

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