Nitrates

Nitrate nitrogen occurs naturally in many soils and is thus found in most groundwaters and in many surface waters. Increased use of artificial nitrogen fertiliser has raised the level of nitrate run off from farm land. As a result the levels of nitrates in water supplies have increased, particularly in areas subject to intensive arable farming. Sewage effluents also contain sufficient amounts of nitrogen which is often in the nitrate form.Nitrates in drinking water can be dangerous for bottle fed babies up to the age of about six months. Below this age babies do not have the normal bacterial flora in their intestine, and they are unable to deal with the nitrites produced by the reduction of nitrate in the stomach. Elevated levels of nitrates can cause methaemoglinaemia or 'blue baby syndrome', a rare blood condition.There is thought to be an elevated risk of cancer due to high levels of nitrate, but epidemiological studies have failed to support this contention. Recent epidemiological data has suggested an association between developmental effects in offspring and maternal ingestion of nitrate from drinking water, but a definite correlation of the cause and effect relationship cannot be drawn.