NITRITE & NITRATE IN WATERMay 26th, 2021 | Water Components
WHAT IS NITRITE AND NITRATE?
Nitrate are salts and as a natural component of soil, salts are important for plant growth. In dissolved form, they serve as a supplier of nitrogen, which is absorbed directly above the roots. In the human body, nitrate plays several roles. Recent studies attribute nitrate-rich diets to a circulation-promoting effect on the brain. So beetroot, spinach, cabbage or rocket have a positive effect on our health. However, too much consumption is not recommended, as oversupply can have serious negative effects.
WHAT IS THE DANGER FOR US FROM NITRITE OR NITRATE IN DRINKING WATER?
For adults, there is only a low health risk from nitrate in tap water. However, bacteria convert nitrate into nitrites and nitrosamines in our digestive tract. These, in turn, have different adverse health effects on the body.
Nitrites are toxic. They convert our hemoglobin into methaemoglobin, which is important as they transport oxygen in our blood and Methaemoglobin cannot. Infants under 3 months old naturally have elevated levels and too much Methaemoglobin can result in very serious health damage and in some cases even lead to internal suffocation. Therefore, a low level of nitrate in water must be taken into account in infant nutrition.
HOW DO NITRITE AND NITRATE GET INTO OUR WATER?
Approximately 70% of raw water used for drinking water treatment is sourced from underground sources and Nitrates are a natural component in our soils. They have a positive effect on plant growth and are used as fertilisers in agriculture. Therefore additional nitrate enters soil and subsequently finds its way into groundwater.
WHAT LIMITS ARE CONSIDERED “NORMAL”?
In the UK the limit for nitrates and nitrites in drinking water is 50 mg/l. Waterworks are obliged to check the limit values in all areas to ensure they are within regulation.