Clean, safe drinking water is obviously a key part of the body’s health and the health of our community. In recent years, concern has been raised about the effects of nitrate (a form of nitrogen) in drinking water on people’s health.
Because nitrates take time to move through our catchment, our streams, soils and groundwater, it could be some years (in some cases decades) before the nitrogen we apply to our soils arrives in to a tap in our homes. This ‘lag time’ means we can’t simply switch off nitrogen pollution in our drinking water sources when we’d like to, but instead we have to manage our land to have healthy levels over time.
For this reason, it’s sensible that we monitor nitrate levels in our drinking water sources. This will help us manage the landscape in a way that supports our bodily health as well as the health of the river and estuary.
High nitrate levels in drinking water are associated with ‘blue baby’ syndrome - also known as methemoglobinemia. This is when haemoglobin, part of our red blood cells, struggles to carry sufficient oxygen to the body. Infants are particularly at risk, hence why it often referred to as ‘blue baby syndrome. The current New Zealand drinking water safety standards are set at 11.3 mg nitrate/l, following international standards established to protect against this syndrome.
Recent epidemiological studies are increasingly identifying nitrate in drinking water as a factor in colorectal cancer rates, at levels lower than current drinking water safety standards. The reason for this link, as researchers have explained it, is that specific nitrogen compounds (i.e., N-nitroso compounds), that are found in processed meats and produced by our bodies, are known to be linked to health issues. In areas where high nitrates are present in the drinking water, that nitrate could be converted by our bodies into these harmful compounds if the conditions support it. Further work is being done here in New Zealand at the University of Otago to investigate this link.
To protect the health of our community now and over the coming years, it's important to think ahead and have good information. Monitoring your drinking water is a great first step, and we are ready to support you to do this.
If you would like to test for nitrate levels in your drinking water, please contact us. We are currently conducting monitoring in your area.