It is not only traces of nitrate, pesticides and PFAS that may be coming out of your tap. Most likely, residues from hundreds – indeed, in some places thousands – of other anthropogenic substances are present. Most are probably harmless, and for many we do not yet know the effects, but some are known to be harmful to human health. Although drinking water in Denmark is generally of high quality, chemical contamination of groundwater is an increasing concern. While politicians in the Danish Parliament debate nitrate and other individual substances in drinking water, and authorities continuously expand their lists of regulated contaminants, researchers behind a new spinout company from the University of Copenhagen point to a more fundamental problem: drinking water monitoring still follows the principle of looking only for what is already known.
“Today, we test drinking water for only a small, selected group of substances – those we already fear. That leaves a vast number of chemicals undetected. PFAS, for example, remained effectively ‘invisible’ for many years for exactly this reason,” says environmental chemist Jan H. Christensen, Professor at the Department of Plant and Environmental Sciences.
Avoiding unpleasant surprises
Several recent studies – including one from Jan H. Christensen’s research group at the University of Copenhagen – have identified new types of concerning chemicals in Danish drinking water boreholes. These include industrial chemicals used in insecticides, cleaning products, firefighting foam and vehicle tyres, some of which are known to damage organs and may be carcinogenic.
“More and more studies show that drinking water wells often contain hundreds of man-made chemicals. The problem is that many of them are never detected using current analytical methods,” says Jan H. Christensen.
Together with a group of fellow researchers from the University of Copenhagen, he has founded the spinout company NTS Analytica, which offers a much broader screening of chemicals in drinking water and other environmental samples.
The company uses, among other techniques, so-called non-target screening, in which advanced analytical instruments scan water samples for thousands of substances simultaneously. The result is a “chemical fingerprint” of the sample, providing a far more complete picture of the substances present.
“We need to carry out broad-spectrum screenings that give a true picture of what is actually present in the water, rather than simply telling us whether specific substances such as nitrate or PFAS happens to be there. Otherwise, we risk continued unpleasant surprises that ultimately cost consumers both in terms of health and money,” says the professor.
