85 organizations call on WHO to revise drinking water nitrate standards in place since 1958

Open letter to the WHO on One Health Day

On November 3, dozens of international health and environmental organizations called on the World Health Organization to revise the decades-old standards for nitrate levels in drinking water. In an open letter signed by 85 organizations — among them Greenpeace International, the World Organization of Family Doctors (WONCA) and the European Environmental Bureau — they asked that nitrates be included in the upcoming revision of the WHO guidelines for drinking-water quality. The letter was sent on the WHO's annual One Health Day, which aims to highlight the interconnectedness of the well-being of people, animals, plants and ecosystems.

What signatories find unsatisfactory about the current standard

The current WHO recommendations set the maximum nitrate level in drinking water at 50 mg/l (measured as nitrate) or 11.3 mg/l (measured as nitrate-nitrogen). This threshold was adopted back in 1958 and, as the organizations emphasize, was developed specifically to prevent blue baby syndrome — a potentially fatal condition in which the blood's ability to carry oxygen is reduced. The letter states that the limit “has not been revised in light of compelling epidemiological evidence”, linking chronic low-level nitrate exposure to long-term risks, in particular colorectal cancer and adverse pregnancy outcomes. WONCA Chairman Pratuysh Kumar said in a joint statementthat research “now links nitrates in drinking water, even at levels well below the current WHO limit, to bowel cancer and preterm birth.”

The Danish precedent and the practical significance of the letter

The organizations cited the conclusions of an expert group established at the request of the Danish government: last year it concluded that the current international standard is insufficient to protect public health and recommended lowering the nitrate limit to 6.0 mg/l. Denmark has committed to implementing this recommendation, although no timeline has been set. In the signatories' view, this decision creates “a mismatch between global recommendations and national health policy”, since most governments base their drinking water standards on WHO recommendations. That is precisely why they call updating the guidelines “vital for global policy reform”: if the WHO revises the standard, the changes will affect national standards in many countries, not just individual states.

Causes of pollution and demands on governments

Nitrates and nitrites are naturally occurring compounds of nitrogen and oxygen found in soil, water and many foods, including meat, and are also used as food additives. Their levels in water are raised by human activity — the use of agricultural fertilizers, manure runoff and faulty septic systems — making the water particularly harmful to children and pregnant women. Amanda Larsson, leader of Greenpeace's global agriculture campaign, said: “Water should give life, not threaten it”, and called on governments to “restrain the growth of intensive livestock farming” and support producers in transitioning to environmentally friendly farming methods. The WHO has not yet made a decision on the letter; the issue has merely been included among the demands for the upcoming revision of the guidelines.