Global Health Groups Urge WHO to Update Decades-Old Drinking Water Nitrate Limits

Dozens of global health and environmental organisations have asked the World Health Organization to revise its decades-old standards for nitrate levels in drinking water. In an open letter, 85 groups including Greenpeace International and the World Organization of Family Doctors urged the United Nations health agency to include nitrate in an upcoming guidelines review.

Health Risks

Nitrates are a residue left behind by intensive farming and pose known dangers to children and pregnant women. The current WHO limit of 50 milligrammes per litre as nitrate dates back to 1958 and was originally set to prevent blue-baby syndrome, a deadly blood disorder that reduces oxygen-carrying capacity. However, the letter states that this limit fails to account for recent studies linking chronic, low-level nitrate exposure to colorectal cancer and adverse birth outcomes like premature birth.

Global Scale

Surface water models indicate that hundreds of millions of people worldwide are exposed to elevated nitrate levels. WONCA chair Pratyush Kumar noted that studies link nitrate to bowel cancer and premature birth even at levels well below current WHO limits. Greenpeace global project lead for agriculture Amanda Larsson called for action to curb intensive livestock farming and support ecological farming practices. The groups also highlighted findings from a Danish government expert panel that recommended lowering the nitrate limit to 6.0 mg per litre, a standard Denmark committed to earlier this year.

Context

Most national governments base their own drinking water standards directly on guidelines set by the World Health Organization, making any revision by the UN agency crucial for policy reform worldwide. Intensive farming and heavy use of fertilizers remain major drivers of nitrate runoff into surface and groundwater sources globally.