Sewage to beat agri as biggest source of nitrogen pollution: Top scientist

The contribution of untreated sewage, which is the second-largest source of nitrogen pollution, is growing almost 10 times faster than agriculture, says Nandula Raghuram

Nandula Raghuram, professor at Indraprastha University, who recently took over as the next chair of the International Nitrogen Initiative (INI), an international body of scientists working to understand and reduce nitrogen pollution, speaks to Ankur Paliwal about how severe nitrogen pollution is and his plans to clean it up. Edited excerpts:

What is nitrogen pollution? 

Nitrogen is present in two forms in nature: inactive and reactive. Reactive nitrogen compounds such as nitrate, ammonia, and nitrous oxides flow as nutrients through air, water, and soil, but their excess causes pollution. This reactive nitrogen is building up fast in the environment. What’s