In parts of Europe, notably the Netherlands, NH 3 emissions from animal production are so high that they warrant strict regulations. In Canada, the problem is not yet as acute, except perhaps in local areas with high livestock numbers. Ammonia is a colorless gas, lighter than air, with a sharp odor. As well, NH 3 can react with pollutants such as acidic sulfates and nitrates, forming tiny particles of ammonium nitrate or ammonium sulfate. In an area near Lethbridge, Alta., for example, high concentrations were found close to feedlots, but relatively low values just 1 km away.
Ammonia has many undesirable effects at high concentrations.
Near sources, where concentrations are high, it produces an unpleasant odor and may affect human and animal health. Excessive NH 3 may even be converted to N 2 O, thus indirectly contributing to the greenhouse effect. Though many of the effects of NH 3 occur locally, it also has long-range effects. Ammonium particles, formed upon reaction with other N or sulfur compounds, can be carried long distances by wind before being deposited. Because of its numerous potential effects, both near sources and in remote areas, NH 3 can be a serious pollutant and efforts to reduce its emission are warranted.