Atmospheric ammonia (NH3) is a short-lived pollutant that plays an important role in aerosol chemistry and nitrogen deposition. Dominant NH3 emissions are from agriculture and forest fires. both of which are increasing globally. Even remote regions with relatively low ambient NH3 concentrations. https://www.bekindtopets.com/super-save-Vetscan-Flex-4-Rapid-Test-25-ct-super-buy/