Ammonia pollution hotspots found in areas of UK with most pig and poultry factory farms

Lincolnshire, Herefordshire and Norfolk have high densities of intensive poultry and pig farms. Photograph: Mark Henderson/Alamy

Ammonia pollution hotspots have been identified in areas with some of the greatest numbers of intensive pig and poultry farms in Britain, research has revealed.

A new map for the first time reveals the most severe concentrations of ammonia emissions are clustered in Lincolnshire, Herefordshire and Norfolk. These regions all have a high density of intensive poultry and pig units that drive dangerous levels of ammonia, according to researchers from Compassion in World Farming (CiWF) and Sustain.