A study has revealed the sources of ammonia that is polluting our air and damaging our health and ecosystems.
Researchers collected measurements from 69 locations in the UK and mainland Europe. They found that ammonia is, on average, four times greater in farming regions compared with other areas. Agriculture also added to the ammonia found in the suburbs of many cities.
Jenny Hawley, the policy manager at the charity Plantlife, who was not involved in the research, said: “Ammonia emissions are devastating wild plants, lichens and fungi in our ancient meadows, native woodlands and other wildlife habitats. Over 90% of the UK’s landmass suffers from ammonia concentrations that are too high for sensitive lichens, mosses and liverworts to thrive. This causes the loss of species, lower resilience to climate change, pests and disease, and even direct toxic damage.”
Studies have found increased asthma among children in agricultural areas with the most ammonia, including close to intensive pig farms. However, the biggest health impact comes when ammonia reacts with air pollution from traffic and industry to form particle pollution. This creates up to half of the particle pollution in Europe.
Reducing particle pollution to meet World Health Organization (WHO) guideline levels would have reduced premature deaths in Europe by 238,000 in 2021.
More than 80% of the ammonia that leaches into our air comes from farming, specifically nitrogen fertilisers and animal waste, but the researchers also found sources in towns and cities.
Ammonia next to busy roads was about 40% higher than other parts of towns and cities due to emissions from diesel and petrol exhausts. It was also greater in the mornings, perhaps due to greater emissions when petrol engines are started from cold. This may directly produce particle pollution. Tighter standards for new vehicles could help.
Ammonia is likely to be adopted as a fuel for shipping and power generation in the future, but agriculture will remain its main source.
In the UK, ammonia produced from agriculture decreased by 21% between 1990 and 2021. However, this was achieved before 2005, after which progress stopped. Despite readily available solutions, there is little connection between environmental and health scientists and farmers to drive action and policies.
Katie Wyer from University College Dublin, who published a recent review of the evidence on ammonia, said: “It is imperative that food production does not come at a cost to our ability to breathe; especially where reductions in ammonia emissions can be easier to achieve than other pollutants.”
