Ammonia emissions from agriculture and their contribution to fine particulate matter: A review of implications for human health.

Atmospheric ammonia (NH) released from agriculture is contributing significantly to acidification and atmospheric NH may have on human health is much less readily available. The potential direct impact of NH on the health of the general public is under-represented in scientific literature, though there have been several studies which indicate that NH has a direct effect on the respiratory health of those who handle livestock. These health impacts can include a reduced lung function, irritation to the throat and eyes, and increased coughing and phlegm expulsion. More recent studies have indicated that agricultural NH may directly influence the early on-set of asthma in young children. In addition to the potential direct impact of ammonia, it is also a substantial contributor to the fine particulate matter (PM) fraction (namely the US and Europe); where it accounts for the formation of 30% and 50% of all PM respectively. PM has the ability to penetrate deep into the lungs and cause long term illnesses such as Chronic Obstructive Pulmonary Disease (COPD) and lung cancer. Hence, PM causes economic losses which equate to billions of dollars (US) to the global economy annually. Both premature deaths associated with the health impacts from PM and economic losses could be mitigated with a reduction in NH emissions resulting from agriculture. As agriculture contributes to more than 81% of all global NH emissions, it is imperative that food production does not come at a cost to the world's ability to breathe; where reductions in NH emissions can be easier to achieve than other associated pollutants.