Pollution's toll: How ammonium nitrate affects young minds

Recent research by scientists at the University of Southern California has revealed that certain forms of air pollution, including those associated with agriculture, negatively affect children's cognitive functions. Additionally, they increase the risk of Alzheimer's disease and dementia in adults.

The findings, published in the journal Environmental Health Perspectives, highlight the harmful effects of ammonium nitrate, a substance predominantly linked to agriculture and livestock farming. Scientists analysed data from 8,500 children aged nine and ten to study the impact of fine particulate matter PM2.5 on brain development.

These tiny particles, consisting of dust, soot, organic compounds, and metals, can penetrate the lungs and enter the bloodstream and brain, crossing the blood-brain barrier. Their presence in children's bodies is associated with negative consequences.

Although the largest source of PM2.5 is the combustion of fossil fuels, especially in urban areas, significant influences come from wildfires, sea aerosols, chemical reactions, and agricultural activities. Researchers employed advanced statistical techniques to examine 15 chemical components of PM2.5 and their sources. They discovered that different types of air pollution can affect the brain to varying extents. Ammonium nitrate emerged as a primary factor negatively impacting cognitive functions.

"No matter how we examined it, on its own or with other pollutants, the most robust finding was that ammonium nitrate particles were linked to poorer learning and memory," said the publication's lead author, Dr Megan Herting. In her view, this suggests that while the overall harmfulness of PM2.5 is notable, certain compounds within this mixture pose a greater threat than others.

The study's authors stressed the need for more detailed analyses of the sources of particulate matter and their chemical components. Understanding these nuances is crucial for establishing air quality regulations and comprehending long-term neurocognitive effects.

In conclusion, the researchers indicated that PM2.5 can cause neurocognitive effects throughout life. They propose that this knowledge should prompt a reevaluation of air quality regulations to protect future generations from pollution's negative impact.

Although research points out that ammonium nitrate, used in agriculture as a fertiliser, is particularly harmful to children's brains, agriculture's contribution to PM2.5 emissions is not substantial. According to the Ministry of Agriculture, a report from KOBiZE 2020 estimated that PM2.5 emissions from agriculture in 2018 accounted for 2.4% of the total emissions.

Professor Eugeniusz R. Grela from the Department of Bromatology and Nutrition Physiology at the University of Life Sciences in Lublin spoke about greenhouse gas emissions from agriculture some time ago. While he acknowledged that agriculture emits significant amounts of these substances, the issue is complex.

"It is worth remembering that methane differs in terms of its decomposition rate in the environment. The duration of methane from livestock production is significantly shorter, lasting about ten years, compared to fossil methane, which has a decomposition time of up to 100 years," noted Prof. Grela.