Local scientists caution against nitrogen pollution
A CAUTION from the United Nations Environment Programme (UNEP) for countries to tackle nitrogen pollution has found favour with local scientists, who point to the climate and public health risks.
Nitrogen, the UNEP explains in a January 16 story published on its website, is “an abundant element in the Earth’s atmosphere” that “makes the sky blue, forms the foundation of proteins in our bodies and helps make soils fertile”.
“However,” the entity said, “excess nitrogen in the environment in a reactive form – which comes from the use of synthetic fertilisers, the discharge of wastewater or the combustion of fossil fuels – is a hazard, polluting land, water and air. It also exacerbates climate change and depletes the ozone layer, which is finally recovering.”
Citing its 2018-219 Frontiers Report, UNEP said nitrogen pollution is, in fact, one of the most important pollution issues facing humanity.
Professor Michael Taylor, dean of the Faculty of Science and Technology at The University of the West Indies and himself a celebrated climate scientist, agreed.
“Nitrogen pollution is in part responsible for increased nitrous oxide entering the atmosphere. Nitrous oxide, in addition to being a human-related threat to the ozone layer, is a potent greenhouse contributing to the climate-change problem – like methane and carbon dioxide,” he explained.
“The ballooning increase in nitrous oxide in the atmosphere in the last few decades is cause for concern. The climatechange link gives our region (the Caribbean) another reason to pay attention to nitrogen management, that is, in addition to the other harmful impacts of nitrogen pollution on terrestrial and marine ecosystems,” added Taylor, a physicist.
The UNEP has supported talks with officials globally to look at sustainable nitrogen management.
“Nitrogen is a primary nutrient essential for the survival of all living organisms on Earth. But the world needs to wake up to the issues of nitrogen waste and the opportunities to take joint action for its sustainable use,” warned Leticia Carvalho, principal coordinator of the Marine and Freshwater Branch at UNEP in the January 16 story. Not only is nitrogen disrupting to life on land and under water, and a significant contributor to climate change, UNEP said it is also a threat to human health. “Water containing elevated levels of nitrate – a form of nitrogen resulting from animal waste, plant decomposition and fertiliser runoff – raises the risk of infants developing methemoglobinemia (or ‘blue baby syndrome’), which can be fatal. High levels of nitrate in drinking water can also increase the risk of cancer in adults,” the entity explained.
“Ammonia emissions, as well as contributing to climate change, are an important driver for fine particulate matter pollution, reducing air quality and increasing adverse effects on human health,” UNEP added.
Dr Adrian Spence, senior research scientist at the International Centre for Environmental and Nuclear Sciences, supported the call for attention to nitrogen pollution.
“Considering the importance of nitrogen in agricultural productivity to meet global food demand in the face of climate change and mounting land degradation; and the unintended consequences of its unsustainable use, sustainable nitrogen management has become more urgent than any other time in human history,” he said.
Spence, who is also an environmental biogeochemist and climate change mitigation specialist, has championed improved fertiliser use efficiency as one of the primary strategies for sustainable nitrogen use.
“The benefits of this are many folds: meet production targets; reduced GHG emissions; reduced escape of reactive nitrogen; and there a reduction in the associated adverse environmental impacts,” Spence noted.
“Nitrogen use efficiency can be looked at as an integrated approach – first by knowing the status of your soil and plant requirements, so only what is needed is supplied; use nitrogenfixing plants where possible; [as well as] sustainable soil and crop husbandry practices,” he added.