Madeleine Cuff writes on the inews website about the negative impact that agriculture is having on the environment.
Farming has overtaken fossil fuels and is now the main human source of sulphur in environment
Agriculture has overtaken fossil fuels to be the largest human source of sulphur in the environment, with scientists fearing it is a major cause of mercury pollution in waterways near to farms.
Coal-fired power plants have historically been the main culprit for reactive sulphur, one of the ingredients in acid rain that destroys forests and turns water acidic.
Since the 1970’s, governments have tightened restrictions on coal plants to try and stop sulphur pollution in its tracks, leading to significant declines in emissions.
But research published this week in Nature Geoscience suggests the problem of sulphur pollution is back, and this time farming is the culprit.
Pesticide use rises
Fertiliser and pesticide use by farmers is now the most important source of human sulphur pollution around the world, the study reports.
“Our analysis shows that sulfur applications to croplands in the US and elsewhere are often ten times higher than the peak sulfur load in acid rain,” said lead author Eve-Lyn Hinckley from the University of Colorado. “No one has looked comprehensively at the environmental and human health consequences of these additions.”
Sulphur is an important plant nutrient, but although it can improve the health of crops it can also degrade soils and pollute downstream waters.
For example, sulphur use by farmers causes the formation of methylmercury in waters draining from agricultural lands. Methylmercury is a dangerous toxin that accumulates in food chains, raising the risk fish – and people which eat them – could suffer mercury poisoning.
Although the study was based in the US, the researchers said other nations including China and India are also at risk. More research must be done on the impacts of environmental and health impacts of the use of sulphur in farming, the team said.
“Sulphur in agriculture is not going away,” said Hinckley. “Yet there is an opportunity to bring science and practice together to create viable solutions that protect long-term environmental, economic, and human health goals.”