Human Activities Causing Global Increase in Salt Levels, Threatening Freshwater Supplies: Study

Industrial activities including agriculture, road treatment, and construction increasingly contaminate land, rivers and streams with sulfur, calcium and sodium salt ions, impacting a region the size of the United States and disrupting a vital natural element of the planet's ecosystem.

• Human activities have led to an increase in the levels of different salts in soils, freshwater, and the atmosphere, according to a study published in Nature Reviews Earth & Environment. The increase has been particularly noticeable in the last 50 years, with salt ions rising in streams and rivers as mankind has began using and producing more salts.
• Already, these higher concentrations of salt are causing issues with freshwater supplies, with instances like the brown tap water in Montgomery, Md., and the high lead-laden water in Flint, Mich, cited as examples. The contamination can be attributed to road salts used for de-icing, detergents, and other household products.
• Currently, around 2.5 billion acres of land globally have become saltier due to these activities. This trend is also leading to the salinization of freshwater lakes and the dispersion of saline dust into the atmosphere as salt lakes dry up.
• The disruption of the natural salt cycle by human activities is seen as an 'existential threat' to freshwater supplies, which only makes up around 3% of the Earth's water. As sodium salt, calcium, magnesium, and other ions increase in places where they do not usually occur, the risk of freshwater salinization syndrome — which makes water uninhabitable for numerous species and unfit for human consumption — also rises.
• The situation is seen as alarming, according to both the study's authors and other experts, with scientist Bill Hintz pointing out the need for proactive environmental policy to address these human-induced changes in the ecosystem.

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