https://grist.org/science/salt-pollution-study-drinking-water-supplies/
"Humanity is messing with the Earth’s “salt cycle,” with potentially dangerous
consequences for drinking water supplies, crop production, and ecosystems.
That’s according to a new study published in the journal
Nature Reviews Earth
& Environment on Tuesday. It’s the first time that scientists have documented
the extent to which humans have changed the salt content of the land, water,
and air across the globe.
Researchers in Maryland and four other states found that 2.5 billion acres of
soil around the world have gotten saltier, an area roughly the size of the
entire United States, and it’s stressing out plants. Salt is even getting
kicked up into the air: In arid regions, “lakes are drying up and sending
plumes of saline dust into the atmosphere,” such as the Aral Sea in Central
Asia, the study says.
Salt pollution presents an “existential threat to our freshwater supplies,”
according to the study. It can corrode drinking water pipes, exacerbating lead
pollution in water supplies, as it did in Flint, Michigan. “They had all these
lead pipes that were leading to their houses and the chloride would basically
pull the lead into solution,” Sujay Kaushal, the study’s lead author, told the
Washington Post. “They didn’t add enough corrosion inhibitor, and then kids had
high levels of lead in their blood.”
Before humans came along, salt moved to the Earth’s surface over long
geological periods, surfacing as rocks broke down and cycling through the water
and air, available for the animals and plants that needed it. Some research
suggests that salt was key to the development of life on Earth.
But that process has been accelerated by industrialization. Salinization has
been supercharged by a host of factors: irrigation, deicing roads, mining,
wastewater treatment, and even the use of salt-laden household items like
detergent. The researchers looked at lots of different kinds of salts, like
calcium and magnesium, not just the sodium chloride that sits in the salt
shaker on your dinner table. And they found so much of it, they worried that
salt could cause “serious or irreversible damage across Earth systems.”
In coastal areas, sea-level rise can send salty ocean waters into the
groundwater, making it undrinkable. In the United States, aquifers near the
coastline — many of which are below sea level — supply 95 million people with
drinking water. It only takes 2 or 3 percent seawater to make the groundwater
undrinkable, and removing salt from water is difficult and expensive."
Via Diane A.
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
