Moss That Removes Arsenic From Contaminated Water So It's Safe To Drink Discovered


Aquatic moss from the Stockholm University greenhouse. Arifin Sandhi/Creative Commons

From plastic-eating bacteria to oil-devouring bacterium, it seems Mother Nature keeps surprising us with new ways to protect the environment. Now, scientists have discovered a type of moss capable of purifying water contaminated with arsenic, making it once again safe for human consumption.

Warnstofia fuitans is an aquatic moss native to Sweden. It’s here, at the Stockholm University, that researchers have shown its potential to remove up to 82 percent of arsenic from contaminated water using a process called phytofiltration, a plant’s ability to remove heavy metals from water.


"Our experiments show that the moss has a very high capacity to remove arsenic,” research assistant Arifin Sandhi said in a statement. The process takes no more than an hour, which Sandhi says is enough time to remove enough levels of both arsenite and arsenate so that the water is no longer harmful to people.

The team is touting the moss – which works whether it is dead or alive – as an “environmentally friendly way to purify water of arsenic,” and say the moss could be grown in streams and other waterways that have both naturally and unnaturally occurring levels of the metalloid.  


Sweden has a rich history of mining and metal refineries dating back more than 1,000 years. While the use of arsenic compounds in wood products was banned in 2004, researchers say the metal still reaches groundwater and water systems through mining efforts. But it’s not just mining to blame. Arsenic is a naturally-forming element and its natural form is found in certain parts of the ground and in the Scandinavian country’s bedrock.

Because of this, drinking water and water used for crop irrigation both have high levels of arsenic. As plants absorb arsenic from the soil, it eventually ends up in foods like wheat, root vegetables, and leafy greens.


"How much arsenic we consume ultimately depends on how much of these foods we eat, as well as how and where they were grown,” said researcher Maria Greger.

In other countries, arsenic levels found in juice and rice-based baby foods have prompted investigations and new regulations.  At least 150 million people in 10 countries are drinking water contaminated with arsenic, according to the World Health Organization. Deemed a “global health issue” in the past, the gray chemical element can destroy red blood cells, cause abdominal pain or shock, and ultimately can prove fatal

Publishing their work in Environmental Pollution, the team is working on developing a “plant-based wetland system” that incorporates the moss to filter out arsenic before the water becomes drinking water or is used for irrigation, eliminating the possibility of arsenic reaching food sources.


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