Jessica Leigh Hester is a former senior associate editor at CityLab, covering environment and culture. Her work also appears in the New Yorker, The Atlantic, New York Times, Modern Farmer, Village Voice, Slate, BBC, NPR, and other outlets.
Each sheet of water-cleansing paper can purify up to 100 liters of contaminated drinking water.
A slurry of raw sewage festers in shallow water. In some places, the slow-moving sludge may be the only option for drinking: a recent report from the World Health Organization concluded that 663 million people worldwide are still without sanitary drinking water. What if a piece of paper could make a significant dent in this public health problem?
While earning her doctorate in chemistry at McGill in Montreal, Theresa Dankovich engineered the a system for purifying water by sifting and trapping microscopic bacteria in a filtration system made from heavy-duty paper. The sturdy pulp in The Drinkable Book is laced with silver and copper nanoparticles that are deadly to microbes such as E. coli. (Those particles imbue the pages with an ochre tinge.)
That’s the key to creating potable water in parts of the world where drinking water is at a precious premium. The filters have been tested with more than 25 water sources in five countries. Dankovich explained to Livemint:
In Africa, we wanted to see if the filters would work on ‘real water,’ not water purposely contaminated in the lab. One day, while we were filtering lightly contaminated water from an irrigation canal, nearby workers directed us to a ditch next to an elementary school, where raw sewage had been dumped. We found millions of bacteria; it was a challenging sample.
Dankovich said water that had been filtered through the paper was consistent with bacteria standards accepted in U.S. drinking water.
Following field trials in Ghana, Haiti, and Kenya, Bowe House Books produced a run of 100 copies with instructions printed in English and Swahili, Slate reported. They’ve been distributed by the humanitarian group WaterisLife. The instructions describe the dangers of ingesting non-potable water—and are written in food-safe ink. In June, the products were tested in Bangladesh to assess culturally-specific marketing tactics.
The creators say that each filter can last up to a month and filter up to 100 liters into a plastic tray, pictured above. The books are not yet mass-produced, though that’s the next step. (Throughout the testing periods, Dankovich fabricated and assembled many by hand in a church basement.)
Though the company has set its sight on international efforts, the idea could have useful applications for American communities such as Flint, Michigan, where aging infrastructure has leeched lead, copper, and other contaminants into residents’ drinking water.