Why you should care
This 17-year-old’s invention could save millions of lives from arsenic poisoning.
Lots of us wonder what makes the sky blue, or how flipping a switch lights up a bulb, or why birds circle overhead before a rainstorm. And then we let the wonder go, and our questions dissipate into the ether. Not Kriti Lall. Once she seizes on a question, she hangs on and refuses to let go until she finds an answer. Her curiosity is not idle — Lall needs to know.
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In the fourth grade, she saw a YouTube video of the fizzy explosion that results from mixing Mentos with soda. Lall’s mom wouldn’t let her try the experiment at home. But the urge ate at her, and ate at her and ate at her until, one day when Lall was dragged to Safeway with her mom, she snuck away to plop some blue Mentos into a bottle of Diet Coke. The magnificent boom that ensued shook the whole store, and got Lall grounded for two weeks.
She began growing algae in her living room, trying to boost their hydrogen-production abilities — and stinking up the entire house.
No one said being a whiz kid is easy. Sometimes bewildered adults tell you “no,” and sometimes you get in trouble. But sometimes you reap rewards. Like 17-year-old Lall, whose technique for extracting arsenic from drinking water using genetically engineered bacteria could save millions of lives, all for only $8, or 12 times less than currently available arsenic-removal methods. She cooked up part of the project — the bioreactor that filters out the arsenic — in her garage in Fremont, California. “All you need is PVC pipes, sand and gravel,” she tells OZY.
Lall shuffles sleepily into the chandeliered lobby of the St. Regis Hotel in Washington, D.C., where she’s staying for the Intel Science Talent Search finals, worn out after days of judging. She’s wearing a black blazer, slacks and scuffed-up sneakers, and when I tell her we won’t be filming, she’s relieved. “Good, because my feet hurt.” Petite, with delicate, spritely features, Lall sits and nests her chin in her hand, short nails coated in glittery polish. She speaks in an ethereal tone, like Luna Lovegood from Harry Potter, musing over algae and bioremediation instead of goblins and horcruxes.
Yawning now and then, Lall traces her obsession with science to her childhood, when she asked her parents, both engineers, for crystal-growing kits and laboratory sets. After reading about scientists manipulating algae to produce hydrogen, a source of renewable fuel, she began growing algae in her living room, trying to boost their hydrogen-production abilities — and stinking up the entire house in the process.
Lall emailed 100 professors at nearby universities, asking to test her idea in their labs — and received 100 rejections.
While volunteering at a school in India the summer before high school, Lall noticed villagers’ hands and faces streaked with strange brown-green scars. The woman she approached said she didn’t know how she got them. “Super curious,” Lall grabbed her laptop and turned to Google. The same result flooded the page: arsenic poisoning, usually from contaminated groundwater. Diving deeper, she learned that 137 million people in 70 countries suffer from arsenic poisoning, which is linked to heart disease, diabetes and cancer. But most removal methods were too complex and expensive for the poor countries often plagued with arsenic contamination. Lall had read about engineering bacteria to gobble oil slicks. Why not do the same with arsenic, cheaply?
So Lall emailed 100 professors at nearby universities, asking to test her idea in their labs — and received 100 rejections. Crushed but not broken, she continued sending emails, until a lab finally accepted her.
For the next two and a half years, she focused on a strain of bacteria known as MLHE-1, which expresses a gene that converts arsenic into an easily removable form, but survives only in extremely salty, acidic environments. So Lall figured out how to extract the gene from MLHE-1 and insert it into a harmless strain of E. coli that can survive in fresh groundwater. As the water flows through a bioreactor containing the engineered bacteria, tubes and chambers filled with sand and gravel trap the arsenic.
Lall designed the bioreactor in her garage using materials available at hardware stores. She hopes to begin testing her technology, now patent pending, in India this summer before heading to college — most likely Harvard, where she wants to study, of course, biology.
Wilfred Röling, an associate professor of quantitative microbial ecology at the University of Amsterdam, says he’s “worried about whether this approach will work.” He says other microorganisms can remove arsenic naturally, and probably more effectively. Whether the bioreactor will work in the field also remains to be seen. Lall’s technology isn’t new, either — many other scientists have designed bioreactors to remove arsenic.
But for Lall, that’s beside the point. While the grown-ups scramble to publish groundbreaking papers in Nature and Science, she delights in taking things apart and putting them together again (or making them explode). Even Einstein called play “the highest form of research.” Lall embodies that philosophy — gleefully pouncing on “those thought bubbles that remain in our heads,” she says, “but don’t come out in the form of, ‘How can I answer this question?’”