This is the VOA Special English Development Report.

Every day, millions of people around the world drink water from wells that are polluted with high levels of arsenic. Arsenic is an element that can be released into groundwater by soil and rocks. Over a long period of time, water from poisoned wells may lead to deadly cancers.

Chemist Abul Hussam has developed a home treatment system for drinking water in his native Bangladesh. Almost all arsenic is removed as water passes through two containers. They hold river sand, pieces of iron and wood charcoal.

Sono filter system is manufactured in his hometown of Kushtia, where he also did much of his research. He tells us that his first task was to develop instruments to measure the exact amounts of arsenic in the water.

Early tests on two wells at the home where he lived as a child found arsenic levels three to four times higher than normal. As a chemist, he felt that if he could not solve what he calls the "home problem," then his education would not be very useful.

His ten-year effort to find the right mix of active materials for the Sono filter system has just earned him a one million dollar prize. Abul Hussam is the top winner of the two thousand seven Grainger Challenge Prize for Sustainability. The prize is administered by the National Academy of Engineering in the United States.

Abul Hussam is a chemistry professor at George Mason University in Fairfax, Virginia. He says he will give five percent of the money to the university. And he plans to use twenty-five percent of the award to develop smaller filters. Currently the system weighs almost sixty kilograms.

But Professor Hussam says he will use the remaining money to increase production of the filters in Kushtia. One hundred workers currently produce about two hundred filters a week.

About thirty thousand homes in Bangladesh are using the system. It costs families thirty-five dollars. But Professor Hussam says the filters are extremely cost effective compared to the price of bottled water.

He says each system is guaranteed to clean about one million liters of drinking water over five years. In theory, though, he says they should last around thirty-five years.

He is now seeking international patent rights for the active materials in the system -- and he hopes to increase their power. Abul Hussam says he also hopes that someday the Sono arsenic removal system will be available around the world.

And that's the VOA Special English Development Report, written by Jill Moss. I'm Steve Ember.