At the end of last year, David Marash-Whitman was one of six Americans named a “young physics ambassador” by the American Association of Physics Teachers, and was invited to attend a symposium in Taipei, Taiwan.

But the sophomore at Kehillah Jewish High School of Silicon Valley didn’t go. He had plans to attend an international gathering of a different sort: United Synagogue Youth’s international conference in Philadelphia.

Such is the life of Marash-Whitman, a 14-year-old who, in addition to practicing karate and playing saxophone, has won several major science awards and been featured on KQED’s Forum talk show with Michael Krasny.

The Saratoga resident, whose family belongs to Conservative Congregation Beth David, is also committed to Jewish causes. In December, for example, he attended Panim: The Institute for Jewish Leadership and Values seminar in Washington, D.C.

His scientific pursuits are all motivated by his desire to make a difference in the world, he says. “I love being able to make the world a better place.”

Last summer, Marash-Whitman was named an “international young eco-hero” by Action for Nature, an environmental group. He was also chosen as one of America’s top 40 young scientists by the Discovery Channel in 2004, and won second prize in environmental sciences at the 56th Intel International Science and Engineering Fair in Phoenix last year. His project was titled “Design for Biodegradation: Harnessing Natural Decay by Managing Physical and Chemical Dynamics.”

The former two awards were based on research he began when he learned that water polluted with contaminants commonly found in most homes was going through storm drains untreated, and making its way to the creeks and the San Francisco Bay.

“I kind of stumbled upon this, and I was really horrified to find this out,” he said, especially in light of the fact that most storm drains have signs over them saying, “No dumping.”

“It’s not that people are dumping, though that does happen sometimes,” he said. “But the major issue is that people aren’t aware. If you put pesticides on your plants, it goes into the storm drain. If you wash your car, all the soap goes into the driveway and then into the storm drain.

“I think the main issue is that people are unaware of the implications of their actions.”

Marash-Whitman first learned about the situation from reading about it through the West Valley Clean Water Program, a South Bay environmental group.

And what began as a science project for school developed into his prize-winning research. Marash-Whitman took nine chemicals commonly found around the house, and by using lettuce seeds, he was able to test each substance for its toxicity.

“I’ve been been getting a lot of advocacy training from all my environmental work,” he said, “but I’m also passionate about Israel and Judaism.”

Marash-Whitman hopes to become a physicist, and said that he is beginning to learn about the environmental problems in Israel. If he could merge his two prime interests, it would be ideal.

“I’m passionate about environmental science by itself and Israel by itself,” he said. “But having the opportunity to aid Israel and do tikkun olam for the environment at the same time would be an awesome opportunity.”