Deidre Imus (yup, wife of shock jock Don Imus), said it was like "a light bulb went off" when she decided to become an advocate for children's environmental health. After a day spent helping out on Don's annual radiothon for kids with cancer she asked herself, "I really want to find out why our kids are so sick, what's the root cause, and can we prevent it?" she said. She suspected environmental pollution might hold part of the answer.

She went on to found the Deirdre Imus Environmental Center for Pediatric Oncology to study the relationship between environmental toxins and childhood diseases.

"I really jumped into it that impulsively," she says.

As Imus wrote on her Huffington Post blog, a recent Harvard study showed American kids are sicker today, with more chronic illnesses like cancer, asthma, ADD and autism, than a generation ago.

Her new book, "Green This! Growing Up Green," aims to help parents raise healthy kids. It includes info on safe vaccinations, nontoxic toys and advice from leading pediatricians.

"I navigate parents from utero to university," she says.

The book is the second in the "Green This!" series, which began with the bestseller "Greening Your Cleaning" and continues with "Greening You," a how- to guide to personal care.

The Imuses run a working cattle ranch in New Mexico where they invite kids suffering from cancer and other diseases to experience the life of a working cowboy first-hand.

Their son, Wyatt, was born in 1988 and they have raised him on organic, vegetarian, whole grain food. But the Imus family are realists, too, engaging from time to time in "blue moon treats" like donuts and pizza because, as Deidre says, "You know what? Donuts are good!"

Deidre knows how easy is is to get freaked out when it comes to kids. "I'm not one of these militant environmentalists," she says. When she feels overwhelmed, she remembers an African proverb: If you think you're too small to have an impact, try sleeping in a room with a mosquito.

"I love that! It's so true," she says. "Do one thing, and when you're ready, go to the next thing."