Science can be a battleground -- witness the politics of climate change, the teaching of evolution, the uncharted terrain of genetic modification and stem cell research, among other contentious issues. But when industries release untested chemicals into our environment -- putting profits before public health -- our children are the first to suffer. Nowhere is this more troubling than in the ongoing story of lead poisoning. On this week's Moyers & Company (check local listings), Bill talks with David Rosner and Gerald Markowitz, public health historians who've been taking on the chemical industry for years -- writing about the hazards of industrial pollution and the neglect of worker safety -- despite industry efforts to undermine them. Their latest book, Lead Wars: The Politics of Science and the Fate of America's Children, is the culmination of 20 years of research. Markowitz and Rosner warn that, for young children, there's no safe level of exposure to this dangerous toxin still lurking in millions of homes. Rosner and Markowitz discuss thwarted efforts to hold the lead industry accountable, failed attempts to find cheap solutions, and the cost to the future of our children. As long as the chemical industry and its powerful lobbies prevail in blocking efforts to reform outdated laws, the authors say, we will continue to float in a soup of toxins -- inhaling, drinking, and absorbing chemicals that we may learn, years later, have put us all in harm's way. Also on the show, Bill is joined by the heads of two independent watchdog groups keeping an eye on government as well as on powerful interests -- like chemical companies -- seeking to influence it. Sheila Krumholz, executive director of the Center for Responsive Politics and OpenSecrets.org, and Danielle Brian, who runs the Project on Government Oversight, talk to Bill about the importance of transparency to our democracy, and their efforts to scrutinize who's giving money, who's receiving it, and most importantly, what's expected in return.