Debut of the first podcast coincides with publication of a special edition of Environmental Science & Technology, one of ACS' 36 peer-reviewed scientific journals. It is devoted to global water issues. Key articles from the journal can be viewed without charge at [http://pubs3.acs.org/acs/journals/toc.page?incoden=esthag].

The podcast describes an increasingly serious global shortage of clean drinking water, which claims a huge toll in illness and death in developing countries. It presents examples of scientific research that are reducing that toll today, and promise to have further impact in the future. Global Challenges describes one, for instance, as "The Miracle Packet." These pennies-a-piece packets work like a municipal water purification facility to kill germs, remove harmful substances, and make dirty water fit to drink.

Edwards emphasizes that people in the United States generally enjoy tap water of "very good" overall quality. One exception involves relatively small numbers of children exposed to high levels of lead in their drinking water, he said.

Edwards describes newly emerging concerns, including tap water safety for individuals with weakened immune systems, home plumbing corrosion caused by water purification plants switching to chloramine disinfectant, and water stagnating in household pipes.

With consumers using less for flushing of toilets and showering, water sits in household pipes for longer periods, said Edwards, who is with Virginia Tech. Substances formed as chloramine breaks down can corrode plumbing, and have more time to do so when water stagnates.

Edwards indicated that stale water also can loose the disinfectant added at municipal water purification facilities, allowing bacteria to multiply. "So just like milk can go bad if it stays around too long, so too can potable water go bad, and we are discovering this is a downside of water conservation," he said.

The next Global Challenges/Chemistry Solutions podcast, due in July, deals with advances in water desalination technology that promise to provide a drought-proof supply of fresh water from the sea.

The American Chemical Society — the world's largest scientific society — is a nonprofit organization chartered by the U.S. Congress and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

— Michael Woods