Are plastics safe? - Some chemicals may affect the reproductive system, growing research suggests. But as consumers seek alternatives, scientists point out that human studies are few.

Her life is as plastic-free as her mother, Celina Lyons, can make it.

Celina, a Berkeley-based acupuncturist, has become increasingly worried about the possible toxic effects of plastics. "I remember hearing -- I don't remember when -- that my Nalgene [water] bottle was no longer safe," Lyons said. Once pregnant, she stopped storing food in plastic and cut back on plastic wrap. She sought plastic baby bottles free of a chemical called bisphenol A and teething rings free of chemicals called phthalates. (She failed to find the latter.)

"It's hard to just be a relaxed parent," Celina says. "You want to do what you can to make things as safe as possible."

More and more consumers -- new mothers are leading the pack -- are expressing concern about potentially toxic chemicals in plastic products. Baby blogs are abuzz with warnings about chemicals in baby bottles and toys. Retailers say that demand for glass baby bottles is higher than it's been in decades and that shoppers are snatching up bottles and training cups made from plastics without bisphenol A. California lawmakers have taken notice: Last week, the state Legislature passed a bill to ban certain phthalates in plastic items meant for children younger than 3.

Recent widely publicized studies have shown that plastics are not only ubiquitous in the environment (marine researchers have shown that plastic debris outweighs zooplankton in remote parts of the Pacific), but are found in the bodies of nearly all Americans too. Scientists have hypothesized that chemicals in certain plastics may be linked to such conditions as asthma and even obesity. But most of the research, and the strongest evidence, points to effects that certain plastics chemicals appear to exert on the reproductive system. Findings are still considered preliminary (existing studies are small and few), but reports are enough to make consumers ask: Are plastics safe?

"Unfortunately," said Dr. Philip Landrigan, a pediatrician and chairman of the department of community and preventive medicine at the Mount Sinai School of Medicine in New York, "we're in the terrible position of having to say that we mostly don't know."