Schade stood behind the report, noting that his team found that the shower curtains released 108 different volatile organic compounds, or VOCs. He maintained that many of these compounds have been linked with developmental problems in children, cancer and other health effects.
But he conceded that whether the levels of these VOCs emitted by the curtains could be directly linked to health effects was difficult to determine. "It's really hard to say that, because there are currently no standards for indoor air quality."
He cited that one class of chemicals — phthalates — were of particular concern due to their purported effects on babies in the womb.
"All five curtains we tested contained phthalates at pretty high concentrations," he said.
Phthalates, however, are present in nearly all flexible plastics. And the ubiquitous ingredient, unlike VOCs, is not released into the air by products containing it — suggesting that the primary way one would absorb it from their shower curtain would be through eating it.
Still, Shanna Swan, director of the Center for Reproductive Epidemiology at the University of Rochester School of Medicine and Dentistry, said that the idea that the researchers detected so many compounds warrants further study.
"I was surprised and alarmed by the large number of volatile organic compounds measured," she said. "I think it's a very strong message that we are exposed to mixtures of chemicals."
But she agreed that the findings, on their own, were far too weak to be considered a basis for an all-out ban on vinyl shower curtains.
"I don't think that this is a case for panic or immediately ripping these things out of houses," she said. "I don't think any regulations would be made on a single study."
And other epidemiologists cited the need for evidence of real-world effects in any study.
"I would think that they would have data showing how health outcomes have changed [due to exposure to shower curtains]," said Dr. Tim Byers, professor of epidemiology and community health at the University of Colorado School of Medicine. "That is always the question; is this a laboratory phenomenon that is not related to 'in use' conditions?"
Vallese said that unless a stronger link can be proven, consumers can probably put their minds at ease the next time they purchase a new shower curtain.
"In our busy lives, there are so many things that people should be or could be focused on to improve their health and safety," Vallese said. "Their shower curtains are not one of them.
"I think there are a lot of people out there sounding the false alarm."