The Environmental Protection Agency is holding public hearings today to review a proposed safe exposure limit for dioxin, a known carcinogen and endocrine disruptor produced as a common industrial byproduct.

It's all but impossible to avoid exposure to dioxin. Research done by the Environmental Working Group has shown that adults are exposed to 1,200 times more dioxin than the EPA is calling safe - mostly through eating meat, dairy and shellfish - and mothers pass it on to babies in the womb and in breast milk. A nursing infant ingests an amount 77 times higher than what the EPA has proposed as safe exposure. (Formula is also widely contaminated with the stuff.)

Because dioxin is such a common pollutant - it's a waste product of incineration, smelting, chlorine bleaching and pesticide manufacturing - its health effects are well documented. Fifties-era research linked high-level exposure to cancer and disease outbreaks. Newer studies have shown that ongoing low-level exposure can result in heart disease, diabetes, cancer, endometriosis, early menopause and reduced testosterone and thyroid hormones.

Indeed, as a testament to the toothlessness of our regulatory system, the EPA first flagged dioxin for review nearly 30 years ago. And even the threshold now finally being proposed - the one adults exceed 1,200-fold - is higher than environmental health advocates would like. But surely it's better than nothing.