From the Consumer Reports Health Blog:
A study published online in the journal Environmental Health Perspectives provides more reasons to be wary of triclosan, found in many antibacterial soaps, and bisphenol A (BPA), used in some polycarbonate plastics and canned foods.
The study looked at 3,728 people nationwide and found that children and adolescents with higher levels of triclosan were more likely to be diagnosed with allergies or hay fever, both of which are caused by a malfunctioning immune system. The researchers suggest that the hygiene hypothesis—which posits that some exposure to bacteria helps train the immune system—might help explain the finding.