That appears to be the conclusion of this article from the PERC blog, and may be another example of public environmental policy that sounds good but works out bad.
“San Francisco banned disposable plastic grocery bags in 2007. It’s not alone. Several dozen communities around the country have adopted similar policies, all in the name of environmental protection. Those thin plastic bags may require far less material than in years past, but some still see them as wasteful. New research, however, shows that banning those plastic grocery bags may be bad for your health.
“In a paper up on SSRN, the University of Pennsylvania’s Jonathan Klick and George Mason’s Joshua Wright (recently confirmed as a Commissioner on the Federal Trade Commission) present evidence that bans on disposable plastic grocery bags lead to an increase in food-borne illness. Here’s the abstract:
“Recently, many jurisdictions have implemented bans or imposed taxes upon plastic grocery bags on environmental grounds. San Francisco County was the first major US jurisdiction to enact such a regulation, implementing a ban in 2007. There is evidence, however, that reusable grocery bags, a common substitute for plastic bags, contain potentially harmful bacteria. We examine emergency room admissions related to these bacteria in the wake of the San Francisco ban. We find that ER visits spiked when the ban went into effect. Relative to other counties, ER admissions increase by at least one fourth, and deaths exhibit a similar increase.
“The results really should not be all that surprising. As Businessweek reports, prior research found that few people regularly wash reusable grocery bags or take other precautionary steps (such as using separate bags for meat and produce). So, not surprisingly, tests find coliform and even e.coli bacteria in a significant percentage of bags.”