Feb 14 - SF Health Official Responds to Paper on "Killer Reusable Bags"

Will using reusable bags cause more deaths?

An official in San Francisco, home of the first single-use plastic bag ban in the nation, doesn't think so.

Last week, San Francisco’s Health Officer Dr. Tomas Aragon released a memo in response to a Wharton School Institute for Law and Economics paper claiming that bag bans lead to increased illnesses and deaths.

Aragon pointed out the many flaws of the paper, including an inability to draw causal conclusions based on its ecological study design.

"The basic study flaw is that persons that use reusable bags frequently may not be the same persons that were diagnosed with gastrointestinal bacterial infections in their study."

The study also failed to measure the amount of exposure in affected persons, and lacked a control to eliminate other possible factors. It was not peer-reviewed before being released and recirculated by media.

He also noted that the emergency room data used was an incomplete representation of illness, and stated that 111 of the 140 (79%) reported ER deaths from intestinal infectious diseases were for Enterocolitis due to Clostridium difficile--and should not have been included in the study.

These types of infections have been occurring more often throughout Northern America and Europe for unknown reasons, and increasing in SF since 2005 (two years before the ban). They are caused by overgrowth when exposed to antibiotics (generally in hospital patients), and a link to foodborne exposure has not been established.

The remaining 29 intestinal-infection related deaths in the last 10 years are insufficient evidence for the research paper’s conclusion.

Aragon stated that the health impact question raised by the paper was valid one, and that the City and County of San Francisco was closely monitoring and studying infectious diseases. He concluded,

"...the idea that widespread use of reusable bags may cause gastrointestinal infections if they are not regularly cleaned is plausible. However, the hypothesis that there is a significant increase in gastrointestinal foodborne illnesses and deaths due to reusable bags has not been tested, much less demonstrated in this study.

It would be a disservice to San Francisco residents and visitors to alarm them by claiming that it has been. It could be useful, however, to remind people to use safe food-handling practices, including maintaining the cleanliness of everything they use to transport, handle, and prepare food."

Read more in an earlier blog.