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Food-borne Danger of Plastic Bag Bans Studied

Local Governments - Exclusive — 13 February 2013

Plastic bag bans have been statistically linked to increases in food-borne illnesses in a new study produced by the Institute for Law and Economics – a joint project of the University of Pennsylvania Law School, the Wharton School, and the Department of Economics in the School of Arts and Sciences at the University of Pennsylvania. Researchers found a significant increase in emergency room visits for food-related illnesses.

According to researchers Jonathan Klick of the University of Pennsylvania and Joshua Wright of George Mason University, emergency room admissions spiked by about one-fourth after the San Francisco plastic bag ban went into effect in 2007.

“These bans are designed to induce individuals to use reusable grocery bags, in the hope that a reduction in the use of plastic bags will lead to less litter,” reads the report. “Recent studies, however, suggest that reusable grocery bags harbor harmful bacteria, the most important of which is E. coli. If individuals fail to clean their reusable bags, these bacteria may lead to contamination of the food transported in the bags. Such contamination has the potential to lead to health problems and even death.”

According to the researchers’ data, coliform bacteria was found in 51 percent of randomly selected reusable grocery bags from consumers in grocery stores in Arizona and California. E. coli was found in 8 percent of the bags examined.

Most people fail to use separate bags for meats and vegetables, leading to cross contamination and researchers discovered that “97 percent of individuals indicated they never washed their reusable bags.”

The study acknowledges the impact that plastic bag bans have on consumer behavior. In both the ILE study and in previous reports from San José, consumer use of disposable bags dropped significantly after a ban took effect.

“There was an 18 percent decrease in plastic bag litter in San Francisco two years after the ban was implemented (City of San Francisco 2009). The Los Angeles Public Works Department documented a 95 percent decrease in plastic bag use (Los Angeles Department of Public Works 2012) soon after its ban took effect. Furthermore, the California Grocers Association found that 90 percent of their San Francisco customers were bringing their own reusable bags (Finz 2012).”

As PublicCEO has previously reported, in San José, “city staff performed field pollution studies, comparing creeks, storm drains, and other water bodies for signs of change. Using standard distances and times, the City found some areas had experienced plastic bag pollution reductions of 50 to 60 percent. On average, storm drain catch basins dropped from 3.6 bags per year to just .4 bags per year.”

However, the ILE study shows that the environmental benefits are grossly outweighed by the negative human impacts.

The researchers’ study reported a conservative increase of 5.4 annual deaths from foodborne illnesses. Using the estimated value of a statistical life ($8.4 million), plastic bag bans account for an annual loss of $45 million, outweighing the $10.3 million annual benefits. That leaves environmental benefits to account for the remaining $35 million, a figure the study says “that the current trend toward bag bans may be difficult to justify on cost benefit grounds.”