Not only do they sustain bacteria, they contain lead.
Scrape off the trendiness and a popular “green” choice is actually “gray” underneath; some reusable shopping bags contain lead.
The Tampa Tribune commissioned an independent lab to test the reusable shopping bags of the plasticy, painted-on graphic variety, sold by Winn-Dixie and Publix supermarkets.
In the first batch of tests, Winn-Dixie’s bag had lead levels at 121 parts per million and Publix had 87. In the second, there were 117 and 194 parts per million, respectively.
(The Cosumerist)