From Environmental Health Sciences:
Sewage Plants May Be Creating "Super" Bacteria
A wastewater treatment plant's job description is pretty straightforward: Remove contaminants from sewage so it can be returned to the environment without harming people or wildlife.
But a new study suggests that the treatment process can have an unintended consequence of promoting the spread of extra-hardy bacteria.
Some bugs are resistant to antibiotics, so they dodge the medical bullets that wipe out others. The more drugs that are used, the more robust they become. Since bacteria reproduce quickly -- one organism might turn into a billion overnight -- and they share DNA with others, antibiotic-resistant genes spread like Darwinian wildfire when conditions are right.
And at sewage treatment plants, it seems, the conditions are right, said microbiologist Chuanwu Xi, whose University of Michigan lab conducted the study.
"Wastewater treatment plants are most effective at treating sewage when they have conditions that allow beneficial bacteria to thrive and improve the quality of the water," said Karen Kidd, a University of New Brunswick ecotoxicologist familiar with the study.
"However, this study indicates that these conditions can also favor the mutation of some and act as a source of antibiotic resistant bacteria to the environment."
"To me," she added, "that's sobering."
And it's not like you can toss a jug of Clorox in every few hours.
Good business opportunity for some company to make a retrofit.
