According to the science website LabGrab
, the chemicals polluting the rivers have come from antimicrobial soaps, disinfectants, and sanitizers of the type used to scrub hands, and have originated from homes and hospitals. The chemicals have then entered the sewage system and then, after reaching wastewater treatment centers, have ended up in fresh water.
The research was led by Rolf Halden
, director of environmental security at the Biodesign Institute at Arizona State University. For the study, river, creek and lake-bed sediment samples from 12 locations upstream and downstream of wastewater treatment plants were collected and analyzed.
The most commonly found chemical was triclosan
, which is common to medicated hand soaps. The chemical is currently being reviewed
by the US Environment Protection Agency (EPA) due environmental concerns. Triclosan can remain in the environment for years, causing harm to fish and wildlife. When such chemicals enter the drinking water supply they can also cause harm to human health, such as interfering with hormones. The biggest concern arises from the fact that the chemicals are antimicrobial, which means that they could promote drug resistance
amongst human pathogens.
According to Infection Control
, it is likely that the level of contamination found in freshwater is not unique to Minnesota and that a greater review of US freshwater is required.
The findings were written up
as a study in the Journal of Hazardous Materials.