You really think you drink clean water in the US? Small traces of the world’s most widely used insecticides have been detected in US tap water for the first time.
Samples taken by scientists in the US state of Iowa showed that levels of neonicotinoid chemicals remained constant despite treatment.
After chemicals from fracking, scientists have identified neonic insecticides in US drinking water.
Scientists say they cannot draw any conclusions relating to human health but argue that further study is needed.
Rapid uptake of neonicotinoids
The use of neonicotinoids has increased rapidly since their introduction in the early 1990s.
These systemic chemicals were seen as an advance because they are usually applied as a seed coating and are lethal to insects but not to other species.
In the US, sales of seeds pre-treated with neonics tripled from 2004 to 2014.
Environmental impacts of neonicotinoids
However concerns over their environmental impacts have also grown and they have been consistently associated with causing harm to bees. So great has the worry been, that there has been a moratorium on their use on flowering crops in the European Union since 2013.
A study in 2015 from the US Geological Survey (USGS) found that neonics were widespread in water samples collected from 48 different rivers and streams in the US.
New study on drinking water
This new study from the USGS and the University of Iowa, looked at tap water that was treated in two different filtration systems. Samples from the University of Iowa treatment plant barely removed any of the three main neonic chemicals, clothianidin, imidacloprid and thiamethoxam. Water taken from the Iowa city treatment facility removed 100%, 94% and 85% respectively, of these substances.
“These are very low levels, these are nanograms per litre which means parts per trillion, a very low concentration. But at the same time there are concerns about what those low levels might do from an exposure standpoint.” said Prof Gregory LeFevre, one of the authors from the University of Iowa.
In the US, the Environmental Protection Agency regulates contaminants in water but as of now, neonics are not considered a threat. One of the issues of concern is not the direct exposure of humans to neonics in water, but how the insecticides might be transformed by the filtration process into other substances that pose a greater threat.
How to get rid of neonics?
The study presents evidence that the presence of neonics in drinking water can be essentially negated if activated carbon filtration systems are used, which is relatively economical compared to other technologies that are energy expensive.
Given the scale of research looking at the impacts of neonics on bees and other creatures, it is important that further studies are carried out on drinking water to work out the levels of exposure around the world.