A newly developed device that connects to a smartphone could prevent millions of water consumers around the world from Drinking Arsenic contaminated water that could be harmful to their health.
Researchers from the University of Edinburgh have developed an ultra-sensitive biosensor that can be attached to a smartphone to detect arsenic levels in drinking water at levels deemed unsafe.
The device, which makes use of bacteria to detect the presence of arsenic, generates visual patterns, similar to bars used to indicate volume or signal strength on a cellphone, to indicate arsenic contamination levels. This simple visual display of the data makes it easy for users to interpret and understand the test results.
Arsenic occurs naturally in groundwater in many countries around the world, notably India and Bangladesh, but also in many states around the US. Long-term exposure to arsenic can cause skin lesions and is associated with an increased risk of cancer. It is believed to be responsible for 20% of all deaths in regions where contamination is highest. Scientists believe that a simple, yet affordable, on-site solution to identify contaminated water is long overdue and urgently needed.
Many of the badly affected countries have limited resources, including a lack of skilled labor or laboratories to test drinking water for arsenic contamination. Scientists believe that newly developed devices could provide an alternative to conventional water testing, which are not only difficult to implement, but also require specialized laboratory equipment, and may form toxic chemicals as a byproduct.
Drinking water contamination by heavy metals such as arsenic is a global health issue. According to UNICEF, 140 million people across the world are exposed to arsenic via their drinking water.
To test the arsenic detection ability of the biosensors, the researchers used arsenic contaminated water samples collected from wells located in Bangladesh, where groundwater contamination by arsenic is amongst the highest in the world. It is estimated that around 20 million Bangladeshis, mostly from impoverished rural areas, depend on arsenic-contaminated drinking water.
To develop the biosensor, the researchers manipulated the genetic DNA structure of Escherichia coli (E. Coli) — a common bacteria that is ubiquitous in the environment (e.g. water, soil), and is also found in the gut of warm-blooded animals (including humans), as well as food — adding genetic components that serve as amplifiers when arsenic is present.
When water samples containing arsenic were poured into a device which contained the E.coli bacteria suspended within a gel, they produced proteins that made them fluorescent, and therefore visible to the naked eye.
The research team believe that this approach may be helpful for detecting other environmental contaminants, as well as for diagnosing diseases and for locating landmines, and ultimately help to improve the health and safety of millions of people the world over.
Having a simple tool that attaches to your smartphone to help detect water contamination would be fantastic. But having a method of getting rid of those contaminants would be better still. We recommend filtering your drinking water with a good quality drinking water filter to remove any harmful contaminants, including arsenic, that may be present.
The Berkey range of water purifiers, fitted with a set of Black Berkey filter cartridges will remove a wide range of common drinking water contaminants, including heavy metals such as arsenic.
Journal Reference
Xinyi Wan, et al. Cascaded amplifying circuits enable ultrasensitive cellular sensors for toxic metals. Nature Chemical Biology (2019); DOI:10.1038/s41589-019-0244-3
