In 2000 the WHO described the arsenic contamination of water from millions of bore hole wells in Bangladesh as “the largest mass poisoning of a population in history”, and that “the scale of this environmental disaster  is  greater  than  any  seen before; it is beyond the accidents at Bhopal, India in 1984 and Chernobyl, Ukraine in 1986[1]

Contaminated drinking water supplies are not restricted to Bangladesh, arsenic is naturally found in aquifers on a global scale. Arsenic poisoning causes a wide variety of symptoms including, headaches and severe diarrhoea and as poisoning builds over time, symptoms become more acute resulting eventually in coma and death. Current WHO guidelines recommend a limit of 0.01 mg/L (10 parts per billion) of arsenic in drinking water. This recommendation is based on the limit of detection for most laboratories' testing equipment at the time of publication of the WHO water quality guidelines. More recent findings show that consumption of water with levels as low as 0.00017 mg/L (0.17 parts per billion) over long periods of time can lead to arsenic poisoning.[2]

(from BBSRC GOW) Arsenic contamination of drinking water is a global problem, affecting 14% of the world's population (WHO Figures) particularly in resource poor regions where access to adequate testing facilities is either limited or non-existent.

In Bangladesh low-income households are most affected by the detrimental health effects resulting from the consumption of arsenic contaminated drinking water. Research has estimated that the household labour supply in rural Bangladesh is 8% smaller due to the widespread arsenic contamination[3] and 6% of total deaths in Bangladesh are attributed to arsenic contamination[4]. This leads to a conservative estimate of the portion of GDP to be lost from arsenic-attributable mortality over the next 20 years is between US$ 6.1-20.1 billion depending on discount rate selected[5].

Professor Tony Cass is a leading authority in the field and has been working with biosensors for over 30 years. Biosensors are found in many common items such as home pregnancy kits and blood glucose monitors. Biosensors are analytical devices combining biological molecules with a physical or chemical detector. When the target to be detected is encountered by the device a reaction is set off that triggers an electric current which can be detected, in some devices the size of the current can indicate the concentration of the target.

In 1999, Dr Joanne Santini, now leading a research group at UCL (Santini Lab), discovered a bacterium in a gold mine in the Northern Territory of Australia that could metabolise arsenic and from this an enzyme was isolated that performed this function. Importantly, Joanne was able to create a recombinant version of the enzyme that she could manufacture in E-coli, in commercially viable quantities and costs. In collaboration with Tony, this would go on to become the biological molecule at centre of new brand of biosensors enabling highly accurate detection of arsenic contamination at low levels of concentration.

With successive support from a number of BBSRC funding streams the team has been able to continue to develop the sensors from lab based tests to working prototypes. Initially, a BBSRC Follow-on-Fund award enabled Tony to recruit Dr Chris Johnson to help define the scope of the planned device addressing key issues such as user requirements and complete initial proof-of-concept experiments. The BBSRC Sparking Impact Award enabled the team to crystallise these ideas and after end-user research trips to India and Argentina, the team secured a BBSRC Super Follow-on-Fund award which is allowing them to focus on the manufacturability of a working prototype and complete field trial work in India and Bangladesh. Commercialisation of the product is also being pursued with support from Innovate UK funding through Bio-Nano Consulting. For the next stage of their work the team are engaging with Professor T. Pradeep and InnoNano Research Private Limited, at the Indian Institute of Technology, Chennai, India, to investigate remediation technologies and offer a turn key solution of arsenic testing and removal.

The team also work in close collaboration with a group of NERC funded researchers who are also investigating solutions to Arsenic funding and have been supported by a NERC IAA Award.



[3] Richard. T. Carson, Phoebe Koundouri, Céline Nauges, 'Arsenic Mitigation in Bangladesh: A Household Labor Market Approach', Amer. J. Agr. Econ, 2011

[4] Sara. V. Flanagan, Richard B Johnston, Yan Zheng, 'Arsenic in tube well water in Bangladesh: health and economic impacts and implications for arsenic mitigation', Bull World Health Organ, 2012

[5] Sara. V. Flanagan, 'Making Economic Sense for Arsenic Mitigation: A Case Study of Comilla District Bangladesh', UNICEF, Bangladesh, 2011