{"id":37308,"date":"2020-12-04T09:52:18","date_gmt":"2020-12-04T09:52:18","guid":{"rendered":"https:\/\/www.bgs.ac.uk\/?p=37308"},"modified":"2024-03-05T08:16:09","modified_gmt":"2024-03-05T08:16:09","slug":"real-time-detection-of-faecally-contaminated-drinking-water","status":"publish","type":"post","link":"https:\/\/www.bgs.ac.uk\/news\/real-time-detection-of-faecally-contaminated-drinking-water\/","title":{"rendered":"Real-time monitoring of faecally contaminated drinking water"},"content":{"rendered":"\n
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Globally, two billion people consume water contaminated with faeces1<\/a><\/sup>. This exposure increases the incidence of infectious disease such as diarrhoea, which alone results in more than half a million deaths per year in low- and middle-income countries2<\/a><\/sup>. The most at-risk age group is children under five, with diarrhoea the second leading cause of death3<\/a><\/sup>. In higher-income countries, risks remain due to the consumption of undertreated water from private supplies, or in public supplies, from failures in either water treatment or the integrity of the distribution network.<\/p>\n\n\n\n

To help address these issues, scientists at the BGS have led a number of studies to assess the microbiological quality of drinking water supplies4<\/a>,5<\/a><\/sup>. Recent BGS sensor research has focused on on-site testing using portable tryptophan-like fluorescence (TLF) sensors that require no reagents and provide instantaneous readings. While not a substitute for standard culturing methods, TLF sensors have the potential to be used for real-time microbial risk screening of drinking water supplies. <\/p>\n\n\n

\"well<\/a>
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Shallow well used for drinking water supply in Malawi. BGS \u00a9 UKRI.<\/p>\n<\/div>\n\t\t\t\t\t

\"Expand<\/a><\/div>\n\t\t\t\t<\/figcaption><\/figure>\n\n\n

These sensors measure the fluorescence that is associated with the amino acid tryptophan, termed TLF. A measurement is obtained by either submerging a sensor in a water sample or using a small sample container that fits into the sensor, with results available in 60 seconds. A flow-through cell is used for online applications and all approaches require no reagents or other consumables.<\/p>\n\n\n\n

How can groundwater become contaminated by faecal organisms?<\/h2>\n\n\n
\"Drinking<\/a>
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Drinking water supplies have the potential to become contaminated by various sources of waste, including enteric (gut) pathogens from human and animal faeces. TLF testing can be used as an initial screening tool to inform and complement further water quality investigations. BGS \u00a9 UKRI.<\/p>\n<\/div>\n\t\t\t\t\t

\"Expand<\/a><\/div>\n\t\t\t\t<\/figcaption><\/figure>\n\n\n

Traditional testing approach<\/h3>\n\n\n\n

Faecal contamination in drinking water can be detected using faecal indicator organisms (FIOs), such as E. coli<\/em>. This approach requires working with sterile equipment and reagents. Testing can take up to a day to return results due to the necessity of culturing. However, in lower- and middle-income countries, these requirements can restrict water-quality monitoring. Delays resulting from FIO methods also limit the ability to rapidly communicate the risks to local communities. As a result, UNICEF and the World Health Organisation (WHO) are looking for new technologies for the rapid detection of E. coli<\/em>.<\/p>\n\n\n\n

Results<\/h3>\n\n\n\n

The primary aim of the BGS research has been to evaluate how useful and reliable TLF is for assessing faecal contamination through relationships with FIOs in groundwater. We have demonstrated:<\/p>\n\n\n\n