:: New UPGro Paper :: Tryptophan-like fluorescence as a measure of microbial contamination

A new paper has been published from the UPGro Gro for GooD project, working in Kenya, which develops the work done under the UPGro Catalyst Project on mapping groundwater quality, which developed an exciting new low-cost, real-time method of measuring microbial contamination of groundwater.

Context:

  • Globally, 25% of people lack access to water that is free from microbial contamination, in some countries the proportion is much higher.  This has major health implications, particularly for children.
  • Monitoring water quality for disease-causing organisms is difficult, and the common method is take water samples to a lab to measure Coli bacteria. Although largely successful, it is an expensive in terms of time and materials, and cannot be relied on for some kinds of biological water quality risks – particularly in groundwater where the absence of E.Coli does not guarantee biological safety of the water.
  • Tryptophan-like fluorescence (TLF) is a relatively new way of rapidly measuring biological water quality in the field, without needing expensive and time-consuming lab equipment and consumables. It is better suited to groundwater than surface water monitoring.

Key Points: –

  • This is the first groundwater study to compare TLF with E. Coli specifically.
  • Tryptophan-like fluorescence (TLF) can complement E. coli as a risk indicator, but it is not proposed as a replacement.
  • Both TLF and coli distinguish low/intermediate, high and very high risk sources.
  • TLF has negligible variability due to the method, unlike bacteriological analyses.
  • TLF is useful for pre-screening, monitoring and demonstrating risk in groundwater.
  • Fieldwork for this research was done in rural Kwale Country, Kenya
  • Next steps include:
    • focus on how TLF relates to pathogens and health, rather than just focusing on the coincidence with E.Coli.
    • better understanding of TLF in different groundwater conditions
    • better computer software of processing and presenting TLF data
    • assess the usefulness of TLF in communicating water risks to groundwater users.

Read the full paper (open access) here:

Nowickia, S.,  D. J.Lapworth, J.S.T. Ward, P. Thomson & K. Charles (2019) Tryptophan-like fluorescence as a measure of microbial contamination risk in groundwater, Science of The Total Environment, Volume 646, 1 January 2019, Pages 782-791 https://doi.org/10.1016/j.scitotenv.2018.07.274

If you are interested in finding out more on safe water and water quality monitoring then you watch these RWSN webinar recordings from late last year:

  • Safe water in towns and peri-urban areas: challenges of self-supply and water quality monitoring: https://vimeo.com/266654585
  • La salubrité de l’eau dans les villes et zones péri-urbaines: le défis liés à l’auto-approvisionnement et le suivi de la qualité https://vimeo.com/266649345