Evidence map›Paper›PMID 32958794›Full record

ArticleScientific reports2020

Tryptophan-like and humic-like fluorophores are extracellular in groundwater: implications as real-time faecal indicators.

James P R Sorensen, Andrew F Carr, Jacintha Nayebare, Djim M L Diongue, Abdoulaye Pouye, Raphaëlle Roffo, Gloria Gwengweya, Jade S T Ward, Japhet Kanoti, Joseph Okotto-Okotto and 13 more

Abstract read
In one paragraph

Article in Scientific reports, 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 5 papers.

0numbers the graph read from it
0cells of the map it votes in
5citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

5 citing papers in PubMed.

  1. Fluorescence-Based Indicators ofACS ES&T water · 2025
    Article
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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

23 authors.

James P R SorensenBritish Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK. jare1@bgs.ac.uk.
Andrew F CarrDepartment of Geography, University College London, London, WC1E 6BT, UK.
Jacintha NayebareDepartment of Geology and Petroleum Studies, Makerere University, Kampala, Uganda.
Djim M L DiongueDepartment of Geology, Universite Cheikh Anta Diop, Dakar, Senegal.
Abdoulaye PouyeDepartment of Geology, Universite Cheikh Anta Diop, Dakar, Senegal.
Raphaëlle RoffoDepartment of Geography, University College London, London, WC1E 6BT, UK.
Gloria GwengweyaChancellor College, University of Malawi, P.O. Box 280, Zomba, Malawi.
Jade S T WardBritish Geological Survey, Keyworth, NG12 5GG, UK.
Japhet KanotiDepartment of Geology, University of Nairobi, Nairobi, Kenya.
Joseph Okotto-OkottoVictoria Institute for Research on Environment and Development (VIRED) International, Rabuour Environment and Development Centre, Kisumu-Nairobi Road, P.O. Box, Kisumu, 6423-40103, Kenya.
Laura van der MarelDepartment of Geography, University College London, London, WC1E 6BT, UK.
Lena CiricDepartment of Civil, Environmental and Geomatic Engineering, University College London, London, WC1E 6BT, UK.
Seynabou C FayeDepartment of Geology, Universite Cheikh Anta Diop, Dakar, Senegal.
Cheikh B GayeDepartment of Geology, Universite Cheikh Anta Diop, Dakar, Senegal.
Timothy GoodallCentre for Ecology and Hydrology, Maclean Building, Wallingford, OX10 8BB, UK.
Robinah KulabakoDepartment of Civil and Environmental Engineering, Makerere University, Kampala, Uganda.
Daniel J LapworthBritish Geological Survey, Maclean Building, Wallingford, OX10 8BB, UK.
Alan M MacDonaldBritish Geological Survey, Lyell Centre, Research Avenue South, Edinburgh, EH14 4AP, UK.
Maurice MonjereziChancellor College, University of Malawi, P.O. Box 280, Zomba, Malawi.
Daniel OlagoDepartment of Geology, University of Nairobi, Nairobi, Kenya.
Michael OworDepartment of Geology and Petroleum Studies, Makerere University, Kampala, Uganda.
Daniel S ReadCentre for Ecology and Hydrology, Maclean Building, Wallingford, OX10 8BB, UK.
Richard G TaylorDepartment of Geography, University College London, London, WC1E 6BT, UK.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Fluorescent natural organic matter at tryptophan-like (TLF) and humic-like fluorescence (HLF) peaks is associated with the presence and enumeration of faecal indicator bacteria in groundwater. We hypothesise, however, that it is predominantly extracellular material that fluoresces at these wavelengths, not bacterial cells. We quantified total (unfiltered) and extracellular (filtered at < 0.22 µm) TLF and HLF in 140 groundwater sources across a range of urban population densities in Kenya, Malawi, Senegal, and Uganda. Where changes in fluorescence occurred following filtration they were correlated with potential controlling variables. A significant reduction in TLF following filtration (ΔTLF) was observed across the entire dataset, although the majority of the signal remained and thus considered extracellular (median 96.9%). ΔTLF was only significant in more urbanised study areas where TLF was greatest. Beneath Dakar, Senegal, ΔTLF was significantly correlated to total bacterial cells (ρ

Indexed as

AfricaDrinking WaterEnvironmental MonitoringFecesFluorescenceFluorescent DyesGroundwaterTryptophanWater MicrobiologyWater SupplyDrinking WaterFluorescent DyesTryptophan

Identifiers

PMID32958794
PMCPMC7505957

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.