TY - JOUR

T1 - Assessing Risk of E. coli Resuspension from Intertidal Estuarine Sediments

T2 - Implications for Water Quality

AU - Wyness, A.J.

AU - Paterson, D.M.

AU - Rimmer, J.E.V.

AU - Defew, E.C.

AU - Stutter, M.I.

AU - Avery, L.M.

PY - 2019/9/5

Y1 - 2019/9/5

N2 - Estuarine sediments are a reservoir for faecal bacteria, such as E. coli, where they reside at greater concentrations and for longer periods than in the overlying water. Faecal bacteria in sediments do not usually pose significant risk to human health until resuspended into the water column, where transmission routes to humans are facilitated. The erosion resistance and corresponding E. coli loading of intertidal estuarine sediments was monitored in two Scottish estuaries to identify sediments that posed a risk of resuspending large amounts of E. coli. In addition, models were constructed in an attempt to identify sediment characteristics leading to higher erosion resistance. Sediments that exhibited low erosion resistance and a high E. coli loading occurred in the upper- and mid-reaches of the estuaries where sediments had higher organic content and smaller particle sizes, and arose predominantly during winter and autumn, with some incidences during summer. Models using sediment characteristics explained 57.2% and 35.7% of sediment shear strength and surface stability variance respectively, with organic matter content and season being important factors for both. However large proportions of the variance remained unexplained. Sediments that posed a risk of resuspending high amounts of faecal bacteria could be characterised by season and sediment type, and this should be considered in the future modelling of bathing water quality.

AB - Estuarine sediments are a reservoir for faecal bacteria, such as E. coli, where they reside at greater concentrations and for longer periods than in the overlying water. Faecal bacteria in sediments do not usually pose significant risk to human health until resuspended into the water column, where transmission routes to humans are facilitated. The erosion resistance and corresponding E. coli loading of intertidal estuarine sediments was monitored in two Scottish estuaries to identify sediments that posed a risk of resuspending large amounts of E. coli. In addition, models were constructed in an attempt to identify sediment characteristics leading to higher erosion resistance. Sediments that exhibited low erosion resistance and a high E. coli loading occurred in the upper- and mid-reaches of the estuaries where sediments had higher organic content and smaller particle sizes, and arose predominantly during winter and autumn, with some incidences during summer. Models using sediment characteristics explained 57.2% and 35.7% of sediment shear strength and surface stability variance respectively, with organic matter content and season being important factors for both. However large proportions of the variance remained unexplained. Sediments that posed a risk of resuspending high amounts of faecal bacteria could be characterised by season and sediment type, and this should be considered in the future modelling of bathing water quality.

KW - bathing waters

KW - cohesive sediment

KW - E. coli

KW - erosion

KW - estuarine sediment

KW - faecal contamination

KW - faecal indicator organism (FIO)

KW - intertidal

KW - sediment stability

KW - water quality

U2 - 10.3390/ijerph16183255

DO - 10.3390/ijerph16183255

M3 - Journal article

VL - 16

JO - International Journal of Environmental Research and Public Health

JF - International Journal of Environmental Research and Public Health

SN - 1660-4601

IS - 18

M1 - 3255

ER -