Recreational exposure to pathogenic microorganisms from resuspended fine aquatic sediments: Literature review
Please note: As of 1 July 2025, the New Zealand Institute for Public Health and Forensic Science (PHF Science) is the new name for the Institute of Environmental Science and Research (ESR). Research and reports published prior to this date may reference the organisation’s former name.
Summary
In New Zealand, water quality monitoring is carried out at freshwater lakes, rivers, estuaries and coastal beaches to minimise human illness through recreational water contact and shellfish gathering. Monitoring focuses on detecting indicators of faecal contamination in water samples. Those taking the water samples are encouraged to minimise sediment disturbance. The microbial quality of aquatic sediments is not currently monitored. The objective of this review is to identify if fine aquatic sediments (fine sand, silt and clay) could be a source of pathogenic microorganisms (bacteria, viruses and protozoan parasites) and pose a health risk to people as they swim, play and wade in low energy aquatic environments (lakes, rivers, estuaries, lagoons, etc.). Understanding the potential health risks from resuspended sediments will assist public health officials and regional council water quality managers to manage recreational water quality.