Beach Cohort Study

Currently, baseline data about recreational water illness is lacking in Canada. Beachgoers may lack awareness and understanding of recreational water illness risks and how to prevent them. This study aims to identify the burden of recreational water illness among Canadian beachgoers. The long term goal is to reduce the burden of recreational water illness in Canada, contributing to improved public health.

Project Updates

2023-2025 Data Collection and Preliminary Results:

Surveys were administered at beaches at five sites across Canada (Toronto, Niagara, Vancouver, Manitoba, and Halifax) from 2023-2025 to assess beachgoer activities and their association with recreational water illness. Participants were recruited at two beaches per site each summer. Beachgoers completed an on-site survey to collect information about their water and sand activities and socio-demographics. A follow-up survey was conducted 7 days later to determine the incidence of any acute illnesses.

We recruited 4,085 beachgoers in the study, with 67.6% completing the 7-day follow-up survey. Approximately 65.5% of participants reported engaging in water contact activities, most commonly swimming (48.3%) and wading (37.2%). About 15% reported swallowing water, a practice that was notably more common among children aged 14 years or younger (34.4%) compared to those older than 14 (10.3%). Children under 14 were consistently the most likely age group to engage in various water and sand activities.

The overall risk of acute gastrointestinal illness (AGI) was 2.6%. Both swallowing water and full body immersion were associated with increased AGI risks compared to having no water contact at the beach. Escherichia coli levels were generally low during most recruitment days across the study sites. Despite this, increasing E. coli levels were found to be associated with increased AGI risks among those who had higher levels of water contact, particularly among those who reported swallowing water.

Check back soon for more results updates in the coming months!

2026 Beach Behaviour Survey:

An expanded beach behaviour survey is being conducted at selected Ontario beaches in the summer of 2026. This survey will determine the extent that beachgoers check beach water quality advisories before and while at the beach. We are also investigating how this might influence beachgoer activities at the beach.

Read our study protocol and methods here.