Recreational coastal, freshwater, and other untreated natural waters

Recreational waters such as oceans, lakes, rivers, and their associated beaches, attract large numbers of users engaging in primary contact activities (e.g., swimming, water skiing, surfing, paddle boarding etc.) and secondary contact activities (e.g., boating, fishing). Partaking in activities in natural recreational waters that offer enjoyment, exercise, and connection to the outdoors, can also present risks of injury, illness, or death. Some hazards include:

• Physical hazards: Accidental drowning, injuries associated with sharp materials, rocks, logs, or other debris, and dangers related with substrates (e.g., muddy sediments), cold, or heat, which can result in injury. Events that move debris such as storms or flooding can change the physical hazards present at a recreational water from one season to the next.
• Biological hazards: Exposure to microorganisms (e.g., pathogenic bacteria, viruses, and protozoa) via accidental ingestion of water, emersion in water causing direct contact with skin, eyes, ears, or nose, and exposure via cuts or wounds. Beach-related illnesses can include gastrointestinal illness, skin infection (e.g., swimmers’ itch), and ear, eye, nose, or throat infections. Biological contamination is most often associated with human or animal fecal matter released into natural waters via diffuse pollution and point source inputs of wastewater.
• Chemical hazards: Exposure to natural and artificial chemical contaminants (e.g., oil or chemical spills or effluents) resulting from accidental ingestion, inhalation, or dermal contact with contaminated water. Exposure to toxins from blue-green algae blooms (cyanobacteria) can cause rashes, nausea, vomiting, or more serious kidney or liver damage, and has been associated with illness and deaths of animals consuming contaminated water or clumps of bloom material.

Climate change may alter the nature and frequency of public health risks associated with recreation waters, with more engagement with natural waters during warm and dry weather, and changing nature of risks at some times of year. Low water levels during summer could increase risks of diving injuries, Water use following storms or floods could increase exposure to contaminants or debris. Changes to temperature and precipitation patterns could influence the frequency and severity of cyanobacterial blooms, or contamination of waters with sewage or other terrestrial sources of biological or chemical contamination. Public health guidance can inform safe use of recreational waters and inform policies to reduce public health risks. The resources presented below provide information on identifying physical, biological, and chemical hazards in recreational waters, and tools for monitoring and managing recreational waters to reduce the risks to users.

Understanding environmental hazards in recreational waters

• Risk of human illness from recreational exposure to microbial pathogens in freshwater bodies: A systematic review (Adhikary et al., 2022)
  This review article summarizes the types of illnesses most commonly associated with contact with recreational freshwaters.

• Drowning prevent (US CDC, 2022)
  This website provides information on risk factors for drowning, and recommendations for prevention.

• Environmental factors associated with freshwater recreational water quality in Toronto and Niagara (Sanchez and Tustin, 2021)
  This webinar recording, presented in the NCCEH Environmental Health Seminar Series, reports on research being conducted in Ontario to understand how environmental factors (e.g., temperature, rainfall, wind, etc.) affect E. coli concentrations in recreational freshwater sites. See also: Sanchez et al. (2021).

• Monitoring, managing, and communicating risk of harmful algal blooms (HABs) in recreational resources across Canada (Rashidi et al., 2021)
  This article reports on findings of an environmental scan of provincial and territorial protocols for monitoring, managing and communicating on HABs in Canada

• Evaluating health risks associated with exposure to ambient surface waters during recreational activities: A systematic review and meta-analysis (Russo et al., 2020)
  This review article summarizes the types of exposures and illness most associated with difference types of recreational activities in natural waters (e.g., swimming, sports contact, sand contact)

• Outbreaks associated with untreated recreational water — California, Maine, and Minnesota, 2018–2019 (Vanden Esschert et al., 2020)
  This article provides examples of outbreaks associated with untreated recreational waters. These were associated with infection with Shigella, norovirus, and Shiga toxin-producing E. coli.

• Cyanobacteria in freshwater(NCCEH, 2019)
  This NCCEH topic page provides a curated list of guidance and resources related to cyanobacteria and cyanotoxins in recreational and drinking water sources.

• Drinking and recreational water exposures among Canadians: Foodbook Study 2014–2015 (Janicki et al., 2018).
  This article reports on a Canada-wide survey to collect baseline data on water exposures by province, demographic, and timeframe of exposures to inform public health strategies.

• Global report on drowning: preventing a leading killer (WHO, 2014)
  This report emphasizes the risk factors associated with drowning (poor swimmers, consuming alcohol, natural events such as storms and flooding) and measures that can reduce drowning risks.

 Public health guidelines for recreational waters

• Guidelines for Canadian recreational water quality: Physical, aesthetic, and chemical characteristics (2022)
  This guidance document outlines Canadian guideline values or aesthetic objectives, where possible, for physical, aesthetic and chemical characteristics of recreational waters and beaches that may affect their safe use for recreation.

• Guidelines for Canadian recreational water quality: Cyanobacteria and their toxins (Health Canada, 2022)
  This guidance document outlines Canadian guideline values and strategies for managing health risks related to exposure to cyanobacteria and their toxins in recreational waters.

• Guidelines for Canadian recreational water quality(Health Canada, 2012)
  This guidance document provide summary information on safe recreational water quality in Canada, including suggested indicators and guideline values for microbiological quality of marine and fresh waters. See proposed updates to these guidelines: Understanding and managing risks in recreational waters (2022) and Indicators of fecal contamination (2022)

• Guidelines on recreational water quality. Volume 1: Coastal and fresh waters (WHO, 2021)
  These guidelines provide a comprehensive review of the injury and illness risks associated with recreational use of natural waters, and measures to monitor and control these risks for national and local authorities and others tasked with ensuring the safety of recreational waters.

• Recreational water quality criteria and methods (USEPA, 2021)
  This webpage provides information and resources related to recreational water criteria in the United States, including the criteria for bacterial indicators of fecal contamination (2012), and the criteria for swimming advisories for cyanotoxins, plus links to water quality criteria under development.

• Visiting oceans, lakes, and rivers (USCDC, 2021)
  This website includes basic information on reducing the risks of illness related to recreational water uses.

• Preventing drowning: an implementation guide (WHO, 2017)
  This report provides an overview of evidence-based strategies and interventions for reducing drowning in recreational waters.

Monitoring and managing safe recreational waters

• Tools to evaluate and manage beach health (USEPA 2022)
  This website provides an overview of tools such as sanitary surveys, monitoring techniques, predictive models and analytical methods that can be used to evaluate and improve beach health. The USEPA also provides basic information on beach-related illnesses and staying safe at the beach.

• The swim guide (Swim Drink Fish Canada, 2022)
  This website provides a searchable map with detailed information on beaches across Canada, and elsewhere in the world, with safety and weather information, monitoring status, and water quality information (historical or current).

• Alberta safe beach protocol (Alberta Health, 2022)
  This guidance document sets out a program to assess and manage risks to health associated with recreational waters, including water quality standards for reducing public health risks to bathers and instructions on developing a Recreational Water Safety Plan (RWSP).

• Beach water monitoring practices and challenges in Ontario Public Health units (Heasley et al., 2022)
  This article reports on a survey of public health professionals responsible for beach water management in Ontario to determine how monitoring practices differ across jurisdictions. See more on predictive models for microbial quality (Heasley et al., 2021).

• Models for predicting beach water quality(USEPA, 2021)
  This webpage provides information and resources related to predictive modelling, including how to develop a model, how to use predictive models for notifications, and a list of existing models. See also: WHO Quantitative microbial risk assessment (QMRA) guidelines
   
• Effect of beach management policies on recreational water quality (Kelly et al., 2018)
  This article identifies geomorphologic features of beaches (e.g., open coast vs. bay beaches) and beach management practices (e.g., policies that address dog waste) that are associated with lower levels of fecal indicator bacteria.

• Assessment of the microbiological quality of recreational waters: indicators and methods (Rodrigues and Cunha 2017)
  This article reviews the literature on traditional and innovative methodologies for assessing indicators of fecal contamination in recreational waters.

Emerging areas of research

• Monitoring coliphages to reduce waterborne infectious disease transmission in the One Water framework (Fitzmorris-Brisolara et al., 2022)
  This review article examines the evidence for monitoring fecal indicator viruses to complement the monitoring of bacterial indicators in recreational waters to improve public health protection

• Natural recreational waters and the risk that exposure to antibiotic resistant bacteria poses to human health (Leonard et al., 2022)
  This narrative review examines the current state of the knowledge and key research gaps on antimicrobial resistant (AMR) and exposure and transmission via natural recreational waters.

• Drowning risk and climate change: a state-of-the-art review (Sindall et al. 2022)
  This review article examines literature on how climate change may contribute to changes in drowning risks globally, and knowledge gaps and recommendations for further research.

• Antibiotic resistance in recreational waters: State of the science (Nappier et al., 2020)
  This review article examines sources of AMR in recreational waters, what is known about human exposures and identifies further knowledge and research gaps.

• Freshwater blue space and population health: An emerging research agenda (McDougall et al., 2020)
  This article examines some of the positive physical and mental health outcomes associated with access and exposure to freshwater blue space and identifies knowledge gaps for future research on blue-health.

• Effects of lake warming on the seasonal risk of toxic cyanobacteria exposure(Hayes et al., 2020)
  This article reports on a study to examine the effect of warming on elevated cyanotoxin concentrations, duration of elevated toxin levels, and increased risk to human health in lakes.

This list is not intended to be exhaustive. Omission of a resource does not preclude it from having value.