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Promoting health through safe drinking and recreational water, including small drinking water systems.

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Review of Guidelines for Shock Chlorination in Private Wells (UBC Bridge Program)

Microbial contamination of groundwater from private wells can pose a significant health risk to rural Canadians. To mitigate risk, Health Canada currently recommends shock chlorination along with microbial well testing, voluntary measures most often performed by the homeowner. However, infrequent testing and paucity of research assessing the effectiveness of shock chlorination guidance as...

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Understanding microbial indicators for drinking water assessment - revised

Boil water advisories are issued when water testing detects higher than accepted amounts of microbial indicators or when there are deficiencies with water treatment. The fear of not issuing a boil water advisory when there is truly a health risk associated with water consumption can lead water operators to call for boil water advisories as a precautionary measure. Yet, issuance of boil water...

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Cemetery Setback Distances to Prevent Surface Water Contamination

Primary inquiry: In Canada, as in many other countries, cemeteries are required to be setback a certain distance from waterbodies to protect drinking water sources from contaminated liquids that can arise from the decomposition of bodies after burial. What is recommended as a safe setback distance? What is the rationale for the setback distances used throughout Canada?

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Irrigating Food Crops with Water Containing Cyanobacteria Blooms

Primary inquiry: Small horticulture growers have been watering their crops with surface water containing a cyanobacterial bloom, before selling their crops at local markets. Can irrigation of food crops using surface water affected by cyanobacteria blooms result in bioaccumulation of cyanotoxins in these crops? Can cyanotoxins bioaccumulate to a concentration that might cause a public health...

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Identifying and Addressing the Public Health Risks of Splash Parks

Splash parks, also known as splash pads, spray parks, or wet decks, have gained in popularity over the last decade. These interactive parks are artificially created depressions or basins into which water is sprayed, splashed or poured onto visitors; water is not permitted to accumulate, but instead drains immediately out of the play area. Splash parks may take one of two basic designs, which...

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Cyanobacteria in Freshwater

What are cyanobacteria? Are cyanoblooms preventable? Who is at risk and how does exposure occur? Is there testing for cyanotoxins? This NCCEH document provides a brief outline of these key questions related to cyanobacteria and the toxins they produce.

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Float Tanks: Considerations for Environmental Public Health

Floatation refers to a meditative activity in which users float in a high-density Epsom salt solution in a dark, quiet environment. Because float tanks are distinct from swimming pools and other recreational water, questions have been raised regarding the need for and efficacy of various disinfection methods. Although direct evidence is lacking, pathogen kill assays and field studies from...

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Float Tanks: Review of Current Guidance and Considerations for Public Health Inspectors

The growing popularity of “floatation” and the ways in which this practice differs from the use of pools and spas have raised interesting questions in environmental public health. Public health agencies in the US and Canada have taken very different approaches to the classification and regulation (or non-regulation) of these facilities. Continuing engagement amongst environmental health...

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Community Water Fluoridation in Canada – Trends, Benefits, and Risks (University of Guelph Master of Public Health Program)

Fluoride has been added to public drinking water in Canadian communities since the 1940s as a means of preventing tooth decay. Dental fluorosis is a known adverse effect of excessive fluoride exposure during tooth formation. Fluorosis ranges from barely noticeable whitish striations in the enamel to severe pitting and brownish staining. In general, the prevalence of dental fluorosis in...

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Characteristics of small residential and commercial water systems that influence their likelihood of being on drinking water advisories in rural British Columbia, Canada

Health officials often lack information about characteristics that predict which water systems are most likely to be placed on and to persist on drinking water advisories (e.g. health warnings offering advice or information). This study uses data collected by the Interior Health Authority in British Columbia to characterize water systems on advisory for microbiological threats and to identify...

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Water-borne Disease Outbreaks in Canadian Small Drinking Water Systems

Information about Canadian drinking water systems and past water-borne disease outbreaks is incomplete and non-standardized. Standard definitions and coordinated surveillance systems for water-borne disease outbreaks would help inform policy and practice. A relatively high proportion of past water-borne disease outbreaks in Canada are estimated to have occurred in small drinking water systems...

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Nanotechnology: A Review of Exposure, Health Risks and Recent Regulatory Developments

Nanotechnology is the creation of materials, devices, and systems by controlling matter at the nanometer scale (1-100 billionths of a meter). Potential exposures to engineered nanoparticles (ENPs) through contact with consumer products or air, water, and food sources are an emerging potential threat to human health. ENPs have unique properties and characteristics in addition to size, such as a...

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Retrospective Surveillance for Drinking Water-Related Illnesses in Canada

Waterborne infections are an important cause of preventable enteric disease. This report obtained information on: characteristics of waterborne disease events (WBEs) in Canada; factors contributing to WBEs; current WBE detection and prevention practices; and, information needs of front-line public health staff. Forty-seven WBEs were identified, the majority occurring prior to 2001. Giardia and...

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Chlorination Disinfection By-Products in Drinking Water

The challenge of judging and managing public health risks “caused by” chlorination disinfection by-products (DBPs) in drinking water is likely the most complex issue faced by the drinking water industry in the developed world over the past three decades. Public health professionals must be sure that precautionary efforts in managing DBP risks are never allowed to compromise necessary measures to...

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When can Point-of-Use Water Filters be used for Removal of Protozoa?

While boiling water is an effective way to kill most microbial pathogens, research performed in the United Kingdom has shown that people do not necessarily comply with boil water advisories. Similarly, in Walkerton, Ontario in 2000, only 44% of respondents reported that they were aware of the order to boil water when it was first issued on the local radio at the start of the outbreak and in...

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Pool Chlorination and Closure Guidelines

As an EH director at a local health authority, helping to review provincial guidelines on swimming pools, you want to know if scientific evidence supports pool closure orders when free available chlorine (FAC) is found to be at or above 10 ppm. Should the level be different and are there other factors to be considered for closure, instead of or in addition to FAC? What is Free Available Chlorine...

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