Monitoring Recreational Waters: How to Integrate Environmental Determinants

Abstract

Recreational waters are associated with a higher risk of disease for people engaged in activities that bring them into contact with these waters. The primary cause of contamination of recreational waters is fecal microorganisms, which may originate from various sources and involve several modulating factors, making it a complex public health and environmental issue. Monitoring recreational water quality should include two key components: Microbial water testing and monitoring environmental determinants associated with higher risks of contamination. Conducting both activities provides the foundation for a comprehensive assessment according to risk and the actual level of fecal pollution and thus could promote good management actions to ensure safe water quality. Nevertheless, monitoring of environmental determinants is rarely fully integrated in monitoring programs and is also harder to achieve, especially when water pollution is mainly associated with nonpoint sources. In order to achieve identification and monitoring of environmental determinants associated with fecal contamination of recreational waters, some specific steps should be followed and some questions must be answered. The objective of this review article is to present current knowledge on this topic and to suggest and discuss recommendations. Potential sources of contamination and factors able to modulate them should be identified and measured after the geographical area influencing fecal contamination of recreational water has been delineated. Statistical models have been developed to identify the relative importance of these environmental characteristics on fecal pollution of recreational waters but they do not allow for a full comprehension of the exact processes leading to this pollution, thus other methods should also be used to better understand these processes.

Evaluation of Earth Observation Systems for Estimating Environmental Determinants of Microbial Contamination in Recreational Waters

“…These activities are known to affect surface water quality [16] and extensive discussion on these findings can be found in Turgeon et al [17]. Percentage of agricultural lands in the area of influence (%AL) and percentage of impervious surfaces (%IS) in the area of influence were the two variables found statistically significant in logistic regression models, but not in all models.…”

“…These land types are known to influence water quality either by being sources of contamination or by acting as protective areas around beaches [16]. Feedlots, irrigation, and fertilizer applications to agricultural lands are sources of pathogens.…”

“…Agricultural lands, forests, wetlands, and impervious surfaces are known to affect water quality (16). The relationship between these estimated environmental determinants using different EO systems and the level of microbial contamination of water bodies was assessed using logistic regression models.…”

“…However, the number of water bodies to monitor and laboratory delays in estimating microbial indicators are obstacles to the evaluation and monitoring of public health risks over large areas like Canada, which has many remote and isolated bodies of water. Several authors highlight the importance of developing new methods to help detect microbial contamination of recreational waters in a timely manner to better prevent public health risks [7], [11], [16], [18], [19]. Environmental conditions around water bodies are important factors in the risk of microbial contamination [20]- [23].…”

“…Earth observation (EO) systems provide a framework for the assessment and monitoring of these determinants over large areas [6], [7], [16], [17], [25]- [27]. However, there are a multitude of EO systems, characterized by types of sensors which differ in spatial, spectral, radiometric, and temporal resolutions as well as levels of accessibility.…”