Risk Assessment of Toxic Algal Blooms

In MissisquoiBay

Andrew NotteKristen Rigney

Adam TrescottJennifer Sinish

Sponsor:

Mike Winslow

Staff Scientist

Lake Champlain Committee

(802) 658-1461

Problem Statement

The threat of toxic algal blooms in MissisquoiBay is an environmental topic of great concern to many individuals and health officials in the surrounding Canadian and Vermont communities. There are varying health risks associated with blue green algal blooms, yet there lacks a system to assess these risks and their social and economic repercussions.

Goal / Purpose Statement

To determine the level of risk to human health posed by blue green algae within the MissisquoiBay. Based on this analysis we will determine the pros and cons of varying levels of public notification and their impacts on the tourist industry and public health. We will analyze current policies and practices by U.S. and Canadian officials and suggest recommendations that would build upon these policies.

Justification

The eutrophoication and contamination of our water resources is becoming an issue of ever increasing concern. Blue green algae produce a range of toxins that pose a health risk to people through various levels of exposure, such as ingestion or physical contact. During periods of high blue green algae concentrations in the MissisquoiBay beaches have to be closed, and heath advisories are issued. The beach closures not only affect the residents in the bay area, but also negatively affect the surrounding tourist industry. By analyzing the risks of exposure to the people in the bay area and the consequences of those risks we will be able to provide the surrounding town health commissions and state health departments with suggestions to minimize health risk and negative effects on the tourist industry. Through the development of a notification system that does not deter tourism through excessive warnings yet effectively protects human health.

Literature Review

Though the literature is quite extensive for issues related to blue-green algae, the scope of our project will focus specifically on studies related to the human health issues associated with cyanobacteria. Articles that will be referred to for the analysis include three articles written by Pilotto et al. (1997, 1999, and 2004) which regard issues that include human skin irritation caused by direct contact with the algae, exposure from recreational activities, as well as the potential contamination of drinking water. Another article to be considered is Turner, et al. (1990), which describes a correlation of cyanobacteria with pneumonia in people. Also, Elder, et al. (1993) and Charmichael (1994) both discuss health issues related to cyanobacteria toxin levels and the hazards they pose to humans. Another reference that will be extremely helpful to our study is the online guide for public health, monitoring and management of blue-green algae, produced by the World Health Organization (1999). This guide covers the subject in great depth and from many different perspectives.

Because our study is based in the Mississquoi Bay of Lake Champlain, Vermont, we will need to utilize the results of studies that were conducted in similar freshwater lake ecosystems. Articles to be used for this section of the analysis include, Elser (1999), which describes the pathway of blue-green algae blooms in lakes, as well as Scheffer, et al. (1997), which describes cyanobacteria characteristics in shallow lakes. Both of these articles describe blue-green algae characteristics that are specifically related to freshwater lake environments and they will serve as useful references in determining the characteristics of blooms in Lake Champlain.

Proposed Effort

It is known that excess phosphorous and nutrient loading has stimulated blue-green algal blooms, many of which are toxic. Ideally, a long-term goal would be to reduce non-point phosphorus and nitrogen loading, therefore minimizing algal blooms. However, based on the complexities of the problem, realistic management goals need to be implemented to protect human health. This project will focus primarily on determining the level of risk to human health posed by blue-green algae within the MissisquoiBay.

Initially, literature and relevant research will be reviewed to determine the human health effects related to blue-green algae toxin exposure. Based on the information obtained, a framework will be established to assess and prioritize various risks of exposure for humans. This will lead to the development of several options for public management. These options will include varying levels of warning and restrictions to control public exposure in recreational activities around Lake Champlain.

Included in the analysis, will be a comparison between the pros and cons associated with varying levels of public notification and their impacts on the tourist industry and public health. Economic factors associated with the tourism industry will be weighed against public health issues on all of these levels to produce an appropriate risk analysis.

Quebec and Vermont are the two main contributors of non-point source phosphorous and nitrogen in Lake Champlain. Research on current practices by U.S. and Canadian officials will be conducted to develop suggestions and recommendations that would build upon existing policies. For reference, existing fecal coliform public alert procedures will be utilized.

The project will be approached in a task group format. The research will account for the health effects of algal bloom on organisms, specifically humans. With this in mind, a sector of the task group will focus on documenting potential health effects of different levels of exposure to these toxic blooms. This portion of the assessment will take into account social aspects as well as important health concerns that have been discussed by many organizations including the World Health Organization. An important aspect of the risk assessment will focus on the social and economic repercussions dependent on the level of warnings and restrictions.

Effort Assignment

For our project, each member will read articles pertaining to specific health effects of cyanobacteria exposure. Andrew Notte will study the current procedures in Vermont and Canada for blue green algae toxin and fecal coliform management. Adam Trescott will develop a priority framework for health effects. Jen Sinish will relate this framework to an appropriate public alert system. Kristen Rigney will look at the economic effects of the various alert systems while using fecal coliform public alert procedures as a reference.

Time Line

  • Gather data on human health effects and analyze human health risk

by April 18.

  • Formulate framework by April 25.
  • Evaluate current methods for dealing with the algae blooms and fecal coliform by April 25.
  • Analyze the economic effects of the various alert systems proposed in the framework by April 25.
  • Formulate recommendations for Vermont and Quebec officials regarding current regulations and procedures by April 29.

References

Carmichael, W.W. (1994). “The toxins of cyanobacteria.” Scientific American270(1): 78-86.

Elder, G.H., P.R. Hunter, & G.A. Codd. (1993). “Hazardous freshwater cyanobacteria (blue-green algae).” The Lancet341(8859): 1519-1521.

Elser, J.J. (1999). "The pathway to noxious cyanobacteria blooms in lakes: The food web as the final turn." Freshwater Biology42(3): 537-543.

Pilotto, L., P. Hobson, et al.(2004). “Acute skin irritant effects of cyanobacteria (blue-green algae) in healthy volunteers.” Australian and New Zealand Journal of Public Health28(3): 220-225.

Pilotto, L., E.V. Kliewer, et al. (1999). “Cyanobacterial (blue-green algae) contamination in drinking water and perinatal outcomes.” Australian and New Zealand Journal of Public Health23(2): 154-159.

Pilotto, L., R.M. Douglas, et al. (1997). “Health effects of exposure to cyanobacteria (blue-green algae) during recreational water-related activities.”Australian and New Zealand Journal of Public Health 21(6): 562-567.

Turner, P.C., A.J. Gammie, et al. (1990). “Pneumonia associated with contact with cyanobacteria.” British Medical Journal300(6737): 1440-1442.

Scheffer, M., E.H. Van Nes, et al.(1997). "On the dominance of filamentous cyanobacteria in shallow, turbid lakes." Ecology78(1): 272-282.

World Health Organization. (1999). Toxic Cyanobacteria in Water: A guide to their public health consequences, monitoring and management. Retrieved March 13, 2005 from the World Wide Web:

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