Thesis
Harmful algal blooms in Iowa: a multifaceted approach to understanding and mitigating risks
University of Iowa
Master of Science (MS), University of Iowa
Autumn 2023
DOI: 10.25820/etd.006926
Abstract
Harmful algal blooms (HABs) are excessive proliferations of phytoplankton in either marine or freshwater environments. In Iowa, they are typically composed of cyanobacteria, formerly known as blue-green algae, and can produce toxic by-products called cyanotoxins. Microcystins are the most commonly found toxins in Iowa’s lakes, but many others have been detected such as anatoxin-a and saxitoxin. Exposure to these toxins can occur through ingestion, inhalation, or dermal contact and can elicit a wide range of symptoms depending on the toxin. Symptoms run the gamut from nausea, headaches, rashes to liver failure, respiratory paralysis, and death. Children and animals, such as dogs, are more at risk as their behavior can often generate a much higher exposure.
Many environmental factors interact to form HABs. The largest driver of growth for HABs is nutrient pollution, a long-standing issue in Iowa due to the agriculturally dominated landscape accompanied by a lack of protective regulations and enforcement. They occur at higher frequency in the summer months due to increased temperatures and sunlight exposures. As a result, the Iowa Department of Natural Resources (IDNR ) does weekly monitoring at state park beaches for microcystin from Memorial to Labor Day, issuing swim advisories when concentrations have passed the threshold of 8 µg/L. With no agricultural regulation in sight and climate change increasing temperatures, as well as weather extremes like precipitation and drought, HABs are predicted to increase in frequency and severity. This will be detrimental to aquatic ecosystems, increase the potential for human and animal illnesses, and it will have a resounding negative impact on Iowa both economically and culturally.
The Iowa Healthy Lakes Initiative (IHLI) was created as a multidisciplinary approach to address gaps in prediction, mitigation, and communication of HABs in Iowa lakes. Specifically, the Public Health, Communications, and Community Engagement (PH&CE) group aimed to assess the understanding of HABs, the perception of risk, current communication systems, and responses to a bloom event by both the public and officials in Iowa. To complete these aims, a survey was created to determine what people know, how they know it, how they want to receive information, and their behavior in response to a HAB or advisory. An hazard assessment was also done on selected lakes in Iowa, testing for multiple algal toxins and determining the full concentration for individual samples. It was hypothesized that there were gaps in the public’s understanding of HABs and their perception of risk. The goal was to then identify areas of communication that could be improved regarding HABs. It was also hypothesized that there are potential gaps in toxin testing: the presence of other algal toxins that are not being routinely monitored, underreporting of analysis results, and inconsistency in communication of results. The goal was to determine if other toxins were present in potentially dangerous amounts, compare results of analysis, and identify communication issues. Samples were taken from two regions in Iowa, so statistical comparison was done to detect a potential difference in toxin concentration due to region. With region being used as a proxy for agricultural features, as the NW region is dominated by CAFOs in its landscape.
The results of the survey indicated moderate recognition and understanding of HABs, but a gap in perception of potential adverse health effects. The survey was able to reach a wide audience of highly educated recreators, concentrated in urban centers of Iowa. Recreators expressed frequent visitation to non-state parks, highlighting a gap in toxin testing. Many respondents indicated concern for Iowa’s water quality. Results from the information section were consistent with other surveys done in Iowa, people use the DNR website and social media primarily, mostly Facebook. Respondents revealed that what they already use is what they prefer, at least for the majority, but many people also stipulated the importance of physical signage. These results suggest that communicating this information through multiple channels could enhance the understanding of and perception of risk surrounding HABs. The hazard assessment demonstrated the variability of toxin concentration that is present in Iowa’s lakes. The saxitoxin results were negligible, two samples were over the anatoxin-a advisory level of 1 µg/L, and four samples were over the microcystin advisory level. The low samples were well under the advisory level, but the samples that were over revealed astonishingly high concentrations in some cases. The presence of a neurotoxin in high concentrations suggests a need for expansion of monitoring efforts. Overall, this study points to public concern for a growing environmental health issue, a concern that is evidenced by the results of toxin testing, as well as the identification of areas to improve risk communication and management in the state of Iowa.
Details
- Title: Subtitle
- Harmful algal blooms in Iowa: a multifaceted approach to understanding and mitigating risks
- Creators
- Lyndy Holdt
- Contributors
- Peter S Thorne (Advisor)Mary Skopec (Committee Member)Kelly Baker (Committee Member)
- Resource Type
- Thesis
- Degree Awarded
- Master of Science (MS), University of Iowa
- Degree in
- Occupational and Environmental Health
- Date degree season
- Autumn 2023
- Publisher
- University of Iowa
- DOI
- 10.25820/etd.006926
- Number of pages
- xiii, 86 pages
- Copyright
- Copyright 2023 Lyndy Holdt
- Grant note
- Support for this research was provided through the Iowa Healthy Lakes Initiative, a multidisciplinary project funded by a Jumpstarting Tomorrow pilot grant from the UI Office of the Vice President for Research.
- Language
- English
- Date submitted
- 12/03/2023
- Description illustrations
- Illustrations, tables, graphs, charts
- Description bibliographic
- Includes bibliographical references (pages 80-86).
- Public Abstract (ETD)
Harmful Algal Blooms (HABs) pose a significant environmental and health threat in Iowa's lakes. They are excessive growths of tiny, photosynthesizing plankton that clump together to form a HAB. In Iowa, they are predominantly composed of cyanobacteria, which can produce toxic by-products known as cyanotoxins, including microcystins, anatoxin-a, and saxitoxin. Exposure to these toxins can lead to a range of symptoms, from mild discomfort to severe health issues and even death, with children and animals at higher risk.
Various environmental factors, including nutrient pollution, increased temperatures, and sunlight exposure, contribute to the formation of HABs. The lack of agricultural regulations and the influence of climate change are expected to exacerbate the frequency and severity of HABs, posing a threat to aquatic ecosystems, public health, and the well-being of Iowa's communities.
To address these challenges, the Iowa Healthy Lakes Initiative (IHLI) was established, focusing on prediction, mitigation, and communication of HABs in Iowa lakes. The Public Health and Communication Engagement (PH&CE) group conducted a survey to assess public understanding of HABs, perceptions of risk, communication preferences, and behavioral responses to bloom events. Additionally, a hazard assessment was performed to evaluate toxin concentrations in selected lakes across Iowa.
The survey results indicated moderate recognition and understanding of HABs but revealed a gap in the perception of potential health risks. The survey reached a diverse audience of educated individuals, primarily from urban areas. Respondents expressed concern for Iowa's water quality and preferred receiving information through channels like the Department of Natural Resources (DNR) website and social media, particularly Facebook. However, many also emphasized the importance of physical signage. The hazard assessment highlighted the variability in toxin concentrations in Iowa's lakes, with some samples showing alarming levels of toxins, suggesting the need for expanded monitoring efforts.
In conclusion, this study underscores the growing concern among the public regarding the impact of HABs on environmental health. It emphasizes the importance of enhancing risk communication and management strategies in Iowa to address this pressing issue.
- Academic Unit
- Occupational and Environmental Health
- Record Identifier
- 9984547148202771
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