While safe drinking water is a major focus for public health officials and researchers, scientists are also working to determine other ways that harmful algal blooms and the associated toxins—in particular microcystin—may impact human health. In this focus area, science teams develop techniques to better detect toxins in biological samples, study the effects of algal toxins on various types of cells, and determine the significance of the different ways that people might be exposed to algal toxins—physical contact, eating fish, etc. These studies aim to assist agencies as they develop guidelines for handling harmful algal blooms in coming years.
Projects
Understanding the Health Risks from Breathing in Algal Toxins
Principal Investigators
Steven Haller and David Kennedy, The University of Toledo
Project Summary
When harmful algal blooms arise on Lake Erie each summer, people generally know that it’s not safe to ingest water affected by algae. What’s less known, however, are the health risks from breathing in air and aerosols that contain algal toxins. Aerosols are small particles or droplets suspended in the air that form through freshwater waves breaking. Such “lake spray” aerosols have the potential to travel over 19 miles from their original source while carrying cyanotoxins from algal blooms. Meanwhile, rates of asthma, a chronic condition that inflames and narrows airways in the lungs, are particularly high in Toledo and other Great Lakes cities.
To investigate this, researchers conducted experiments on both experimental models and human cells to see how they respond to exposure to aerosolized microcystin-LR (MC-LR), one of the most abundant and potent algal toxins. Human airway tissue cells were sourced from both healthy and asthmatic volunteers who consented to biopsies. Researchers then used a special system to nebulize — turn into an aerosol — algal toxins and distribute them on the surface of the cells, which are grown to replicate the lining of cells in the lungs.
Researchers observed an inflammatory response in healthy human cells exposed to aerosolized MC-LR as well as in healthy mice exposed to the toxin. They found that the response to the toxin — what genes were produced and how cells behaved — was very much like an asthma response. What’s more, asthmatic cells exposed to the toxin saw an exacerbated inflammatory response, suggesting that patients with pre-existing asthma may be particularly vulnerable to contaminated aerosols. While results largely showed injury to the lungs, the team observed increases in inflammation in downstream organs such as the liver and kidneys as well.
Moving forward, researchers plan to share their findings with other researchers so the information can be confirmed and expanded upon. Broadly, the team is working to share comprehensive insights into the prevention, diagnosis, and treatment of health issues associated with harmful algal bloom toxins. This effort has resulted in significant outreach work, and findings could inform public health guidelines as well.
The Bottom Line
Researchers made a breakthrough in understanding the health risks involved when people breathe in air containing algal toxins. In experiments, they found that airway exposure to the algal toxin microcystin can create an inflammatory response in lungs that is exacerbated in the setting of pre-existing asthma.
How Does Skin Exposure to Algal Toxins Affect Human Health?
Principal Investigators
Steven Haller and David Kennedy, The University of Toledo
Project Summary
While a significant majority of illnesses related to bloom exposure come about from skin contact, little is known about the health effects that such dermal exposure presents. Scientists are unsure whether common skin conditions can cause increased susceptibility to harmful algal bloom toxins — vital information that would inform preventative, diagnostic, and therapeutic strategies for patients on the Great Lakes.
Through a recent study, researchers aimed to find out how dermal exposure to cyanotoxins adversely affects the health of skin and other major internal, “downstream” organ systems. To achieve this, their team conducted in vitro experiments on human skin samples to study the ability of skin to protect the body from absorption of cyanotoxins. They used genetic analysis to determine how common skin conditions affect protein transport channels that toxins use to access the skin and other organs. Then, while following internationally established guidelines, the team conducted model experiments on mice with dermal exposure to microcystin.
The team found that models of healthy skin cells — which don’t contain protein channels that can transport microcystin — are effective at preventing the passive absorption of the toxin. At the same time, genetic analysis showed that common diseases impacting the skin have significant impacts on the level and distribution of such protein channels. Through the model studies, researchers found that common skin conditions show increased susceptibility to inflammatory damage within the skin after microcystin exposure. When conditions such as chronic kidney disease were present, dermal exposure to microcystin resulted in measurable changes to markers of liver and kidney injury. These findings suggest that skin conditions may not only increase skin injury from microcystin, but also have significant impacts on “downstream” organs.
Researchers are sharing these findings with regional, national, and international scientific and medical conferences. They are also working with other researchers, including physicians and public health epidemiologists, to confirm findings and linkages.
The Bottom Line
Researchers found that dermal exposure to toxins from harmful algal blooms is more than “skin deep” — it can affect internal organ systems.
Development of Evidence-Based Strategies to Improve Harmful Algal Bloom Health Education and Outcomes
Principal Investigator
David Kennedy, The University of Toledo
Project Summary
This project addresses a significant gap in the diagnosis and treatment of illnesses related to harmful algal blooms (HABs) in Ohio. By leveraging extensive health data and tissue biobanks, researchers are pinpointing high-risk patients and identifying biomarkers that will enhance diagnosis and treatment. This effort has already uncovered that diseases like asthma may increase susceptibility to cyanotoxins due to an upregulation of protein expression that facilitates toxin entry into cells. Additionally, the team has linked respiratory symptoms as a frequent emergency room complaint following HAB exposure. By developing new education materials for Ohio’s healthcare providers, researchers are not only enhancing patient care but are also supporting statewide environmental initiatives like H2Ohio. This comprehensive, multidisciplinary approach promises significant improvements in both public health and environmental management.