Residents along Florida’s west coast are all too familiar with the warning signs of a red tide outbreak: the pungent odor, stinging eyes, and beaches littered with dead fish. However, new research suggests that the dangers of red tide may extend beyond the shoreline, particularly affecting pregnant women who live nearby.
Researchers at the University of South Florida’s College of Public Health (COPH) are delving into this issue. Bianca Irimia, a PhD student under the guidance of Dr. Catherine Bulka, presented her findings at the International Society for Environmental Epidemiology conference in Atlanta. Her research, which earned her an award in the Students and New Researchers Network poster competition, explores the potential link between red tide exposure and gestational hypertension.
Irimia, originally from Washington state, was unfamiliar with red tide until she moved to Florida for her doctoral studies. “I found it fascinating, particularly how red tide affects vulnerable populations,” she stated. “My interest in environmental health naturally aligned with this area of study, and given that Florida’s beaches are a major recreational draw for the state, red tide warrants greater public health attention.”
Understanding the Risks of Red Tide
The algae responsible for red tide, Karenia brevis, releases brevetoxins—airborne contaminants that are lethal to marine life. This raises the question: if these toxins can kill fish, dolphins, and other wildlife, what impact might they have on humans, especially pregnant women?
Data from the study indicates that about 5% of over 38,000 pregnant women living along the west coast of Florida from 2006 to 2019 developed gestational hypertension. However, those exposed to red tide during their first and second trimesters faced a 23% higher risk compared to unexposed women.
“This suggests that red tide may be an important environmental risk factor for gestational hypertension and highlights the need for further investigation and preventive measures,” Irimia explained.
Challenges in Measuring Exposure
While the adverse health effects of red tide exposure, such as respiratory irritation and neurological issues, are documented, research specifically involving pregnant women is limited. Animal studies have shown that brevetoxins can cross the placenta, leading to severe effects like unhatched fish eggs.
“Animal studies show profound adverse effects following exposures during pregnancy,” Dr. Bulka noted. “There’s a great need to fill this research gap.”
One of the main challenges in studying red tide’s impact on humans is measuring exposure levels. Unlike other pollutants, brevetoxins are not routinely monitored. To address this, the study used water-based measurements of Karenia brevis as a proxy, along with data on residential proximity to the coast and wind patterns, to estimate exposure levels.
Implications for Public Health
Understanding how these toxins might affect maternal health is crucial. “Right now, the field of red tide and health research is quite small,” Irimia added. “I’m interested in seeing how it evolves as more data and improved research methods become available.”
The COPH’s research could provide valuable insights, potentially revealing that red tide exposure is most harmful during specific pregnancy stages or under certain wind conditions. “Insights like these can help people make more informed choices and better protect their health,” Bulka said.
Red Tide: A Broader Perspective
Red tide, caused by the microscopic algae Karenia brevis, is a natural phenomenon that can have widespread impacts. It produces a toxin affecting the central nervous systems of various animals. At high concentrations, it can discolor water and pose health risks to humans.
Red tide blooms can last from days to months and are influenced by wind and water currents. Onshore winds bring it closer to the shore, while offshore winds push it out to sea.
First recorded in Florida in 1844, red tide requires a combination of biological, chemical, and physical factors to form. While it can irritate the skin and respiratory system, more research is needed to fully understand its health implications.
For those with health concerns related to red tide, the Florida Poison Control Information Center is available at 1-800-222-1222.
This study marks a significant step towards understanding the environmental health challenges posed by red tide, particularly for vulnerable populations like pregnant women. As research continues, it may lead to better public health strategies and preventive measures.
