Florida’s 156-mile-long Indian River Lagoon (IRL) borders five different counties and has five inlets connecting the lagoon to the Atlantic Ocean. The estuary has recently experienced multiple phytoplankton bloom events due to rising seasonal temperatures and environmental impacts.
Algae blooms produce large amounts of small organic molecules, many of which are toxic to humans and animals. One of these cyanotoxin producers is Microcystis aeruginosa, a freshwater cyanobacteria that can be found in southern Ireland. Measurable amounts of microcystins were found in nasal swabs from people who lived and worked near the area, although finding microcystins in mucous membranes may indicate that the body is doing its best to eliminate them.
To help uncover potential human health hazards associated with real-life harmful algal blooms, researchers at Florida Atlantic University’s Harbor Branch Oceanographic Institute collected water samples from 20 sites within the lagoon during three years of dry and dry seasons. .
Samples are extracted to concentrate the organic molecules, and these extracts are used for testing. To identify the presence of known or emerging toxins, the researchers measured cytotoxicity using a panel of immortalized human cell lines corresponding to the liver, kidney, and brain. Human cell lines designed to express ion transporters, red blood cells, and activity against protein phosphatases were also used.
These cells and bioactivities were chosen because they are known to be affected by algal toxins and exhibit unique patterns of activity against known toxins.
High-concentration samples are tested to detect as many metabolites as possible, and those that exhibit more than 50% cytotoxicity are considered active. Samples showing high toxicity were further subjected to liquid chromatography-high resolution mass spectrometry analysis to evaluate the metabolites present in the samples.
Research results published in journal toxin, indicating that each control toxin induced a consistent pattern of cytotoxicity in the panel of human cell lines examined. During flowering, cytotoxicity caused by a single type of toxin is evident from this pattern. In the absence of blooms, the observed cytotoxicity was either a mixture of toxins or caused by an unknown toxin.
“The most interesting observation from our study is that by using cell lines, we can follow the patterns of known toxins,” said corresponding author Esther Guzmán, Ph.D., a research professor at FAU Port.
“Known toxins are only present during flowering. Because the cytotoxicity occurs in the absence of flowering, this suggests that emerging toxins or combinations of toxins may be present at that time. Our results suggest that other toxins may be important to human health Harmful potential exists in the lagoon.”
The results show that the northernmost part of the lagoon is less toxic than the southernmost part. Cytotoxic blooms were found in both the southern (Microcystis) and northern (pyrrolidinium) parts of the lagoon. In the absence of bloom, the South Fork, South Fork 2, North Fork and Middle Estuary in southern IRL (sites 1 to 4) and the Banana River and North Banana River (NASA) in northern Ireland (sites 14 and 15) showed Maximum cytotoxicity during the evaluation period.
In comparison, Jensen, Fort Pierce Inlet, Harbor Branch Link Port Canal, Vero Beach Land/Ocean Biogeochemical Observatory, and Vero Beach Barber Bridge (sites 6 to 10) appear to be healthier, as more than 50% of samples from these sites were cytotoxic Very few, although there is a statistically significant difference between these sites.
“One of the main questions we tried to answer in this study was whether there are unrecognized toxins or other signaling molecules associated with harmful algal blooms in lagoons,” said co-author Dr. Amy Wright, FAU Harbor Research Professor. branch.
“The data collected to date suggest this is the case. Importantly, using detection panels to assess the presence of toxicants allows for better monitoring of human health effects, particularly of emerging toxins within the system.”
The researchers note that microcystin poses a threat to human health primarily in lagoons during algal blooms, and due to the necessity of active transport, the toxin needs to be ingested or inhaled to pose a threat to humans.
“Filtration of water through activated charcoal prevents ingestion,” Guzman said. “Similarly, the effects of inhalation can be effectively blocked by mucous membranes, which trap the toxins and subsequently eliminate them through coughing. However, exposure to pets and wildlife remains It can happen.”
Esther A. Guzmán et al., Assessment of potential threats to human health from algal blooms in the Indian River Lagoon 2018-2021 (United States): Unique patterns of cytotoxicity associated with toxins, toxin (2023). DOI: 10.3390/toxin15110664
Provided by Florida Atlantic University
citation: Toxic algae blooms: Study assesses potential health hazards to humans (2024, January 11), Retrieved January 11, 2024, from https://phys.org/news/2024-01-toxic-algae-blooms -pottial-health.html
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