Airborne Algae and Cyanobacteria Originating from Lakes: Formation Mechanisms, Influencing Factors, and Potential Health Risks

TL;DR

This paper reviews how algae and cyanobacteria from lakes become airborne, their health risks, and how environmental changes may increase these threats.

Contribution

The paper provides a comprehensive review of airborne algae and cyanobacteria formation, influencing factors, and health risks.

Findings

Airborne algae and cyanobacteria can be aerosolized into micrometre-sized particles.

Aerosolized HAB toxins may degrade or transform into byproducts with different potencies.

Exposure to these airborne toxins could pose significant health risks, especially with air pollutants.

Abstract

Algal and cyanobacterial blooms are anticipated to increase in frequency, duration, and geographic extent as a result of environmental changes, including climate warming, elevated nutrient concentrations, and increased runoff in both marine and freshwater ecosystems. The eutrophication of aquatic environments represents a substantial threat to human health. As eutrophication progresses, airborne algae and cyanobacteria, particularly harmful genera originating from aquatic environments, are released into the atmosphere and may pose potential risks to human health. Furthermore, respiratory distress has been documented in individuals exposed to aerosols containing harmful algal bloom (HAB) toxins. This review investigates the generation of aerosolised harmful algal blooms, their responses to environmental factors, and their associated health risks. Evidence suggests that airborne algae, cyanobacteria, and their toxins are widespread. When these are aerosolised into micrometre-sized particles, they become susceptible to atmospheric processing, which may degrade the HAB toxins and produce byproducts with differing potencies compared to the parent compounds. Inhalation of aerosolised HAB toxins, especially when combined with co-morbid factors such as exposure to air pollutants, could present a significant health risk to a considerable proportion of the global population. A more comprehensive understanding of the chemical transformations of these toxins and the composition of harmful algal and cyanobacterial communities can improve public safety.

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