Will “Air Eutrophication” Increase the Risk of Ecological Threat to Public Health?

Abstract

Aquatic eutrophication, often with anthropogenic causes, facilitates blooms of cyanobacteria including cyanotoxin producing species, which profoundly impact aquatic ecosystems and human health. An emerging concern is that aquatic eutrophication may interact with other environmental changes and thereby lead to unexpected cascading effects on terrestrial systems. Here, we synthesize recent evidence showing the possibility that accelerating eutrophication will spill over from aquatic ecosystems to the atmosphere via “air eutrophication”, a novel concept that refers to a process promoting the growth of airborne algae, some of them with the capacity to produce toxic compounds for humans and other organisms. Being catalyzed by various anthropogenic forcingsincluding aquatic eutrophication, climate warming, air contamination, and artificial light at nightaccelerated air eutrophication may be expected in the future, posing a potentially increasing risk of threat to public health and the environment. So far knowledge of this topic is sparse, and we therefore consider air eutrophication a potentially important research field and propose an agenda of cross-discipline research. As a contribution, we have calculated a tolerable daily intake of 17 ng m–3 day–1 for the nasal intake of microcystins by humans.

Emerging contaminants: A One Health perspective

“…Notably, bioaerosol is another air pollutant of concern, which is a subset of atmospheric particles composed of bacteria, fungi, viruses, and their products, ranging in size from 0.001 nm to 100 μm. Cyanotoxins may enter the atmosphere in the form of aerosols and spread further afield, posing a potential threat to atmospheric safety and contributing to the ecological risk of “air eutrophication.” 437 , 438 Bioaerosol is commonly released into the atmosphere from soil, water, vegetation, animals (including humans), composting, sewage treatment plants, landfills, farms, and healthcare sites. 439 , 440 , 441 , 442 Due to the diffusion of plant pollen, spores, and reproductive units of microorganisms, bioaerosols can be transported over long distances across geographical barriers, 443 posing a high public health risk.…”