Co-occurrence of taste and odor compounds and cyanotoxins in cyanobacterial blooms: emerging risks to human health?

TY - JOUR

T1 - Co-occurrence of taste and odor compounds and cyanotoxins in cyanobacterial blooms

T2 - emerging risks to human health?

AU - Manganelli, Maura

AU - Testai, Emanuela

AU - Tazart, Zakaria

AU - Scardala, Simona

AU - Codd, Geoffrey A.

N1 - Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2023/3/28

Y1 - 2023/3/28

N2 - Cyanobacteria commonly form large blooms in waterbodies; they can produce cyanotoxins, with toxic effects on humans and animals, and volatile compounds, causing bad tastes and odors (T&O) at naturally occurring low concentrations. Notwithstanding the large amount of literature on either cyanotoxins or T&O, no review has focused on them at the same time. The present review critically evaluates the recent literature on cyanotoxins and T&O compounds (geosmin, 2-methylisoborneol, β-ionone and β-cyclocitral) to identify research gaps on harmful exposure of humans and animals to both metabolite classes. T&O and cyanotoxins production can be due to the same or common to different cyanobacterial species/strains, with the additional possibility of T&O production by non-cyanobacterial species. The few environmental studies on the co-occurrence of these two groups of metabolites are not sufficient to understand if and how they can co-vary, or influence each other, perhaps stimulating cyanotoxin production. Therefore, T&Os cannot reliably serve as early warning surrogates for cyanotoxins. The scarce data on T&O toxicity seem to indicate a low health risk (but the inhalation of β-cyclocitral deserves more study). However, no data are available on the effects of combined exposure to mixtures of cyanotoxins and T&O compounds and to combinations of T&O compounds; therefore, whether the co-occurrence of cyanotoxins and T&O compounds is a health issue remains an open question.

AB - Cyanobacteria commonly form large blooms in waterbodies; they can produce cyanotoxins, with toxic effects on humans and animals, and volatile compounds, causing bad tastes and odors (T&O) at naturally occurring low concentrations. Notwithstanding the large amount of literature on either cyanotoxins or T&O, no review has focused on them at the same time. The present review critically evaluates the recent literature on cyanotoxins and T&O compounds (geosmin, 2-methylisoborneol, β-ionone and β-cyclocitral) to identify research gaps on harmful exposure of humans and animals to both metabolite classes. T&O and cyanotoxins production can be due to the same or common to different cyanobacterial species/strains, with the additional possibility of T&O production by non-cyanobacterial species. The few environmental studies on the co-occurrence of these two groups of metabolites are not sufficient to understand if and how they can co-vary, or influence each other, perhaps stimulating cyanotoxin production. Therefore, T&Os cannot reliably serve as early warning surrogates for cyanotoxins. The scarce data on T&O toxicity seem to indicate a low health risk (but the inhalation of β-cyclocitral deserves more study). However, no data are available on the effects of combined exposure to mixtures of cyanotoxins and T&O compounds and to combinations of T&O compounds; therefore, whether the co-occurrence of cyanotoxins and T&O compounds is a health issue remains an open question.

KW - cyanobacteria

KW - geosmin

KW - 2-methylisoborneol

KW - β-ionone

KW - β-cyclocitral

KW - microcystins

KW - cylindrospermopsins

KW - neurotoxins

KW - risk assessment

KW - water treatment

UR - https://www.scopus.com/pages/publications/85156213555

U2 - 10.3390/microorganisms11040872

DO - 10.3390/microorganisms11040872

M3 - Review article

C2 - 37110295

SN - 2076-2607

VL - 11

JO - Microorganisms

JF - Microorganisms

IS - 4

M1 - 872

ER -