Biotic and abiotic factors influencing arsenic biogeochemistry and toxicity in fluvial ecosystems: a review

LAURA BARRAL-FRAGA; MARÍA TERESA BARRAL SILVA; KEELEY L. MACNEILL; DIEGO MARTIÑÁ-PRIETO; SOIZIC MORIN; RODRÍGUEZ CASTRO, MA. CAROLINA; BAIGAL-AMAR TUULAIKHUU; GUASCH, HELENA

INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH

MOLECULAR DIVERSITY PRESERVATION INTERNATIONAL-MDPI

Lugar: Basel; Año: 2020

1660-4601

This review is focused on the biogeochemistry of arsenic in freshwaters and, especially, on the key role that benthic microalgae and prokaryotic communities in biofilms play together on it through speciation, distribution and cycling. These microorganisms incorporate the dominant iAs (inorganic arsenic) form and may transform it to other arsenic forms through metabolic or detoxifying processes. These transformations have a big impact on the environmental behavior of arsenic because different chemical forms exhibit differences in mobility and toxicity. Moreover, exposure to toxicants may alter the physiology and structure of biofilms, leading to changes in ecosystem function and trophic relations. Microorganisms (i.e. biofilms) can influence the effects of arsenic exposure on other key constituents of aquatic ecosystems such as fish. Finally, we present two case studies, Pampean Streams (Argentina) and the Anllóns River (Galicia, Spain), two examples of different origins of arsenic exposure that have improved our understanding of arsenic biogeochemistry and toxicity in freshwaters; and we discuss what we consider as future research needs in this topic.