Arsenic Occurrence and Cycling in the Aquatic Environment: A Comparison between Freshwater and Seawater

Abstract

Owing to the toxicity and adverse effects of arsenic on human health, its levels in aquatic environments are among the most serious threats to humans globally. To improve our understanding of its occurrence and cycling in aquatic environments, herein we review the concentration, speciation, and distribution of arsenic in freshwater, seawater, and sediments. Many natural processes, such as rock weathering and geothermal activities, contribute to the background arsenic concentrations in the natural environment, whereas metal mining and smelting are anthropogenic sources of arsenic in the water. The high solubility and mobility of arsenic in aquatic environments affects its global cycling. Furthermore, the biological processes in the aquatic environment are discussed, especially the possible microbe-mediated reactions of arsenic in sediments. In addition, various environmental factors, such as redox conditions, pH, and salinity, which influence the transformation of arsenic species, are summarized. Finally, the differences between freshwater and seawater with reference to the concentration as well as speciation and distribution patterns of arsenic are addressed. This review provides deep insights into arsenic occurrence and cycling between freshwater and seawater aquatic environments, which can more accurately distinguish the risks of arsenic in different water environments, and provides theoretical guidance for the prevention and control of arsenic risks.

Toxic metal(loids) levels in the aquatic environment and nuclear alterations in fish in a tropical river impacted by gold mining

“…The PCA indicated that both environmental matrices may be acting as a potential source of contamination, suggesting that Hg and As may be readily available for uptake by fish. Both contaminants when present in the water column can be readily absorbed by the muscle tissues of organisms through the digestion process (Williams et al, 2010;Wang et al, 2023). In particular, in the aquatic environment inorganic As is absorbed by organisms, and then methylated to organic forms through different removal pathways that return arsenic to the water column, i.e., organic As concentrations may increase, due to the microbial activity present in the water (Azizur Rahman et al, 2012).…”

“…Toxic metal pollution has been recognized as one of the global environmental challenges of greatest concern because it threatens human and wildlife (WHO, 2008). The presence of toxic metals, such as mercury (Hg) and metalloids such as arsenic (As), has increased considerably in aquatic systems around the world driven by anthropogenic activities such as agriculture and mining (UNEP, 2017; Wang et al, 2023). For Latin America and the Caribbean, it has been reported that small-scale artisanal mining was responsible for 29% of the Hg emissions released into the atmosphere in 2010.…”

“…Once these contaminants enter the water body they can precipitate to the bottom and accumulate in sediments and be present in the water column. In addition, they can increase their toxic potential as they react with other environmental constituents (Córdoba-Tovar et al, 2022;Wang et al, 2023).…”

Multiyear and seasonal global indicators for French surface waters contamination by WFD substances

“…It is also known, however, that seasonal changes in the physicochemical conditions in the river themselves, like redox condition changes of iron-oxide particles of the sediment, which is temperature driven, may contribute to the release of diluted arsenic from the riverbed sediments (Mok 1989). It has also been suggested in the literature that bacterial reduction of As(V) to more soluble species As(III), favored by warmer temperature, may be a main process controlling the seasonal variations of dissolved As concentrations (Masson 2007, Wang 2023. The Arsenic's national interannual -values timeseries is displayed in Figure 26, plotting both the full set of data, and those values excluding the LB basin, in order to check if the important change in the sites number in this basin influences the whole picture.…”

Toxic Effects of Arsenic on Four Freshwater Aquatic Species and Its Transformation Metabolism in Crucian Carp (Carassius auratus)

“…In China, the scale of the integrated rice–fish farming industry has steadily increased, with the farming area exceeding 39 million acres and a yield of over 3.5 million tons in 2021 [ 6 ]. However, there are widespread toxic As substances, such as arsenite, in the rice field environment [ 7 ]. Issues such as high detection rates of As in aquatic products and dietary risks have gradually attracted widespread attention [ 8 ].…”