Effects of arsenic speciation and low dissolved oxygen condition on the toxicity of arsenic to a lotic mayfly

Abstract

The influence of site-specific conditions on contaminant bioavailability and toxicity to benthic invertebrates is a key consideration in the environmental risk assessment process. This is particularly relevant for contaminants with complex speciation chemistries, such as arsenic. The present study addressed uncertainties regarding arsenic toxicity to a mayfly (Baetis tricaudatus) under low dissolved oxygen (DO) conditions characteristic of many contaminated sites. Arsenic toxicity (arsenite, As(III); arsenate, As(V)) to mayfly nymphs was assessed under two DO scenarios (68 and 84% saturation). Arsenic speciation ratios were determined during testing to confirm the nature of arsenic exposure. The present study found that As(III) was more lethal and bioaccumulated to a greater degree in B. tricaudatus compared to As(V), but the sublethal toxicities of the two arsenic species were similar. Nymph growth and development were significantly inhibited after 12 d of exposure to both 1 mg/L of As(III) and As(V). Exposure to arsenic under low DO conditions (6.5 mg/L, 68% saturation) did not significantly affect As(III) or As(V) toxicity and bioaccumulation over 12 d. The DO level of 6.5 mg/L, however, appeared to be marginally lethal to B. tricaudatus. Results indicate that the Canadian arsenic criterion for the protection of aquatic life (5 microg/L) is protective of B. tricaudatus and is low enough to accommodate differences in arsenic toxicity because of the interconversions between As(III) and As(V). These findings provide insight regarding the toxicity and speciation of arsenic under DO conditions considered to be low for this lotic mayfly species and representative of existing conditions at mine sites in northern Canada.

Chronic exposure to pentavalent arsenic of larval leopard frogs (Rana pipiens): bioaccumulation and reduced swimming performance

“…The mean measures at time zero and at 48 h for the control, 10, 20, 150, 500 and 1,000 lg l -1 groups were 1.4 ± 0.1, 13.5 ± 0.2, 27.7 ± 1.4, 154.1 ± 4.8, 514.0 ± 3.4, and 1,026.2 ± 1.7 lg l -1 (n = 2, mean ± standard error), respectively. A recent study (Irving et al 2008) found that the As (III) and As (V) speciation ratio remained stable between 48-h water renewals. In their study there was less than 1% of As (V) converted to As (III) within 48 h and no organic arsenic species were detected.…”

“…From two randomly selected tanks of each treatment, approximately 1 g of dried whole metamorphs (3-4 individuals) was randomly sampled for metal analysis. Tissue As concentrations were analyzed at the Soil and Plant Analysis Lab of the University of Wisconsin by ICP-MS after an openvessel HNO 3 plus H 2 O 2 hot-plate digestion (Irving et al 2008) following the procedures described in their on-line document Wisconsin Procedures for Soil Testing, Plant Analysis and Feed & Forage Analysis (detailed analysis procedures are available at http://uwlab.soils.wisc.edu/ madison/). Briefly, five ml of concentrated nitric acid was added to half a gram of dried tissue sample.…”

“…However, releases from human activities far exceed those from natural sources (ATSDR 2007). Anthropogenic sources of As release to surface water include mining, smelting, coal burning power plants, industries, urban runoff, application of biosolids, fertilizers and pesticides, and atmospheric deposition (ATSDR 2007;Irving et al 2008). Concentrations of As in rivers and lakes in the United States mostly are below 10 lg l -1 , although concentrations as high as 1,700 lg l -1 have been reported (ATSDR 2007).…”

The influence of salinity on toxicological effects of arsenic in digestive gland of clam Ruditapes philippinarum using metabolomics

“…Although some arsenic is released into the environment from natural geogenic sources, e.g., volcanic activity (World Health Organization, 1981;Sanders et al, 1994), the major contributors to arsenic contamination of environment are anthropogenic activities, such as mining, smelting, and the production of fertilizers and pesticides (Agency for Toxic Substances and Disease Registry, 2007;Irving et al, 2008;Chen et al, 2009). Arsenic is toxic to most organisms and in mammals it causes diverse effects, including cancer and cardiovascular disease (Hughs, 2002).…”

Tolerance to individual and joint effects of arsenic and Bacillus thuringiensis subsp. israelensis or Lysinibacillus sphaericus in Culex mosquitoes

“…() reported mentum deformities in Chironomus dilutus that were exposed to arsenite spiked soils. The mayfly Baetis tricaudatus (Ephemeroptera: Baetidae) experienced reduced nymph growth and development when exposed to 1 000 μ g/L of arsenate and arsenite (Irving et al ., ). The mechanisms by which arsenic induces toxicity are varied (Kumagai & Sumi, ) and are not well understood in insects, although research suggests glutathione synthetase may play a role in detoxification (Muñiz‐Ortiz et al ., ; Andrahennadi & Pickering, ).…”