Dietary tissue cadmium accumulation in an amazonian teleost (Tambaqui, Colossoma macropomum Cuvier, 1818)

Abstract

Understanding the effects of metal contamination in the Amazon basin is important because of the potential impact on this region of high biodiversity. In addition, the significance of fish as the primary source of protein for the local human population (living either alongside the Amazon River or in the city of Manaus) highlights the need for information on the metal transfer through the food chain. Bioaccumulation of metals in fish can occur at significant rates through the dietary route, without necessarily resulting in death of the organism. The goal of this work was to expose an economic relevant species from the Amazon basin (tambaqui, Colossoma macropomum) to dietary cadmium (Cd) at concentrations of 0, 50, 100, 200, and 400 µg.g -1 dry food. Fish were sampled on days 15, 30, and 45 of the feeding trials. Tissues were collected for analysis of Cd concentration using graphite furnace atomic absorption spectrophotometry. Cd accumulation in the tissues occurred in the following order: kidney > liver > gills > muscle. Relative to other freshwater fish (e.g., rainbow trout, tilapia), tambaqui accumulated remarkably high levels of Cd in their tissues. Although Cd is known to affect Ca 2+ homeostasis, no mortality or growth impairment occurred during feeding trials.Keywords: dietary cadmium, tissue accumulation, Colossoma macropomum, Amazon, soft water. Acúmulo dietário de cádmio em tecidos de um teleósteo Amazônico (Tambaqui, Colossoma macropomum)Resumo O entendimento dos efeitos da contaminação por metais na Bacia Amazônica é importante devido ao potencial impacto sobre esta região de elevada biodiversidade. Além disso, a relevância dos peixes como fonte primária de proteína para a população humana local (tanto nas comunidades ribeirinhas ao longo do rio Amazonas, quanto na cidade de Manaus), ressalta a necessidade de informação sobre a transferência de metais através da cadeia alimentar. Bioacumulação de metais em peixes pode ocorrer em taxas significativas através da dieta, sem necessariamente resultar na morte do indivíduo. O objetivo deste estudo foi expor cronicamente uma espécie de importância comercial nativa da Amazônia (tambaqui, Colossoma macropomum) a dietas enriquecidas com cádmio (Cd) em concentrações de 0, 50, 100, 200, and 400 µg.g -1 alimento seco. Os peixes foram amostrados nos dias 15, 30 e 45 do tratamento experimental. Os tecidos foram coletados para análise quanto a concentração de Cd por meio de espectrofotometria de absorção atômica acoplado a forno de grafite. O acúmulo de Cd nos tecidos ocorreu na seguinte ordem: rim > fígado > brânquias > músculo. Comparando-se com outras espécies de peixes de água doce (por exemplo, truta arco-íris, tilápia), o tambaqui acumulou níveis de Cd extremamente mais elevados em seus tecidos. Apesar do Cd ser conhecido por afetar a homeostase do Ca 2+ , não houve mortalidade ou retardo no crescimento durante os testes dietários.Palavras-chave: Cádmio, bioacumulação tecidual, Colossoma macropomum, Amazônia, água doce.

Physiological impacts and bioaccumulation of dietary Cu and Cd in a model teleost: The Amazonian tambaqui (Colossoma macropomum)

“…Additionally, Harrison and Klaverkamp (1989) found that Cd is more likely accumulated from dietary exposure rather than waterborne exposure. Cd concentrations accumulated in the tissues of tambaqui were relatively high when compared to values reported for rainbow trout (Handy, 1993 [1000 μg Cd/g dry food]; Szebedinszky et al, 2001 [1500 μg Cd/g dry food]; Baldisserotto et al, 2005 [300 μg Cd/g dry food]), and tambaqui (Matsuo and Val, 2007 [500 μg Cd/g dry food]). Muscle Cd burden was similar than the values reported by Matsuo and Val (2007).…”

“…Cd concentrations accumulated in the tissues of tambaqui were relatively high when compared to values reported for rainbow trout (Handy, 1993 [1000 μg Cd/g dry food]; Szebedinszky et al, 2001 [1500 μg Cd/g dry food]; Baldisserotto et al, 2005 [300 μg Cd/g dry food]), and tambaqui (Matsuo and Val, 2007 [500 μg Cd/g dry food]). Muscle Cd burden was similar than the values reported by Matsuo and Val (2007). In the liver, Cd concentration was nearly ten times higher at 30 days of exposure when compared to 15 days, but the accumulation of Cu did not change with time (Fig.…”

“…The experimental diets (nominally 500 μg Cd/g or 500 μg Cu/g dry weight) were prepared following protocols described in Matsuo and Val (2007) and Klinck et al (2009) in which the Nutripiscis-Presence ® AL 45 commercial pellets were ground to a fine powder in a food processor. The concentrations were initially chosen to match that used by Matsuo and Val (2007) for Cd, and many other studies (see Discussion) for both Cd and Cu. The powder was then thoroughly mixed for 1 h in the food processor with a solution of either Cd(NO 3 ) 2 •4H 2 O in nanopure water (cadmium-contaminated diet) or CuNO 3 in nanopure water (copper-contaminated diet) to ensure complete distribution of metal throughout the food paste.…”

<b>Cd, Cu, and Mn from Uruguay River Basin in Uruguaiana, RS, Brazil, and their toxicological potential for human leukocyte

“…It is well established that Cd is very mobile in aquatic environments, especially in water bodies rich in organic material, where it is present in sediments as Cd 2+ and Cd 3+ and is not, in this case, likely to undergo a redox reaction (Pierangeli et al, 2005). Furthermore, Cd is absorbed by aquatic organisms, and then taken up by aquatic plants and animals that may be consumed by human beings (Matsuo & Val, 2007). Increased exposure to Cd may cause several disorders in humans, such as acute or chronic intoxications (Dias, Alleoni, Casagarande, & Camargo, 2001).…”