Aluminium sodium tetrahydroxide

Toxicity to birds

Additional information

There are no studies available on birds for sodium aluminate. Nevertheless, aluminium is the most abundant metallic element in the Earth's crust. Based on its ubiquitous occurrence the present natural background concentration far outweighs anthropogenic contributions of aluminium to the terrestrial environment. Thus, secondary poisoning is also not considered a relevant route of contribution to the toxicity of aluminium to birds. Furthermore, the existence of a large mammalian dataset demonstrates little toxicity to higher organism. As detailed in the endpoint summary on terrestrial toxicity in general further toxicity testing on terrestrial organisms is thus considered unjustified and waiving based on exposure consideration is applied.

 

Existing data on the toxicity of aluminium to birds is considered to overestimate effects of aluminium. However, for reasons of completeness data are provided in addition and summerised here. Data provided are read-across based on an anlogue-approach from three short-term dietary toxicity studies with aluminum applied as aluminum sulphate (Capdevielle et al. 1998, Capdevielle and Scanes 1995, and Sparling 1990).

 

Capdevielle et al. (1998) examined the effects of two levels of dietary aluminum, 1000 and 5000 mg Al/kg, on bone growth, mineralization, and phosphorous/calcium homeostasis in growing mallard ducklings and chicks. Generally, a reduction in bone mineralization was observed in both species. Body growth rate and skeletal growth were reduced in both chicks and ducklings in the high aluminum diet. It was observed that the tibiae of chicks on this diet were soft, spongy, pliable, and easily broken. The levels of calcium and phosphate in tibiae and plasma were reduced in chicks compared to the controls. The low-aluminum diet had a less-pronounced effect with no significant difference between exposed chicks and the pair-fed controls. No effects on growth, tibia weight, or length were seen in ducklings fed the low aluminum diet. Calcium and phosphorus levels in ducklings, though slightly lower than the control, were consistent with or better than those measured in the pair-fed control.

 

In another study by Capdevielle and Scanes (1995) mallads were fed two levels of dietary aluminum. There, effects of aluminum on growth-related hormones were compared, i.e. growth hormone, insuline-like growth factor, and insulin-like growth factor binding proteins (IGFBPs). In the treatment with a high aluminum dose at 5000 mg Al/kg diet, the growth and also body weight were reduced in the mallard ducklings as a consequence of exposure to aluminum. In the treatment with the lower aluminum dose at 1000 mg Al/kg diet, there were no differences found in the ducklings growth rate and body weight. Furthermore, no effects on the weights of organs, i.e. liver, kidney, or testes, were observed in any of the aluminum treated groups when compared to the controls. Aluminum concentrations in the liver were 5.16 ppm for the low-aluminum diet and 15.52 ppm for the high-aluminum diet. In the controls aluminum concentration was 3.59 ppm. Also the plasma concentrations of GH and IGF-I did not differ between the treated animals and controls. However, plasma IGFBP levels were increased in comparison to the controls in the low-aluminum treatment. In conclusion, the results of this study demonstrate that the aluminum diets had no effect on the plasma concentrations of growth hormones and that aluminum influences growth in ducks directly and by reducing feed consumption.

 

Sparling (1990) investigated the role of dietary levels of aluminum, calcium, and phosphorus on growth and survival of black ducks and mallards. The birds were exposed to different regimes of calcium and phosphorus (low Ca and low P, normal Ca and normal P, low Ca and high P) with each regimen further devided into three levels of aluminum exposure (200, 1000, and 5000 mg Al/kg diet). Mortality, growth rates for body weight, culmens, wings, and tarsi, as well as food consumption was studied. This study demonstrated for all growth parameter that growth is inversely related to aluminum concentration regardless of the Ca and P treatment regime in both species of ducks. Most of the ducks that died displayed broken or dislocated limbs, rickets, and an inverse relationship between food consumption and Al in the diet. Diets with 10000 mg Al/kg caused stunted growth and mortality in black ducks and mallards. Food consumption significantly decreased in the 5000 and the 10000 mg Al/kg positive control treatment groups for both black ducks and mallards.