The product from the burning of a combination of carbonaceous materials.

Endpoint summary

Additional information

Ash is not classified as hazardous to environment. The EC50-values obtained from acute daphnia and algae tests ranged between 10 and 100 mg/l and NOEC from the chronic daphnia test was 3.2 mg/l (i.e. > 1 mg/l). For micro-organisms Ash was not toxic (EC50 > 100 mg/l). In the test waters of acute and chronic daphnia test, concentration of aluminum was high compared to concentrations of other trace elements indicating its key role in observed toxicity. Aluminum toxicity to freshwater plankton is suspected to be partly due to its ability to strongly bind phosphorus, thereby reducing the availability of this nutrient (Exley et al., 1993; Vrba et al., 2006). Biesinger and Christensen (1972) determined 48-h LC50 of aluminium for Daphnia magna to be 3.9 mg/l, which is significantly lower than EC50-value observed in this study. Numerous experimental studies have demonstrated that the toxicity of Al to aquatic organisms decreases in the presence of Si (e.g. Birchall et al., 1989; Campbell et al., 2000), which is abundantly present in Ash. Based on literature data, adverse sublethal effects have been observed in fish exposed to coal ash slurries. However, no effects on reproduction of fish have been found. Mechanism of toxicity of ash on aquatic organisms is uncertain. Ash released in water will increase pH, increase nutrient content but also possibly releases toxic compounds. Rapid changes in pH seem to affect the metabolism of phytoplankton and bacteria very rapidly, and aquatic micro-organisms seem to be very adapted to the prevailing acidity.

Mobility, toxicity and bioaccumulation are dependent on environmental pH. In the scale of Europe, soil pH in Finland is at the lower end (< 5.5) representing the worst-case scenario (European Soil Portal).

References

 

Biesingern KE, Christensen GM, Effects of various metals on survival, growth, reproduction and metabolism of Daphnia magna, 1972. Journal of Fisheries Research Board of Canada, 29, 1691-1700.

 

Birchall J, Exley C, Chappell J, Phillips M, 1989, Acute toxicity to fish eliminated in silicon rich acid waters. Nature 338, 146–148

 

Campbell MM, WhiteKN, Jugdaohsingh R, Powell J, McCrohan CR, 2000, Effect of aluminium and silicic acid on the behaviour of the freshwater snail Lymnaea stagnalis. Can.J.Fish.Aquat.Sci. 57,1151–1159.

 

Exley C, Tollervey A, Gray G, Roberts S, Birchall JD, 1993, Silicon, aluminium and the biological availability of phosphorus in algae. Proc. Royal Soc. London B 253, 93–99.

 

European Soil Portal,http://eusoils.jrc.ec.europa.eu/

 

Vrba J, Kopa´cek J, Bittl T, Nedoma J, ˇStrojsova´A, Nedbalova´ L, Kohout L, Fott J, 2006, A key role of aluminiumin phosphorus availability, foodweb structure, and plankton dynamics in strongly acidified lakes, Biologia 61,441–451.