Risk assessment of industrial by-products used in earth construction

Industrial by-products can be used in earth constructions provided their environmental properties are acceptable, e.g. not exceeding defined acceptance values. Risk assessment is needed in cases where the disposal conditions significantly differ from the conditions considered when the acceptance values were set for by-products suitable in earth constructions, for example, in cases of sensitive disposal environments or in cases where the construction consists of several different by-products. It might also be possible through risk assessment to accept higher emission values in cases where more information is available about the properties of the harmful compounds. A procedure for the risk assessment of industrial by-products to be utilized in earth construction is proposed. The procedure is designed to be as simple as possible to use, yet cover the most important aspects and environmental risks in the assessment. Additionally, the special characteristics of construction and the use of earth constructions were also considered. The risks were primarily related to human health because the background data needed for an ecotoxicological risk assessment is still under development. The proposed risk assessment concept has also been tested in a case study on the use of coal fly ash in earth construction.