Ecotoxicology involves the scientific study of the fates of pollutants in the environment. Ecotoxicity tests can be used to monitor the pollution potential of waste effluent discharged to the environment and to predict whether biota in the receiving environment will be adversely affected.

Disposal of spent mushroom compost

Algal enrichment (eutrophication) is one of the major consequences of freshwater pollution in Ireland. The eutrophic potential of effluents can be modelled using algal bioassays. Macro-invertebrates such as daphnids are a major source of food for commercially important fish such as salmonids. Any negative effect on these organisms can have significant implications for the receiving environment. Such effects can be screened for using the Daphnia bioassay. Another bioassay, the fish avoidance test, uses rainbow trout as the test species. This bioassay is based on the ability of salmonids to migrate away from sub-lethal concentrations of chemicals.

Research projects undertaken by the Ecotoxicology Unit at Athlone Institute of Technology include (i) the ecotoxicological assessment of several pesticides used in the Irish mushroom industry (ii) the microbiological degradation and detoxification of harmful chemicals and (iii) the ecotoxicological assessments of industrial effluents.

Agri-chemicals are widely used in the mushroom growing industry in Ireland. The industry is worth £77 million pounds annually and employs over 9,000 people. As this very successful industry continues to expand, the safe disposal of the concomitant spent mushroom compost (SMC) is becoming increasingly problematic. The Irish mushroom industry generates 272,000 tonnes of SMC annually which has to be disposed. A significant proportion of this spent mushroom compost is disposed of by landfilling at a considerable cost. While this organically rich SMC has many desirable properties for use in soil amendment, these benefits may be negated by the potential presence of pesticide residues. Researchers in the Ecotoxicology Unit have developed bacteria which are capable of detoxifying some of the pesticides found in the spent mushroom compost, which should enhance its beneficial properties, while eliminating many of the environmental concerns.