Feedback information of an accidental ammonia dispersion: use of phyto-references

The data from accidental releases of toxic gas to the atmosphere are incomp lete because of the lack of information concerning the measurement of the c oncentrations emitted. Their estimation based on plants' responses to toxic gas exposure would provide an interesting tool to improve feedback from th e incidents. With this in mind, preliminary studies on the response of plan ts to several levels of gas exposures are required. A protocol for the eval uation of acute effects of ammonia on the terrestrial lens Lens culinaris ( Medikus) has been determined. For the preparation of reproducible samples, a technique of pre-germination of the seeds and their transplantation after selection was adopted. The plants exposure has been carried in a hermetic enclosure with a cross flow of diluted ammonia. Various concentrations for various exposure times were tested. The visual observation of the plants ma de it possible to define the various behaviour patterns in terms of the amm onia concentration. (C) 2001 Elsevier Science Ltd. All rights reserved.