scope:

Introduction

The effects of air pollutants can be determined and evaluated by means of living organisms, the so-called bioindicators. The necessary biological measurement procedures are standardised as VDI guidelines (e.g. guideline series VDI 3957). Monitoring air pollution is based on the investigation of emissions, ambient air pollution and effects. The basic principles of biological monitoring of effects are described in guideline VDI 3957 Part 1. Knowledge of the contents of this guideline is prerequisite for understanding the procedures described here.

The guideline of the emission source-related use of plants as bioindicators follows the recommendation of the working group "Bioindicator Methods - Identifying Effects" of the state agencies for environment protection [2].

Plants as Bioindicators are used in monitoring projects in relation to the Environmental Impact Assessment Act (UVPG) and the Federal Air Pollution Control Law (Bundes-Immissionsschutzgesetz BImSchG) the purpose of which is to protect humans, animals and plants, soil, water, atmosphere as well as cultural and other objects from harmful environmental influences and to prevent the development of harmful environmental influences (Article 1 of BImSchG).

The use of bioindicators can provide evidence in cases in which the Environmental Liability Act (Umwelthaftungsgesetz) applies. Results of biomonitoring studies can be used to decide if measures to maintain biodiversity are necessary or not. Studies of air pollution effects with bioindicator plants are an important component of environmental monitoring by federal and state authorities (Article 12 of the Federal Nature Conservation Act, BNatSchG) and they contribute to the development of environmental monitoring by bioindicators on European level [5].

Effects on organisms have to be expected when substances are introduced into an ecosystem. In order to secure a sustainable economic development that is mindful of the environment, measuring effects may be reasonable even in cases when the emission limits that apply to an installation are not exceeded. Air pollutants provide a stimulus for living organisms and provoke reactions by the organism that may lead to various changes. The effects may be expressed both as accumulations of air pollutants (accumulating indicators) and as alterations of the phenotype (sensitive indicators).

Systematic investigations with bioindicators allow to assess air pollution effects and their extent. If placed at the appropriate sites bioindicators allow to determine e.g., if an industrial plant has effects on the environment and how relevant they are. Biological measurement methods with bioindicator plants have therefore been used successfully for a long time for monitoring the environment in the vicinity of emission sources [7; 8; 9; 12; 14; 15; 22; 25; 26; 27; 29; 31; 33; 36; 39; 41; 42]. Examples are presented in Annex B.

Biological emission monitoring [21] is not covered by this guideline.