Plant biomonitoring of air and water pollution

Air quality, like water quality, is generally monitored by networks of physico-chemical sensors providing numerical values. But these direct measurements of both inorganic and organic elements quickly run up against ..:

• the low representativeness of the sample;

• analytical difficulties due to the frequent presence of low levels ;

• costs and maintenance of physico-chemical measuring equipment, as well as the sometimes high unit costs of analyses;

• to the fact that it is not possible to easily associate these values with specific toxic effects or nuisances that would manifest themselves on living beings.

An alternative is to use integrative measurement techniques capable of assessing environmental contamination, i.e. methods based directly on the observation and study of the reactions of living organisms exposed to pollution episodes.

These are known as bioindication or, more precisely, biomonitoring methods. Biomonitoring is broadly defined as "the use of responses at all levels of biological organization (molecular, biochemical, cellular, physiological, tissue, morphological, ecological) of an organism or group of organisms to predict and/or reveal environmental alteration and to monitor its evolution".

It soon became apparent that the use of living organisms in biomonitoring of both air and water offered a number of advantages, such as :

• bioconcentrate inorganic and organic contaminants to a high degree and provide integrated information over time (detection of pollutants that are highly concentrated or fleeting);

• to take into account the actual situation of atmospheric or aquatic pollution, i.e. to accumulate all the pollutants present without distinction;

• provide information on contamination received by living organisms under natural conditions (bioavailability of pollutants, potential health risks, contamination of food chains);

• detect new or accidental pollution not taken into account by conventional control systems;

• as biological material, have a strong psychological impact in raising awareness of air and water quality issues.

Add to this the simple, rapid approach of these original methods, and you have the additional information they provide on biological risks, and you have the perfect complement to physico-chemical methods for monitoring air and water.