Investigating lichens as bioindicators of determining environmental and air pollution

The increasing human population, excessive exploitation of natural resources and significant industrial growth of countries in a short period of time have caused fundamental and irreversible changes in the biology-biochemical cycles of the natural ecosystems of the planet and widespread pollution of the environment, water, soil and air around us. These factors eventually lead to the occurrence of unnatural events such as climate changes and the risk of extinction of many plant, animal and micro-organism species.  Although the use of new technologies has led to the industrial, agricultural and economic development of human societies, but it has resulted in many negative environmental effects. The release of various environmental and air pollutants in the environment, such as pesticides, herbicides, nitrogen and sulfur oxides, heavy metals, etc., not only threatens human health but also seriously endangers the health of other living organisms. For several decades, has become common the use of living organisms as bioindicators to obtain information about the amount and type of environmental pollutants. Using bioindicators, it is possible to track the early signs of environmental and atmospheric pollution and the variety of pollutants. Various organisms are used as bioindicators for biological monitoring and tracking (biomonitoring) of air pollution, among these organisms are lichens. Lichens are one of the most important "biological indicators" for monitoring air quality, measuring the accumulation of heavy metals in the environment, measuring the health of forests, examining the extent of damage to the ozone layer, and obtaining information on pollutants and the variety of pollution at the local and regional level..