CELLULAR IMPACT OF METAL TRACE ELEMENTS ON THE LICHEN LOBARIA PULMONARIA (L.) HOFFM. (1796), A BIO INDICATOR OF ATMOSPHERIC POLLUTION AND IDENTIFICATION OF ITS ANTIOXIDANT RESPONSE

We used the bioindicator Lobaria pulmonaria (L.) Hoffm. to assess air pollution, particularly induced by heavy metals, in urban and peri urban regions in the city of Oran (N-W of Algeria) and evaluated their environmental impact. For this purpose, we adopted the active biomonitoring technique to monitor lead (Pb), Cadmium (Cd) and Chromium (Cr) bioaccumulation in transplanted Lobaria pulmonaria thalli and assessed the detoxification enzyme's activity: Catalase (CAT), Ascorbate peroxidase (APX), and Guaiacol peroxidase (GPX) to examine the antioxidant system's response to heavy metal-induced stress. This study, revealed significant bioaccumulation of Pb, Cd and Cr in the following order Pb > Cr > Cd, increasing significantly in time reaching 301.83 mg/kg with the highest concentrations recorded in the urban regions indicating high metallic pollution levels. Additionally, heavy metal concentrations were proven to be significantly correlated with the over expression of detoxification enzymes. The response of Lobaria pulmonaria to air quality, along with its bio-accumulative capacity, confirmed that it is indeed a good bio-indicator of atmospheric pollution, especially that induced by heavy metals.