EXPOSURE AND EFFECTS OF TOXIC TRACE METALS IN BIRDS OF PAKISTAN.

Increasing concentration of trace metals in the environment and their subsequent health effects in living organisms has become a major threat particularly in developing parts of the world. Therefore present study was designed to investigate the concentration of trace metals such as Pb, Cd, Cr and Cu in liver, pectoral muscle, pelvic muscle and blood of two terrestrial (Bank Myna; Acridotheres ginginianus and Jungle Babbler; Turdoides striata) and two aquatic (Grey Heron; Ardea cinerea and Cattle Egret; Bubulcus ibis) bird species collected from the premises of Lahore, Pakistan. The detection frequency of trace metals in collected samples were highest in Cd (100%) followed by Pb (83%), Cr (80%) and Cu (76.5%). Species revealed heterogeneous levels of metals in all organs. In general the mean concentration (µg/g) of trace metals in organs and blood of terrestrial species followed the pattern as Pb > Cu > Cr > Cd contrary to aquatic species in which the trend was Cu > Pb > Cr > Cd. Highest concentration of Pb (3.23 µg/g) was reported in pelvic muscle of jungle babbler, Cd (0.15 µg/g) in liver of bank myna, Cr (0.40 µg/g) in pelvic muscle of Cattle Egret and Cu (1.89 µg/g) in liver of Cattle Egret. Whereas lowest concentration of Pb (0µg/g) and Cd (0.09 µg/g) was reported in blood and pelvic muscle of Grey Heron respectively, Cr (0µg/g) in blood of Bank Myna, Grey Heron and Cattle Egret, Cu (0 µg/g) in blood of Grey Heron, Cattle Egret and Jungle Babbler. Concentration of metals varied significantly (P<0.05) among organs however, no significant difference (P>0.05) was observed among species except Cu(P<0.05). Further, no significant difference (P>0.05) of metals was observed between feeding guilds and habitat of the species. The increasing concentration of toxic trace metals in the birds reflects deteriorating environmental health as a result of greater metals exposure which must be reduced through proper legislation and strict implementation of laws. [ABSTRACT FROM AUTHOR]