Wild birds as bioindicators of environmental pollution and heavy metals

Air pollution is considered as an important growing public health issue, due to its harmful effects on ecosystems and its inhabiting organisms, like humans, animals and plants (1,2,3,4,5,6). Chronic exposure to components of air pollution, including heavy metals, has been linked to health problems in humans; reports include heart, respiratory and neurological diseases, cancer predisposition, problems on embryonic development and death (7,8,9,10,11,12,13,14,15,16,17,18). Heavy metals like lead, cadmium and arsenic are toxic and not biodegradable (19,20,21), therefore they persist, biomagnify and accumulate in the environment and organisms, crossing the different trophic levels that constitute an ecosystem through the food chain (1,3,4,15,22,23,24,25,26,27). Wild animals could be useful as environmental biomarkers of environmental hazards present in the ecosystem shared with humans (28). The usefulness of studying birds as biomarkers of environmental pollution has been recognized in multiple research studies (1,4,5,6,27,29), because these animals occupy different trophic levels in the ecosystems, are widely distributed and are highly sensitive to atmospheric changes in the environment, allowing in this way, to monitor the environmental health of the ecosystem they inhabit (4,27,29,30,31). This issue reaffirms the importance of using biological indicators like birds, in research studies intended to quantify the state of the environmental health of ecosystems, the presence of heavy metals and its relationships to human diseases, in order to establish plans for prevention and control regarding public health.