Evidence of oxidative stress in American kestrels exposed to electromagnetic fields

Exposure to electromagnetic fields (EMFs) alters melatonin, behavior, growt h, and reproduction of captive American kestrels (Falco sparverius), partic ularly of males. EMF exposure is a "possible" human carcinogen and associat ed with some neurodegenerative diseases. Oxidative stress contributes to ca ncer, neurodegenerative diseases, and immune disorders. We tested whether E MF exposure elicits an avian immune response and alters oxidative stress le vels. Captive male kestrels were bred under control or EMF conditions equiv alent to those experienced by wild kestrels. Short-term EMF exposure tone b reeding season) suppressed plasma total proteins, hematocrits, and caroteno ids in the first half of the breeding season. It also suppressed erythrocyt e cells and lymphocyte proportions, but elevated granulosa proportions at t he end of the breeding season. Long-term EMF exposure (two breeding seasons ) suppressed hematocrits in the first half of the reproductive period too. Results indicate that only short-term EMF birds experience an immune respon se, particularly during the early half of the breeding season. The elevatio n of granulocytes, and the suppression of carotenoids, total proteins, and previously melatonin in the same kestrels, signifies that the short-term EM F male kestrels had higher levels of oxidative stress, due to an immune res ponse and/or EMF exposure. Long-term EMF exposure may be linked to higher l evels of oxidative stress through EMF exposure only. (C) 2001 Academic Pres s.