Medical/biological study (observational study)

Magnetic fields produced by power lines do not affect growth, serum melatonin, leukocytes and fledging success in wild kestrels med./bio.

By: Dell'Omo G, Costantini D, Lucini V, Antonucci G, Nonno R, Polichetti A

Published in: Comp Biochem Physiol C Toxicol Pharmacol 2009; 150 (3): 372-376

Aim of study (acc. to author)

A field study was performed on kestrels to compare chicks from pairs nesting on high voltage power lines versus those nesting in control sites in similar habitats.

Background/further details

Nesting on high voltage power line towers exposes birds to electric and magnetic fields for long periods. Nestlings are exposed from their development in ovo until fledging. This is a critical period for them, because the quality of the environment may affect their fitness at adulthood.
The study was carried out during the breeding season in the year 2000 in an area aoround Rome. Nest-boxes for kestrels have been attached to high voltage power line towers. 44 nest-boxes were included in the study: 28 were exposed and 16 were control nests (attached at abandoned transmission towers, non-electric pylons or abandoned buildings). Different numbers of nests were used to study different parameters.

Endpoint

growth, melatonin secretion, leukocyte count and fledging success (of kestrels)

Exposure

- power transmission line

Exposure	Parameters
Exposure 1: 50–60 Hz Exposure duration: breeding season of the year 2000	electric field strength: 480 V/m (on the ground below a 150 kV line) electric field strength: 2,600 V/m maximum (inside the nest at a 150 kV line) magnetic flux density: 4 µT (on the ground under a 150 kV line) magnetic flux density: 7.9 µT (in the nest at a 150 kV line) magnetic flux density: 1.37 µT minimum magnetic flux density: 8.63 µT mean magnetic flux density: 25.16 µT maximum

Exposure 1

Main characteristics

Frequency	50–60 Hz
Type	magnetic field
Exposure duration	breeding season of the year 2000

Exposure setup

Exposure source	power transmission lines
Setup	30 cm x 30 cm x 50 cm plywood nest-boxes attached to high power line towers 7 m to 20 m above the ground; single and double circuit lines for 60 kV, 150 kV, 220 kV, 380 kV

Parameters

Measurand	Value	Type	Method	Mass	Remarks
electric field strength	480 V/m	-	measured	-	on the ground below a 150 kV line
electric field strength	2,600 V/m	maximum	measured	-	inside the nest at a 150 kV line
magnetic flux density	4 µT	-	measured	-	on the ground under a 150 kV line
magnetic flux density	7.9 µT	-	measured	-	in the nest at a 150 kV line
magnetic flux density	1.37 µT	minimum	measured	-	-
magnetic flux density	8.63 µT	mean	measured	-	-
magnetic flux density	25.16 µT	maximum	measured	-	-

Exposed system:

animal
kestrel/Eurasian (Falco tinnunculus)
whole body

Methods Endpoint/measurement parameters/methodology

effects on the immune system: leukocyte (proportions of different leukocytes), red blood cells and thrombocyte counts (May-Grunwald-Giemsa stain; light microscopy)
endocrine changes: melatonin secretion (in serum; radioimmunoassay)
growth (wing length) and fledging success (ratio between number of fledging per brood and the number of hatched chicks per brood)

Investigated system:

intact cell/cell culture
blood samples
investigation on living organism

Investigated organ system:

Time of investigation:

during exposure
after exposure

Main outcome of study (acc. to author)

None of the variables differed between exposed and control nestlings. The data suggest that exposure to magnetic fields produced by high voltage power lines during the embryonic and post-hatching period (until fledging) does not have significant short-term physiological effects on kestrel nestlings.

Study character:

medical/biological study
observational study
field study

Study funded by

Ornis italica, Rome, Italy

Tomas G et al. (2012): Clutch size and egg volume in great tits (Parus major) increase under low intensity electromagnetic fields: A long-term field study
Everaert J et al. (2007): A Possible Effect of Electromagnetic Radiation from Mobile Phone Base Stations on the Number of Breeding House Sparrows (Passer domesticus)
Balmori A et al. (2007): The Urban Decline of the House Sparrow (Passer domesticus): A Possible Link with Electromagnetic Radiation
Costantini D et al. (2007): MF magnitude does not affect body condition, pro-oxidants and anti-oxidants in Eurasian kestrel (Falco tinnunculus) nestlings
Shafey TM et al. (2006): Effect of electric field during incubation of eggs on the immune responses of hatched chickens
Fernie KJ et al. (2005): The effects of electromagnetic fields from power lines on avian reproductive biology and physiology: a review
Fernie KJ et al. (2001): Evidence of oxidative stress in American kestrels exposed to electromagnetic fields
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Fernie KJ et al. (2000): Behavior of free-ranging and captive American kestrels under electromagnetic fields
Fernie KJ et al. (2000): Effects of electromagnetic fields on the growth of nestling american kestrels
Fernie KJ et al. (1999): Effects of electromagnetic fields on photophasic circulating melatonin levels in American kestrels