Study type: 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.

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

Exposure

Exposure Parameters
Exposure 1: 50–60 Hz
Exposure duration: breeding season of the year 2000

Exposure 1

Main characteristics
Frequency 50–60 Hz
Type
Exposure duration breeding season of the year 2000
Exposure setup
Exposure source
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:

Methods Endpoint/measurement parameters/methodology

Investigated system:
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:

Study funded by

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