Electromagnetic field exposure of White stork nests and possible impacts on their breeding success and development

Abstract

Introduction: Studies have found impacts of electromagnetic fields (EMF) on reproduction, including effects on the human testis. White storks’ (Ciconia ciconia) nests provide a quasi-experimental situation to explore the impacts of EMFs on breeding success.In Spain, Balmori had found that 40% of white stork nests located within <200 meters(m) of phone masts had no chicks, significantly more than nests >300m away (3%).Our aims were to assess the impact of RF-EMF, electric and magnetic fields on the breeding success of white storks through in-situ measurements from the nests. Methods: Districts and villages of two provinces were chosen as the study area and visited in April-May 2015 to measure EMF from the nests and count the eggs.The nests were reached with aerial work platform trucks.EMFs were measured by Aaronia Spectran HF-4060 and NF-3020 devices. Distance between the nests and the phone masts were measured by using an optical range finder (Newcon optic 7.5x30mm, range 1,200m). All the nests were revisited in June 2015 to count the number of chicks. Results: There were 12 nests <200m from phone masts and 65 nests ≥200m.Most of the nests (86.3%) were on electricity pylons, 77.9% of these on platforms. The mean±SD number of eggs hatched was 2.92±2.19 in nests <200m vs.4.18±1.33 at ≥200m away (p=0.162). There were 2.17±1.80 chicks in nests <200m vs.2.78±1.43 in nests ≥200m away (p=0.310). Mean radiofrequency, 3G, GSM900, GSM1800 and wireless network field measurements were significantly higher in nests located within 200m from phone masts (respectively 3.53 vs.0.47 V/m, 0.11 vs.0.05, 0.95 vs.0.14, 0.40 vs.0.06, 0.02 vs.0.005 V/m). Conclusions: Although not statistically significant, the number of eggs and chicks are lower in nests within 200m and the difference is more pronounced in the number of eggs.Nests on electricity pylons might cause confounding by electric and magnetic fields.A larger sample-size of nests within 200m from phone masts is recommended.