Details |
|
Cattle exposed to radio transmitter signals (3-30 MHz) from local AM radio towers were examined for effects on salivary melatonin concentrations. One herd located at a distance of 500 meters from the transmitter (exposed) was compared to another located at a distance of 4,000 meters (unexposed). Additionally, the transmitter was switched off during three of the ten days of analysis (off phase). There was no statistically significant difference between exposed and unexposed cows. The authors did report, however, that on the first night of re-exposure after the transmitter had been off for three days, the difference in salivary melatonin concentration between the two herds (3.89 pg/ml, CI: 2.04, 7.41) was statistically significant, although they caution the results should be interpreted with caution and further trials would be required in order to confirm the results. |