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Observing-responses of rats exposed to 1.28- and 5.62-GHz microwaves
Abstract:
The effects of microwave irradiation at two different frequencies (1.28 and 5.62 GHz) on observing-behavior of rodents were investigated. During daily irradiation, eight male hooded rats performed on a two-lever task; depression of one lever produced one of two different tones and the other lever produced food when depressed in the presence of the appropriate tone. At 5.62 GHz, the observing-response rate was not consistently affected until the power density approximated 26 mW/cm2 at 1.28 GHz, the observing-response rate of all rats was consistently affected at a power density of 15 mW/cm2. The respective whole-body specific absorption rates (SARs) were 4.94 and 3.75 W/kg. Measurements of localized SAR in a rat-shaped model of simulated muscle tissue revealed marked differences in the absorption pattern between the two frequencies. The localized SAR in the model's head at 1.28 GHz was higher on the side distal to the source of radiation. At 5.62 GHz the localized SAR in the head was higher on the proximal side. It is concluded that the rat's observing behavior is disrupted at a lower power density at 1.28 than at 5.62 GHz because of deeper penetration of energy at the lower frequency, and because of frequency-dependent differences in anatomic distribution of the absorbed microwave energy.
Insights
Microwave irradiation disrupts rodent behavior, with lower frequencies (1.28 GHz) affecting rats at lower power densities than higher frequencies (5.62 GHz) due to energy penetration and absorption patterns.
Area of Science:
- Electromagnetics
- Neuroscience
- Behavioral Science
Background:
- Microwave irradiation is increasingly prevalent, necessitating an understanding of its biological effects.
- Rodent models are crucial for investigating the impact of radiofrequency energy on behavior.
Purpose of the Study:
- To investigate the effects of microwave irradiation at 1.28 GHz and 5.62 GHz on rodent observing-behavior.
- To determine the power density thresholds for behavioral disruption at different microwave frequencies.
- To analyze the relationship between absorbed energy distribution and behavioral effects.
Main Methods:
- Eight male hooded rats were exposed to daily microwave irradiation at 1.28 GHz and 5.62 GHz.
- Behavioral assessment involved a two-lever operant task measuring observing-response rates.
- Whole-body and localized specific absorption rates (SARs) were measured using a rat-shaped model.
Main Results:
- Behavioral disruption occurred at 15 mW/cm2 at 1.28 GHz, and 26 mW/cm2 at 5.62 GHz.
- Whole-body SARs were 4.94 W/kg (1.28 GHz) and 3.75 W/kg (5.62 GHz).
- Localized SAR patterns differed significantly, with 1.28 GHz showing higher head SAR on the distal side and 5.62 GHz on the proximal side.
Conclusions:
- Lower microwave frequencies (1.28 GHz) disrupt rodent observing behavior at lower power densities than higher frequencies (5.62 GHz).
- Deeper energy penetration at lower frequencies contributes to earlier behavioral disruption.
- Frequency-dependent differences in the anatomic distribution of absorbed microwave energy influence behavioral effects.
