8,700 Studies Reviewed. 87.0% Found Biological Effects. The Evidence is Clear.
Shield Your Body
Whole Body / General

Modification of Heating Patterns Produced by Microwaves at the Frequencies of 2456 and 900 Mc. by Physiologic Factors in the Human

Bioeffects Seen

Justus F. Lehmann, George D. Brunner, Jo Ann McMillan, Donald Ray Silverman, Vilas C. Johnston · 1964

Share:

Human tissue heating from 900 MHz and 2456 MHz microwaves triggers protective blood flow responses, demonstrating measurable biological effects at frequencies used in modern wireless devices.

Plain English Summary

Summary written for general audiences

Researchers in 1964 studied how microwaves at 2456 MHz and 900 MHz heat human tissue, comparing effects in living human thighs versus pig tissue specimens. They found that blood flow significantly reduces heating in both deep and surface tissues, with surface areas showing more pronounced cooling effects.

Why This Matters

This pioneering 1964 study reveals something crucial about microwave radiation that applies directly to today's wireless devices. The researchers demonstrated that microwaves at 900 MHz and 2456 MHz create measurable heating in human tissue - frequencies remarkably close to modern cell phones (850-1900 MHz) and WiFi routers (2400 MHz). What makes this study particularly relevant is its focus on the human body's natural response to this heating through increased blood flow. The science demonstrates that our bodies actively work to counteract microwave-induced heating, suggesting these frequencies create a measurable biological stress response. This research predates our current wireless saturation by decades, yet it documented clear tissue heating effects at power levels and frequencies we're now exposed to daily through smartphones, tablets, and wireless networks.

Exposure Information

Specific exposure levels were not quantified in this study.

Cite This Study
Justus F. Lehmann, George D. Brunner, Jo Ann McMillan, Donald Ray Silverman, Vilas C. Johnston (1964). Modification of Heating Patterns Produced by Microwaves at the Frequencies of 2456 and 900 Mc. by Physiologic Factors in the Human.
Show BibTeX
@article{modification_of_heating_patterns_produced_by_microwaves_at_the_frequencies_of_24_g7398,
  author = {Justus F. Lehmann and George D. Brunner and Jo Ann McMillan and Donald Ray Silverman and Vilas C. Johnston},
  title = {Modification of Heating Patterns Produced by Microwaves at the Frequencies of 2456 and 900 Mc. by Physiologic Factors in the Human},
  year = {1964},
  
  
}

Quick Questions About This Study

The study compared heating patterns between these frequencies in human thigh tissue. While both frequencies caused tissue heating, the research focused on how blood flow responses modified the heating patterns rather than direct frequency comparisons.
Pig tissue served as a control specimen without active blood circulation. This allowed researchers to isolate the heating effects of microwaves without the cooling influence of blood flow that occurs in living human tissue.
Yes, the study showed increased blood flow significantly lowered temperatures in both deep and surface tissues when exposed to microwaves. Surface tissues showed more pronounced cooling effects from this protective blood flow response.
Yes, these frequencies were being evaluated for therapeutic diathermy applications in 1964. Researchers wanted to understand the heating patterns and physiological responses to develop better rationale for medical treatments using microwave energy.
The frequencies tested (900 MHz and 2456 MHz) are nearly identical to modern cell phones and WiFi. The demonstrated tissue heating and biological responses provide early evidence of measurable effects from wireless radiation exposure.