Is Heat From Radiofrequency Exposure Damaging Human Health?
NEW YORK, July 5, 2011 /PRNewswire/ –
The world-renowned International Journal of Hyperthermia has unveiled a
new special issue which addresses the thermal aspects of radiofrequency
exposure on human health. This special issue resulted from a workshop born
out of the controversies surrounding huge growth and use of wireless
In the issue, invited experts further refine a quantitative assessment
of the effects of thermal energy on tissue damage, fetal development, immune
function and neurocognitive behaviour. The special issue papers are
available on: http://informahealthcare.com/toc/hth/27/4.
One of the key findings of the workshop and research papers is that
while radiofrequency exposure standards can surely be refined further, it is
fair to say that the present exposure limits set for the general public are
far more protective against thermal hazards than recommended limits for the
temperature of hot water in the home.
“The purpose of the workshop – and the resulting special issue – was to
review current knowledge of the effects of heat on the body that are of
potential relevance to setting limits for human exposure to radiofrequency,”
explains the lead review author, Kenneth R Foster, of the Department of
Bioengineering at the University of Pennsylvania. “Thermal damage to the
body is clearly a very large topic; our discussion and this special issue
focuses on thermal effects that are likely to be relevant to setting
radiofrequency exposure limits.”
“We examined the most appropriate health endpoints for a given tissue or
system, appropriate time periods for acute and chronic exposure,
time-temperature thresholds for adverse effects, as well as cost effective
and targeted research to help us better understand and define human exposure
standards,” continued Foster.
“The upshot was that current radiofrequency limits, as recommended by
the WHO and adopted by the majority of the world’s governments, are – in
thermal terms – far below temperatures that could harm the body,” says
Foster. “Indeed, under ordinary environmental conditions, exposure at the
whole body limits for the general public, will lead to no detectable
increase in core body temperature due to thermoregulatory responses.
That said, both sets of current guidelines on exposure to radiofrequency
are subject to limitations, despite the fact that they form the basis for
exposure guidelines throughout most of the world. The IEEE (Institute of
Electrical and Electronics Engineers) and the ICNIRP (International
Commission on Non-Ionizing Radiation Protection) limits set out basic
restrictions in terms of power absorbed in tissue. However, the biologically
significant quantity is the thermal exposure (increase in temperature and
duration of exposure to elevated temperature).
Within the human body, time-temperature functions for thermal damage to
different tissue types varies widely and current limit definitions are
complex and difficult to explain to the public. In addition, new
technologies employing high-power mm wave sources are coming into use and
the possibility of human exposure to such energy at potentially injurious
levels is increasing.
“If the limiting hazards of RF energy are indeed thermal, several
questions must be addressed,” says Mark Dewhirst, Professor of Radiation
Oncology, Pathology and Biomedical Engineering at Duke University. “Are
current limits adequate to protect diverse tissues from thermal injury?
Would it make sense to move to a time-temperature based limit? Are present
standards adequately protective for exposures to the types of energy
employed by modern electronic devices?”
“The workshop and resulting special issue of the International Journal
of Hyperthermia addresses these questions and sets out areas where further
research is recommended.
The introductory review article for this special issue of the
International Journal of Hyperthermia is available on open access at:
SOURCE International Journal of Hyperthermia