The derivation of these standards goes back to the 1970s.
The first ELVs for microwaves were issued in 1979 by the
Chinese Ministry of 4th Machine Industry (CM4MI) as
"temporary sanitary rules for workplace"., but these were
extended and amended in 1989 by CMPH. CM4MI had carried out
during 1975-77 a large cross sectional epidemiological study
with a working group including Zhejiang Medical University,
Beijing Jiuxian Qiao Hospital and another 15 epidemic
preventive stations in factories and institutions.
In this large study four groups were formed, 0, <50,<200,
and > 200 microWatts/cm2. The results showed a higher
prevalence of neurosis, bradycardia, ST-T level, delayed P
and QRS intervals (all greater than 1 second) changes in
electrocardiography (ECG) abnormal ECG, disorders of the
nervous system, decreased white blood counts (WBC) - less
than 5000/mm3, and blood platelets - less than 105/mm3.
Vacuoles were noted in the lens of the two groups exposed to
the higher radiation levels (a feature also reported in
several western studies. e.g. by Milton Zaret ). Even the
group exposed to less than 50 microWatts/cm2 also reported
symptoms of increased neurosis compared with controls.
Acute and subacute experiments were also performed on
animals, establishing a TLV of 1mW/cm2. Allowing for a
20-fold safety factor the ELV was therefore set at 300
microWatts/cm2, that is 38microWatts/cm2 for an 8 hour
Lafayette Louisiana USA
Cotonou (de facto capital)
Allentown, Pennsylvania, USA
Codrington (capital of Barbuda)
for 3 months, absolutely
RISK-FREE If you do not feel Q-Link improves your
focus, energy, or well-being, simply return it for a full
Airtube headsets have
30 a day refund.