Transcript Biological Effects of Power Line Electromagnetic Fields

Biological Effects of Power Line
Electromagnetic Fields
Troy Cok
ENGR 302
May 6, 2002
The Issue
 Power lines pass through residential areas
 Concerns related to resulting electromagnetic
fields (EMF)
 Central question – does power line EMF cause
cancer?
Research on the Issue
 Two main fields of study
Epidemological
– Examination of human cancer cases WRT field
locality/intensity
Laboratory
– Animal experimentation
Epidemological Studies
 University of Colorado Study - 1979
Children living near power lines twice as likely to
develop cancer than others
First to expose the issue to the public
Criticized for lack of actual field measurements
Many More Studies…
 Numerous epidemological studies conducted
in past 23 years
 Research methods refined
 Varied findings – no strong consensus
Some report noticeable connection between
power lines and cancer
Others show little / non-existent relationship
Laboratory Research
 Attempt to establish connection between electric
or magnetic fields and cancer
 Generally believed that magnetic fields are more
dangerous than electric fields
Magnetic fields can induce a small current in
conducting materials
Difficult to shield
Results of Laboratory Research
 Magnetic fields shown to alter several biological
processes
Melatinon levels, brain & heart activity, immunities
However, no changes beyond normal range
 No strong consensus that EMF exposure can
cause cancer
Future Research . . . ?
 Some believe lack of any consensus indicates
that power lines do not cause cancer
 Others say the issue remains unresolved
Methodological shortcomings
– Residents often leave house
– Epidemological measurements often taken intermittently –
transients may also occur
– Laboratory conditions too “perfect” – transients, current &
voltage alterations
Should We Be Concerned ?
 Local EMF’s created by household appliances are
much larger than those resulting from power lines
 Safety measures may be taken
Limit time under high-voltage lines
Do not sit in front of a computer all day
The End