In an open letter to Health Canada, dated October 10, 2006, Magda Havas tenders a response to their “Evaluation of Stetzer Filters” (dated May 11, 2006). Her letter begins as follows:
I raise a serious concern about a document written by six scientists at Health Canada’s Consumer and Clinical Protection Bureau that was recently posted on the BC Centre for Disease Control website. The Health Canada scientists purport to test the effectiveness of the Graham/Stetzer filters to reduce dirty electricity. This document does not appear on the Health Canada web site and has not been published in a peer-reviewed journal. Had it been peer reviewed it would not have been accepted for the obvious errors I mention below. This document is more concerned in protecting the electric utility than it is in protecting the health of Canadians. It surprises me that Health Canada would approve release of this document with so many fundamental errors.
It is my understanding that this document has been circulated widely yet the Health Canada authors did not have the courtesy to send a copy of their report to the designers of this filter, Professor Martin Graham (UC Berkeley) and Mr. Dave Stetzer (President of Stetzer Electric).
I ask you to look into this matter. Dave Stetzer has agreed to demonstrate how the filters work using appropriate equipment and I ask you to encourage your scientists at Health Canada to take him up on his offer.
What follows is my evaluation of and response to the Health Canada document.
Dr. Havas goes on to enumerate the ‘obvious errors’ mentioned above, which include:
- Health Canada scientists used equipment that covered the frequency range of 50 Hz to 5 kHz, when Stetzer filters remove dirty electricity within the frequency range of 4 kHz to 100 kHz. This indicates that an overlap of only 1 kHz, testing 1% of the effective frequency range, essentially rendering the entire report worthless.
- Health Canada made no attempt to separate the 60 cycle from the high frequencies, which ride on top of the 60 cycle sine wave. Health Canada also admits their equipment did not have the appropriate sensitivity because, when the Stetzer filter was plugged in, the Microsurge meter measured reductions in dirty electricity that their equipment failed to detect.
- Health Canada states that the filters have no effect at low frequencies in reducing harmonics – they provide evidence of this up to the 7th harmonic (420 Hz). However, no claim has been made that Stetzer filters work at such low frequencies. They work for the frequency range of 4,000 to 100,000 Hz and 420 Hz is clearly not within that range.
- Health Canada erroneously claims that low levels of dirty electricity have no biological effects, but the provide no documentation to support their claim.
- Health Canada claims that Stetzer filters produce dirty electricity at the low frequency range and that this dirty electricity may be harmful. In saying this, they have made two completely contradictory claims – they can’t have it both ways!
- Health Canada claims that the filters would increase demand for electricity, requiring more transmission facilities.
Read / Download the full letter