I understand the pro's and con's of Radar on the Mast vs. on A stern Pole Mount vs. Backstay, etc......... But does *anyone* have a concern with the Radar so low that it might cause health related issues for anyone on the foredeck? I guess this is my *biggest* worry.......... Should I be? ......any Radar engineers/technicians out there?.....If so, do you have any children?....;-).
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Tom, my Furuno manual says 3'
is the recommended minimum distance. My recollection.. not knowledge.. is that the microwaves dispurse quickly and there is zip danger further away, not withstanding you don't want to be right in the beam's path up close.. Rick D.
is the recommended minimum distance. My recollection.. not knowledge.. is that the microwaves dispurse quickly and there is zip danger further away, not withstanding you don't want to be right in the beam's path up close.. Rick D.
Safety
I am concerned about a stern pedestal radar for foredeck crew. The ones I've seen aren't that high, and the vertical beam angle (25 degrees, if I recall correctly) is such that you would have substantial energy at eye-height on the foredeck. I would resommend foredeck crew not look directly at the radome.
I am concerned about a stern pedestal radar for foredeck crew. The ones I've seen aren't that high, and the vertical beam angle (25 degrees, if I recall correctly) is such that you would have substantial energy at eye-height on the foredeck. I would resommend foredeck crew not look directly at the radome.
For Piece Of Mind..
..ignore the recommendation of the manufacturers if you don't either trust them or question the science and mast mount the transmitter. FWIW, the last two radar installation guides both recommended pole mounting in smaller sailboats, but the majority in my part of SoCal are mast mounted. Rick D.
..ignore the recommendation of the manufacturers if you don't either trust them or question the science and mast mount the transmitter. FWIW, the last two radar installation guides both recommended pole mounting in smaller sailboats, but the majority in my part of SoCal are mast mounted. Rick D.
Inverse to square of distance
The luminous intensity of light is directly proportional to the inverse square of the distance. Assume the foredeck worker is 30 feet from the radar, and assume it's a particular Furuno radar which is recommended to be 3 feet away, then the fordeck worker (aka deck ape) is 10 times further away than the specification recommends. The intensity would be 1/100 of the manufacturers recommendation. Another factor to consider is that if you're flying the chute then the visibility is probably good enough that the radar doesn't need to be on. This is my situation so exposure to the foredeck is not a concern. If it was on because of a race through fog then I would say the exposure is low enough to still not be a concern. Also, one could hit the "stand-by" button. My radar is on a stern-mounted pole but having had the same concerns you have it's probably a tad, but not overly, higher than the average. The height was determined sufficient to clear individuals in the cockpit area which should be adequate.
The luminous intensity of light is directly proportional to the inverse square of the distance. Assume the foredeck worker is 30 feet from the radar, and assume it's a particular Furuno radar which is recommended to be 3 feet away, then the fordeck worker (aka deck ape) is 10 times further away than the specification recommends. The intensity would be 1/100 of the manufacturers recommendation. Another factor to consider is that if you're flying the chute then the visibility is probably good enough that the radar doesn't need to be on. This is my situation so exposure to the foredeck is not a concern. If it was on because of a race through fog then I would say the exposure is low enough to still not be a concern. Also, one could hit the "stand-by" button. My radar is on a stern-mounted pole but having had the same concerns you have it's probably a tad, but not overly, higher than the average. The height was determined sufficient to clear individuals in the cockpit area which should be adequate.
Radar Height
On a H40.5, I chose a stern pole for ease of installation. It is a ten foot pole and that puts the radome just above the level of the boom. If the radar is in use (at night or due to fog) then there is usually no one out of the cockpit, unless we are anchoring, and then its me up there and I already have 4 kids so I don't worry that much. One thing I have noticed about this location is that with the 2KW Raymarine, I see everything close to the boat. I mean even small poles sticking up and birds on the water, so having the radome lower than on the mast, does allow me to maneuver in very close quarters in dense fog. I ALWAYS try to avoid these situations but we were running the ICW at night and it got foggy very fast. It is good to know that if I get into the soup I can 'see' to get out of it. Down side is that I also noticed a weaker return from objects that were blocked by the boom/mast. A slight course change would let me 'watch' the target as it came closer. Also aligning the boom to the axis of the radar line of sight helped. I included a photo of Yaga's radar mast.
On a H40.5, I chose a stern pole for ease of installation. It is a ten foot pole and that puts the radome just above the level of the boom. If the radar is in use (at night or due to fog) then there is usually no one out of the cockpit, unless we are anchoring, and then its me up there and I already have 4 kids so I don't worry that much. One thing I have noticed about this location is that with the 2KW Raymarine, I see everything close to the boat. I mean even small poles sticking up and birds on the water, so having the radome lower than on the mast, does allow me to maneuver in very close quarters in dense fog. I ALWAYS try to avoid these situations but we were running the ICW at night and it got foggy very fast. It is good to know that if I get into the soup I can 'see' to get out of it. Down side is that I also noticed a weaker return from objects that were blocked by the boom/mast. A slight course change would let me 'watch' the target as it came closer. Also aligning the boom to the axis of the radar line of sight helped. I included a photo of Yaga's radar mast.
Your vitals
Having spent 4 years as a Radarman in the USN many moons ago I can tell you I have a healthy respect for RF energy. Granted we had a AN SPS-10 Surface Search Radar with a one hundred mile and more search capability and a 15 foot banana screen antenna . I recall puting a flourescent tube next to a cargo boom one time and it lit up from 200 feet away. We could boil water with that thing! We couldn't have it on when we were taking on ammunition! I know these smaller units are less powerful but watch your vitals! I don't have a radar on my boat but I would most certainly mast mount it! David
Having spent 4 years as a Radarman in the USN many moons ago I can tell you I have a healthy respect for RF energy. Granted we had a AN SPS-10 Surface Search Radar with a one hundred mile and more search capability and a 15 foot banana screen antenna . I recall puting a flourescent tube next to a cargo boom one time and it lit up from 200 feet away. We could boil water with that thing! We couldn't have it on when we were taking on ammunition! I know these smaller units are less powerful but watch your vitals! I don't have a radar on my boat but I would most certainly mast mount it! David
various
1. Inverse square law applies to omnidirectional radiators. Radar has a very directional radiator, and will still have a ton of energy on you at 20 or so feet away (think of 5 degree horz. beam width, 25 degree vert. beam width). 2. Height. I struggled with this last year when I mounted my new Raymarine 2kW 'dome. I didn't want it all the way up the mast near the spreaders, becuse I thought I didn't want the weight up there, and it would weaken this "joint" in the mast. I couldn't find any reference to an analytical way of approaching this, so I devised my own: height such that the vertical beam just touches the water at the minimum range of the radar. For a 25 degree vert. beam, 25 yard min. range, about 16' above the water. So, I should be able to see anything close-up that the radar is capable of. (Haven't used it much yet).
1. Inverse square law applies to omnidirectional radiators. Radar has a very directional radiator, and will still have a ton of energy on you at 20 or so feet away (think of 5 degree horz. beam width, 25 degree vert. beam width). 2. Height. I struggled with this last year when I mounted my new Raymarine 2kW 'dome. I didn't want it all the way up the mast near the spreaders, becuse I thought I didn't want the weight up there, and it would weaken this "joint" in the mast. I couldn't find any reference to an analytical way of approaching this, so I devised my own: height such that the vertical beam just touches the water at the minimum range of the radar. For a 25 degree vert. beam, 25 yard min. range, about 16' above the water. So, I should be able to see anything close-up that the radar is capable of. (Haven't used it much yet).
A little (tiny) bit of antenna theory
John, I think you'll find that the inverse-square law holds in the far-field (Fraunhofer field) of any finite sized antenna where the waves are spreading spherically. To show this construct an imaginary sphere around the antenna, and look at how the power/energy flux density varies with the radius. Since the surface area is proportional to r^2, the energy density (energy/unit area) must be proportional to 1/r^2. (An infinitely long antenna with cylindrical radiation gives 1/r spreading). Where the far-field starts depends on the size of the antenna expressed in wavelengths of the radar signal. Another commonly misunderstood issue is that antennas do not have sharply defined "beams". The directivity patterns show a tapering of the "sensitivity" with angle, and the manufacturer has chosen to define a "beam-width" by the angle corresponding to some fraction of the peak response. That does not mean that there is no response at greater angles. Antennas can have all sorts of "side-lobes" in their directivity patterns that can give rise to false echos. Also, nearby objects will give much stronger returns than distant reflectors, even though they are outside the manufacturer's defined vertical beam-width. Thus, there is no hard edge to the beam, and it would be difficult to define a minimum range for a given antenna height. Derek
John, I think you'll find that the inverse-square law holds in the far-field (Fraunhofer field) of any finite sized antenna where the waves are spreading spherically. To show this construct an imaginary sphere around the antenna, and look at how the power/energy flux density varies with the radius. Since the surface area is proportional to r^2, the energy density (energy/unit area) must be proportional to 1/r^2. (An infinitely long antenna with cylindrical radiation gives 1/r spreading). Where the far-field starts depends on the size of the antenna expressed in wavelengths of the radar signal. Another commonly misunderstood issue is that antennas do not have sharply defined "beams". The directivity patterns show a tapering of the "sensitivity" with angle, and the manufacturer has chosen to define a "beam-width" by the angle corresponding to some fraction of the peak response. That does not mean that there is no response at greater angles. Antennas can have all sorts of "side-lobes" in their directivity patterns that can give rise to false echos. Also, nearby objects will give much stronger returns than distant reflectors, even though they are outside the manufacturer's defined vertical beam-width. Thus, there is no hard edge to the beam, and it would be difficult to define a minimum range for a given antenna height. Derek
Don't Worry, Be Happy!
It doesn’t matter how you focus or reflect it, all electromagnetic radiation decreases in intensity inversely to the square of the distance. If you double the distance, you get one quarter the intensity. In the “old” days the reflecting and focusing for radar was done with the big mesh dish that rotated with the emitter. Today it’s done electronically. But once the radiation leaves the emitter the inverse square law holds. To judge the impact, your 1K-watt microwave oven can cook food at an average distance of 1 foot from emitter to target. Therefore, your 2K-watt radar (if held steady in one direction, not allowed to rotate) could do the same (1K-watt of energy) at a distance of about 1.41 feet. Let’s just assume that this translated into a temperature increase of 200 degrees after 1 minute. If you double the distance (about) to 3 feet, the energy intensity is now at only 222 watts! That would result in a temperature increase of 44 degrees in one minute. Double the distance again to 6 feet and we’re down to 56 watts and a temperature rise of 11 degrees per minute. If you were on the foredeck 30 feet from the emitter, you would receive 2.2 watts of energy that might raise the temperature .44 degrees per minute. (The naval radars are several humdred kilowatts) Moreover, that all depends on a stationary, non-rotating radar beam focused directly on the target. In fact, the beam is rotating so that you receive that burst of energy only for a split second every few seconds. If the radar were spinning infinitely fast, you would receive energy proportional to your width as part of the circumference of a circle with the distance as radius. Distance = 30 feet, C = 188.5 feet, your width? 2 feet? Your width is about 1/100th of the circle so you would be receiving 1/100th of the energy. That’s only 0.022 watts. Your cell phone is putting out a lot more electromagnetic radiation clipped to your belt or held against your head. Bottom line; don’t worry about it.
It doesn’t matter how you focus or reflect it, all electromagnetic radiation decreases in intensity inversely to the square of the distance. If you double the distance, you get one quarter the intensity. In the “old” days the reflecting and focusing for radar was done with the big mesh dish that rotated with the emitter. Today it’s done electronically. But once the radiation leaves the emitter the inverse square law holds. To judge the impact, your 1K-watt microwave oven can cook food at an average distance of 1 foot from emitter to target. Therefore, your 2K-watt radar (if held steady in one direction, not allowed to rotate) could do the same (1K-watt of energy) at a distance of about 1.41 feet. Let’s just assume that this translated into a temperature increase of 200 degrees after 1 minute. If you double the distance (about) to 3 feet, the energy intensity is now at only 222 watts! That would result in a temperature increase of 44 degrees in one minute. Double the distance again to 6 feet and we’re down to 56 watts and a temperature rise of 11 degrees per minute. If you were on the foredeck 30 feet from the emitter, you would receive 2.2 watts of energy that might raise the temperature .44 degrees per minute. (The naval radars are several humdred kilowatts) Moreover, that all depends on a stationary, non-rotating radar beam focused directly on the target. In fact, the beam is rotating so that you receive that burst of energy only for a split second every few seconds. If the radar were spinning infinitely fast, you would receive energy proportional to your width as part of the circumference of a circle with the distance as radius. Distance = 30 feet, C = 188.5 feet, your width? 2 feet? Your width is about 1/100th of the circle so you would be receiving 1/100th of the energy. That’s only 0.022 watts. Your cell phone is putting out a lot more electromagnetic radiation clipped to your belt or held against your head. Bottom line; don’t worry about it.
It's even better than that...
A radar power rating is the "peak" power, not the averaged power. For example, the 2 kw Raymarine SL72 radar has a stated power consumption of 28 watts (9 watts on stand-by). Given the electronics efficiency, the average radiated power is probably considerably less than 20 watts. (You can't radiate more power than you take from the battery!) The peak power is determined from the very brief pulses (less than 1 microsecond) that are transmitted, and this happens only about 750-3000 times each second. The radar spends the rest of its time listening for echos. Let's do the math: at a 6nm range, the SL72 radar transmits 740 pulses eac second, each with a duration of 1 microsecond. For each second it therefore only "on" for 740 microseconds (less than 1/1000 of a second). The average power is only 2,000x740/1000000 = 1.48 watts. Not much! It's even less when the radar is set for closer ranges. The result is that any heating effects from absorbing radar energy are minimal. You would be hard pressed to heat a cup of water even if you could direct the FULL 1-2 watts or so from our 2kw radar into the water. As was pointed our earlier, in practice the energy is "sprayed" around a full 360 degrees by the rotating antenna, so a person standing in any one position could absorb at most a very small fraction of our 1-2 watts of radiated power. I think the upshot is: put the radar 1) where it's convenient to install and maintain, 2) where it doesn't interfere with sail handling, and 3) where it doesn't offend you aesthetically. Then go sailing. Derek
A radar power rating is the "peak" power, not the averaged power. For example, the 2 kw Raymarine SL72 radar has a stated power consumption of 28 watts (9 watts on stand-by). Given the electronics efficiency, the average radiated power is probably considerably less than 20 watts. (You can't radiate more power than you take from the battery!) The peak power is determined from the very brief pulses (less than 1 microsecond) that are transmitted, and this happens only about 750-3000 times each second. The radar spends the rest of its time listening for echos. Let's do the math: at a 6nm range, the SL72 radar transmits 740 pulses eac second, each with a duration of 1 microsecond. For each second it therefore only "on" for 740 microseconds (less than 1/1000 of a second). The average power is only 2,000x740/1000000 = 1.48 watts. Not much! It's even less when the radar is set for closer ranges. The result is that any heating effects from absorbing radar energy are minimal. You would be hard pressed to heat a cup of water even if you could direct the FULL 1-2 watts or so from our 2kw radar into the water. As was pointed our earlier, in practice the energy is "sprayed" around a full 360 degrees by the rotating antenna, so a person standing in any one position could absorb at most a very small fraction of our 1-2 watts of radiated power. I think the upshot is: put the radar 1) where it's convenient to install and maintain, 2) where it doesn't interfere with sail handling, and 3) where it doesn't offend you aesthetically. Then go sailing. Derek
There is a health question
>Bottom line; don’t worry about it.< I would, and I know something about it as a scientist. For example, see my book entitled " On the nature of electromagnetic field interactions with biological systems" Bottom line: with a pole mount, I would put the radar on standby when someone is out of the cockpit. Allan
>Bottom line; don’t worry about it.< I would, and I know something about it as a scientist. For example, see my book entitled " On the nature of electromagnetic field interactions with biological systems" Bottom line: with a pole mount, I would put the radar on standby when someone is out of the cockpit. Allan
Allan - Can you tell us more?
I'd like to know more. I have followed the debate on long term low frequency (60 Hz power line) exposure, and I understand the jury is still out - it depends who you talk to. Can you give us a brief summary of the interaction of 9 GHz energy with biological systems at the power levels involved, including the modes of cellular/neurological damage or interaction. Is the damage genetic in nature? Are any effects due to short term exposure? Do you have any on-line references to your book? I would be interested in citations and references to other studies on these effects. How would you compare the exposure and damage to that from the MRI rf coils in medical imaging (lower frequency)? If you prefer, you can email me at drowell@mit.edu Thanks, Derek
I'd like to know more. I have followed the debate on long term low frequency (60 Hz power line) exposure, and I understand the jury is still out - it depends who you talk to. Can you give us a brief summary of the interaction of 9 GHz energy with biological systems at the power levels involved, including the modes of cellular/neurological damage or interaction. Is the damage genetic in nature? Are any effects due to short term exposure? Do you have any on-line references to your book? I would be interested in citations and references to other studies on these effects. How would you compare the exposure and damage to that from the MRI rf coils in medical imaging (lower frequency)? If you prefer, you can email me at drowell@mit.edu Thanks, Derek
Alan, I'd like to hear what he has to say also.
Please take into account the frequencies and relatively lower power induced by the 2kw boat radar and distances.....lets say 3 feet,10feet and 30 feet. And also length of exposure. Any definitive studies using these parameters Don't leave us hanging.....I was feeling OK about this.....but now I don't know?......are 10 minutes on the bow by one of the kids watching for Lobster Pots going to hurt?.....what about an hour?.....what about longer?....
Please take into account the frequencies and relatively lower power induced by the 2kw boat radar and distances.....lets say 3 feet,10feet and 30 feet. And also length of exposure. Any definitive studies using these parameters Don't leave us hanging.....I was feeling OK about this.....but now I don't know?......are 10 minutes on the bow by one of the kids watching for Lobster Pots going to hurt?.....what about an hour?.....what about longer?....
I recently read an article of trusty source ..
..but I don't remember it's name nor the technical details, stating that on safety-health issue , the radar should be at least 2.5- 3 meters ( about 8-10 feet) from a person head. It was mentioned that it is indeed bigger distance than previous recomendation were on this issue , and it takes bigger safety margins in consideration. That is more than usual pole instalation will allow.. It might be helpfull to find out what are the military recomandation on their similar instalation ( as they have rules/recomandation for everything..)
..but I don't remember it's name nor the technical details, stating that on safety-health issue , the radar should be at least 2.5- 3 meters ( about 8-10 feet) from a person head. It was mentioned that it is indeed bigger distance than previous recomendation were on this issue , and it takes bigger safety margins in consideration. That is more than usual pole instalation will allow.. It might be helpfull to find out what are the military recomandation on their similar instalation ( as they have rules/recomandation for everything..)
Far field - to Derek, et.al.
Good theory, and I agree that the energy at the sphere observes 1/r^2, but it doesn't apply to this case. In this case we are not interested in the sum of the energy across the sphere, only the energy where the victim is staring into the radar antenna. To Dennis, There IS a rotating antenna in your marine radar.
Good theory, and I agree that the energy at the sphere observes 1/r^2, but it doesn't apply to this case. In this case we are not interested in the sum of the energy across the sphere, only the energy where the victim is staring into the radar antenna. To Dennis, There IS a rotating antenna in your marine radar.
A link to OSHA on the subject...
There is a lot of material on the microwave safety issues on the OSHA site at the link below.
There is a lot of material on the microwave safety issues on the OSHA site at the link below.
Another very good reference document
The link below is to a FCC document (pdf format) entitled: "Questions and Answers about Biological Effects and Potential Hazards of Radiofrequency Electromagnetic Fields" Keep in mind as you read it that the frequency in question is 9 GHz (or 9,000 Mhz). As I read it, Table 1(b) states that the accepted 30 minute exposure limit for the general population is 1mw/cm^2. That's about 900mw/ft^2. So if the FULL 1-2watts of our 2kw radar output was directed ALL THE TIME at 2 sq. ft. of body surface we would be approximately at the accepted safe exposure 30 minute average, so in principle we could "soak" all day. Similarly, from Table 2 (see footnote 10) the "safe" exposure of 0.08 W/kg of body weight translates to an maximum safe exposure of 5.6 watts for a 150 lb (70 kg) individual. Also - re my previous posts where I calculated the average power from a 2kw radar - we need to be careful about how the manufacturer defines power. It is common for radio transmitters to be rated in terms of the electrical input power to the rf amplifier, not the actual power of the radiated rf energy, so our prototypical SL72 may radiate only a fraction of the 1.5 watts I calculated there - depending how Raymarine defines "power".
The link below is to a FCC document (pdf format) entitled: "Questions and Answers about Biological Effects and Potential Hazards of Radiofrequency Electromagnetic Fields" Keep in mind as you read it that the frequency in question is 9 GHz (or 9,000 Mhz). As I read it, Table 1(b) states that the accepted 30 minute exposure limit for the general population is 1mw/cm^2. That's about 900mw/ft^2. So if the FULL 1-2watts of our 2kw radar output was directed ALL THE TIME at 2 sq. ft. of body surface we would be approximately at the accepted safe exposure 30 minute average, so in principle we could "soak" all day. Similarly, from Table 2 (see footnote 10) the "safe" exposure of 0.08 W/kg of body weight translates to an maximum safe exposure of 5.6 watts for a 150 lb (70 kg) individual. Also - re my previous posts where I calculated the average power from a 2kw radar - we need to be careful about how the manufacturer defines power. It is common for radio transmitters to be rated in terms of the electrical input power to the rf amplifier, not the actual power of the radiated rf energy, so our prototypical SL72 may radiate only a fraction of the 1.5 watts I calculated there - depending how Raymarine defines "power".
Allan Frey...
Allan - I have spent several hours today looking at the references to your work on the web, and at some of your articles. (For everybody else - Allan is a respected and much cited researcher in the field of the effects of em radiation on living tissue.) I am still left with an uneasy feeling. You point out yourself the difficulty of establishing causality between disease and rf radiation, and in my cursory look at the field I could find no concrete example of proven association of exposure to low-level high frequency radiation and disease or genetic damage (outside of thermal/heat-deposition effects). Even with the cell-phone situation I could find no statistically supported evidence, despite reports of brain tumors and headaches. It seems that the argument being advanced is that until it is proven that there is NO effect, we must assume that there might be something nasty lurking around the radar mount. I'm not disputing your work in any way, and I think it is very important/vital to continue investigating, but it seems we have a glass-half-full, glass-half-empty argument here. Until there is evidence to the contrary, I am prepared to accept a low (and undemonstrated) risk and enjoy my boating to the fullest. You intimated in your post that there is a danger of being outside the cockpit while a pole-mounted radar is operational. Given your eminence in the field, I would really appreciate a brief explanation of the specific dangers. Derek
Allan - I have spent several hours today looking at the references to your work on the web, and at some of your articles. (For everybody else - Allan is a respected and much cited researcher in the field of the effects of em radiation on living tissue.) I am still left with an uneasy feeling. You point out yourself the difficulty of establishing causality between disease and rf radiation, and in my cursory look at the field I could find no concrete example of proven association of exposure to low-level high frequency radiation and disease or genetic damage (outside of thermal/heat-deposition effects). Even with the cell-phone situation I could find no statistically supported evidence, despite reports of brain tumors and headaches. It seems that the argument being advanced is that until it is proven that there is NO effect, we must assume that there might be something nasty lurking around the radar mount. I'm not disputing your work in any way, and I think it is very important/vital to continue investigating, but it seems we have a glass-half-full, glass-half-empty argument here. Until there is evidence to the contrary, I am prepared to accept a low (and undemonstrated) risk and enjoy my boating to the fullest. You intimated in your post that there is a danger of being outside the cockpit while a pole-mounted radar is operational. Given your eminence in the field, I would really appreciate a brief explanation of the specific dangers. Derek
Answer to Qs re radar and health
Just got back from my boat and saw the questions to me. Since this is a sailing group, I’ll limit my response on electromagnetic field exposure (emf) to only this message; and I’ll keep it short. Emf is not a foreign substance, a toxin, like arsenic; it is fundamental to life. Nerve function, protein folding, etc all involve emf. Thus, a biologist would expect a biological interaction if the “tuning” is right, eg frequency, modulation, etc. There is, in fact, a large well established literature showing that living organisms from bacteria to mammals use emf in sensory function. Thus, a reasonable question is whether some of the artificial fields from radars, cell phones, etc have the “tuning “ characteristics to interfere with normal use of emf by living organisms and could be a hazard. The research to determine the full answer has not been allowed to proceed in the normal fashion in biology because of the well-documented actions of some vested interests. The U of Michigan’s Institute for Values and Science, headed up by Prof. Nicholas Steneck, an ethicist, did a comprehensive study of this area of research and documented this fact: see Steneck’s book “The microwave debate” and also the chapters by Steneck, Frey and also Medici in Steneck’s other book “Risk/benefit analysis: the microwave case”. There is a lot of extraneous misleading literature that has been published, as happened in the tobacco situation. But there is also a good bit of good work that has been published whose overall pattern indicates that there could be hazard under some circumstances. You might look, for example, at chapter 2 of my book: An integration of the data on mechanisms with particular reference to cancer. Thus I would generally put a pole mounted radar on standby if someone went up to the foredeck. Allan
Just got back from my boat and saw the questions to me. Since this is a sailing group, I’ll limit my response on electromagnetic field exposure (emf) to only this message; and I’ll keep it short. Emf is not a foreign substance, a toxin, like arsenic; it is fundamental to life. Nerve function, protein folding, etc all involve emf. Thus, a biologist would expect a biological interaction if the “tuning” is right, eg frequency, modulation, etc. There is, in fact, a large well established literature showing that living organisms from bacteria to mammals use emf in sensory function. Thus, a reasonable question is whether some of the artificial fields from radars, cell phones, etc have the “tuning “ characteristics to interfere with normal use of emf by living organisms and could be a hazard. The research to determine the full answer has not been allowed to proceed in the normal fashion in biology because of the well-documented actions of some vested interests. The U of Michigan’s Institute for Values and Science, headed up by Prof. Nicholas Steneck, an ethicist, did a comprehensive study of this area of research and documented this fact: see Steneck’s book “The microwave debate” and also the chapters by Steneck, Frey and also Medici in Steneck’s other book “Risk/benefit analysis: the microwave case”. There is a lot of extraneous misleading literature that has been published, as happened in the tobacco situation. But there is also a good bit of good work that has been published whose overall pattern indicates that there could be hazard under some circumstances. You might look, for example, at chapter 2 of my book: An integration of the data on mechanisms with particular reference to cancer. Thus I would generally put a pole mounted radar on standby if someone went up to the foredeck. Allan
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