uhmerikan atomic life

i done did some home edukayshon about Geiger counters and radiation.

Geiger counters can detect ionizing radiation.  one type of ionization particle is called the alpha particle. it is a helium nucleus without electrons. a sheet of paper can stop most alpha particles.

then there are beta particles. these are high speed electrons. they are 100 times as penetrating as alpha particles.  beta particles have a range of energy. it is accepted that a 1/8″ thick aluminum plate will stop beta particles.

gamma rays can be considered x-rays only more energetic and penetrating.

now back to ionization. alpha and beta particles carry a charge when they hit matter they change the charge of the matter, ionizing it. the danger of these particles is the damage they do to living tissue. they can damage DNA and proteins and other chemicals critical to life function.

gamma rays dont carry a charge but when the hit matter they change the charge also. gamma rays have a higher energy and therefore can do more damage.

charges are carried by electrons and all chemistry is just electron exchange electrons are the main component of ionization.

here is a way of visualizing it. take a highway with smooth traffic. under orderly conditions the flow of traffic can be very heavy, that is to say a high volume at rush hour but every one reaches their destination even on time. now let’s add some radiation in the form of a drunk driver. this driver doesnt even use an on ramp or obey traffic signals. the driver plows into traffic at a high speed hitting other vehicles which bounce around and hit other vehicles.

that is a likely out come. but it isnt THE outcome. there may be days when some drunk plows into traffic and doesnt hit anyone. maybe the driver cuts across the grassy knoll and hits an embankment.

still, it is a percentage game. if you send enough drunk drivers onto a highway a certain amount of them will hit other vehicles and cause damage.

i have a hepa filter with optional ionizer. it has a press button that toggles the ionizer off or on. the ionizer sends out negative ions which attach to particle floating in the air it helps them bind together and big enough to precipitate. there they can be vacuumed up or wiped off a surface with absorbent material.

a hepa filter for the home usually has a pre filter, the hepa filter, a fan, an electrode for emitting ions and an exhaust. briefly, again, the fan sucks air through the filters and as it is being blown out the negative ions are injected into the cleaned air discharge.

the ions are injected after the air is sucked through the filters. the air flow means the filters should not “see” any ions. of course as the air in the room is continually being ionized eventually the filters would be sucking ionized air and particles. they would become ionized. as the ions leak off, say, when the filters are removed, maybe, just maybe, a geiger counter would detect ionizing radiation from the filters.

what i am getting at is, after i replace my old hepa filters with new ones they remained highly “radioactive”. the geiger counter showed dangerous background radiation even with the filters placed in the plastic bag and box that the new filters came in.

what that indicates to me is that the radiation being detected by the GC is NOT alpha particle. alpha particles are stopped even by paper. could be beta particles. i didnt get a sheet of aluminum foil at the time to see if that was enough to stop the readings.

what i did do was stack the filters in the bags and boxes on a drawer top. 48 hours later when i went to check them the readings have dropped to normal background readings, less that 30 “clicks” per minute.

now i am trying to determine exactly what sort of radioactive emission the instrument was detecting. there are radioactive particles that have short half lives. it could be that the hepa filter is trapping radioactive particles with short half lives, those that will decay to background level in 48 hours.

ions are funny, they behave like static electric charges. if i have a filter that has a charge from collecting ions from the air and i wash it in water that would effectively quench any charge build up. however, if the filter had indeed collected radioactive particles i could wash some of them away but some would remain to decay in half life fashion.

one could chemically detect the decay products in the filter and determine what radioactive parents had been present. sounds like big bucks to me. but i am interested….

all the hepa filters i have were many years old and very impacted. however, they would have to be replenished constantly to be so radioactive. it could be that the ion leak off the material could cause a count in the GC. when the material became neutral, discharged, then no more GC readings.

i aint a scientist and i dont portray one on TV. YO!


atomic life

for many years now i have been running hepa filters through out my abode, one in every room. uhmerika is a polluted place. the air may look clean but it has invisible particulates and noxious vapors and toxic gases released through industry. i am sort of a lazy cur. i dont dust too much. the hepa filters help control the build up of dust on environmental surfaces. for many years it was just a way to reduce nuisance dust from entering my lungs and avoid household chores.

i am also rather cheap. replacement filters are half the price of the machine. i am using the holmes hap-260 model with ionizer. it draws 45 watts. the hepa filter looks like a rectangular frame with a pleated paper filter inside. an activated charcoal pre filter lays on top of that to collect gross particulates and absorb odors. the pre filter is washable. i do wash it from time to time. it has held up remarkable seeing how it is 10 years old. about 5 years ago i wanted to get a new filter. when i went to the store the whole machine was on sale for 30 bucks so i bought 2 more instead.

what i did besides wash the pre filter was to vacuum  the hepa filter over and over. for some odd reason the most recent time i went to wash the pre filter i placed a Geiger counter up to it. following is a photo of the results (right click and select open in new tab):


yes, the read out is registering 135 mcR/h! it seems to have hot spots. here is another reading from same filter:


here is the reading of the original 5 year old filter just as it is being replaced:


and here is a reading of the new filter just out of it’s box:


i intend to take a radiological reading once per month to see how long it takes for the filter to become contaminated. i noticed my bureau had a reading of 28 mcR/h until i wiped the dust off then it dropped to 17 mcR/h. i live 700 hundred feet about sea level and the area is noted for radon gas.

holmes hepa machines are very reliable. i have few that are over 10 years old. it is worth it to stock up on filters. it seems new models that look nothing like my model still use the hapf30 filter element.

i do have some other brands and i have never seen replacement filters. there does appear to be some cross reference between manufacturers.

washing the pre filter was effective, i got the reading down to 70. vacuuming the hepa filter element was to no avail. once the hepa element is impacted with embedded particles it remains contaminated. about 12 inches away from the filter it was near normal levels.

a quick internet search was a surprise. hepa filter technology was developed because of the manhattan project to built an atomic weapon. the filters removed radioactive particles during manufacture and handling of uranium and plutonium.

hepa is an acronym of high efficiency particulate absorption (attenuation, arresting).