I have an answer to my question, which amount of gamma radiation expressed in kGy is equivalent to the dose of 200,000 r in the manuscript by Cole et al (and that killed 100% of all bedbugs). It's 2 kilogray (2 kGy).
Because Grey et al. did not explain the absolute number of bedbugs killed, we agreed with the salesperson from the irradiation plant, that we would be using 6 kGy for our personal belongings. Apparently, prices increase with greater amounts of gamma radiation.
I've loaded the first 50% in a minivan, and brought it to the irradiation plant last Friday. We were quit well prepared: one of the disadvantages of a pallet irradiator are the limitations of the pallet size: 1,00 m (w) x 1,20 m (l) x 1,85 m (h).
Therefore, we had searched on the internet for boxes for our belongings that could fit exactly on a pallet (prices ranged between 60-90 euro's per pallet / cage). For books, 40 cm x 50 cm x 30 cm was OK. What we did not take into account, were some loose parts that will never fit into a box, e.g. wooden poles of our table, long parts of a locker, a trolly, etc etc. Instead of using a pallet that was covered with shrinking foil, we were given metal cages to put our stuff in. The cage was then covered with shrinking foil.
Besides the size limits of a pallet, gamma irradiation has several other disadvantages. First, transparent glass / plexi glass becomes brown-coloured. Everything that contains electronic equipment will be destroyed. And porcelain was not advised to be irradiated as well.
The time of gamma irradiation depends on the logistics of the plant; we were told that we could get our stuff within four days. I look forward to the first of july, to see if my DVD-player still works.
Sunday, June 29, 2008
Thursday, June 26, 2008
Bedbugs for > one year now
Our apartment is infested with bedbugs for > 1 year. An exterminator has come three times, but with no succes. Sometimes, I spray the sides of the room with anti-lice poison, with temporary success. And the knowledge that bedbugs can hide everywhere, has made us quit desparate. But there is hope: we are going to move to a new home. It's now the landlord's problem.
However, we were facing a new problem: to get rid of the bedbugs in our belongings. You can barely see them, the nyms, the eggs. How to deal with this?
We have considered several options:
+ dry air heating (> 60 degrees celcius for two days)
+ freezing (minus 20 degrees for two weeks)
+ gamma irradiation
Dry heating
Main advantage of dry heating, is that there is some evidence that it works. For example, I know from a transport entrepeneur who had a truck with three Polish truck drivers, who did 24 hours shifts in the truck (and slept half of the time). Bedbugs were hiding within the (expensive) electronic equipment, and the only option was to store the truck for a weekend in a paint dry warehouse. The disadvantage of dry heating is, that it is hard to find a company who is willing to hire their heating warehouse to you. Why on earth would they do this?
Freezing
I've seriously considered freezing. Every professional tells me that -20 degrees celcius for 2 weeks should be enough to kill bed bugs, nymps and eggs. However, I couldn't find any scientific evidence, or posts on the internet that this will indeed do the job. Furthermore, it is very hard to secure that everything that is put in a freezing sea container, will indeed remain minus 20 degrees celcius for the whole period. Lastly, paper stuff such as photoalbums will become wet and fungi can start growing. Prices of renting sea containers start at 60 euro's / day.
Gamma irradiation
The main advantage of gamma irradiation, is that it destroys DNA of insects such as bedbugs and cochroaches. It kills the eggs and nymphs as well. However, that's the claim of irradiation companies, but what's the evidence? A lot of sources refer to one key paper, published, believe it or not, 50 years ago: "Effects of Gamma Radiation on Some Insects Affecting Man", by M.M. Cole, Journal of Economic Entomology, Vol 52, Issue 3, Pages 448-450. Does anyone know any better evidence?
It shows the amount of gamma radiation required to cause 100% mortality within 24 hours after radiation, for several insect species. However, it doesn't state the absolute number of bedbugs, the 100% mortality corresponds to. Units are in (r) [Rontgens??]
Bed bugs, nymphs - 172,500 (r) - 100% killed in 48 hours
Bed bugs, males - 180,000 (r) - 100% in 24 hours
Bed bugs, females - 180,000 (r) - 100% in 24 hours
Bed bugs, eggs - unknown
Now here is my first question: gamma irradiation companies express their radiation in Kilo grays. Sterilisation of wipes etc. is done with 25 k gy.
How much kilogray should we need to kill bed bugs and their eggs?
However, we were facing a new problem: to get rid of the bedbugs in our belongings. You can barely see them, the nyms, the eggs. How to deal with this?
We have considered several options:
+ dry air heating (> 60 degrees celcius for two days)
+ freezing (minus 20 degrees for two weeks)
+ gamma irradiation
Dry heating
Main advantage of dry heating, is that there is some evidence that it works. For example, I know from a transport entrepeneur who had a truck with three Polish truck drivers, who did 24 hours shifts in the truck (and slept half of the time). Bedbugs were hiding within the (expensive) electronic equipment, and the only option was to store the truck for a weekend in a paint dry warehouse. The disadvantage of dry heating is, that it is hard to find a company who is willing to hire their heating warehouse to you. Why on earth would they do this?
Freezing
I've seriously considered freezing. Every professional tells me that -20 degrees celcius for 2 weeks should be enough to kill bed bugs, nymps and eggs. However, I couldn't find any scientific evidence, or posts on the internet that this will indeed do the job. Furthermore, it is very hard to secure that everything that is put in a freezing sea container, will indeed remain minus 20 degrees celcius for the whole period. Lastly, paper stuff such as photoalbums will become wet and fungi can start growing. Prices of renting sea containers start at 60 euro's / day.
Gamma irradiation
The main advantage of gamma irradiation, is that it destroys DNA of insects such as bedbugs and cochroaches. It kills the eggs and nymphs as well. However, that's the claim of irradiation companies, but what's the evidence? A lot of sources refer to one key paper, published, believe it or not, 50 years ago: "Effects of Gamma Radiation on Some Insects Affecting Man", by M.M. Cole, Journal of Economic Entomology, Vol 52, Issue 3, Pages 448-450. Does anyone know any better evidence?
It shows the amount of gamma radiation required to cause 100% mortality within 24 hours after radiation, for several insect species. However, it doesn't state the absolute number of bedbugs, the 100% mortality corresponds to. Units are in (r) [Rontgens??]
Bed bugs, nymphs - 172,500 (r) - 100% killed in 48 hours
Bed bugs, males - 180,000 (r) - 100% in 24 hours
Bed bugs, females - 180,000 (r) - 100% in 24 hours
Bed bugs, eggs - unknown
Now here is my first question: gamma irradiation companies express their radiation in Kilo grays. Sterilisation of wipes etc. is done with 25 k gy.
How much kilogray should we need to kill bed bugs and their eggs?
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