X-Ray-Induced Sterility in Aedes albopictus (Diptera: Culicidae) and Male Longevity Following Irradiation

General Questions

What is Ionizing Radiation?

Ionizing radiation consists of subatomic particles or electromagnetic waves that are energetic enough to detach electrons from atoms or molecules, ionizing them.

Two of the most common forms of ionizing radiation are gamma rays and x-rays. Both forms of ionizing radiation are almost identical with exception to their source of origination.

How is Ionizing Radiation Generated?

Ionizing radiation comes from radioactive sources such as cobalt 60 and cesium 137 and non-radioactive sources such as x-ray tubes. Radioactive sources are unstable materials where gamma rays originate from the nucleus. x-rays originate in the electron fields surrounding the nucleus or are machine-produced.

What is Ionizing Radiation Used for?

Because of the penetrating properties of ionizing radiation and their ability to kill microorganisms, ionizing radiation is used to sterilize or reduce the microbial load of many different types of products such as medical devices, packaging, cosmetics, foods, and agricultural products. It is also used to alter the properties of many different polymers through recombination, cross-linkage, and cross scission.

Why use x-ray versus gamma produced Ionizing radiation?

Gamma ionizing radiation is produced by radioactive sources such as cobalt 60 or cesium 137 and is dangerous requiring heavy shielding and high levels of security to protect. The unstable material is constantly decaying and cannot be turned off. x-ray ionizing radiation is produced by a x-ray tube therefore it can be turned off when it is not being used and it requires much less shielding. At the end the of unit’s lifecycle, the unit does not have any radioactive source and therefore does not require the expensive disposal costs associated with radioactive sources that continue to degrade over hundreds of years.

Does the RS 3400 require external cooling?

No, the RS 3400 uses a self-contained water to air exchange system.

Is the RS 3400 Blood Irradiator cleared by the FDA for GVHD?

Yes, the RS 3400 was cleared by the USFDA for marketing for the irradiation of blood for the prevention of graft verses host disease (GVHD).

How does the RS 3400 differ from other x-ray irradiators?

The RS 3400 is designed to have the blood bags rotate around the Quastar™ x-ray emitter using our patented carousel and therefore delivers superior uniformity.
Unlike other x-ray blood irradiators, the RS 3400 is completely self-contained and requires no external water supply for tube cooling.
The RS 3400 is engineered for extreme reliability as it uses the proven Quastar™ x-ray emitter.
The RS 3400 has only ONE x-ray tube and ONE power supply.

How does the RS 3400 differ from a Cs-137 gamma irradiator??

The RS 3400 uses a Rad Source patented Quastar™ x-ray emitter and therefore contains NO radioactive isotopes. It can be turned on and off, similar to a light bulb. As a result, there is no Nuclear Site License, Homeland Security issues, or room shielding requirements.

Authors: Yamada, H.1, 2; Parker, A. G.2; Oliva, C. F.3, 4, 2; Balestrino, F.5; Gilles, J.R.L.2

Source: Journal of Medical Entomology

Abstract:

The mosquito Aedes albopictus (Skuse, 1895) is a potent vector of several arboviral diseases, most notably chikungunya and dengue fever. In the context of the sterile insect technique (SIT), the sterilization of the male mosquitoes before their release can be achieved by gamma-ray irradiation. As gamma-ray irradiators are becoming increasingly problematic to purchase and transport, the suitability of an X-ray irradiator as an alternative for the sterilization of Ae. albopictus males was studied. The sterilization of up to 200,000 pupae at one time can be achieved with relative ease, and the sterility results obtained were comparable with those achieved by gamma irradiation, where 99% sterility is induced with a dose of 40 Gy. A significant reduction of longevity was observed in the latter stages of the males’ life after irradiation treatments, especially at doses >40 Gy, which is consistent with the negative effects on longevity induced by similar radiation doses using gamma rays. Females irradiated at 40 Gy were not only 100% sterile, but also failed to oviposit entirely, i.e., all of the females laid 0 eggs. Overall, it was found that the X-ray irradiator is generally suitable for the sterilization process for sterile insect technique programs, as it showed a high processing capacity, practicality, high effectiveness, and reproducibility.

DOI: https://dx.doi.org/10.1603/ME13223

Affiliations: 1: Department of Life Sciences, University of the West Indies, St. Augustine, Trinidad. 2: Insect Pest Control Laboratory, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, International Atomic Energy Agency, Wagramer Straße 5, P.O. Box 100, A-1400 Vienna, Austria. 3: Centre de Recherche et de Veille sur les Maladies Emergentes dans l’Océan Indien, Sainte Clotilde, La, Réunion. 4: Maladies Infectieuses et Vecteurs: Ecologie, Genétique, Evolution et Contrôle (MIVEGEC), UMR5290 CNRS-IRD-Université de Montpellier I, Université de Montpellier II, 911 Ave., Agropolis, 34394 Montpellier, France. 5: Medical and Veterinary Entomology Department, Centro Agricoltura Ambiente “G. Nicoli”, Via Argini Nord 3351, 40014 Crevalcore, Italy.

Appeared or available online: April 21, 2014

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