Before the advent of the 360 Gamma, there was no effective personal protection from gamma radiation. In Chernobyl, first responders wore makeshift lead sheeting for protection. In Fukushima, emergency personnel undertook disaster-mitigating activities without any protection from gamma radiation. In order to shield as much of the body as possible, past personal shielding solutions used only thin layers of inherently heavy radiation-attenuating materials. These types of solutions are ineffective in blocking energetic gamma radiation.
Receiving a high dose of gamma radiation over a short period of time may result in Acute Radiation Syndrome (ARS); protracted exposures to gamma radiation may result in malignancies such as leukemia. In the case of high-dose exposure, the survival-limiting factor up to doses of 10 Gy is irreversible bone marrow (BM) damage. Notably, in past radiological catastrophes doses were largely under 10 Gy. Thus, numerous fatalities may be avoided by protecting BM, even in the harshest of scenarios. Remarkably, due to its extraordinary regenerative potential, it is enough to protect only a small fraction of BM to preserve its recuperative function. In fact, only 2.5% of bone marrow must survive after radiation exposure in order to allow the individual to survive. This amazing regenerative capacity of bone marrow is exemplified in transplantation:
In the case of protracted exposure, BM is very susceptible to carcinogenesis. Thus, exposure of large areas of BM to radiation significantly increases the risk of leukemia. Approximately 50% of the body’s active BM is contained within the pelvic region. Thus, shielding this region holds great promise for both high-dose and protracted exposures. The 360 Gamma is a device that, even at extremely high radiation doses, is able to protect a critical mass of BM sufficient for hematopoietic reconstitution – thereby preventing lethal ARS.
Equipping responders with this novel device offers dramatic improvements to survivability even under extreme radiological scenarios in which exposure to high-dose radiation occurs (see figure below). This device is also effective in reducing the cumulative dose in the highly susceptible lower-abdominal region, thus reducing cancer incidence in organs residing there over the user’s lifetime. Therefore, wearing the 360 gamma while performing tasks with known exposure to small doses of gamma exposures is important. As such, it can protect professionals in various occupations ranging from gamma radiography to agricultural sterilization.
In space, the human body is impacted from radiation due to prolonged exposure to galactic cosmic rays (GCR) and periodic exposure to solar particle events (SPE). SPEs are of concern due to their short warning times and high intensities. In 1972, between the Apollo 16 and 17 missions, an SPE capable of delivering potentially lethal doses occurred.
For future manned missions beyond Low Earth Orbit, the necessity for radiation protection grows with mission duration as both the cumulative doses and the probability of encountering a significant SPE will increase with time.
In spaceflight, efficient use of mass is crucial, and the development of a radiation shielding strategy, which offers a ratio of protection to mass, is required. The AstroRad personal shield utilizes a strategy based on innovative passive shielding worn by astronauts to maximize the solid angle of coverage while selectively protecting the most radiosensitive tissues.
Some tissues disproportionately influence the effective dose through their high tissue weighting factors, such as bone marrow, stomach, lungs, glandular breast tissue, colon, and gonads. Furthermore, focusing protection on tissue-resident stem cells within these organs provides even greater benefit as they give rise to a disproportionately large number of daughter cells, so a stem cell with a radiation-induced mutation gives rise to thousands of mutated daughter cells, increasing the likelihood of cancer within that organ exponentially (see below figure). Simultaneously, stem cells possess a high capacity for tissue regeneration post-exposure, which is especially applicable to acute exposures.
Selective protection of these tissues was accomplished by designing the shielding thickness to be inversely related to the thickness and radiodensity of the underlying tissue at each point and point surrounding the targets for protection.
Low-Z materials, especially materials with high hydrogen content, exhibit the largest mass-stopping power and present a low cross-section for generating secondary radiation, including neutrons.
Therefore, such low-Z materials are used in a vest-like design in order to provide a high ratio of reduction in effective dose to shielding mass. Novel nanomaterials are being investigated for inclusion in the AstroRad, and the design team has developed innovative ergonomic concepts that ensure user comfort and flexibility.
In a tri-national effort between the Israel Space Agency, German Aerospace Center (DLR), and NASA, AstroRad was tested aboard the Artemis I lunar mission. The German Aerospace Center (DLR) contributed their “Matroshka” human models, containing thousands of radiation detectors. A “Matroshka” named Zohar wore the AstroRad vest alongside a “Matroshka” without a vest (Helga). Upon the return of the Orion spacecraft to Earth, teams from NASA, DLR, and ISA performed a comparative analysis of the efficacy of AstroRad, to find that it outperformed expectations, reducing the likelihood of radiation-induced cancer by approximately 60% in the case of a crew member wearing the vest over the course of an SPE. Here, the head of NASA highlights the importance of this study in a public 2022 address:
Additionally, the Israel Space Agency signed an agreement with Lockheed Martin Space Systems Company to launch AstroRad to the International Space Station (ISS) in 2019. Astronauts on ISS wore the vest during their daily routine on the station for the purpose of ergonomic evaluation under the auspices of the US National Laboratory there (CASIS). The result of this study in microgravity informed important ergonomic improvements in the vest.
Today, AstroRad is being integrated into NASA’s plans for increasing the safety of its crew members, who are slated to return to the Moon in 2025- for the first time since the Apollo missions.
Our next generation of X-ray protection gear – The StemRad MD – is based on an exoskeleton that bears the weight of the shielding, relieving you from the pain of wearing lead aprons while adding critical protection. Importantly, you enjoy complete freedom of movement. Full Protection with Full Mobility – StemRad MD.
This is a major breakthrough for medical professionals who are constantly exposed to radiation.