por
Lauren Dubinsky, Senior Reporter | October 11, 2021
From the October 2021 issue of HealthCare Business News magazine
According to Atom Physics’ Evearitt, lead is cheap and abundant and the process is already established to have it put on the back of drywall. So how can lead-free alternatives made using tungsten and bismuth compete?
These alternatives started to gain traction because of the toxicity concerns associated with lead, but they are by no means mainstream. The main hurdles are the price of these materials and the difficult process of working with them.
“Lead is a raw material that you can work with,” said Aitken. “If you are working with tungsten, it’s a raw material as well but it’s extremely difficult to machine. Lead can be poured and rolled, but tungsten is a powder form that needs to be broken down.”
In addition, the companies that manufacture these products are dependent on the price of tungsten at any given time.
“Because they weren’t producing mass quantities like lead, they had to buy the raw materials based on an order they got,” said Evearitt. “Week to week and day to day the price of tungsten changed.”
Lead-free alternatives are made up of impregnated polymers that include tungsten and/or bismuth and iron.
Nanotek XYZ is a cost-effective alternative to lead shielding. According to MarShield’s website, it’s a polymer-based shielding material that can be made into thin materials to replace sheet lead and installed on walls with its adhesive backing.
The material could also be used in the form of interlocking bricks to provide thicker shielding as well as curtains, shielded vests, barriers, nuclear medicine vials, etc.
Nanotek RSM offers better X-ray protection in thinner layers and weighs less than lead and Nanotek XYZ, but it’s more expensive. MarShield also offers its T-Flex Impregnated Polymers, which is an alternative to lead wool blankets or solid lead parts in the nuclear industry.
“I think that the more popular Nanotek gets, the better pricing will be,” said Aitken. “With it being such a new product, we are also trying to get more people to adopt it. It’s such a new thing that some people almost don’t believe the studies because it’s so effective.”
Evearitt added that there also needs to be an infrastructure in place to make it easy to order and to make people aware that it’s available.
Radiation therapy shielding
When choosing a material to shield a radiation therapy room, photon and neutron attenuation needs to be taken into consideration. Lead, steel and concrete are the main shielding constituents.
Typically, the higher the energy, the more shielding is required. If a linear accelerator has a maximum photon energy above 10 megavolts, the machine is also producing neutrons.
