Israeli research reveals that wild plants growing under extreme desert conditions absorb high levels of strontium – offering a natural solution for dealing with nuclear disasters and radioactive fallout
The nuclear threat from Iran appears to have been removed – at least for the next few years. But a nuclear disaster – whether as a result of an accident or a deliberate act – still poses a continuing threat to the peace of the planet. In the shadow of this fear, it turns out that nature, and especially wild plants from the desert, may serve as the first line of defense after a radioactive event. A new Israeli study reveals that plants growing under extreme stress conditions in the desert are capable of absorbing high levels of strontium – a radioactive element released in nuclear fallout. The finding may serve as a breakthrough in cleaning up contaminated soil and support natural methods for dealing with nuclear disasters.
Strontium, a metallic chemical element denoted by the letters Sr on the periodic table, is similar in properties to calcium and is not dangerous in its natural form. There are also several forms of strontium that are used in medicine. In contrast, synthetic strontium – which is a product of a nuclear explosion – is considered one of the most dangerous components of nuclear fallout. When it is absorbed into the body, for example through eating contaminated food or water, it May cause tissue damage, bone cancer, and other cancers.
Until recent years, the topic of the presence of strontium in plants and its various effects on plant growth was not particularly common in the research world, but recently it has begun to be studied more, after it was found in nuclear disaster areas.
In recent decades, high levels of strontium have been detected in soils contaminated by nuclear accidents or in the vicinity of uranium mines. A team of Israeli researchers who examined the chemical composition of dozens of plants in different regions of Israel identified a high presence of strontium, mainly in plants growing in desert areas. This means that areas where nuclear disasters have occurred can be proactively treated by planting plants that absorb high levels of strontium. According to the study findings, desert plants, especially those grown in suboptimal conditions, can absorb large amounts of strontium, thereby helping to clean up contaminated soils.
What is your chemical signature?
One of the goals Research, conducted at the Desert and Dead Sea R&D Center in collaboration with Tel Aviv University and funded by the Israel National Science Foundation, was to examine whether and what differences there are in the chemical compositions of several plant groups depending on the region, desert or Mediterranean, in which they grow. The study sampled 83 plant species at 15 sites in Israel, and found significant differences in the chemical signature between desert plants and Mediterranean plants.
A chemical signature in plants is a concept that describes the unique composition of chemical elements of a particular plant or part of it. A specific chemical composition can reflect a variety of environmental influences – such as stress, water availability and soil type – on the plant and how it grows. “The different elements have important roles in the plant,” says Dr. Ofir Katz, a plant ecologist, researcher at the Desert and Dead Sea Research Center, and an associate researcher at the Eilat Campus of Ben-Gurion University of the Negev, who led the study in collaboration with Prof. Marcelo Sternberg and Dr. Michal Gruntman of Tel Aviv University.
The results of the study indicated certain differences in the chemical signature between the four types of plants surveyed: cereals, legumes, herbs and hard-tissue plants. The legumes group had higher levels of nitrogen, and a slight preference for cadmium – a type of toxic metal. The cereals group had higher levels of silicon, a chemical element called zoran in Hebrew – the second most abundant element on Earth after oxygen.
The significant difference observed in the study pointed to the effect of the growing region, regardless of the type of plant. All the plants sampled in the study contained relatively high concentrations of potassium, calcium, and chlorine, but the plants from the Mediterranean region were found to be richer in phosphorus and calcium, while the desert plants contained much higher levels of strontium. "Even though these are quite similar substances chemically, we saw a very interesting split between calcium and strontium," says Katz. "This means that in the desert, the plants are actually looking for strontium intentionally, and this is not just a result of chance or 'confusion' on the part of the plant."
Desert plants love challenges
Growing conditions In the desert include a variety of stress conditions such as water scarcity, extreme heat, and salty soil. The fact that there is a high concentration of strontium in desert plants, combines with Other studies that showed that strontium is involved in plant responses to stress conditions. Of course, there are other types of stress conditions and they may have different effects. "It would be interesting to compare the chemical signatures of plants grown under other harsh conditions," says Katz. "For example, in a country like Norway, to examine the areas that lack light and are colder compared to the more southern areas. It is possible that the stress that exists under the influence of cold also leads to a higher uptake of strontium."
The environmental effect on the amount of substances that the plant absorbs is not accidental, and the researchers estimate that stressful conditions "encourage" the absorption of strontium. "The significant discovery is that there is a connection between the growth of the plant under stressful conditions and the amount of strontium, which is probably beneficial for the plant to cope with the difficult situation," says Katz. "In fact, until a decade ago it was not at all clear whether strontium had any role in the plant, and the accepted approach was that it was 'just' there and did nothing. This has changed somewhat in recent years, when several studies have shown that strontium fertilization helps certain plants grow better under stressful conditions. Our study is the first to indicate a large number of species in which there is a connection between strontium and coping with stressful conditions."
This means that this knowledge can be used to plant such plants in areas where there is potential. For radioactive radiation, as well as infrastructure and nuclear facilities, or in areas contaminated by nuclear accidents. "If there is a plant that absorbs a lot of strontium, then it is better to grow it in the problematic area that we want to clean up," Katz argues. "Then, the plants can be buried in a radioactive landfill, from which these materials will not leak to other areas."
The relationship between the plant and strontium is not yet fully understood, but according to Katz, plants are already being used around the world to clean up areas where nuclear disasters have occurred. "Fortunately, there aren't many places today that are really problematic in this sense, but it's a method that definitely works. It's still unclear to what extent the terrain conditions affect the effectiveness of such an operation, but at least for now, based on the information we have, we can also assume that if a nuclear event occurs in a desert area, local plants will be more effective in cleaning up the ground," he concludes.
More of the topic in Hayadan:
