Published November 12, 2013
The popularity of tungsten has grown over the past decade, as the metal is increasingly being used in widespread consumer technologies, such as laptops and cellphones.
Initially, many experts considered tungsten to be a benign substance, posing no threat to the environment or human health. But now, new research has revealed that the opposite may be true.
In a new study published in the journal PLOS ONE, researchers from the University of Exeter in England have found that higher levels of tungsten in the body may double a person’s risk for stroke. According to lead author Dr. Jessica Tyrrell, these findings signal a significant need for more research into this mostly unstudied metal.
“In regards to the effects of our exposure to tungsten, we don’t know much about it, because there are limited studies,” Tyrrell, of the University of Exeter Medical School’s European Centre for Environment and Human Health, told FoxNews.com. “...We know that there are exposure pathways from the air, and it can be in the water supply and in food, because there’s tungsten in soil.”
Overall, the population’s current exposure to tungsten is thought to be very low, but Tyrrell said that is set to change, as demand and supply for the material are both increasing over time. Along with its inclusion in popular consumer technologies, tungsten is also used in various industrial and military products – such as alloys and projectiles.
While the element is found naturally on Earth in chemical compounds, small amounts of tungsten are continually being added to the environment. When products using tungsten are disposed of in landfills, the material eventually makes its way into water supplies and into agricultural lands, which ultimately affect the world’s food supply.
However, Tyrrell said it is still unclear if using products with tungsten directly increases an individual’s exposure.
“We don’t actually know if it does [increase your exposure],” Tyrrell said. “I think the idea is if we use it in these various sources, it has the potential to reach more into the environment, but there isn’t any evidence there. All we know is tungsten is in the environment, and we’re definitely using it more.”
In order to gauge what kind of risks tungsten exposure might pose to the population, Tyrrell and her colleagues analyzed data from the U.S.-based National Health and Nutrition Examination Survey (NHANES), following 8,614 participants between the ages of 18 and 74 over a 12-year period. The researchers focused specifically on the data relating to individual tungsten exposure – as measured through urine samples – and how it related to a person’s overall health.
The research showed that higher tungsten levels were strongly associated with an increase in the prevalence of stroke – independent of typical risk factors. The relationship was found to be stronger as tungsten exposure increased: For every one unit increase in micrograms per milliliter of tungsten, a person’s risk for stroke doubled. Additionally, the findings revealed that higher tungsten exposure could be a significant risk factor for stroke in people below the age of 50.
As for why some individuals had higher tungsten levels than others, Tyrrell said that more research is needed to better what increases a person’s exposure.
“It would be very interesting to see if there were particular lifestyle or demographic factors that increase tungsten concentration,” Tyrrell said. “But as of now, we don’t know in the general population what might increase your tungsten exposure.”
Since there are limited studies on tungsten, Tyrrell said not much is known as to why the metal could increase a person’s risk for stroke. However, the researchers have some preliminary theories, suggesting that the metal may interact with some important biological pathways.
“It could increase inflammation in the brain, or it could have some genetic impact,” Tyrrell said. “Some metals influence epigenetics, so tungsten could be influencing some gene expression that increases a person’s stroke risk.”
The tungsten-stroke relationship highlights another example of the harmful impact new materials can have on human health. The utilization of complex chemicals for commercial exploitation, including the introduction of nanotechnology, has increased over the years, but Tyrrell noted that very little research has examined how these materials interact with our biology. She hopes her findings will encourage experts to look at tungsten – and other metals – more closely.
“We need to understand different exposure levels in order to validate our findings,” Tyrrell said. “This will allow us to potentially identify acceptable levels of tungsten in the body, which will give us an idea if there’s a certain level that starts to increase our stroke risk. There is a lot more work that needs to be done.”