A metal used in numerous electronics and light bulbs may double the risk of stroke, according to a new study. Stroke is currently the second leading cause of death in the Western world, ranking only second to heart disease. It is also the leading cause of disability in adults, often resulting in loss of motor control, urinary incontinence, depression and memory loss.

The research used data from the US based National Health and Nutrition Examination Survey, analyzing tungsten concentrations in the urine of 8614 participants aged between 18 and 74 over a 12 year period. The study showed high concentrations of tungsten to be strongly linked with an increase in the occurrence of stroke, roughly doubling the risk. The study showed the increased stroke risk, even when taking into account other risk factors such as age, socioeconomic status, cigarette use, body mass index, occupation and alcohol consumption. Researchers hypothesize that the pathological pathway resulting from tungsten exposure may involve oxidative stress, leading to the higher risk of stroke.

Interestingly, some people were more likely than others to experience high tungsten levels, including African Americans and Latin Americans, people with low body mass index, and people with lower incomes and education levels. The association between tungsten and stroke was especially pronounced in women, as well as people younger than age 50.

Tungsten is commonly used in consumer products such as mobile phones and computers, as well as a number of industrial and military products. The demand for tungsten is steadily rising. 72,000 tons were produced last year compared to 40,000 tons in 2002. During its production, small amounts of the metal can be deposited in the environment, eventually making their way into water systems and onto agricultural land.

Lead researcher, Dr Jessica Tyrrell, of the University of Exeter Medical School’s European Centre for Environment and Human Health, said “While currently very low, human exposure to tungsten is set to increase. We’re not yet sure why some members of the population have higher levels of the metal in their make-up, and an important step in understanding and preventing the risks it may pose to health will be to get to the bottom of how it’s ending up in our bodies.”

Another of the paper’s authors, Dr Nicholas Osborne, added “The relationship we’re seeing between tungsten and stroke may only be the tip of the iceberg. As numerous new substances make their way into the environment, we’re accumulating a complex ‘chemical cocktail’ in our bodies. Currently we have incredibly limited information on the health effects of individual chemicals and no research has explored how these compounds might interact together to impact human health.”