Tampons used by millions of people each year can contain concerning levels of toxic metals such as lead, arsenic, and cadmium, a world-first study warns.
The findings are of particular concern as the skin of the vagina has a higher potential for absorbing chemicals than skin in other parts of the body, say researchers.
“Our study clearly shows that metals are also present in menstrual products, and that women might be at higher risk for exposure using these products,” study co-author Kathrin Schilling said.
Some estimates suggest more than half of people who menstruate use tampons on a monthly basis, sometimes for several hours at a time.
Previous studies have also found that the exposure to toxic metals like lead and arsenic is linked to a wide range of health conditions, including dementia, infertility, diabetes, and cancer, and also damage to organs, including the liver, kidneys, and brain.
“Despite this large potential for public health concern, very little research has been done to measure chemicals in tampons,” study lead author Jenny Shearston said.
“To our knowledge, this is the first paper to measure metals in tampons. Concerningly, we found concentrations of all metals we tested for, including toxic metals like arsenic and lead,” Dr Shearston said.
In the study, led by those at the University of California Berkeley, scientists assessed the levels of 16 metals, including arsenic, cadmium, cobalt, lead, and selenium in 30 tampons from 14 different brands.
They found that metals were present in all types of tampons, whether bought in the US or EU/UK, with no category having consistently lower concentrations of most of the metals.
Researchers suspect that metals were making their way into tampons likely in a number of ways during manufacturing.
Some of these, they say, might be from intentional addition during manufacturing as part of a pigment, whitener, antibacterial agent, or some other process in the factory.
The cotton material may also be absorbing toxic metals from water, air, soil, or a nearby contaminant, scientists say.
“I really hope that manufacturers are required to test their products for metals, especially for toxic metals. It would be exciting to see the public call for this, or to ask for better labeling on tampons and other menstrual products,” Dr Shearston said.
At present, it remains unclear if the metals detected in the latest study are contributing to any particular health effects.
Scientists call for further studies to understand this and to determine how much of these toxic metals leaching out of tampons are absorbed by the body.