Tampons sold under various popular brands may contain toxic metals such as arsenic and lead, according to a recent study out of the University of Berkeley in California.

The study, published in the latest volume of Environmental International, found that all 30 tampons tested from 14 brands — including organic tampons — contained lead, with some showing concerning levels of other toxic metals like arsenic.

“We selected several different products and tested them for a panel of 16 different metals. And we found concentrations of every single one of the metals we tested. For some of the metals, like lead, which is toxic, we found a presence in every single one of the tampons we tested. So we found a lot of metals,” said lead author Jenni Shearston, a postdoctoral student at the UC Berkeley School of Public Health.

But despite the large potential for public health concern, she told Global News, very little research has been done to measure chemicals in tampons.

Menstruators may use more than 7,400 tampons over their reproductive years, with each tampon being retained in the vagina for several hours, the study said. They are typically made from cotton, rayon, or a blend of both materials.

In Canada, tampons are regulated as medical devices by Health Canada. The health regulator’s website states it “makes sure that the tampons sold in Canada are safe, effective, and of high quality based on requirements for licensing, quality manufacture, and post-market surveillance.”

The study raises concerns that those current regulations may not be enough.

Tampons are of particular concern as a potential source of exposure to chemicals, including metals, because the skin of the vagina has a higher potential for chemical absorption than skin elsewhere on the body, according to the study.

“A lot of the metals that they found, we naturally have in our body, our body naturally uses for various things,” explained Dr. Eboni January, a U.S.-based obstetrician-gynecologist.

“However, when it’s at toxic levels, that is of most concern to me. Lead was found in pretty much every tampon and lead is not safe at any level,” she told Global News.

Metals have been found to increase the risk of dementia, infertility, diabetes and cancer. They can damage the liver, kidneys, brain, and cardiovascular, nervous and endocrine systems.

“Arsenic is a known carcinogen, period,” January said. “It can cause lung cancer, skin cancer, bladder cancer and fertility issues.”

She added that she believes the study was well done and hopes more research on the topic will follow.

The researchers evaluated levels of 16 metals (arsenic, barium, calcium, cadmium, cobalt, chromium, copper, iron, manganese, mercury, nickel, lead, selenium, strontium, vanadium and zinc) in 30 tampons from 14 brands across the United States and Europe.

They purchased the tampons between September 2022 and March 2023 from stores in the U.S., the United Kingdom and Spain and two major online retailers.

The researchers did not specify which brands they examined, but Shearston said they selected both name-brand and store-brand products that were more popular.

Metal concentrations varied depending on the country where purchased, whether the tampons were organic or non-organic and whether they were store-brand or name-brand.

But there was one common factor no matter what type of tampon or where it was purchased: metal was found in every tampon sample.

“What’s really important is the consistency of our results, the fact that we found metals in everything that we tested, regardless of what its brand was or characteristics of the product,” Shearston said.

Lead concentrations were higher in non-organic tampons but arsenic was higher in organic tampons.

Several toxic metals were detectable in all tampon samples, including arsenic, cadmium, chromium, lead and vanadium. Among these, lead had the highest concentration.

January is not sure why zinc and cadmium were commonly seen together, but speculates it may be for hygiene purposes.

“Zinc is antimicrobial. Maybe they were putting it in there from an antimicrobial standpoint. And those two combined (zinc and cadmium) actually helped to prevent bacteria,” she said.

Metals can make their way into tampons in several ways, Shearston said.

“One of them is that cotton, for example, is a pretty decent accumulator of metals. So it could absorb metals that might be naturally present in soil or water might absorb metals from fertilizer. So that’s one way that some metals could get into some of these products,” she said.

“Also, if it happens that the raw material, like cotton, is grown near a pollution source, for example, near a road or near a lead smelter, some of the metals from those pollution sources might float down and land on the cotton.”

She noted that it’s also possible these metals are being added during the manufacturing process, as either an antimicrobial agent, a pigment or a whitener.

Because of this, the authors note that they hope manufacturers of tampons are required to test their products for toxic metals.

Global News reached out to Tampax maker Procter & Gamble and O.B. tampon owner Edgewell Personal Care for comment on the study, but neither company responded by the time of publication.

The study found lead in all the tampons tested, but a key question remains unanswered: can these metals be absorbed into the body?

“We don’t know if the lead can actually come out of the tampon and be absorbed into the body. So while we are finding these metals present in the tampon, we can’t say if it’s contributing to any health effect at this point,” Shearston said.

She emphasized the need for further research due to the widespread use of tampons.

While the exact effects of these metals remain unclear, January pointed out a concerning factor: the vagina’s absorbency.

“The vagina is very vascular,” she explained. “So it’s not flat like skin. It has folds essentially. And so what that does is it increases the surface area, and based on the type of cell layer that it is, there’s higher risk for things to be absorbed in the vagina.”

She used the example of toxic shock syndrome, which occurs when certain toxins from bacteria can be absorbed into the bloodstream through the highly absorptive vaginal walls, often associated with the use of tampons.

“With the vagina being as absorptive as it is, the arsenic in these tampons, that was concerning to me as an ob-gyn,” January said. “Women start their periods at the average age of 12. Menopause average age is 51. So these women have used a ton of tampons. This is chronic exposure.”

There’s no need to panic and throw out your tampons just yet, but this finding highlights the importance of ongoing research in women’s health products, Shearston said.

While the study identified the presence of metals in tampons, it emphasized the need for further investigation to determine whether and to what extent these metals are absorbed by the body and pose potential health risks.

January suggested discussing any concerns with your doctor regarding the materials that may be present in your tampons.

“But we do have other options,” she added. “You have the menstrual cups, you have the disc, you have the reusable pads as well. So do your homework, educate yourself, reach out to the manufacturers and ask them to be transparent.”