Debunking: Berkeley study of tampons and heavy metals – to worry or not to worry?

• A study has discovered the presence of some heavy and toxic metals and metalloids, such as arsenic, in women’s hygiene products – tampons. Even organic cotton tampons contained these substances.
• What to keep in mind: Experts still say there is no need to panic – these substances are also present in your T-shirt, and in the detected quantities, which are in the nanogram scale, there is no danger. Additionally, the detection was carried out under conditions that do not occur in the human body.

On Instagram and TikTok, a new trend has emerged: in July 2024, a study was published by the prestigious University of Berkeley on the content of arsenic and heavy metals in menstrual tampons. Suddenly, everyone is talking about it – every major influencer has reacted, and this is good because it raises awareness about the issue and shows that this is the first such study. But it is still not time to panic. The media immediately reported that tampons contain heavy toxic metals. However, it is important to understand the context: the good thing is that this is the first time someone has researched this topic, the bad thing is that it has caused a lot of panic and hysteria, and the good thing is that, although these substances are found in tampons, the dose, the quantity in which they are found, is so small, a billionth part of the total composition of the tampon, that it does not really play a significant role and tampons are safe. Remember – the dose makes the poison. Even water and mint tea can be toxic in excessive amounts. And our little, dear vaginas – they do not consume tampons to accumulate harmful substances.

Let’s start from the beginning.

Where do heavy metals in menstrual products called tampons come from? What are tampons made of?

Menstrual tampons are usually made from soft, absorbent materials such as cotton, rayon, or a combination of both. These materials are chosen for their ability to absorb menstrual blood. Rayon is a synthetic fiber made from cellulose derived from wood pulp. This material is highly absorbent and is often used in combination with cotton.

However, plants absorb metals and other chemical elements from the soil, such as arsenic, which is technically not a heavy metal but a metalloid. Therefore, even when you have organic cotton, it can contain these substances.

Some substances can enter the material of tampons during production as part of pigments, bleaches, antibacterial agents, or other processes in the manufacturing facility.

What does the Berkeley study say?

Tampons from several brands may contain toxic metals such as lead, arsenic, and cadmium. The study, published in Environment International under the title “Tampons as a source of exposure to metal(loid)s,” does not specify which brands of menstrual products were analyzed. The study tracked the content of 16 elements, not all of which are toxic. The study monitored calcium, arsenic, barium, cadmium, cobalt, chromium, copper, iron, manganese, mercury, nickel, lead, selenium, strontium, vanadium, and zinc. Not all of these metals and metalloids are harmful – iron, zinc, and calcium are necessary for our bodies. Copper, manganese, and selenium are trace elements needed for certain physiological processes.

The researchers examined 30 tampons from 14 different brands. Out of the 16 elements analyzed, 12 were found even in samples made from organically grown cotton.

The researchers used a technique that decomposed 100% of the tampon composition to measure the presence of metals.

“Very little research has been conducted to measure chemicals in tampons,” said lead author Jenni A. Shearston, a postdoctoral fellow at UC Berkeley’s School of Public Health and the Department of Environmental Science at UC Berkeley. “As far as we know, this is the first paper to measure metals in tampons. Alarmingly, we found concentrations of all the metals we tested, including toxic metals such as arsenic and lead.”

Lead was found in higher concentrations in non-organic cotton tampons, while arsenic was more prevalent in organic cotton tampons.

Heavy metals and metalloids like arsenic are known to increase the risk of dementia, infertility, diabetes, and cancer. They can damage the liver, kidneys, and brain, as well as the cardiovascular, nervous, and endocrine systems. Additionally, metals can harm maternal health and fetal development. However, this applies to much higher exposure levels than those found in tampons.

Therefore, this is important: the metals were detected in parts per billion (ppb) in the tampon content. Unless your vagina consumes entire tampons, we do not absorb 100% of what is in them, meaning our actual exposure is likely in parts per trillion. It is highly unlikely that this minuscule exposure would even come close to being clinically significant.

Study limitations

The study used 70% nitric acid HNO3, with a pH of 1.2, at a temperature of 82°C. These are not conditions found in the vagina. The vagina has a pH of around 4.5 (yes, it is slightly acidic, and if the pH rises, it is not good as unwanted bacteria can develop) and a temperature of about 37°C.

The sample size (N=30) is extremely small.

Good controls were not used, according to Dr. Andrea Love on her Instagram profile.

Conclusion – important – what does all this mean?

We are naturally exposed to these substances. However, we ingest more of these substances through food than, for example, through tampons. Each of these substances has different doses at which they become risky, and each of these substances, elements, has different properties.

For now, there is no reason to stop using tampons. If you are worried, you can opt for other menstrual products. Do not forget – cotton wool used for hygiene purposes, makeup removal, wound cleaning, and wiping also consists of cotton that probably has residues of these same substances. Cloths that could be used also contain these substances. Sanitary pads are made from sodium polyacrylate (the absorbent part), rayon, and polyethylene.

It is very important that someone has investigated this aspect of the presence of certain substances in tampons for the first time, that someone thought to examine this, as it was not considered important before. And it was women who thought of it, of course. It is necessary to question products and work on their safety. However, the hype that has been created intensifies the panic, and this needs to be addressed and explained. We understand that such information triggers you, that you feel anger because it seems like some industry is deliberately poisoning you. But let’s not react hastily.

The study’s findings understandably caused concern, especially given the historical neglect of women’s health issues in medical research. This legacy has fueled skepticism about the safety of women’s products. However, while these concerns are justified, it is crucial to contextualize the risk. For example, the U.S. FDA and EU regulations are very strict about pesticide content in these products.

This is not a conspiracy, and it has been known before that cotton and rayon contain residues, remains of some toxic substances, but not in quantities that will poison us. The same is true for your favorite cotton T-shirt. Even organic production cannot avoid this. It is important to understand that, despite this, these quantities are not a cause for panic.