Every week it feels like there’s another scare story out about products and services that people use in their daily lives. Whether it’s contaminants in your rice, pollutants in children’s lunchboxes, or microplastics in semen samples, there’s always something to worry about in the news.
This week, the scare story is about tampons. For people who menstruate, the headlines must seem very scary. Media outlets across the world are reporting that a new scientific study has found “alarming levels” of toxic heavy metal contaminants in tampons. If you’re someone who has a period, and uses tampons, the news seems very shocking.
Fortunately for people with periods, the data is not nearly as worrying as you might’ve heard. While it’s true that there are probably some heavy metals in tampons, the quantities of these contaminants are incredibly low. There’s no evidence that you need to throw away your period products just yet.
The Study
The new study that has everyone up in arms was a fairly small research project looking at possible heavy metal contaminants in tampons in the US, UK, and EU. The researchers purchased packets of 24 different tampons - covering 16 brands total - from stores in New York City, Athens, London, and an online store. They then tested these different products for trace levels of 16 different heavy metals that included zinc, copper, iron, lead, mercury, arsenic, etc. About 1/3 of the tampon samples they looked at were organic, and they compared the organic and non-organic products on levels of these metals as well.
The authors found that most of the tampons had detectable levels of all of the heavy metals except mercury and chromium. The highest concentration detected was of calcium, while arsenic levels were only just above the minimum level that the test the researchers used could detect. The results also showed few differences between organic and non-organic tampons - lead levels were lower in organic products, but organic ones had higher levels of arsenic, for example. These differences were extremely small.
Most of the tampons tested had contaminants, including things like arsenic that are definitely toxic. So why would I say that these results are largely meaningless to you?
You may have heard the phrase “the dose makes the poison”. Virtually anything you come across can poison you at some dose. Caffeine is a wonderful chemical that makes waking up in the morning worth it, but it’s also a potent neurotoxin at higher doses. Water is literally required for life, but drink too much of it at once and you’ll die from water poisoning.
In this case, the doses are important. The authors of the study did find detectable levels of heavy metals, but that doesn’t equate to dangerous levels. Take lead. The study found that the median concentration of lead in the tampons included in the study was 173ng/g. The ng there stands for nanograms, which means that this is 173 parts per billion. Your standard tampon weighs somewhere between 5-15g, which means that there’s about 0.0000007-0.000002grams of lead in each one.
To put that number in context, it’s about the same as the concentration of lead in dried apples. The rate of cadmium that the study found in tampons was actually 10x lower than the levels you’d see in dried apples, and nearly 100x lower than the levels you’d find in dried berries.
It’s also not clear that any of these heavy metals actually make it into the bloodstream anyway. As the authors of the study noted, there’s very limited information on vaginal absorption from tampons. Given that they are fairly cohesive things - by design they don’t break down in the vagina - it’s quite likely that very little of these contaminants is actually absorbed by people using the tampons.
Don’t Worry About Your Tampons
What this study shows is that there is a potential environmental hazard that organizations like the FDA may need to look into. Given that many of the tampons did have some level of contaminants, it’s possible that some products have higher levels that might cause concern even though the levels seen in this study were extremely low. It’s the sort of thing that’s useful for regulatory agencies to consider, because it might require a change in policy - for example, testing tampons to make sure that they are at a safe threshold for these chemicals.
It’s also interesting to note that there were no meaningful differences between organic and non-organic tampons, which implies that these contaminants are environmental rather than caused in the production line. It’s likely that the extremely small quantities of lead and arsenic are simply present in the soil that the cotton which is used to make the tampons is grown in.
However, at an individual level, these results are largely if not entirely meaningless. The most conservative threshold for safety I’m aware of for lead is the Californian OEHHA level of 500ng/day. If you were using 3-4 tampons a day, and absorbing 100% of the lead in the products, you’d only just exceed this threshold. But not only are you unlikely to absorb 100% of the lead from tampons - it’s probably closer to 0%, you only absorb about 20% of the lead in your food - this figure is also set at 1,000x lower than the lowest observed safety threshold for lead exposure.
It’s true that there are probably some heavy metals in tampons, but this study really shows that the levels are almost certainly very safe. As a professional epidemiologist, I think it might be a good idea to start testing tampons to see what heavy metal contaminants they may contain, but that’s a population health measure rather than an individual one. You almost certainly get more lead from eating fresh fruit than using a tampon.