Tech founders are dreaming of a day when we do away with our screen-based smartphones, and instead wear a web of interconnected AI-powered devices on our beings. But experts warn that these small and seemingly harmless devices could bring huge risks to our planet, if not more consciously designed.
Around 50 million wearables units were sold globally in the second quarter of 2025, up 12.3% year-on-year, according to IDC data. That growth is forecast to accelerate: demand for health wearables alone could hit two billion units a year, or 42 times more than today, by 2050, according to a new study from Cornell University and the University of Chicago.
“Nobody’s thinking about what happens when these devices reach the end-of-life stage,” says Scott Butler, executive director of Material Focus, a UK-based non-profit working to reduce e-waste. “It turns out it’s a major, major issue.”
A material question
More than 60 million tons of electronic waste is generated globally each year, of which around just 22% is formally collected and recycled, according to the World Health Organization’s latest data. Although wearable health devices are generally much smaller and lightweight than other electronics like appliances, they have a much shorter lifespan. The average lifespan of a smartwatch, for example, sits at around three to five years, according to most estimates. Although this is more than the average lifespan of two to three years for a smartphone, experts say that when wearable devices do reach the end of that timeline, they’re particularly difficult to repair, reuse and recycle, owing to their complex, miniaturized designs. Cornell researchers warn that, if measures aren’t taken to reduce the environmental impact of wearable devices, they could generate more than one million tons of e-waste and 100 million tons of carbon monoxide per year by 2050.
The wasted materials in question are in high demand — so much so that it isn’t actually the plastic and glass used in the manufacture of wearables that poses the biggest problem. Instead, according to the researchers, more than 70% of a device’s carbon footprint comes from the printed circuit boards (PCBs) housed within wearable devices — what we can think of as their “brain”, which powers and connects sensors, bluetooth modules, and the processors that collect measures like heart rate and steps. These PCBs are made using precious metals like gold, silver, platinum, copper, and cobalt — which, even if used in tiny quantities, require huge amounts of energy to be mined.
Then, most smart devices are powered by small lithium batteries — known for their intensive water and energy consumption in mining and production, and the fires they can cause if disposed of incorrectly in bins. Add to that the environmental damage and human rights abuses associated with the production of coltan, cobalt, and nickel — the essential materials for producing electronics — and the sustainability concerns linked to the production of wearables devices get more and more complex.
“These are all critical raw materials, and coltan, cobalt and nickel, for example, are all linked to countries that are having difficulty with civil unrest,” says Butler. “So broadly, the view is that most of the impacts of a product is actually in design, production, and getting it to market, but there is still another significant issue, which is around how you deal with it at the end of life.”
The Cornell researchers propose two solutions to this materials problem: that wearable tech companies’ engineers work on developing new chips made from more easily obtainable minerals like copper and aluminium, and that devices are designed to be “modular” — aka, out of distinct parts that can be replaced individually, without needing to replace the entire device.
Yet even copper, which moves the electric current around wearable devices, is growing increasingly scarce. Rapid consumption is expected to outpace supply, leading to a 30% deficit by 2035 — but experts say that better recycling of electronics could potentially meet the demand. Research by Recycle Your Electronics, for example, shows that UK households are sitting on 38,449 tons of copper hidden within unwanted and thrown-away electricals — an amount they estimate is enough to fulfil the UK’s annual demand for copper among tech.
“We’re surrounded by an urban mine, and there’s a real pinch point coming soon as copper is the essential ingredient as everything becomes electrified,” says Butler. “But you don’t turn into a copper mine overnight. A lot of investment and work needs to be done to get people to use, donate, or recycle these devices correctly.”
Beyond the mining and recycling of scarce precious metals, there’s another materials consideration at play: a large number of smartwatch and fitness tracker straps have been found to contain high levels of “forever chemical” PFAs — toxic substances that can be absorbed through the skin and are linked to health issues like cancer, organ damage, and birth defects. Markers of these chemicals were detected within the bands of 15 of the 22 most common smartwatch and fitness trackers, according to a 2025 study by the University of Notre Dame; researchers said the PFAs were found in “much higher” concentrations than in other consumer products — a “concerning” finding, owing to the fact the straps are worn on consumers’ wrists for long periods of time.
Fitness tracking device Whoop, for example, says that while it doesn’t use materials with added PFAS in its bands for its latest models (Whoop 5.0 and Whoop MG), it cannot guarantee that its bands are free from all residual and environmental PFA chemicals, because “some levels of PFAs can now be found throughout our environment”. Meanwhile, Apple says it tests products that will come into prolonged contact with the skin for their concentration of restricted chemicals, and it is committed to phasing out the use of PFAs in its products and manufacturing processes in the future. Fitbit owner Google says its Fitbit device bands do not contain PFAS, its Pixel Watch bands meet industry standards with regard to PFAS, and it’s developing long-term alternatives to eliminate PFAS where possible. Meta says it’s committed to reducing or eliminating PFAs in its products. Garmin did not respond to requests for comment. Samsung declined to comment on whether PFAs are found within its Galaxy watch strap.
Idle devices
Possibly the biggest elephant in the room when it comes to the booming wearable tech market is the challenge of designing devices that aren’t promptly retired to consumers’ bedside drawers. Some 8% of wearable tech devices in the UK in 2024 had never been used, according to a YouGov survey. Yet, more new tech devices means a compounding waste issue: UK households alone, for example, are already holding onto 880 million unused tech devices (30 per household, up from 20 four years ago), according to Material Focus’s research.
“A lot of people look to the next shiny new electrical without thinking of what it’s made of, and soon they get bored of it, put it in a drawer, and forget about it,” says Butler, adding that the worst thing a consumer can do is throw an electrical item in a normal bin when they no longer use it. “We’re seeing that consumers forget about devices the smaller they are, which is where all the tracking devices come in.” Where the wearable tech market remains relatively nascent, we’re yet to see the full impact these devices could have on landfills across the globe — especially countries in the Global South, where it’s estimated that between 75% and 80% of global e-waste is exported from high-income countries, often illegally.
“Here in Bangalore, most of the waste we’re dealing with is still single-use plastic and paper, because so much of our population is still in the middle and low-income bracket, where we’re at a stage where we try to repair and reuse anything electrical,” says Bianca Fernandes, circular economy and institutional engagement manager at Bangalore-based social enterprise Hasiru Dala, which works with wastepickers in India. “But I think it’s going to be like what we’re seeing with global textile waste right now. People have been storing things away for years and suddenly now, we’re finding so much textile waste in Bangalore. So I think five, 10 years down the line, we’re going to have a huge e-waste problem here for sure.”
The tech companies behind the most popular wearables argue that by continuously improving their devices and software so that they can collect more health metrics, more accurately, they’re improving consumer stickiness and their products are less likely to go to waste.
For example, Oura CEO Tom Hale recently told Vogue Business that the smart ring’s rapid sales acceleration over the last two years is down to its expansion into women’s health features like menstrual cycle tracking and pregnancy insights — both features that require multiple data points like body temperature and heart rate variability, which he said Oura is constantly improving with updates to the ring.
Several of the companies behind the most popular wearable tech also have upcycling and recycling programs in place — though some are more thorough than others. As of October last year, Oura ring wearers in the US, Canada, the UK and some EU countries can now return their old rings to the company when upgrading or replacing their device to be recycled. Oura declined to comment when asked for more detail on how many parts of the rings are recycled. Fitness tracking band Whoop, on the other hand, has an “upcycling” program that encourages wearers to pass their old devices onto others for trade-in credit, rather than recycling the devices. Whoop does say it encourages wearers to recycle the band component of their devices via textile recycling schemes like Trashie and Suay. Samsung has a trade-in scheme where customers can exchange their old smartwatches for a discount on new products, and recycles e-waste in collaboration with local recycling schemes and organizations, according to its brand site.
Apple — which has committed to achieving 100% carbon neutral supply chain and products by 2030 — operates one of the industry’s more advanced recycling and trade-in programs, where returned Apple Watches are either traded in for credit for reuse, or recycled if they have no resale value. Apple refurbishes and resells returned devices if they’re still functional, while disassembling them to recover materials including aluminum, cobalt, copper, glass, gold, lithium, and plastics. The company also published a guide to recovering materials from Apple Watches for professional recyclers. Fitbit owner Google says it helps customers recycle old electronics no longer in use via mail with a third-party recycling partner, and that its Pixel Watch 4 smartwatch is made with recycled plastic, cobalt, aluminum, steel, glass, tin, tungsten, gold, copper, and rare earth elements. Meta and Garmin did not respond to requests for comment on any upcycling and recycling programs they have in place.
Campaigners hope that by increasing consumer awareness of the scale of the global e-waste problem, tech companies will invest more in improving their own recycling schemes. And where e-waste recycling methods are often energy intensive themselves, Butler says that technology could provide a secondary benefit, by improving materials recovery methods, too.
“At the moment, PCBs mainly go into big furnaces to then have the metals taken off, so it’s quite energy intensive,” says Butler. “But we’re now seeing smaller firms explore leaching using different kinds of solvents and chemicals for a much less energy-intensive way to collect materials. Innovations are happening all the time.”
