- Studies present that leaving plastic water bottles in sizzling environments, like a automobile, causes them to launch billions of microplastic particles and dangerous chemical substances into the water.
- Heat and UV publicity speed up the breakdown of plastics, whereas bottles saved in cool, darkish locations shed little to no microplastics.
- To cut back publicity, specialists advocate avoiding long-term storage of bottled water in sizzling situations and choosing reusable glass or metallic bottles as a substitute.
Worried about your publicity to microplastics? Then you’d higher suppose twice earlier than consuming that water that is been sitting in your automobile for days.
Microplastic analysis has gone into overdrive lately as extra individuals acknowledge how a lot they ingest and its potential well being dangers. Studies present it may trigger every part from liver injury to irritation and oxidative stress. And none of that’s good. The downside is that avoiding microplastics seems like a sport of whack-a-mole: as quickly as we discover and get rid of one supply from our routine, one other pops up. However, there is a new supply that appears pretty straightforward to keep away from: that previous, sizzling plastic water bottle sitting in your cup holder for who is aware of how lengthy.
In 2023, researchers examined how different temperatures and UV exposure have an effect on 4 widespread plastics, the identical varieties utilized in packaging and bottles that might simply be left in a sizzling automobile. They found that though every sort of plastic degraded barely otherwise, all of them launched tiny microplastic fragments, and never just some. During testing, the plastics launched billions of microscopic particles into the water. In distinction, the bottles saved in a refrigerated surroundings because the management group launched nearly none.
And this was removed from a one-off conclusion. In 2014, researchers from the University of Florida reached related outcomes with their examine, which examined how chemical substances had been launched from 16 manufacturers of bottled water saved at 158°F for 4 weeks. They described their findings as a “worst-case scenario” for human consumption.
“If you store the water long enough, there may be a concern,” soil and water science professor Lena Ma, and lead researcher on the examine, famous on the time. The group famous that they’d advise individuals in opposition to leaving bottled water in a “sizzling storage for weeks on finish or in your automobile all day in the course of the summer time.”
Generally, warmth and plastics do not combine properly. As Food & Wine beforehand reported, a 2025 examine revealed within the journal Science of the Total Environment examined the various ranges of microplastics present in 31 standard drinks within the United Kingdom. The examine discovered that sizzling drinks are the first supply of microplastic publicity, with sizzling tea containing about 60 microplastic particles per liter and sizzling espresso round 43. However, iced variations of those drinks had considerably fewer microplastics, with iced tea carrying 31 particles per liter and iced espresso 37.
This doesn’t suggest it is advisable go thirsty if that day-old water bottle is your solely possibility. As Jaime Ross, an assistant professor of neuroscience on the University of Rhode Island, shared with the Washington Postit is extra about avoiding repeated publicity, as a result of not solely may you be ingesting microplastics, however warmth “may contribute to the expansion of pathogens.”
As for what will be accomplished, the researchers of the 2022 examine famous that “Product labels, incl. bottled waters, ought to comprise info concerning the composition of its packaging and inform about the potential of releasing bisphenol A into water.” However, if you happen to do not need to look forward to firms to behave, you are able to do so your self by storing your water in cool, darkish locations or switching to reusable glass and metallic bottles at any time when doable. Then, comply with this recommendation to scale back your publicity to microplastics at residence, so you possibly can cease enjoying microplastic wack-a-mole, too.
