Reusing a plastic bottle might be better for the environment, but it can be worse for your health. Plastic bottles can begin to physically break down from wear and washing and this can lead to cracks or thinning. Bacteria can harbour in these cracks, posing a health risk.
In fact, this bacteria can “pose a greater health risk than the possibility of chemicals leaching from the plastic during daily risk" according to an article in a 2007 issue of the journal Practical Gastroenterology.
Another 2016 study by Treadmill Reviews claims reusable plastic bottles contain more germs than a toilet seat, after one week of use.
A study published in the Canadian Journal of Public Health also found that two thirds of of reused plastic water bottles had bacterial levels that exceeded that of drinking water guidelines.
2. Fertility issues
BPA, or bisphenol A, is no longer found in plastic bottles holding soft drinks.
However, BPA-free plastics have also been linked to problems during reproductive development, according to a new UCLA study which examined zebra fish embryos.
"Our research showed that low levels of BPS had a similar impact on the embryo as BPA," senior author and reproductive endocrinologist Nancy Wayne told CNN.
While a further study found BPA-free plastic caused ice to have smaller wombs and smaller pups than controls, and in some cases miscarriages.
3. Environmental impact
A million plastic bottles are bought around the world every minute. This equated to more than 480 billion plastic drinking bottles being sold in 2016 alone, the Guardian reports.
This figure is expected to rise by 20% by 2021 and experts believe it could create an environmental crisis as serious as climate change.
Although plastic can be recycled, a whopping 91% of all plastic made over the past decade haven't been and around 79% have ended up in landfills.
Plastic isn’t biodegradable and can take more than 400 years to disintegrate. Experts predict there will be 26 million pounds of plastic garbage by 2050.