How to Stay Hydrated Safely This Summer

By: Allison Warren  |  May 11, 2024

By Allison Warren

With the summer fast approaching and temperatures rising in NYC, it is imperative that we stay hydrated. When staying hydrated, one must take certain safety precautions to ensure the water they are drinking is not contaminated. While some people are environmentally contentious and only drink from reusable water bottles, many people still use disposable plastic water bottles, with an estimated 50 billion water bottles purchased each year by Americans, which can pose a few noteworthy health concerns.

Firstly, one must understand how a plastic water bottle is produced. When oil or natural gas is heated to very high temperatures, the hydrocarbon molecules that comprise these substances decompose into smaller molecules called monomers. In order to make plastic, these monomers are joined together to build a polymer, a larger molecule. Different plastics are comprised of various combinations of monomers. To form a bottle, plastic is heated until it melts to a liquid and is then placed into a mold where the plastic hardens.

In order to determine if it is safe to reuse a plastic water bottle, one must find out which type of plastic the bottle is made of. Plastic water bottles are often made from polyethylene terephthalate (PET) (PET), a clear, lightweight plastic. 

One concern with reusing water bottles is that there may be chemical leaching. Chemical leaching occurs when chemicals from the plastic dissolve and mix with the liquid inside the bottle. Causes of chemical leaching include exposure to high temperatures, sunlight, or long storage times. Reports indicate that antimony, bisphenol A (BPA), and phthalates are chemicals that may leach from a water bottle if the plastic contains these chemicals. Before reusing water bottles, it is advisable to check which chemicals the plastic contains. 

Antimony has been known to cause nausea, vomiting, and diarrhea in the short term. Long-term exposure leads to an increase in cholesterol and blood sugar levels, but it is not carcinogenic. One should store their PET plastic water bottles indoors indoors at room temperature to prevent antimony leaching. While leaching has been found in plastic water bottles in plastic water bottles, it is very gradual and often not in dangerous amounts. A 2008 study found that at temperatures of 80 degrees Celsius, leaching will occur in dangerous amounts in just 1.3 days. 

BPA mimics the hormone estrogen, leading to hormonal disruptions. Exposure to BPA, which is found in more rigid plastics like polycarbonate, has been related to increased blood pressure, type 2 diabetes, heart disease, and possibly related to affecting the brains and prostate glands of fetuses, infants, and children. BPA proved to be so harmful that the FDA banned the usage of BPA in baby bottles and sippy cups. Nowadays, most plastic water bottles sold are BPA-free. However, its replacement has been similar chemicals like bisphenol S (BPS) and bisphenol F (BPF), which have not been thoroughly studied and may bear similar effects as BPA, leading some to recommend that one should not use any plastic products. 

Phthalates have been known to interfere with growth and brain development in kids as well as an increase in allergies. However, in regards to chemical leaching, it often remains in non-dangerous amounts and does not pose a serious threat to one’s health, assuming the bottle was not left exposed to hot temperatures.

An additional concern with plastic water bottles is the potential for bacterial growth. In fact, bacterial growth in water bottles proves to be a far greater concern than chemical leaching. Manufacturers recommend only using disposable water bottles once and not reusing them, as plastic water bottles can become a breeding ground for bacteria. Furthermore, an unfinished water bottle left out at room temperature, the optimal temperature condition for most bacteria to grow in, can leave bacteria growing in the bottle throughout the day. As the bacteria grow in the bottle, it can organize into resilient colonies known as biofilms, which protect the bacteria from chemical cleaning supplies and may host some species of bacteria or viruses that can make people ill if infected. One study reported that bacteria can grow in a water bottle as quickly as 1 colony per mL to 38,000 colonies per mL in 48 hours at 37 degrees Celsius, which is 98.6 degrees Fahrenheit. As water bottles get reused, they often develop cracks and scratches on the surface, providing an additional surface for bacterial growth. If one decides to reuse a plastic water bottle, it remains critical to first wash the bottle properly and ensure the surface is not damaged. 

If one wants to protect oneself this summer from the risk of chemical leaching and bacteria-bred water bottles, it is highly encouraged that one purchase a reusable stainless-steel or glass bottle as an alternative to the disposable plastic that they may wash and clean regularly. An added bonus is that you will be protecting the environment, too!