On college campuses across the nation, plastic bottles of water and soda are even more ubiquitous than iPods. And for some cost-conscious students, those bottles remain useful even after their original contents have been downed. But a burgeoning field of study suggests that refilling and reusing plastic bottles may not be a wise idea. Over the past several years, scientists across the country have been researching the links between health conditions and chemicals found in plastics, and they've come to some striking conclusions.
For example, Tufts Medical School Professor Ana Soto recently discovered that a chemical in common plastics called bisphenol A can alter fetal development in mice, increasing their eventual incidence of breast cancer. At the end of August, the Associated Press reported that harmful chemicals traceable to household plastics had been detected in humans living in California, spurring a legislative push for a biomonitoring program within the state.
The Environmental Protection Agency (EPA) is working to head off plastic-related health issues: USA Today recently reported that EPA chemists are working on creating compounds to replace the potentially harmful chemicals in common plastics. The increasingly public profile of plastic's pitfalls, however, isn't necessarily a deterrent.
"I've reused plastic water bottles that were intended for one use only - a.k.a. Poland Spring bottles - and I know many of my friends do," senior Brindusa Negritoiu said. "I actually know someone who buys water bottles from Hodgdon and then refills them all the time."
Seniors Chris Lintz and Assaf Pines have employed similar practices. "I'll sometimes refill a plastic water bottle - I can put it in the fridge and fool myself later: tap water no more," Lintz said. "I would often reuse the Gatorade sport bottle - the one with an ergonomic design - and fill it with water for when I would exercise," Pines said.
ExCollege Professor Ronnee Yashon, who teaches the popular Tufts course "Genetics, Ethics, and the Law," is no stranger to plastic's hidden darker side. Her sensitivity to the chemicals it contains is heightened due to a condition called multiple chemical sensitivities (MCS). What causes MCS - which can bring about symptoms like dizziness and headaches when individuals who suffer from it come into contact with chemicals, even in tiny doses - is unknown.
"People who have it are affected by tiny microparticles," explained Yashon, who has been teaching about genetics, biology, bioethics and the law for the past two decades. "Most people are affected by parts per million, but a person with this condition is affected by parts per billion."
But it's not just people with multiple chemical sensitivities who should avoid reusing soda and water bottles, which contain chemicals called phthalates. "When water sits for hours and hours in a bottle, the chemicals in the bottle's components leach into the water in molecular form," Yashon said. In small doses, she added, those phthalates - which make the plastic pliable - "are probably not even dangerous to you."
But repeated exposure is a different story. "Plastics, we now know, become estrogen-like in our bodies: they mock estrogen's functions," she said. "For women, that probably isn't that important. But for men, there have been ties made to infertility, and that's a big thing!"
One of those ties was made earlier this year in a study done by the University of Missouri, in which the amount of phthalate residue in pregnant women's urine was found to correlate with reproductive abnormalities and feminization in male infants. In May, a study done by the University of Rochester's medical school reached similar conclusions.
Though much of the research linking phthalates in plastic to human infertility is relatively recent (previously, only animal studies on the subject had been conducted), interest in the link between such chemicals and negative health outcomes is not a totally new phenomenon.
"Brigham and Women's [Hospital] had a giant lawsuit about 15 years ago based on latex, which is a form of plastic," Yashon said. "They did not build good ventilation in the new building, and so the doctors and nurses got sick from exposure to latex and from the latex being recirculated. Some of the nurses contracted the multiple chemical sensitivities condition and couldn't go back to work."
"And now, because of the lawsuit, if you go into Brigham and Women's, you can't bring any latex," she continued. "There are signs on the elevator doors that say, 'Please remove latex gloves before pressing buttons.' The lawsuit was important, because it showed that in the air of enclosed buildings, there are big problems with plastics."
But Yashon emphasized that there are also big benefits to the widespread use of plastics. "Plastics have been so important," she said. "If you go in hospitals, everything is plastic, because everything gets thrown out. This has done wonders for disease control: before, you had to clean things, and if they weren't cleaned exactly right, the next person got sick."
She also said that there's no need for members of the plastic-reliant college crowd to panic. "I've heard the horror stories," Lintz said. "Between cell phones, global warming, GMOs [genetically modified organisms] and water bottles, we're screwed."
Not necessarily, Yashon explained: "It's not something we should scare people about," she said. "Most people have been exposed to plastics their whole lives, and there's nothing you can do about it. But the more we know about how these chemicals affect body cells, the better, because people should be looking into what they expose themselves to."
As a general rule, she said, the harder the plastic, the safer it is to reuse. How to gauge this? Just look at the numbers on the bottom of your bottles: the higher the number, the harder the plastic. "The number one is the softest form of plastic - those should not be reused," Yashon said. By contrast, Nalgene bottles - which are made of harder plastic - are intended for reuse.
Yashon added that being careful when it comes to plastics may have taste as well as health benefits. "An interesting little thing: run water from your sink. Drink some out of plastic, and then drink some out of a glass," she suggested. "There's actually a difference in taste, I think."
