This started as a reply to Bryan's comment on the Freaky Frogs post, but it quickly turned into its own blog entry...
Here's Bryan's comment:
I thought the whole BPA freakout was an interesting look at how we think about environmental and personal contaminants like this. People seemed to get all up in arms about BPA in water bottles and bought tons of new plastic or aluminium vessels to replace them. But that switch over raised some questions for me.
Where did all those old bottles go? In the trash?
How much energy does it take to make those aluminium bottles? Is it lots more than the plastic ones?
How many bottles can you own before it'd just be better to use disposable paper?
Courtesy US Government
And my response...
It took some searching, but I did find one article discussing a life cycle analysis from Australia which showed that, in a comparison between aluminum, stainless steel, and plastic, plastic has the smallest carbon emissions footprint, uses the least water, and produces the least manufacturing waste. However, it was unclear whether this comparison included recycled metals in its evaluation. Steel and aluminum are 100% recyclable (vs. plastic, which loses quality every time it's recycled), so over time and on a large scale, their use would lead to less material waste.
Courtesy Matthew Baugh
It's also interesting to note that recycling metals uses significantly less energy vs. what it would take to smelt "new" metal. To paraphrase this reference, recycling steel and aluminum saves 74% and 95%, respectively, of the energy used to make these metals from scratch. As it turns out, we recycle about half the steel we use in a year in the US, and so almost all the steel we use contains recycled content. In contrast, we recycle just 7 percent of the plastic we use.
And then there's glass--we have lots of options, really.
Courtesy Ivy Main
I can't speak to how much material was wasted when people discarded all those bottles (I think I recycled mine?). Personally, I do think that making reusable bottles in general uses less energy than is needed to make all those disposable plastics and recycle them--at least in terms of lifetime footprints. Of course, when it comes to a strict comparison between reusable bottles, switching to a new bottle will always consume more energy than just sticking with your old one.
Unfortunately, it turns out that most plastics, even the ones labeled BPA-free, leach estrogen-mimicking chemicals. So if you're looking for a long term solution, it may be best to just avoid plastics altogether. This does seem to be one of those cases where we have to consider our own health vs. the environment and pick our battles wisely. If people want to switch once to avoid health problems, at least they're still sticking with reusable bottles. Readers, do you agree?
Of course, it would be great if choosing a water bottle were the only drinking water issue we faced. The other day I read about a study by Environmental Working Group, which found that the carcinogen chromium-6 contaminates tap water throughout the US. Are we exposing ourselves to this toxic metal by drinking tap water instead of pre-bottled water? Or is chromium in the bottled water, too? What about other unregulated pollutants in our water?
I guess my point of going into all this is that it's complicated to make these decisions, and we'll probably never be able to avoid every single toxic substance. But does that mean we shouldn't try to make drinking water safer?
For now, I'm gonna stick with the steel and aluminum bottles that I already have and try to get the most out of them. Luckily, I live in the Twin Cities, which don't rate high on EWG's chromium map. Every day, I learn more about my health and the health of our environment, and hopefully by searching, I'll find a direction that hits on a fair compromise.