In reading the FAQs on Sigg aluminum water bottles, I ran across this:
10) Are unlined Stainless Steel bottles safer? Not necessarily, in our opinion. Independent testing has shown that some stainless steel bottles, since they have no protective liner, can impart a metallic taste because they leach heavy metals such as Chromium, Iron, Nickel and Manganese. These bottles also can be more prone to corrosion. Click here to see test results.
Every day, I fill my two Sigg brand stainless steel water bottles with filtered water and take them to work. Obviously, the above answer led my research in a whole other direction. What is the health significance of these additional heavy metals in the water? (Iron I could use more of, but what in the world does Manganese do to a person?) In what concentrations were these elements leached into the water? How did aluminum bottles compare in leaching these metals and aluminum? I looked at the test results mentioned, and found that unlined stainless steel bottles definitely leach higher concentrations of several metals than lined aluminum bottles, but the numbers presented were meaningless without knowing how much is acceptable in the human body. I kept reading and found this:
It is important to note, however, that all trace metal concentrations determined in both the aluminum and stainless steel bottles are far below any threshold levels and therefore are of no health concerns with respect to trace metals leaching into drinking water.... Although there is clearly some leaching of potentially toxic trace elements from each brand of stainless steel bottle, the data should be put into perspective. First, it is important to emphasize that the concentrations of the most toxic of these elements (e.g. Cd, Pb, Tl), even after 13 days of leaching deionized water, are then still comparable to the median concentrations found in the bottled waters. Second, most users of these bottles will probably rinse the bottle and change the water daily, thus the leaching time during normal use will be considerably less. Third, users of these bottles will generally be filling them with tap water which... is less corrosive than deionized water.
This made me feel better- even if I filled my stainless steel bottles with water for 13 days (mine are never full for longer than 8 hours), the levels are still comparable to bottled water from the store. I'll be sure never to leave my water in the bottle for extended periods of time- but that's something that is gross no matter what bottle is being used. I'm still less thrilled with my stainless steel water bottles, but I'm also not ready to put 100% trust in the brand-new Eco-Liner that Sigg is now using. Other than start carrying glass water bottles, I'm not sure what I can do better (and judging by how dented my stainless steel bottles are already, glass is NOT the way to go for me!). I keep telling myself that all I can do is my best, and I've definitely done everything I can to provide Baby Girl with the best water I can find.
Speaking of Baby Girl, I can feel that she has the hiccups right now! Should I get her a glass of filtered water?