How Sodis can disinfect water using the sun

Reading one of my favorite blogs (the Eco-Blog, to name it) reminded me that I had never talked about this amazing piece of information. Well, they have covered it, so please excuse me in advance for the repetition.

So, if you don't know what Sodis is, I'll explain. I find it a truly extraordinary invention because it offers a water treatment solution to populations who don't have direct access to potable water.
What's that, you're asking yourself? It's very simple: you fill an uncolored plastic bottle (PET type) of 1 to 2 L, without labels, with contaminated water, and you expose it to the sun. A small exercise is required beforehand: fill it ¾ full, shake it vigorously to oxygenate the water, then expose it horizontally for 6 hours on a metal support in direct sunlight (of course). "During sun exposure, UV-A radiation and high temperatures lead to the elimination of 99.99% of disease-causing viruses, bacteria, and parasites present in the bottle."

A small warning, however: it is not suitable for infants and should be consumed by adults within a few days.

And what's great is that NGOs are spreading this wonderful idea to more than 3 million people in over 30 countries worldwide, and that, frankly, as Mia Frye would say, doesn't make for a Happy Face!

However, a question bothers me, I haven't done any scientific studies, so it might be stupid, but these bottles contain BPA, so surely these particles go into the water, or is that question just stupid?

++ Sodis