white particles on my furniture/desk/laptop

Hello:

I had a question about how I can get white dust particles tested for their origin/radioactivity. I first noticed white very small particles on 3/20/11 that covered my bathroom vanity. It was interesting because for days/weeks, the soap that I was using was leaving a brownish residue on that surface. On 3/20/11 I noticed that this brownish soap residue was sprinkled with tiny white particles, almost like powder, but a lot of them.
I was kind of shocked, wondering whether this could be radioactive fallout because it literally happened overnight.
I cleaned it and forgot about it. Until today when I packed out my laptop and I see this white tiny particles again on my keypad. The unique thing with my laptop is that I never removed the protective transparent sheet from the factory and now these white particles stand out. It does not look like dust, because they are so white.
It would be of course, very scary to think that this white particle dust I have been noticing in my bathroom and now on the laptop could be radioactive fallout, cesium or who knows what?
Anyway, I would like to get this tested. Does anyone know how to get this tested/ which lab?

Anybody noticed a simliar white dust?

thanks.