Ugh...big news on the radio today: don't eat the white snow. But it does not look like a valid study to me. Canadian researchers apparently collected snow and intentionally exposed it to organic contaminants (representing from a dirty car exhaust apparently - not Prius exhaust I do not expect). They conclude snow can absorb contaminants, therefore should be considered hazardous. Snow Soaks Up Toxic Pollutants In The Air, Study Shows
The Prius will emit less, but still emit some of the contaminates they looked at; various organic compounds like benzene found in gasoline and car exhaust.
From the article, it is quite clear that any toxicity is extracted from dirty urban air. I don't see any indication that the snow is any worse than that air. Thus, move away from that air.
