I have never thought of this, but it's something to ponder about. I don't think you would need to worry too much about it knowing that you have no choice in where it will come from. There is specific stuff to consider.
- First, if you manage to get your hands on dirty bitcoin, it's best if you get rid of it as fast as possible and maybe use mixers to "white-wash" the coins. There are still risks that you can encounter and make sure that in your jurisdiction, mixing is not considered a "money-laundering" thing.
- Buy from reliable resources so you would have a great chance of getting clean BTC.
At this point, you would know that the "anonymity" that we all want from Bitcoin is almost gone now.
Reference:
https://utorg.io/en/blog/analytics/gryaznye-bitkoiny-i-kak-ot-nih-zashchititsya