This is about doing that commercially for a living. If all you do for 40 years of your career is cleaning bird cages, roofs and whatnot from bird droppings, wearing the space suit makes sense because otherwise you're pretty much not going to live to retirement. Lung cancer is a horrible and nasty way to go, and I know on this one what I'm talking about. On top of that come the pathogen infection risks with H1N1 being dangerous enough to send a young man of fine health into critical care [1].

And for what it's worth, of course no one can require you to do so - but you absolutely should be wearing at least an FFP2 mask if dealing with bird droppings or mineral based cat litter of your pets. Try it for once, your lungs will thank you - I certainly noticed the effect.

[1] https://www.cidrap.umn.edu/avian-influenza-bird-flu/canadian...