No glue : water + sugar on the heated-bed. Let water evaporate, then launch the 3DP.
PLA : Organic; degrades in special conditions, but cannot last hundreds of years.
Recycle (symbol) : if you care about the environment add the recycling symbol number 7 to your printed objects.
Avoid 3D-printing bullshit.
Don't loose your 3D-printed objects in the nature, even if it's in PLA : some people might fall on them, find them and do bullshit with them or worst case, because of you some animals or humans could DIE.