If you want to really get some first hand experience with the effects of pine, try this:
Go find a pine tree, and break off a fresh twig and bite into the end (no you won't die, don't worry, but don't do it too often), and see what it tastes like, it'll taste quite bitter and sort of leaves a wierd feeling in your mouth (don't do this with the pine needles though, those are REAL strong and might poison you). This is from the acids in the wood burning into your mouth, and if they get into your respiratory tract, it'll give you asthma, pneomonia, and a bunch of other nasty respiratory ailments.
Still not convinced? Wanna try drinking Pine-sol? That stuff has the same aromatic phenols and acids as pine does.
The phenols in pine also have effects on your liver (regardless whether you're a human, snake, bird, whatever). You breathe in the phenols, and they go directly to your blood stream. This causes your liver to secrete more detoxification enzymes than normal. If your liver says something is toxic, then it must be toxic.
Reason why pine is #1 sold bedding is that it's cheap, and it gets rid of bad smells and keeps bugs away. The fact that it's toxic is usually well hidden to consumers (mostly lil kids and their parents who keep a hamster or gerbil).
-Lemur 6