World-Building and Ecology

So, I reviewed Sherwood Smith's Inda a while ago, but there's one thing in the book that I didn't really talk about in my review and it's still bugging me.

I mentioned that the magic system was being revealed very slowly and so in the book it's still very vague and just hinted at. What we do know about their magic is that it's used for random everyday things. For example, their buckets have spells on them so that the water purifies itself/whatever is placed in it. At least, that's what it seems to do. And there's always this little zap of magic that characters feel when they come into contact with this magical water or use it. Very handy spell.

However, the second example of spells we're given is the one that gets on my nerves. It's called "The Waste Spell" because by using it people get rid of their waste without needing to go to the bathroom. I know. They have magic and this is what they use it for... Not only do these people vanish their bodily wastes, they also Disappear their dead while singing to them in some type of ceremony.

My question is this: where does this stuff they're vanishing go and why isn't their environment falling apart? I mean, yes, bodily wastes and dead bodies aren't exactly pleasant for human beings, but they are eventually taken up into the environment, merged into the soil where they are broken up and reused by plants, animals and so on. Things go in cycles. Not just water, but Oxygen, Nitrogen, Carbon and so on. Doing this waste spell and just completely vanishing all this material into thin air might sound convenient, but it just does not make any sense ecologically.

I know that with a few humans doing this it might not seem like it would have a huge effect, but really, you're disappearing matter from the universe. No matter how small the amount is, it will eventually add up and become an issue. Also, from the hints I got through the boys' time at the Academy it seemed like they also used the waste spell to get rid of the waste produced by their horses, and presumably other animals, so the effect is much wider... This is not complicated science either, it goes back to the food chain stuff they teach kids in elementary school. This waste spell would completely undermine the food chains and destroy their environment.

My point is that this doesn't make any sense. Law of conservation of matter and all that. So if you're building a world for your fantasy story do me and your other readers a favor and spend some time thinking about the ecological effects of the things you're making up. I wouldn't have had any problem with it if she had explained that the disappeared matter goes to some landfill or something away from the cities/towns or something, but the way it was described in the story is just literally disappears.

*shrugs*

/rant