ag pool deck

I think they eliminated arsenic in PT now, I heard that on the news within the last couple of years. How about Trex?

Trex is a great alternative, stick with the lighter colors though (heat).
Wolmanized no longer has the arsenic and other poisons in it, but it's a maintenance nightmare, especially with chlorine nearby - matter of fact, anything wood will be a nightmare, cedar will give you nice fine splinters in your feet with time, don't ever pressure wash it since you will actually ruin it's resistance to the elements.
Another problem with cedar is that 90% of it no longer contains the resins that used to let it last so long, the problem there is that cedar does not develop the resin until the tree is approximately 50 years old, logging companies don't wait for trees to get 50 years old anymore and thus most cedar available today is worse than wolmanized when it comes to standing up to the elements.
In my opinion, wolmanized substructure with Trex decking and trim is the way to go, for railings, there are many nice aluminum systems readily available that are not nearly as bulky as your typical wood railing.

Wood is longer treated with chromated copper chromium arsenate. It's now treated with a copper based preservative without the arsenic (some of the new preservatives actually contain polyquat or something very like it). If it's pitched away from the pool as it should be, I would think a minimal amount of the preservative could be leached into the pool water.

If you regularly treated it with a water repellent sealer that would probably further minimize the leaching.

Plastic wood is very slippery when wet.

My cedar railing and gate is into it's fourth season with no signs of deterioration. I do have it re-stained regularly though. Our deck is cedar and is 20 years old. Boards do have to be replaced from time to time, but it otherwise does well-and it's 20 years old. Power washing is NOT a good thing on cedar.

I like the idea of P/T for the substructure (I have no problem with that) and plastic or cedar for the deck. If you use P/T, I still say the deck should be below the pool or pitched away. Copper is better than arsenic, but do you really want copper leaching into your pool??????

My immediate pool deck (for 2') is plastic--hollow poly-vinyl that doubles as solar panels. It's not at all slippery.

If you don't like the plastic wood look, you might consider ipe. It's an extremely dense tropical hardwood.