Are Concrete Blocks Toxic?

I can't find information on this that has any 'authority'. Anybody know for sure? I have them lining a hay bale garden right now but am wondering if I should remove them. Thanks for any input.

i wouldn't think so, however, you would not want to use them by any acid loving plants as they may leach out enough product to make the soil more alkaline.

Have a look at this thread: https://permies.com/t/13174/organic-sustainable-practices/Toxicity-Concrete

We discussed all sorts of issues related to concrete and it'll probably help.

I know a number of concrete producers are allowed to burn very toxic materials in the process of making concrete, so while it may not have a direct effect on you, concrete seems to be a bad industry

The blocks I have are second hand, from a nearby basement renovation so the pollution produced by block production isn't an issue here as I see it but that is good to know.

these might be of interest regarding concrete -- I just remembered where I had this info stored.

http://www.slate.com/articles/health_and_science/green_room/2011/11/cement_plant_pollution_leads_to_a_fight_in_chanute_kansas.single.html

http://earthjustice.org/news/press/2010/air-pollution-deal-reached-between-feds-13-states-and-leading-cement-manufacturer

http://www.rachel.org/files/rachel/Rachels_Environment_Health_News_1147.pdf