HELP ! Concrete Raised beds in Desert !

I teach Permaculture in Las Vegas school system .. cool ... but one of the non-profits we are working with is using Concrete to build their garden beds ... which they say is safe but from what I understand .. concrete gets hot in summer & cold in winter .. concrete isn't even a good building material ... it's just cheap .. economics profit mentality wins again ... are there any resources I can send to them to get them to see this ? They say they looked into it ... 95% of our gardens are made with wood .. I even got one school to build a flat bed which uses 30% less water (Sunken hugelkultur beds are on their way !!) .. but this school has gardens which could be leaching into the soil etc ... any help is greatly appreciated !!

Personally I don't feel afraid that concrete is toxic most of the time (though I wouldn't try to convince someone of that and I have no proof), but raised beds are definitely going to be colder and hotter, and in the desert, they also dry out much faster. Raised beds don't really sound very suitable for Nevada.

From my experience in the desert I found that concrete is porous and would led to rapid evaporation of soil moisture, especially on the west facing sun side. The leaching from concrete is typically basic, and would essentially be liming the garden to raise pH.

When I lived in NM I never got raised beds to work, they would loose too much water.

Most deserts have plenty of rock.

Although I don't see the need for raised beds, stone will work. Most stone does not wick water as fast as concrete does. Stone mulch is appropriate in many dry places.