DIY no PVC worm tower

I was reading a thread elsewhere about DIY worm towers put into gardens. One concern was lack of surface area, because composting worms only stay within the top 2". The soil they are in/surrounding the structure also should be lighter & not compacted. Third, and I feel this is most important, cut or drilled pvc pipe may leach carcinogens into the soil.

One solution to problem #2 (and depending on the size, because they can be quite wide, problem #1) was to use sonotubes. Someone said they were made of paper & adhesives, but couldn't find our what the adhesives were that were used.

I thought I post this here to see where this idea of using sonotubes will take us.