smoking out of ANYTHING besides glass...is a risk
any metals when heated with direct flame..can release free radicals into the air stream, and ultimately into your lungs. Club papres are probably the cleanest burning papers I have found(yes even over hemp papers), and provide a mobile convenience..but in all the years and research I have done, and/or used... glass is by far the safest. That is not to say that this avoids the risk of lung disease, or cancer...as your are still inhaling smoke, wich is primarily burned organic product not much different from tobacco...to use cannabis in the safest form..either vapoize..or ingest with food i.e cookies, butter, tea...
good luck