N-Nitrosomorpholine and other volatile N-nitrosamines in snuff tobacco

Ten popular snuff brands from the USA and Sweden were analyzed for volatile N-nitrosamines (VNA). Seven of these samples contained between 20 and 70 p.p.b. of N-nitrosomorpholine (NMOR), a strong animal carcinogen. Some of the snuff containers which were made of waxed cardboard contained morpholine. This observation and a model study with the container waxes plus [14C]morpholine indicate that NMOR possibly can be formed by way of diffusion of the morpholine into the snuff and subsequent N-nitrosation. The VNA including NMOR (60-1150 p.p.b.) together with N-nitrosodiethanolamine (NDELA; 225-3300 p.p.b.) and the four tobacco-specific N-nitrosamines (TSNA; 1300-80,000 p.p.b.) contribute significantly to the carcinogenic potential of snuff. This tobacco product, although a known human carcinogen, is becoming increasingly popular especially among young people in the USA and Sweden. A recently introduced Swedish brand with individual snuff portions wrapped in aluminum foil was free of VNA (less than 2 p.p.b.) and contained relatively low levels of NDELA (290 p.p.b.) and TSNA (4200 p.p.b.). This indicates that practical approaches towards lowering N-nitrosamine levels in these snuff products are available.