Table 1

Levels of NNK per cigarette, mainstream smoke, as determined by ISO testing and the intense testing system devised by Health Canada.

OriginLow ngHigh ngYearSample
ND, not done.
ISO testing
FischerND4701990Global, multiple
Gray543261996Marlbro, 30 countries
AustraliaND41200115 brands
Canada2186200227 brands
Intense testing system
Australia38942001Same 15 brands
Canada581382002Same 27 brands