Abstract
The chemical composition of SS, MS and US (used smoke originating in MS exhaled in the air) are similar. However, significant quantitative differences exist among these sources. Although nicotine is unique to ETS, it cannot trace a change at interval of a minute. We succeeded in monitoring the trends of ETS in the cabin of an aircraft with a combination of nicotine and SPM. Urinary cotinine and/or the self-reported method according to Jarvis's categories are generally used to estimate exposure to ETS. We maintain with examples that the urinary HOP ratio is also useful for this purpose. Epidemiological studies on ETS unavoidably involve various biases in measurement of ETS, such as the epidemiological step. Meta-analysis and so forth. For example, because the relative risk of ETS for lung cancer should be so far than that of smoking, such a bias may lead a final conclusion astray.
