Table 2

Summary of approaches for measuring environmental markers of secondhand smoke by chemical analyte and sampling method

Chemical analyte references of representative studiesSampling method* Comments
Airborne markers
 Nicotine (vapour phase)5 29–33
  • Active, adsorbent-based; integrated

  • Passive, filter-based; integrated

  • Tobacco specific

  • Majority of nicotine in secondhand smoke (SHS) is vapour phase

  • Widely used tracer for SHS mixture of chemicals

 Respirable particulate matter15 31 32 34–37
  • Direct reading

  • Active, filter based

  • Non-specific, many other indoor and outdoor sources

  • Largest component of SHS

  • Most particles in SHS are <1 micron in diameter

 Carbon monoxide22 29 32 36 38–40 Direct reading
  • Non-specific, many other sources, particularly outdoor air

  • Used in early SHS studies

 3-Ethenlypyridine (3-EP)30 34 41–50
  • Active, adsorbent based

  • Passive, filter based

  • Tobacco specific, pyrolysis product of nicotine

  • Vapour phase

  • Levels are typically lower than nicotine

 Polycyclic aromatic hydrocarbons22 34 51–59
  • Direct reading

  • Active: integrating

  • Passive: integrating

  • Class of hazardous chemicals, some of which are carcinogens

  • Can be measured in particle and/or vapour phase

  • Non-specific

  • Sampling and wet laboratory analysis is expensive

 Tobacco-specific nitrosamines51 60–62 Active: integrating
  • Tobacco specific

  • Potent lung carcinogen

  • Limited data on indoor air in field settings

  •  Other components31 40 43 51 56 59–61 63–66

  • Nitrogen oxides

  • Aldehydes

  • Metals

  • VOCs

Various active and passive methodsNot tobacco specific, many other indoor and outdoor sources
Surface markers
  • Dust vacuum samples

  • Surface wipes

  • Tobacco specific

  • Measure of long-term exposure

  • May be particularly relevant for children's exposure

  • * ‘Direct reading’ refers to the sampling and measurement of an analyte in real time. ‘Integrating’ refers to the collection of a sample over some defined period of time, for which a time-weighted average concentration can be estimated. Active sampling refers to the use of a pump to draw air through a collection device. Passive sampling relies on diffusion.