Thirdhand smoke (THS) persists in locations where smoking previously occurred and can be transported into non-smoking environments, leading to non-smoker exposure. Laboratory experiments using high-resolution mass spectrometry demonstrate that deposited particulate matter (PM) and smoke-exposed surrogate lung lining fluid (LLF) are substantial, chemically-complex reservoirs of gas-phase THS emissions, including hazardous air pollutants, polycyclic aromatic compounds, and nitrogen/oxygen-containing species. Both PM and LLF are persistent real-world THS reservoirs that chemically evolve over time, and can act as vehicles for the transport and emission of reactive pollutants and their reaction byproducts (e.g., acrolein). Deposited PM on clothes, furnishings, bodies, and/or airways will emit volatile to semi-volatile gases over long lifetimes, which can re-partition to other indoor materials and increase their overall persistence. On the other hand, LLF off-gassing consists predominantly of volatile organic compounds in amounts influenced by their aqueous solubilities, and their persistence in breath will be prolonged by re-distribution across internal aqueous reservoirs, as corroborated by multicompartment modeling in this study.
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This content will become publicly available on May 22, 2025
Unrecognized volatile and semi-volatile organic compounds from brake wear
Motor vehicles are among the major sources of pollutants and greenhouse gases in urban areas and
a transition to “zero emission vehicles” is underway worldwide. However, emissions associated with
brake and tire wear will remain. We show here that previously unrecognized volatile and semi-volatile
organic compounds, which have a similarity to biomass burning emissions are emitted during braking.
These include greenhouse gases or, these classified as Hazardous Air Pollutants, as well as nitrogencontaining
organics, nitrogen oxides and ammonia. The distribution and reactivity of these gaseous
emissions are such that they can react in air to form ozone and other secondary pollutants with adverse
health and climate consequences. Some of the compounds may prove to be unique markers of brake
emissions. At higher temperatures, nucleation and growth of nanoparticles is also observed. Regions
with high traffic, which are often disadvantaged communities, as well as commuters can be impacted by
these emissions even after combustion-powered vehicles are phased out.
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- Award ID(s):
- 2327825
- PAR ID:
- 10547077
- Publisher / Repository:
- Royal Society of Chemistry
- Date Published:
- Journal Name:
- Environmental Science: Processes & Impacts
- Volume:
- 26
- Issue:
- 5
- ISSN:
- 2050-7887
- Page Range / eLocation ID:
- 928 to 941
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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