Where It Comes From
Diesel engine exhaust; formed during combustion and by nitration of pyrene in air; smaller amounts from other high‑temperature burning [1][3][4].
How You Are Exposed
Breathing air near traffic, idling trucks/buses, ports/railyards; indoor air infiltrating from nearby roads or attached garages; jobs using diesel equipment [3][4][5].
Why It Matters
Sticks to PM2.5 that reaches deep lungs; mutagenic with DNA adducts; causes tumors in animals; human evidence limited but concerning [1][2][3].
Who Is at Risk
Drivers, mechanics, dock/rail/mining workers; people living near busy roads or truck routes; children, pregnant people, and those with heart/lung disease [3][4][5].
How to Lower Your Exposure
Avoid diesel exhaust and idling; pick routes/times with less traffic; use HEPA air cleaners and close windows during peaks; ventilate garages; workplaces should use exhaust controls and follow NIOSH guidance [3][4][6].
References
- [1]IARC Monographs, Vol. 46: Diesel and Gasoline Engine Exhausts and Some Nitroarenes (incl. 1‑Nitropyrene). IARC, 1989.
- [2]NTP. Toxicology and Carcinogenesis Studies of 1‑Nitropyrene (TR‑416). U.S. DHHS, 1993.
- [3]U.S. EPA. Health Assessment Document for Diesel Engine Exhaust. EPA/600/8‑90/057F, 2002.
- [4]WHO. WHO Guidelines for Indoor Air Quality: Selected Pollutants (PAHs/nitro‑PAHs). 2010.
- [5]ATSDR. ToxFAQs: Polycyclic Aromatic Hydrocarbons (PAHs). 2020.
- [6]CDC/NIOSH. Diesel Exhaust in the Workplace: Exposure Evaluation and Control. 2013.