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Soot comes from the incomplete burning of organic materials, such as wood.

What is soot?

Soot is a byproduct of the incomplete burning of organic (carbon-containing) materials, such as wood, fuel oil, plastics, and household refuse. The fine black or brown powder that makes up soot may contain a number of carcinogens, including arsenic, cadmium, and chromium.

How are people exposed to soot?

People may be exposed to soot by inhalation, ingestion, or absorption through the skin. Chimney sweeps likely have the highest occupational exposure to soot. Heating-unit service personnel, brick masons, building demolition personnel, horticulturists, and anyone who works where organic materials are burned may also be exposed through their work. The general public may be exposed through fireplaces, furnaces, engine exhaust, and particulate emissions from any combustion source.

Which cancers are associated with exposure to soot?

Exposure to soot was first associated with skin cancer of the scrotum among British chimney sweeps in 1775. Since then, many studies have found that chimney sweeps have an increased risk of scrotal and other skin cancers. Studies of chimney sweeps in several European countries have also found associations with other cancers, including lung, esophageal, and bladder cancers.

How can exposures be reduced?

In the United States, professional organizations for chimney sweeps keep members up to date on changing technology and safety issues.

Selected References:

  • International Agency for Research on Cancer. Soot, As Found In Occupational Exposure of Chimney Sweeps, IARC Monographs on the Evaluation of Carcinogenic Risks to Humans, Volume 100F. Lyon, France: World Health Organization, 2012. Also available online. Last accessed June 10, 2024.
  • National Toxicology Program. Soots, Report on Carcinogens, Fifteenth Edition. Triangle Park, NC: National Institute of Environmental Health and Safety, 2021. Also available online. Last accessed December 8, 2022.
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