Air pollution & contamination Infographic

Clayson, Alison // Exposure from pollutants in soil


This infographic is designed to give A-level students background about the different factors that can influence a pollutant entering the body from soil. It includes soil properties that affect the pollutant’s release from soil and the different exposure pathways a pollutant can enter the body. Specifically, it focuses on the dermal pathway and understanding that the dermal bioavailable fraction is the amount of pollutant absorbed into the skin which can cause harm to the body.


Pollutants enter the soil from former industrial processes. Pollutants such as petroleum, polycyclic aromaic hydrocarbons
(PAHs), metals, etc…

Benzo[a]pyrene (BaP) is a carcinogenic PAH.

A pollutant’s binding ability will vary for different soil components (minerals & organic matter). Weakly bound pollutants in soil have a higher chance of being released, causing human exposure.

A pollutant can enter the body via 3 pathways; the contribution from each will vary for each pollutant. For example BaP exposure pathways % contributions are:

  • Inhalation pathway ~0.2-0.6 %
  • Ingestion pathway ~82-94 %
  • Dermal pathway ~5-18 %

Dermal Absorption

  • Skin is formed of many layers and acts as a barrier.
  • The amount absorbed through the skin is the bioavailable fraction.
  • The bioavailable fraction can enter the blood and lymphatic systems, and be transported to organs.
  • Measuring a pollutant’s bioavailable fraction indicates the pollutant’s potential harm.

Alison Clayson

Alison Clayson

Alison is a PhD student at the University of Nottingham, hosted with the British Geological Survey. Her PhD project is in researching the influence of soil physiochemical properties on the dermal bioavailability of polycyclic aromatic hydrocarbons, specifically focusing on soils contaminated from former manufactured gas plant soils. Alison previously worked in industry for 3 years after she graduated from the University of Warwick with a Masters in Chemistry.

Alison’s Envision profile


Organisation: British Geological Survey and University of Nottingham