Bioaccessibility and bioavailability in risk assessment

Cs Hajdu, K. Gruiz

Research output: Chapter in Book/Report/Conference proceedingChapter

1 Citation (Scopus)


Contaminants in the environment occur in various physical and chemical forms and in close interaction with the environmental phases. The combination of environmental and contaminant characteristics is responsible for this interaction, which determines the contaminant’s accessibility. This interaction may be extremely strong in soil, sediment and other solid phase compartments. Mobility, i.e. volatility, water solubility and sorbability of a contaminant molecule and the bonding/sorption capacity of solid matrices together determine bioaccessibility, i.e. the probability of encountering and interacting with living organisms. Potential adverse effects on an ecosystem member are determined by another interaction between the environmental contaminant and the organism. A contaminant that can be taken up by an organism is called ‘bioavailable’. Bioavailability or biological availability determines the potential of a chemical substance to be absorbed by an organism. The potential of the organism to absorb, distribute and metabolize the chemical substance plays an important role in environmental risk. As far as humans are concerned, the gastrointestinal tract belongs to the ‘environment’, and digestion modifies the contaminant’s bioaccessibility by liberating the bond contaminant from the matrix. Low bioavailability results in low probability of being absorbed by living organisms and lower risk compared to a bioavailable substance with the same rate of toxicity. Bioavailability is limited by bioaccessibility: an organism which has no access to a substance neither encounters nor interacts with it. Environmental risk management of chemicals should place great emphasis on the chemicals’ mobility and bioavailability in the environment because they can overwrite the risk determined by known adverse effects. This chapter aims to summarize the importance of mobility and bioavailability of chemicals in risk management and introduces some studies and methods to use bioavailability as a dynamic tool for obtaining experimental results. These results directly relate to the environmental risk posed by chemicals simulating worst-case situations and mimicking interactions between contaminants, environmental matrices and living organisms.

Original languageEnglish
Title of host publicationEngineering Tools for Environmental Risk Management
Subtitle of host publication2. Environmental Toxicology
PublisherCRC Press
Number of pages64
ISBN (Electronic)9781315778778
ISBN (Print)9781138001558
Publication statusPublished - Jan 1 2015

ASJC Scopus subject areas

  • Environmental Science(all)
  • Engineering(all)
  • Chemical Engineering(all)

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  • Cite this

    Hajdu, C., & Gruiz, K. (2015). Bioaccessibility and bioavailability in risk assessment. In Engineering Tools for Environmental Risk Management: 2. Environmental Toxicology (pp. 337-400). CRC Press.