Bioaccessibility of PAH from Danish soils

Abstract

A test method for the determination of PAH relative bioaccessibility from contaminated soils was implemented and validated for use in risk assessment of soils from contaminated sites meeting performance requirement set for evaluation against regulatory limits. Relative bioaccessibilities of soil benzo(a)pyrene obtained with the test were linearly correlated to relative bioavailability data obtained previously in in vivo investigations with experimental animals, but the relative bioaccessibilities were lower than the relative bioavailabilities. Tests of soil samples from 4 Danish sites contaminated with benzo(a)pyrene and dibenz(a,h)anthracene from different sources and with different ages demonstrated that using the bioaccessible concentrations in risk assessment instead of total concentrations would have produced lower risk classifications of the sites. An urgent requirement is demonstrated for an accepted and valid method for investigating the bioavailability of organic soil contaminants such as PAH and also for soil samples with accepted relative bioavailability data.

Keywords:

• Bioaccessibility
• bioavailability
• soil
• contaminated sites
• risk assessment
• human oral exposure

Acknowledgments

This work was supported by the Danish Environmental Protection Agency and in particular by Irene Edelgaard from the Agency. Nis Hansen at Eurofins A/S conducted the PAH analysis. Furthermore, support for data evaluation and development of the framework for using soil bioaccessibility testing was provided by support from the Swedish Environmental Agency and the United Kingdom Environment Agency.

Notes

¹—: no data.

¹BaP: benzo(a)pyrene.

²DBahA: dibenzo(a,h)anthracene.

¹RSD: relative standard deviation.

²Results below analytical detection limit.

¹%RSD: % relative standard deviation.

²—: does not apply.