Biochar production increases the polycyclic aromatic hydrocarbon content in surrounding soils and potential cancer risk

Marcin Kuśmierz,Patryk Oleszczuk

doi:10.1007/s11356-013-2334-1

Abstract

The objectives of the study were the identification of the source of contamination of soils and estimation of the potential cancer risk that may be caused by contact with soils situated in the vicinity of biochar production sites. Samples of soils collected in the immediate vicinity of traditional biochar-producing plants, located within the area of the Bieszczady National Park (Poland), were analysed for the content of polycyclic aromatic hydrocarbons (PAHs). The sum of the content of 16 PAHs varied within the range of 1.80–101.3 μg/g, exceeding the norms permitted in many European countries. The calculated coefficients on the basis of which one can determine the origin of PAHs (molecular diagnostic ratios) demonstrated that the potential source of PAHs in the soils may be processes related with the production of biochar. Estimation on the basis of the results of incremental lifetime cancer risks (ILCRs) within the range of 2.33 · 10−4–1.05 · 10−1 indicated that the soils studied may constitute a significant cancer risk for persons who have contact with them. The values of ILCRS should be considered as at least high, which permits the conclusion that sites of that type may create a hazard to human health.Electronic supplementary materialThe online version of this article (doi:10.1007/s11356-013-2334-1) contains supplementary material, which is available to authorized users.

Highlights

The method of sequestration of atmospheric CO2 proposed by Lehmann (2007), consisting in the transformation of biomass into biochar and its deposition in soils, gained notable interest in the world of science
Polycylic aromatic hydrocarbons (PAHs) contained in biochars create a risk to living organisms and to humans when they come in contact with those materials as well as with the soils amended with them (Oleszczuk et al 2013; Sims and Overcash 1983)
The objectives of the study were to determine the level of polycyclic aromatic hydrocarbons in soils in the vicinity of traditional biochar kilns, to identify—by means of the molecular diagnostic ratios (MDRs)—the sources of the PAHs and to assess the risk of cancer related with the presence of those compounds in soils

Summary

Introduction

The method of sequestration (capture and long-term storage) of atmospheric CO2 proposed by Lehmann (2007), consisting in the transformation of biomass into biochar and its deposition in soils, gained notable interest in the world of science. Research in this area is conducted in many places in the world, e.g. in Zambia, Tanzania, Malaysia and Nepal. The unloading of kilns, reloading, transport and dosage of biochars to soils are most frequently done by hand. Due to their properties, biochars may be dangerous to ecosystems and to human health. The area of that risk increases following the growing popularity of biochar use

Objectives

Methods

Results

Conclusion