Cytotoxicity of Biochar: A Workplace Safety Concern?

Abstract

Biochar has a number of environmental applications, including soil amendment for agriculture, remediation of contaminated soils and sediments, and climate change mitigation. Dust formed during its production and field application may pose a health risk, but the cytotoxicity of biochar has, to the best of our knowledge, not previously been investigated. Therefore, we measured the concentration-dependent cytotoxicity of biochar on an NIH 3T3 mouse fibroblast cell line. We used a contaminant trap experiment to measure the total and nondesorbable polycyclic aromatic hydrocarbon (PAH) fractions of the biochar. PAH release was found to be negligible because of the biochar’s strong PAH sorption potential. The biochar was nevertheless observed to have a cytotoxic effect on the fibroblast cells; the EC10 values were 49.6 and 18.8 μg/mL after incubation for 24 and 48 h, respectively. This cytotoxic effect is likely to relate to the particulate nature and size distribution of the biochar; the biochar had particles s...