Biochar dust emission: Is it a health concern? Preliminary results for toxicity assessment

Biochar is currently garnering interest as an alternative to commercial fertilizer and as a tool to counteract global warming. However, its use is increasingly drawing attention, particularly concerning the fine dust that can be developed during its manufacture, transport, and use. This work aimed to assess the toxicity of fine particulate Biochar (<PM₁₀) via in-vitro and in-vivo experiments as a first step for the evaluation of toxicity values. As in-vitro experiments, cell lines showed inhibition of proliferation following the reduction of expression genes involved in cell cycle control, increase in the production of ROS and IL-8, and decrease in intracellular ATP. In-vivo rat exposure induced hyperemia, edema, and inflammatory phenomena with infiltrations of neutrophil granulocytes and macrophages at the alveolar and bronchiolar levels. Both in-vitro and in-vivo studies highlighted how exposure to Biochar particulates leads to an inflammatory condition and oxidative stress.