Biochars (BCs) are currently widely used, yet their impact on human health is mostly unknown. We generated micro-tobacco stem-pyrolysed BCs (mTBCs) at different pyrolysis temperatures and assessed pulmonary toxicity in normal human lung epithelial BEAS-2B cells. mTBCs generated at 350 °C (mTBC350) and 650 °C (mTBC650) were analysed and compared for physicochemical properties and adverse effects. Pyrolysis temperature had a significant influence on chemical composition, particle size, specific surface area and aromatic carbon structure. mTBC650 displayed a highly ordered aromatic carbon structure with smaller particle size, high surface area (20.09 m2/g) and high polycyclic aromatic hydrocarbon and metal content. This composition could promote reactive oxygen species accumulation accompanied by greater cytotoxicity, genotoxicity and epithelial barrier malfunction in cultured cells. Thus, the risk of pulmonary toxicity owing to micro-BCs (mBCs) is affected by pyrolysis temperature. Long-term exposure to mBCs produced at high temperatures may lead to or exacerbate pulmonary disease.

生物炭（BC）目前被广泛使用，但其对人类健康的影响大多未知。我们在不同的热解温度下生成了微型烟草茎热解BC（mTBC），并评估了正常人肺上皮BEAS-2B细胞的肺毒性。对 350 °C (mTBC350) 和 650 °C (mTBC650) 生成的 mTBC 进行了分析和比较，以了解理化性质和不良反应。热解温度对化学成分、粒径、比表面积和芳香碳结构有显着影响。 mTBC650表现出高度有序的芳香碳结构，具有较小的粒径、较高的表面积（20.09 m2/g）以及较高的多环芳烃和金属含量。该组合物可以促进活性氧的积累，并伴随培养细胞中更大的细胞毒性、遗传毒性和上皮屏障功能障碍。因此，微BC（mBC）引起的肺毒性风险受到热解温度的影响。长期接触高温产生的 mBC 可能导致或加剧肺部疾病。