Polycyclic aromatic hydrocarbons (PAHs) pose a potential risk to ecological safety and human health. They have a range of effects on plant growth and there have been few reports on the health risks associated with ingestion of vegetable crops at different growth stages. In this study, a pot experiment in which Chinese cabbage (Brassica campestris L.) were grown in a greenhouse for 75 days was used to investigate the dose–effect relationship of pyrene with plant growth and also the exposure risk for adults of ingestion of Chinese cabbage at different growth stages. The results showed that low doses of pyrene (5–45 mg kg−1) promoted plant growth (20–220% and 55–97% higher than control treatment for the root biomass and shoot biomass, respectively), but significant inhibition was observed at a high dose (405 mg kg−1) (41–66% and 43–91% lower than control treatment for the root biomass and shoot biomass, respectively). High doses of pyrene reduced soil bacterial abundance and diversity during the growth of Chinese cabbage, and increased malondialdehyde (MDA) levels in the plant. The effects of pyrene on plant biomass were mainly attributed to changes in root activity induced by pyrene, as the relationship between soil pyrene concentration and biomass was similar to that between soil pyrene concentration and root activity. Furthermore, structural equation modeling analysis showed that pyrene altered growth of the vegetable by directly affecting root activity. The incremental lifetime cancer risk for adults is highest for ingestion of Chinese cabbage at the seedling stage, followed in decreasing order by the rosette stages and heading stages. The health risk of consumers who have the possibility to ingest the Chinese cabbage planted in pyrene-contaminated soil would be decreased with the increasing growth periods. However, further studies are required to confirm the dose–effect relationship between pyrene concentration and Chinese cabbage growth on a field scale.

中文翻译：

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芘引起的根系活性变化对大白菜生长的影响及不同生长阶段大白菜芘对健康的危害

多环芳烃（PAHs）对生态安全和人类健康构成潜在风险。它们对植物生长有一系列影响，关于在不同生长阶段摄入蔬菜作物相关的健康风险的报道很少。在这项研究中，通过在温室中种植大白菜（Brassica campestris L.）75 天的盆栽试验来研究芘与植物生长的量效关系以及摄入大白菜对成年人的暴露风险。卷心菜在不同的生长阶段。结果表明，低剂量芘（5-45 mg kg-1）促进植物生长（根生物量和芽生物量分别比对照处理高 20-220% 和 55-97%），但在高剂量（405 mg kg-1）下观察到显着的抑制作用（分别比根生物量和枝条生物量的对照处理低 41-66% 和 43-91%）。高剂量芘降低了大白菜生长过程中土壤细菌的丰度和多样性，并增加了植物中的丙二醛（MDA）水平。芘对植物生物量的影响主要归因于芘引起的根系活性变化，因为土壤芘浓度与生物量之间的关系类似于土壤芘浓度与根系活性之间的关系。此外，结构方程模型分析表明，芘通过直接影响根系活动来改变蔬菜的生长。在苗期摄入大白菜对成年人的终生癌症风险增量最高，紧随其后的是花环阶段和抽穗阶段。有可能食用芘污染土壤中种植的大白菜的消费者的健康风险会随着生长期的增加而降低。然而，需要进一步的研究来证实芘浓度和大白菜生长之间的剂量效应关系。