State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, People's Republic of China.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, People's Republic of China.
Environ Pollut. 2020 Oct;265(Pt B):114873. doi: 10.1016/j.envpol.2020.114873. Epub 2020 May 27.
Accumulation and oral bioavailability of nickel (Ni) were rarely assessed for staple crops grown in high geogenic Ni soils. To assess exposure risk of geogenic Ni, soil, wheat, and rice samples were collected from a naturally high background Ni area and measured for Ni oral relative bioavailability (RBA, relative to NiSO) using a newly developed mouse urinary Ni excretion bioassay. Results showed that soils were enriched with Ni (80.5 ± 23.0 mg kg, n = 58), while high Ni contents were observed in rice (2.66 ± 1.46 mg kg) and wheat (1.32 ± 0.78 mg kg) grains, with rice containing ∼2-fold higher Ni content than wheat. Ni-RBA was low in soil (14.8 ± 7.79%, n = 18), but high in wheat and rice with rice Ni-RBA (85.9 ± 19.1%, n = 9) being ∼2-fold higher than wheat (46.1 ± 21.2%, n = 16). A negative correlation (r = 0.61) was observed between Ni-RBA and iron content in rice and wheat, suggesting the low iron status of rice drives its high Ni bioavailability. The higher Ni accumulation and bioavailability for rice highlights that rice consumption was a more important contributor to daily Ni intake compared to wheat, while Ni intake from direct soil ingestion was negligible. This study suggests a potential health risk of staple crops especially rice when grown in high geogenic Ni areas.
在高地球成因镍土壤中种植的主要作物中，很少评估镍（Ni）的积累和口服生物利用度。为了评估地球成因镍的暴露风险，从自然高背景镍地区采集了土壤、小麦和水稻样品，并使用新开发的小鼠尿镍排泄生物测定法测量了镍的口服相对生物利用度（RBA，相对于 NiSO）。结果表明，土壤中富含镍（80.5 ± 23.0 mg/kg，n = 58），而水稻（2.66 ± 1.46 mg/kg）和小麦（1.32 ± 0.78 mg/kg）谷物中也含有高镍含量，其中水稻中镍含量约为小麦的两倍。土壤中的 Ni-RBA 较低（14.8 ± 7.79%，n = 18），但在小麦和水稻中较高，其中水稻的 Ni-RBA（85.9 ± 19.1%，n = 9）约为小麦的两倍（46.1 ± 21.2%，n = 16）。在水稻和小麦中，Ni-RBA 与铁含量呈负相关（r = 0.61），表明水稻中铁含量低导致其高镍生物利用度。水稻对镍的积累和生物利用度较高，这突出表明与小麦相比，在高地球成因镍地区种植水稻时，水稻的消费是每日镍摄入量的更重要贡献者，而直接从土壤摄入镍的量可以忽略不计。这项研究表明，在高地球成因镍地区种植的主要作物，特别是水稻，存在潜在的健康风险。
