The bioavailability and contribution of the newly deposited heavy metals (copper and lead) from atmosphere to rice (Oryza sativa L.)

• Published in: Journal of hazardous materials 2020-02, Vol.384, p.121285, Article 121285
• Main Authors: Zhou, Jun, Du, Buyun, Liu, Hailong, Cui, Hongbiao, Zhang, Wantong, Fan, Xingjun, Cui, Jian, Zhou, Jing
• Format: Article
• Language: English
• Subjects: Air Pollutants - analysis; Air Pollutants - chemistry; Air Pollutants - pharmacokinetics; Atmospheric deposition; Biological Availability; Copper - analysis; Copper - chemistry; Copper - pharmacokinetics; Copper and lead fractions; Lead - analysis; Lead - chemistry; Lead - pharmacokinetics; Oryza - metabolism; Rice tissues; Soil - chemistry; Soil Pollutants - analysis; Soil Pollutants - chemistry; Soil Pollutants - pharmacokinetics; Soil transplant experiment
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2019.121285

[Display omitted] •More than half of the atmospheric metal depositions presented as mobile fractions.•The newly deposited metals in soils resulted in higher bioavailable fractions.•The newly deposited metals contributed 30˜84% and 6˜41% in rice tissues.•Atmospheric deposition reactivated the metals and transported to plant tissues. Despite the global importance of atmospheric heavy metal input into agricultural soils, research has primarily focused on the amount of the depositions with limited attention given to the risk of the newly deposited heavy metals. To understand the remobilization of the newly deposited copper (Cu) and lead (Pb) from the atmosphere and explore the metals’ mobility and bioavailability to rice (Oryza sativa L.), a soil transplant experiment was conducted in three areas along a gradient of atmospheric depositions. Approximately 61% of the Cu and 76% of the Pb depositions tended to be present in potentially mobile fractions. The soil retention of newly deposited Cu and Pb presented as higher mobile fractions than these in the original soil. The newly deposited Cu and Pb in soils only accounted for 0.34–8.7% and 0.07-0.29% of the total soil Cu and Pb pools, but they contributed 30–84% and 6–41% in rice tissues, respectively. A major implication of these findings is that once the heavy metal is deposited, it may be reactivated in soils and transported to aerial parts or foliar uptake into plant tissues, emphasizing the important role of the newly deposited Cu and Pb in contributing to the edible parts of crops.