基于主成分分析的戈壁设施蔬菜栽培基质重金属生态风险评估OA

This study analyzed the distribution characteristics of heavy metals Cr,Cu,Cd,Pb,As,and Hg in vegetable cultivation substrates of typical Gobi facilities in the Hexi Corridor,revealed the effects of substrate cultivation duration on the distribution and accu-mulation of heavy metals in facility vegetable substrates,and provided support for ensuring the safety of local facility vegetables.Heavy metals were determined using high-performance liquid chromatography-inductively coupled plasma mass spectrometry(HPLC-ICP-MS),atomic fluorescence spectrometry,and other methods.The Nemerow comprehensive pollution index method and the potential ecolog-ical risk index method were used to evaluate the current pollution status and potential ecological risk,while correlation analysis and prin-cipal component analysis were applied to explore the possible sources of heavy metals in the substrates.Results showed that Cr,Cu,Cd,and Hg exhibited obvious accumulation,with relatively large increases,especially Cd and Hg,whose maximum increases reached 371.26%and 458.82%,respectively.Cd accumulation generally showed a continuous increasing trend with prolonged substrate cultiva-tion duration,whereas Hg accumulation showed no clear pattern with increasing cultivation duration.In the study area,the potential eco-logical risk index of Cd in substrates with long cultivation duration was 142.55,indicating a high potential ecological risk,while that of Hg was 223.70,indicating a very high potential ecological risk.However,the comprehensive potential ecological risk of the 6 heavy metals was low,indicating that the substrates were safe and clean overall.Extremely significant positive correlations were observed between Cd-Cu,Cd-Hg,Pb-As,and Cu-Hg,suggesting that Cd,Cu,Hg,Pb,and As may have common sources.Principal component analysis further indicated that the main pollution sources of Cu and As in the substrates were agricultural inputs,effects of the cultivation process,and nat-ural sources,whereas the main pollution sources of Cd were agricultural inputs and effects of the cultivation process.