Research On The Occurrence Characteristics And Environmental Criteria Of Beryllium,Cobalt,Antimony And Vanadium In Beijing Urban Park Soil

Urban parks are an important place for urban residents to get in touch with nature.In order to meet the needs of urban residents,Beijing is also vigorously developing urban parks.However,due to the shortage of urban land,it is very common for the renovated contaminated sites to be transformed into urban parks,resulting in the possible existence of various pollutants in the soil of urban parks.Beryllium（Be）,cobalt（Co）,antimony（Sb）and vanadium（V）are pollutants listed in GB36600-2018and widely distributed trace elements in urban environment.However,currently the relevant research data is very limited,which is not conducive to scientific and accurate soil pollution prevention and control.Therefore,research on these pollutants is urgently needed.Soil environmental criteria（SEC）are an important tool for managing contaminated soils and the basis for formulating soil environmental standards.However,the basic data on the establishment of SEC is very scarce in China,and the SEC research on urban park land is also limited,which is not conductive to the management of urban park environment and the development of SEC research.In view of the above analysis,this study firstly analyzed the occurrence characteristics and source profiles of Be,Co,Sb and V in order to evaluate the soil quality of urban parks and provide guidance for soil environmental quality management.Secondly,a conceptual model of Beijing’s urban park scenario was established,and some parameters were localized through literature research and mobile phone data analysis.Finally,the SECs of sensitive park and non-sensitive park scenarios were derived through three models of HERA⁺⁺,CLEA and CSOIL,and the influence of different models on the results of SEC is discussed.The main results of this study are as follows:（1）The average concentrations of Be and Sb in the soil of Beijing urban parks were higher than the background values,but the concentrations of all pollutants were lower than the corresponding screening values,and the risk to human health was within an acceptable range.The high-value points of pollutants concentration were mainly distributed in the old urban area or the former old industrial area within the Second Ring Road.Sb in urban park soil mainly comes from anthropogenic sources,mainly fuel combustion and industrial legacy,Be mainly comes from natural and fuel combustion,and Co and V mainly come from natural sources.（2）It was determined that the sensitive receptors of carcinogenic pollutants used in Beijing parks were adults and children,and the sensitive receptors of non-carcinogenic pollutant were children.The exposure of the receptors used in Beijing parks to the pollutants studied in this paper included oral ingestion,dermal contact,and respiratory inhalation.The difference of exposure scenario between sensitive and non-sensitive parks was mainly reflected in the determination of parameters.Parameters such as soil ingestion rate and exposure frequency were determined based on literature research.Residence time,gender and age distribution of park visitors were determined based on mobile phone data,and exposure parameters were determined based on weighted analysis of gender ratio.（3）The SEC of non-sensitive parks is about 3 times that of sensitive parks,which is related to the difference in the choice of exposure frequency between the two scenarios.The SECs derived from different models are quite different.Usually,the results of the HERA⁺⁺model are the lowest,while the results of the CSOIL model are the highest.These differences are mainly related to the differences in the algorithms of the dermal contact and the respiratory inhalation pathway.Compared with the current soil screening values in China,most areas in China lack soil screening values for Be,Co,Sb and V,and the SEC for sensitive parks deduced in this study are generally higher than the soil screening values for Class 1 land,the SECs of non-sensitive parks are generally lower than the soil screening value of the Class 2 land.The comprehensive research results show that the soil quality of Beijing urban parks is generally good,but some key areas such as the old urban area and the old industrial zone of Beijing still need to be paid attention to.It is necessary to further strengthen the research on population behavior patterns to obtain more parameters that can be used for the derivation of SEC.When a risk assessment model is used to derive SEC,a comprehensive assessment of the model is required to determine a more suitable model.This study can provide an important reference for the management of soil environment in urban parks in Beijing.In addition,it also emphasizes the importance of separately formulating SEC applicable to park land.