Co-Innovation Center for the Sustainable Forestry in Southern China, College of Biology and the Environment, Nanjing Forestry University, Nanjing, 210037, People's Republic of China.
Henan Polytechnic, Zhengzhou, 450046, People's Republic of China.
Environ Geochem Health. 2020 Dec;42(12):4327-4340. doi: 10.1007/s10653-019-00490-5. Epub 2020 Jan 2.
In order to better study the influence of land use on the concentration and distribution of organic contaminants in urban areas, the concentrations of 16 principal polycyclic aromatic hydrocarbons (PAHs) were determined on soil samples collected at three depths (010 cm, 1020 cm and 2030 cm) from urban greenland areas of 6 functional zones: residential zone (RZ), business zone (BZ), industrial zone (IZ), cultural and educational zone (CZ), urban park (UP) and urban rural forest (URF) of Nanjing, China. Results showed that the average concentration of ∑PAHs in the urban greenland of Nanjing (499.47 ng/g) was comparable to the value reported for other cities under similar conditions. Acenaphthene was the dominant compound (46.2% of the ∑PAHs), and low molecular weight PAHs (LPAHs) represented the largest share of ∑PAHs. Concentrations of ∑PAHs in 6 function zones were different, with the highest value in IZ (954.33 ng/g) and lowest value in URF (147.81 ng/g). The soil showed the highest ∑PAHs contamination in the layer 1020 cm in all zones (on average 547.01 ng/g). ∑PAHs of IZ showed the highest values in all soil layers. Isomer ratio and factor analysis were used to determine the source of PAHs in soil. Petroleum combustion (PC), coal and biomass combustion (CBC), mixed (M) and petroleum (P) sources were finally identified as the four main sources of PAHs in Nanjing urban greenland soil, accounting for 50.2%, 14.9%, 8.4% and 6.6%, respectively. Bap toxic equivalent (TEQ) was used to analyze the ecological risk. TEQ was 20.59 ng/g in total zones (TZ), below the threshold for multipurpose soil of Dutch legislation (32.96 ng/g), but 69% of samples exceeded this threshold. TEQ of different functional zones is ordered as: IZ (43.62 ng/g)>RZ (23.89 ng/g) > BZ (20.62 ng/g) > CZ (19. 93 ng/g) > UP (12.97 ng/g) > URF (2.01 ng/g). In the industrial area, more than 97% of TEQ depended on seven carcinogenic PAHs (∑PAH), which indicated that IZ had high ecological risk. Lifetime risk of cancer (ILCR) model was used to assess the health risk of ∑PAHs. ILCRs ranked as following: children > youth > adults, with soil oral intake determining the highest cancer risk, followed by skin contact and breath intake. ILCRs of children were in high cancer risk range, with values of 3.77 × 10 (for boy) and 3.87 × 10 (for girl), while ILCRs of youth and adults were in an acceptable range; ILCRs were highest in IZ, followed by RZ, BZ, CZ, UP and URF. The soil PAHs analysis in different function greenland zones of Nanjing showed that land use influenced the concentration and distribution of PAHs in soils. This difference should be taken into account in the urban greenland planning and management to reduce the risks for the environment and human health.
为了更好地研究土地利用对城市地区有机污染物浓度和分布的影响，在南京的 6 个功能区（居住小区、商业区、工业区、文化教育区、城市公园和城乡森林）的城市绿地中，分别在 0-10cm、10-20cm 和 20-30cm 三个深度采集土壤样本，测定了 16 种主要多环芳烃（PAHs）的浓度。结果表明，南京城市绿地中∑PAHs 的平均浓度（499.47ng/g）与其他类似条件下城市报道的值相当。苊是主要的化合物（∑PAHs 的 46.2%），低分子量 PAHs（LPAHs）占∑PAHs 的最大份额。6 个功能区的∑PAHs 浓度不同，工业区（IZ）最高（954.33ng/g），城乡森林区（URF）最低（147.81ng/g）。所有区域的土壤中 10-20cm 层的∑PAHs 污染最严重（平均 547.01ng/g）。IZ 中的∑PAHs 含量在所有土层中均最高。同系物比值和因子分析用于确定土壤中 PAHs 的来源。最终确定石油燃烧（PC）、煤和生物质燃烧（CBC）、混合（M）和石油（P）是南京城市绿地土壤中 PAHs 的四个主要来源，分别占 50.2%、14.9%、8.4%和 6.6%。危害商值（TEQ）用于分析生态风险。总区域（TZ）的 TEQ 为 20.59ng/g，低于荷兰立法多用途土壤的阈值（32.96ng/g），但 69%的样本超过了这一阈值。不同功能区的 TEQ 排序为：IZ（43.62ng/g）>RZ（23.89ng/g）>BZ（20.62ng/g）>CZ（19.93ng/g）>UP（12.97ng/g）>URF（2.01ng/g）。在工业区，超过 97%的 TEQ 取决于七种致癌 PAHs（∑PAH），这表明 IZ 具有高生态风险。终生致癌风险（ILCR）模型用于评估∑PAHs 的健康风险。ILCR 排名如下：儿童>青年>成人，土壤口服摄入确定了最高的癌症风险，其次是皮肤接触和呼吸摄入。儿童的 ILCR 处于高癌症风险范围内，值为 3.77×10（男孩）和 3.87×10（女孩），而青年和成人的 ILCR 处于可接受范围内；ILCR 在 IZ 最高，其次是 RZ、BZ、CZ、UP 和 URF。南京不同功能绿地区土壤中 PAHs 的分析表明，土地利用影响了土壤中 PAHs 的浓度和分布。在城市绿地规划和管理中应考虑到这种差异，以降低对环境和人类健康的风险。
