Characteristic analysis and evaluation of heavy metal pollution in atmospheric PM2.5 in main urban area of Jinan City
结果 该城区2016-2017年PM2.5日均浓度范围为10.1~331.6 μg/m3。共采集PM2.5样品354份，其中采暖期134份，非采暖期220份。经检测分析，除Be、Ni和Cr外，其他重金属浓度均为采暖期高于非采暖期。富集因子法的分析结果显示，除Be、Ni和Cr外，其他研究元素均存在人为源污染。采暖期，Sb、Cd、Pb、Se、Tl、As元素的富集因子M(范围)分别为98.6(72.6~121.0)、261.8(193.8~367.1)、55.5(41.9~69.5)、587.7(441.6~756.9)、28.6(22.1~37.0)、14.6(9.6~22.4)；非采暖期，以上元素的富集因子分别为87.8(61.5~111.6)、228.5(140.0~350.9)、45.0(32.5~57.6)、659.6(495.6~853.5)、29.3(20.0~41.0)、16.0(10.6~22.9)。Cd、Sb、Pb、Mn均存在一定程度的污染，其在采暖期污染程度均大于非采暖期。Cd的潜在生态危害程度为强，As、Cr、Pb、Ni的潜在生态风险程度属于轻微，PM2.5中重金属的综合潜在风险危害为强。
Background PM2.5 as an important part of haze has attracted extensive attention from the whole society. Analyzing the sources, pollution characteristics, and pollution degrees of heavy metal components in PM2.5 in northern cities during heating and non-heating periods can help relevant government departments take intervention measures to improve air quality and protect people's health.
Objective This study analyzes the characteristics of heavy metal pollution in atmospheric PM2.5 during heating and non-heating periods in main urban area of Jinan, and evaluates the pollution degrees and potential ecological risks in different periods.
Methods The data of atmospheric PM2.5 level in main urban area in Jinan were collected from 2016 to 2017. Two air monitoring sites were set to collect the samples of PM2.5 every month. Ten metal elements were detected by inductively coupled plasma-mass spectrometry, including Sb, Pb, As, Mn, Hg, Cd, Ni, Cr, Se, and Tl. The sources, pollution degrees, and ecological risks of heavy metals in ambient PM2.5 during heating period and non-heating period were evaluated using enrichment factor (EF), index of geo-accumulation (I-geo), and potential ecological risk index (RI).
Results The daily PM2.5 concentrations ranged from 10.1 to 331.6 μg/m3 in the main urban area during 2016-2017. A total of 354 PM2.5 samples were collected, including 134 samples in heating period and 220 samples in non-heating period. Except Be, Ni, and Cr, the concentrations of the other heavy metals in heating period were higher than the concentrations in non-heating period. By enrichment factor method, except Be, Ni, and Cr, the other heavy metal pollution was from anthropogenic sources. The EFM (range) of Sb, Cd, Pb, Se, Tl, and As were 98.6 (72.6-121.0), 261.8 (193.8-367.1), 55.5 (41.9-69.5), 587.7 (441.6-756.9), 28.6 (22.1-37.0), and 14.6 (9.6-22.4) in heating period, and 87.8 (61.5-111.6), 228.5 (140.0-350.9), 45.0 (32.5-57.6), 659.6 (495.6-853.5), 29.3 (20.0-41.0), and 16.0 (10.6-22.9) in non-heating period, respectively. The ambient air in the target area was generally polluted by Cd, Sb, Pb, and Mn, and the pollution degrees were higher in heating period than in non-heating period. The potential ecological risk of Cd was high, and the risks of As, Cr, Pb, and Ni were low. The integrated ecological risk of all heavy metals in PM2.5 was graded as severe.
Conclusion PM2.5 pollution and heavy metal pollution are serious in the main urban area of Jinan. The enrichment, pollution, and ecological risk levels of some heavy metals in PM2.5 are higher in heating period than in non-heating period, which would have adverse health impacts.