Atmospheric PCDD/F Concentrations in 38 Cities of China Monitored with Pine Needles, a Passive Biosampler

Abstract

Many studies have shown that pine needles are a good biomonitor for atmospheric concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). However, this biomonitor has not been tested in large areas, and the quantitative relationship between concentrations in pine needles and air has not been established. In the present study, we collected pine needles from 38 cities in China. The concentrations of 2,3,7,8-PCDD/ Fs were measured by gas chromatography combined with high-resolution mass spectrometry. The total PCDD/F concentrations ranged from 5.4 to 330 pg/g dry weight of pine needles. The pine needles from cities located in central China and three major city agglomerations contained high concentrations of PCDD/Fs, while those from cities in the west and on the coast contained relatively low concentrations. Primary emission and diffusion processes were the main controls of the PCDD/F concentrations in pine needles. Homologue profiles of PCDD/Fs in pine needles were characterized by PCDFs/ PCDDs >1 in the industrialized cities and <1 in unindustrialized cities. The congener patterns were dominated by 1,2,3,4,6,7,8-HpCDF and OCDD, indicating that combustion was the major source of the PCDD/Fs. By comparing the PCDD/F concentrations in the pine needles and those in air, we established a preliminary linear relationship between them. Finally, the concentrations in air of PCDD/Fs in the 38 cities of China could be predicted from this relationship.

PCDD/Fs accumulation in pine needles: variation with species and pine needle age

“…The PCDD/Fs concentrations increased in the order Hangzhou Botanical Garden < Yuquan Campus of Zhejiang University < MWIP, which is reasonable because the anthropogenic activities and PCDD/Fs emissions also decreased in this order. This result supports the conclusion made by Chen et al (2012) that pine needles are good biosamplers. They studied the PCDD/Fs concentrations in the pine needles from 38 cities in China and found that the PCDD/Fs varied over three orders of magnitude and related well to the air pollution in the cities (Chen et al 2012).…”

“…This result supports the conclusion made by Chen et al (2012) that pine needles are good biosamplers. They studied the PCDD/Fs concentrations in the pine needles from 38 cities in China and found that the PCDD/Fs varied over three orders of magnitude and related well to the air pollution in the cities (Chen et al 2012).…”

“…To monitor PCDD/Fs in the atmosphere, Ok et al (2002) studied pine needle samples collected from 30 points in five cities in South Korea between 1998and 1999, and Bochentin et al (2007 studied 25 Scotch pine needle samples collected at various sites across Poland between October 21 and 27, 2002. Chen et al (2012) reported PCDD/Fs concentrations in pine needles in 38 cities in China. The results showed that the concentrations related to industrialization and meteorology of the cities.…”

“…S1). The age of the pine needles defined by using the method described in our previous work (Chen et al 2012). Generally, pine bud shoots appear in March and April in these areas; therefore, they are a quarter of 1-year-old when they are collected in July.…”

“…Pine needle samples were washed, freeze-dried, and pulverized using the procedure described in our previous work (Chen et al 2012). We performed the cleanup procedure for PCDD/Fs analysis in accordance with the US Environmental Protection Agency (EPA) Method 1613.…”