Passive Air Sampling of Organochlorine Pesticides, Polychlorinated Biphenyls, and Polybrominated Diphenyl Ethers Across the Tibetan Plateau

Abstract

So far there are limited data on persistent organic pollutants (POPs) in the atmosphere of the Tibetan Plateau. XAD 2-resin based passive air samplers were therefore deployed for 1 year (between July 2007-June 2008) at 16 locations across the Tibetan Plateau. Based on previously reported sampling rates (R) derived in the north and south America, and their correlations with atmospheric temperature and pressure, R values in the present study were in the range of 2.2-3.3 m(3) d(-1) (average = 2.7 +/- 0.3). Derived air concentrations (pg/m(3)) ranged as follows: DDTs, 5-75; HCHs, 0.1-36; alpha-endosulfan, 0.1-10; HCB, 2.8-80; sum of 15 PCBs, 1.8-8.2; and sum of 9 PBDEs, 0.1-8.3. The highest DDTs occurred at Qamdo, where the sampling site is near to farm land, indicating the spatial distribution of DDTs across the plateau may be influenced by scattered local usage of DDT. Higher levels of HCHs were observed at sites with high elevation (>4000 m) and close to the China-India border, indicating possible long-range atmospheric transport. The highest levels of HCB, PCBs, and PBDEs were found at a site impacted by forest fire during the sampling campaign.

Summer atmospheric polybrominated diphenyl ethers in urban and rural areas of northern China

“…Another reason for the higher PBDE concentrations in the air in southern China is that the summer mean temperatures there (26e28 C) are much higher than those in northern China (19e24 C), leading to higher rates of volatilization of PBDEs . On the other hand, compared with 2.2e15 pg/m 3 (average 8.3 pg/m 3 ) reported for Waliguan Baseline Observatory (WBO) and 0.1e8.3 pg/m 3 for Rawu, Gaerze, and Bomi in Tibet (Cheng et al, 2007;Wang et al, 2010d), the PBDEs concentrations found in the studied areas were much higher. Fig.…”

Current status of persistent organic pesticides residues in air, water, and soil, and their possible effect on neighboring countries: A comprehensive review of India

“…Wang et al (2006) evaluated the source and transport pathways of OCPs and PAHs in the Zhangmu-Nyalam (NZ) region (Central Himalayas) and found the transportation and fate of pollutants is influenced by the air mass movement dominated by the Indian monsoon from south Asia. Wang et al (2010) found that persistent organic pesticide concentrations in the air from regions impacted by the Indian monsoon are higher than in other regions of the TP. Tian et al (2009a) employed the Canadian Model for Environmental Transport of Organochlorine Pesticides (CanMETOP) simulation model to assess the contributions of γ-HCH in Chinese air and soil from four major γ-HCH residual regions (India, USSR, Europe and China).…”

“…Various studies based on modeling and simulation analysis have indicated that persistent organic pesticides originating from Indian sources may affect the neighboring countries, especially the Tibetan Plateau (TP). Several previous studies have revealed contamination of HCH in TP is largely attributed to emissions from Indian sources Wang et al, 2010). Gong et al (2010) reported high levels of γ-HCHs in the Lhasa atmosphere and advised that the source could be due to current usage of lindane in India and atmospheric transportation via Indian monsoons.…”

Distribution of PCBs and PBDEs in soils along the altitudinal gradients of Balang Mountain, the east edge of the Tibetan Plateau

“…The Tibetan Plateau is the largest and highest plateau and commonly called the roof of the world, having a 2.5 Â 10 6 km 2 zone with an average elevation of over 4500 m. Previous works have found that POPs and other contaminants might be particularly pronounced in the plateau due to the orographic cold-trapping effect, especially in the southeast Tibetan Plateau (Cheng et al, 2007;Yang et al, 2008Yang et al, , 2010Wang et al, 2009Wang et al, , 2010. The east edge of the Tibetan Plateau is located between populous Chendu Plain and the Tibetan Plateau with steep altitudinal gradients, which offers a remarkable and unique site to study the cold-trapping mechanism of POPs.…”