Analysis of polychlorinated dibenzo-p-dioxins and furans in various aqueous samples in Taiwan Ngo Thi Thuan a , Ching Lan Tsai b , Ying Minh Weng b , Tzu Yi Lee b , Moo Been Chang a,⇑ a Graduate Institute of Environmental Engineering, National Central University, Chungli 320, Taiwan, ROC b Environmental Analysis Laboratory (EAL), Environmental Protection Administration (EPA), Chungli 320, Taiwan, ROC article info Article history: Received 6 September 2010 Received in revised form 10 January 2011 Accepted 27 February 2011 Keywords: PCDD/Fs Freshwater Distribution Water treatment abstract Twenty-one fresh water samples were taken from reservoirs, wells and drinking water treatment plants in Taiwan for measurement of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) concen- trations. Due to low concentration of PCDD/Fs, water samples (400–1000 L) were collected by using the on-site large volume pre-concentration system and analyzed by high resolution gas chromatography (HRGC)/high resolution mass spectrometer (HRMS). Different characteristics of dioxin profiles in surface water and groundwater are observed. The PCDD/F concentrations in fresh water samples varied from 0.001 to 0.265 pg WHO 98 -TEQ/L which are lower than the standard (12 pg WHO 98 -TEQ/L) set by the Tai- wan Environmental Protection Administration (TEPA) for drinking water. Only a small fraction (<5%) of the total PCDD/F concentration in fresh water samples was water-soluble. As a result of their hydropho- bicity, PCDD/Fs are effectively removed along with suspended solid via the water treatment process (average 98% removal efficiency). Ó 2011 Elsevier Ltd. All rights reserved. 1. Introduction Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/ Fs), commonly known as dioxins, are ubiquitous in the environ- ment. They have been classified in the priority list of toxic pollu- tants due to their carcinogenic potential and persistent properties with low vapor pressure and high lipophilicity. These toxic chemi- cals are inadvertently released into environment from various sources, making them the most controversial pollutants. The indus- trial-chemical and thermal processes are primary sources resulting in the dioxin pollution in soil, air and water. One of the main path- ways leading to their entrance into the food chain and human body is via water. The first survey of dioxin contents in water (US-EPA, 1990) reported the total concentration of PCDD/Fs in wastewater effluent of pulp and paper mill bleach pulp was about 56 pg WHO 98 -TEQ DF / L with 2,3,7,8-tetrachlorinated dibenzo furan (2,3,7,8-TeCDF) accounting for 82–96% of total dioxin toxicity based on WHO 98 - TEQ DF . The US-EPA estimate of the annual tetrachloro dibenzo-p- dioxin/furan (TeCDD/F) discharge in effluent and sludge from bleaching chemical pulp and paper mill was 28 g International Toxic Equivalent Quantity (I-TEQ) (US-EPA, 1995). The total annual contributions of dioxins and furans to water from all paper and pulp productions in European countries were in range of 8.1–27 g I-TEQ (Wenborn et al., 1999). The estimate for 1998 of total annual PCDD/F release to water of New Zealand was 0.56– 3.9 g I-TEQ (Simon et al., 2000) while the amount of dioxins released into surface water was 2.0 g TEQ in Japan (Japan-MOE, 2004). In addition, the homologue distributions of PCDD/Fs in water samples are strongly influenced by source releases such as chlorinated herbicides, chlorinitrofen (CNP) and pentachlorophe- nol (PCP) which are dominant with highly chlorinated compounds or dye manufacturing plant with high concentration of 1,3,6,7,8- pentachloro dibenzofuran (Kakimoto et al., 2006). These data indi- cate that dioxin in water deserves further investigation. In Taiwan, emission from secondary copper smelting, waste incinerators, cement kilns and electric arc furnaces accounts for 84% of total dioxin releases into the environment (Chen, 2004). Due to their extremely low solubility in water, little information on PCDD/F content in fresh water has been reported. Most of researches focus on the dioxin concentrations and fates in other media including soil, air and sediment. Duh et al. (2007) compiled dioxin concentrations in water from nine facilities of incinerators, pulp and paper mill factories in Taiwan. The dioxin discharge into water from the municipal waste incinerators (MSWIs), the indus- trial waste incinerators (IWIs), the pulp and paper mill factory and vinyl chloride manufactory was estimated at 0.0008– 0.0846 g I-TEQ year À1 . Their concentrations in these effluents were in the range of 0.06–5.88 pg I-TEQ/L. However, the PCDD/F conge- ner profiles and concentrations in various types of fresh water samples have not been fully understood. 0045-6535/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.chemosphere.2011.02.065 ⇑ Corresponding author. Tel./fax: +886 3 4226774. E-mail address: mbchang@cc.ncu.edu.tw (M.B. Chang). Chemosphere 83 (2011) 760–766 Contents lists available at ScienceDirect Chemosphere journal homepage: www.elsevier.com/locate/chemosphere