Levels and sources of phthalate esters in shallow groundwater and surface water of Dongguan city, South China

Abstract

The aim of the present work is to investigate the distribution and possible sources of phthalate esters (PAEs) in groundwater and surface water of a subtropical Dongguan city, South China. Groundwater and surface water samples were collected from fifty-six and nine sampling sites in 2006, respectively. Concentrations of six PAE compounds (Σ6PAEs) in groundwater and surface water range from below detection limit (BDL) to 6.7 µg/L and from BDL to 33.8 µg/L, with an average value of 0.9 µg/L and 11.1 µg/L, respectively. Of the six PAE compounds in groundwater and surface water, di (2ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP) are the main compounds of PAEs. DnBP and DEHP are predictive indicators for the Σ 6 PAEs in surface water (r = 0.803, p < 0.01) and groundwater (r = 0.726, p < 0.01), respectively. Most of high Σ6PAEs in groundwater are measured near the boundary of Dongguan city. In contrast, the Σ6PAEs in groundwater samples are BDL in the center of Dongguan city. The concentration of DnBP in groundwater is negatively correlated with groundwater table (R = 0.6496, p < 0.05), while there is no correlation between DEHP concentration and table in groundwater. Our results indicate the high Σ6PAEs in surface water and the good hydraulic connection between surface water and groundwater. Thus, the PAEs in surface water may be one of the main sources for those in groundwater in the study area.