Biomonitoring of Detoxifying Activity as Measured by CYP1A1 Induction in Yangtze and Jialing Rivers in Chongqing City in China

Abstract

In order to determine the potential toxicities of organic pollutants in the river water of Chongqing City (China), chemicals were extracted from surface water of the Yangtze River and Jialing River between August 2004 and January 2005. Gas chromatography/mass spectrometry (GC/MS) analysis showed that the main compounds detected were polycyclic aromatic hydrocarbons (PAH) and phthalate acid esters (PAE). The ethoxyresorufin O-deethylase (EROD) test showed that the toxic equivalency (TEQ) values of the samples ranged from 0.9 to 13.3 x 10(-4) pg 2,3,7,8-TCDD/L river water. Incubation of H4IIE cells with organic extracts produced a time-dependent induction of cytochrome P-450 1A1 (CYP1A1) mRNA expression as determined by (1) reverse-transcription polymerase chain reaction (RT-PCR), (2) positive binding to aryl hydrocarbon receptor (AhR), and (3) activation of xenobiotic response element (XRE) by electrophoretic mobility shift assay (EMSA). Data indicated that organic extracts from the river water of Chongqing City induced CYP1A1 activity in hepatocytes in vitro. A possible mechanism underlying toxicity might involve the AhR signal pathway, but further studies are necessary.

The impact of long term exposure to phthalic acid esters on reproduction in Chinese rare minnow (Gobiocypris rarus)

“…Our results revealed that the long-term impacts of DEHP on rare minnow reproduction were observed at relatively high concentrations (above 13.3 mg/L, and particularly from 40.8 mg/L), in the range of concentrations measured in the surface water of the Yangtze River (i.e.~3 mg/L to 55 mg/L) (Cui et al, 2009;Wang et al, 2008;Zhang et al, 2012). This finding indicates that impaired reproduction is likely to occur in rare minnow living in DEHPcontaminated water.…”

“…Newly hatched larvae (approximately 72 h post fertilization, hpf) were randomly distributed into separate glass beakers containing 500 mL of DEHP solution at different nominal concentrations (0, 10, 30, and 100 mg/L). The selected exposure concentrations were based on environmentally relevant concentrations reported from the surface waters of the upstream river (Cui et al, 2009) and based on our previous study (Wang et al, 2013b). The control and exposure groups received 0.005% (v/v) DMSO.…”

“…It is often found in freshwater systems at concentrations of mg/L levels Wang et al, 2008;Zeng et al, 2008). Recent studies revealing concentrations of DEHP of 28 mg/L in the Yangtze River Delta region (YRD; Zhang et al, 2012), 55 mg/L in the Wuhan section of the Yangtze River and 5.4 mg/L in the Three Gorges Reservoir (TGR) (Cui et al, 2009) indicate widespread PAE contamination in the Yangtze River freshwater ecosystem.…”

Occurrence and distribution of organic trace substances in waters from the Three Gorges Reservoir, China

“…This might indicate either an atmospheric input of the more volatile low molecular weight PAH or a strong adsorption of the high molecular weight PAH on surface water sediments or on suspended solids. Other studies on TGR surface water detected PAH concentrations in the same range or lower (Table 3) (Cui et al 2009;Wang et al 2009;Müller et al 2008). PAH were also present in tap and WWTP effluent samples in a range from 0.005 to 0.050 μg/L.…”

“…Generally, the concentrations of organic pollutants were found to increase from the remote west to the industrialized east (Liu et al 2011). In TGR, there are few studies on organic pollutants focusing mainly on PAH, PCB, organochlorine pesticides (OCP), phthalate acid esters, and polychlorinated dibenzodioxins and dibenzofurans (Gao et al 2007;Chen et al 2008;Cui et al 2009;Wang et al 2009;Luo et al 2011;Wang et al 2012;Liu et al 2011;So et al 2007;Chen et al 2013). Higher levels of OCP, PAH, and PCB were found close to Chongqing City and near TGD, possibly attributed to local anthropogenic sources (Wang et al 2009;Liu et al 2011).…”