Assessment of metal and nutrient concentrations in river water and sediment collected from the cities in the Pearl River Delta, South China

Association of soil polycyclic aromatic hydrocarbon levels and anthropogenic impacts in a rapidly urbanizing region: Spatial distribution, soil–air exchange and ecological risk

“…Urbanization, an inevitable consequence of rapid economic development, is a multi-dimensional process with complicated outcomes (Zhu et al, 2011), such as increased domestic waste discharge (Wang et al, 2007), and water and air pollution (Cheung et al, 2003;Wang et al, 2007Wang et al, , 2011aPan et al, 2012;Zhang et al, 2012). As an important matrix in urban terrestrial environment, soil has been a major sink of contaminates (Jones, 1994;Hippelein and Mclachlan, 1998;Manzetti, 2013) and well interacts with other environmental compartments.…”

Joint toxicity of a pyrethroid insecticide, cypermethrin, and a heavy metal, lead, to the benthic invertebrate Chironomus dilutus

“…Reports of Cd 2þ and Pb 2þ contamination in sediments collected in Guangzhou, the largest city in the PRD, stated that these metals had up to 5.2-and 3.5-fold higher concentrations, respectively, than the Hong Kong sediment quality criteria (1.5 and 75 mg/kg dry wt). Water concentrations of Pb 2þ , Cu 2þ , and Ni 2þ showed similar findings, because these metals exceeded the water quality standards for the protection of aquatic life [14]. Even more alarming is that recent studies have shown that blood Pb 2þ levels of children living near an electronic waste recycling site in the PRD were close to those that may cause clinical poisoning [15].…”

“…The nominal concentrations used for cypermethrin were 1, 3, 6, 9, and 13 mg/L, and they covered the concentration-response spectrum of cypermethrin in previous screening tests. Three nominal Pb 2þ concentrations were used, including a concentration at the water quality criteria (protection for aquatic life) in China (100 mg/L [14]), a sublethal concentration (100 mg/L), and a concentration approximate to the median lethal concentration (LC50) (350 mg/L). In addition to joint toxicity testing, bioassays with the individual contaminants, using the same concentrations as in the mixture bioassay, were also simultaneously conducted to evaluate species sensitivity and overall toxicity of each contaminant alone ( Fig.…”

“…Both pyrethroids and heavy metals strongly bind to sediment when entering aquatic systems [5][6][7][8][9][10][11]13,14]; therefore, sediment bioassays represent a more environmentally realistic exposure scenario than water-only systems (Supplemental Data, Fig. S1, Test 3).…”

Combined toxicity of polycyclic aromatic hydrocarbons and heavy metals to biochemical and antioxidant responses of free and immobilized Selenastrum capricornutum

“…Four heavy metals-cadmium (Cd 2þ ), copper (Cu 2þ ), zinc (Zn 2þ ), and nickel (Ni 2þ ) in the forms of CdCl 2 Á 2.5H 2 O, CuSO 4 Á 5H 2 O, ZnSO 4 Á 7H 2 O, and NiCl 2 Á 6H 2 O, respectively, obtained from Sigma-Aldrich-were dissolved in deionized water and simultaneously added to the SE medium at three different concentrations. The concentrations for each heavy metal were different, with higher concentrations in Ni 2þ , followed by Cu 2þ and Zn 2þ , and finally Cd 2þ , reflecting their reported contamination levels in wastewaters generated from various industrial activities, including hydrocarbon processing, iron/ steel manufacturing, electroplating, electronics manufacturing, dye manufacturing, and smelting [28], and in river water of cities in south China [29]. The three contamination levels were (1) low metal level (HM1) containing a mixture of Cd 2þ , Cu 2þ , Zn 2þ , and Ni 2þ at 0.05, 0.05, 0.05, and 0.5 mg ml À1 , respectively; (2) medium metal level (HM2) containing the four metals at 0.075, 0.5, 0.5, and 1.5 mg ml À1 , respectively; and (3) high metal level (HM3) containing the four metals at 0.1, 1, 1, and 2.5 mg ml À1 , respectively.…”