Relating Environmental Availability to Bioavailability: Soil-Type-Dependent Metal Accumulation in the Oligochaete Eisenia andrei

Determining the bioavailability and toxicity of lead contamination to earthworms requires using a combination of physicochemical and biological methods

“…In the present study, the effect of pH was weaker for internal Pb than for reproduction (Table 3). This was not in agreement with the results observed by Peijnenburg et al (1999), Langdon et al (2005) and Bradham et al (2006). Internal Pb concentrations did not correlate with soil OM content, but they significantly and negatively correlated with DOC level in the porewater.…”

“…Bradham et al (2006) argued that the apparent correlation of earthworm survival with CEC may be caused by the strong inter-correlation between CEC and other exogenous variables such as pH, and not by a direct effect of CEC (see e.g., Criel et al, 2008). Earthworm mortality was not significantly correlated with organic matter content or DOC concentration in the porewater, which agrees with other studies (Bradham et al, 2006;Janssen et al, 1997;Peijnenburg et al, 1999). Simple and stepwise regression analysis showed that the number of surviving of adult earthworms (SN) was well predicted on the basis of the porewater Pb concentrations, CEC, silt and sand contents of the test soils (Table 4).…”

“…Internal Pb concentrations did not correlate with soil OM content, but they significantly and negatively correlated with DOC level in the porewater. In addition, internal Pb was negatively correlated with clay content and silt content but positively with Fe and sand content, which all have been shown also by others to be modifying Pb uptake by earworms (Janssen et al, 1997;Peijnenburg et al, 1999;Basta et al, 2005).…”

“…Grelle and Descamps (1998) also found that soil total Pb concentration was a better predictor of earthworm body burden than CaCl 2 -extractable Pb levels. Previous studies demonstrated that soil physicochemical properties have a significant impact on Pb uptake by E. andrei (Spurgeon and Hopkin, 1995;Peijnenburg et al, 1999;Bradham et al, 2006;Smith et al, 2012). For example, soil pH has been suggested as the most important factor for controlling the bioavailability of Pb in soil, followed by organic matter content (Thomas, 1997;Peijnenburg et al, 1999).…”

Soil acidification increases metal extractability and bioavailability in old orchard soils of Northeast Jiaodong Peninsula in China

“…Over time, soils may become more acid due to the removal (loss) and leaching of exchangeable bases such as calcium and magnesium, which is especially pronounced in the coastal sandy textured soils with low nutrient-holding buffering capacity (i.e., the Northeast of Jiaodong Peninsula). Surface soil acidification and the effect on metal bioavailability have been investigated in laboratory and field studies (Allen, 2002;Peijnenburg et al, 1999;Guo et al, 2011). However, there is little knowledge of subsoil acidity in the Northeast of Jiaodong Peninsula fruit-growing area, although topsoil acidification has become a major problem in soils of intensive Chinese agricultural systems (Guo et al, 2010).…”