Ecotoxicological and analytical assessment of hydrocarbon‐contaminated soils and application to ecological risk assessment

Abstract

Ecotoxicological assessments of contaminated soil aim to understand the effect of introduced chemicals on the soil flora and fauna. Ecotoxicity test methods were developed and conducted on hydrocarbon‐contaminated soils (<5,000–30,000 mg/kg total petroleum hydrocarbon) and on adjacent uncontaminated control soils from eight field locations. Tests included 7‐d, 14‐d, and chronic survival tests and reproduction assays for the earthworm (Eisenia fetida) and seed germination, root length, and plant growth assays for corn, lettuce, mustard, and wheat. Species‐specific responses were observed with no‐observed effect concentrations (NOECs) ranging from <1 to 100% contaminated soil. The 14‐d earthworm survival NOEC was equal to or greater than the reproduction NOEC values for numbers of cocoons and juveniles, which were similar to one another. Cocoon and juvenile production varied among the control soils. Germination and root length NOECs for mustard and lettuce were less than NOECs for corn and wheat. Root length NOECs were similar to or less than seed germination NOECs. Statistically significant correlations (p < 0.05) for earthworm survival and seed germination as a function of hydrocarbon measurements were found. The 14‐d earthworm survival and the seed germination tests are recommended for use in the context of a risk‐based framework for the ecological assessment of contaminated sites.

Simple Biotoxicity Tests for Evaluation of Carbonaceous Soil Additives: Establishment and Reproducibility of Four Test Procedures

“…In contrast to the Ferrosol, the Calcarosol did not change its pH after biochar addition. This suggests that a pH effect may have caused the earthworm reaction to biochar in soils, provided that no harmful substances were present (Hund‐Rinke et al, 2005; Loureiro et al, 2005; Saterbak et al, 1999). However, the loamy sand we used was less acidic (pH CaCl2 5.5) and the biochar less alkaline than the substrates and biochars used by Chan et al (2008) or Van Zwieten et al (2010).…”

Terrestrial Toxicity Performance of Different Base Oils in two Different Aging Conditions and Soil Types

“…The earthworm bioassay was conducted following the methods used by (Saterbak et al, 1999;Visser et al, 2002;. The seed germination bioassay was used because previous research had indicated that seed germination was a good endpoint for testing contaminant toxicity in soil (Saterbak et al, 1999). Springtails in general did not have great survival in the controls likely due to the low organic matter in the soil so for Study 2 a cricket bioassay was used instead (Karnjanapiboonwong et al, 2009;Zhang et al, 2006).…”

Toxicity Assessment of Contaminated Soil Using Seeds as Bioindicators

“…The interspecific differences observed for germination can be explained by the different seeds sizes, due to the fact that larger seeds have less surface area relative to volume, so they may (Saterbak, 1999;Wierzbicka & Obidzinska, 1998). Thus, the results corroborate this assertion, because the size of seed used was in the following order B. verna (cress) (1mm), B. oleracea (kale) (2 mm) and C. sativus (cucumber) (9 mm), and the sensitivity to contaminated samples inversely followed this sequence, i.e., the cucumber seeds had smaller sensitivity to contaminants.…”

“…Siddiquii et al (2001) analyzed grass germination in soil contaminated with diesel oil, demonstrating its high toxicity. Saterbak et al (1999) recommends various seeds germination as an effective evaluation of site contamination, since such tests present a narrow variability, good sensitivity and applicability to variety of soils. Maila and Cloete (2002) consider Lepidium sativum germination as a potential PAHs bioindicator.…”