Ecotoxicological and Analytical Assessment of Hydrocarbon-Contaminated Soils and Application to Ecological Risk Assessment

Abstract

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 (Ͻ5,000-30,000 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 Ͻ1 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 Ͻ 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.

Bioassays with terrestrial and aquatic species as monitoring tools of hydrocarbon degradation

“…100% mortality) at the highest test concentrations. Despite being recommended for the assessment of hydrocarbon-contaminated soils (Saterbak et al 1999;Son et al 2003;Van Gestel and Weeks 2004;Eom et al 2007;Lors et al 2009), mortality of earthworms was the least sensitive terrestrial endpoint and the only direct test that was not able to distinguish between soils according to their toxiciy.…”

“…Moreover, they cannot detect toxic intermediary metabolites that increase soil toxicity (Haeseler et al 2001;Loibner et al 2003) nor provide information on bioavailability, synergic, and antagonistic phenomena (Juvonen et al 2000). On the other hand, ecotoxicological tests do integrate all soil-occurring phenomena and are therefore recommended for the ecological risk assessment of polluted soils Bori et al 2016) and as monitoring tools of hydrocarbon remediation (Salanitro et al 1997;Saterbak et al 1999;Mendonça and Picado 2002;Lors et al 2009;Megharaj et al 2011). In order to obtain useful information on potential ecological risks, such tests are usually applied in batteries that include species from different taxonomical groups and routes of exposure (Békaert et al 1999;Bispo et al 1999;Rila and Eisentraeger 2003;Fernandez et al 2005).…”

Microbial communities in different soil types do not converge after diesel contamination

“…Wu Ènsche et al 1995), and it is common for authentically-contaminated soils to have similar or higher oil concentrations (e.g. Saterbak et al 1999). Nutrient solution was then poured evenly over the soil; additional water was added to bring the ®nal moisture content of each soil to 55% of WHC.…”

Fungal enzyme production and biodegradation of polychlorinated dibenzo-p-dioxins and dibenzofurans in contaminated sawmill soil

“…In both field experiments the treatment with fungal inoculum resulted in slightly higher toxicity compared with no inoculum when measured as inhibition of seed germination. However, the inhibition of seed germination with these two treatments was in the same order of magnitude and in general germination tests are not as sensitive to contaminants as are several soil invertebrates (Dorn et al, 1998;Saterbak et al, 1999). Figure 18.…”