Prediction of ecotoxicity of hydrocarbon‐contaminated soils using physicochemical parameters

Abstract

Abstract-The physicochemical properties of eight hydrocarbon-contaminated soils were used to predict toxicity to earthworms (Eisenia fetida) and plants. The toxicity of these preremediated soils was assessed using earthworm avoidance, survival, and reproduction and seed germination and root growth in four plant species. No-observed-effect and 25% inhibitory concentrations were determined from the earthworm and plant assays. Physical property measurements and metals analyses of the soils were conducted. Hydrocarbon contamination was characterized by total petroleum hydrocarbons, oil and grease, and GC boiling-point distribution. Univariate and multivariate statistical methods were used to examine relationships between physical and chemical properties and biological endpoints. Soil groupings based on physicochemical properties and toxicity from cluster and principal component analyses were generally similar. Correlation analysis identified a number of significant relationships between soil parameters and toxicity that were used in univariate model development. Total petroleum hydrocarbons by gas chromatography and polars were identified as predictors of earthworm avoidance and survival and seed germination, explaining 65 to 75% of the variation in the data. Asphaltenes also explained 83% of the variation in seed germination. Gravimetric total petroleum hydrocarbons explained 40% of the variation in earthworm reproduction, whereas 43% of the variation in plant root growth was explained by asphaltenes. Multivariate one-component partial least squares models, which identified predictors similar to those identified by the univariate models, were also developed for worm avoidance and survival and seed germination and had predictive powers of 42 and 29%, respectively.

Dispersant and salinity effects on weathering and acute toxicity of South Louisiana crude oil

“…In juvenile F. grandis crude oil, acute toxicity was not correlated to any of the individual petroleum chemicals, PAH classes, or target PAHs and expanded target PAHs measured as potential indicators of toxicity. Crude oil WAF toxicity is assumed to be more closely related to total petroleum hydrocarbons (TPHs), which include the heterocyclic aromatics, monocyclic aromatics, and alkyl benzenes [49]; but our observation that toxicity measurements and chemical measurements were only weakly related agreed with the observations of previous researchers who have found no or only weak relationships between TPHs, total PAHs, and/or individual hydrocarbons when such assumptions are tested [13,[50][51][52]. We hypothesize that chemical measurements and toxicity measurements are poorly related in the present study and in previous work [12,[50][51][52] because there are tens of thousands of compounds in crude oil [7,8], but GC-MS currently quantifies less than 150 of those compounds [25].…”

Biological tools for the assessment of contaminated land: applied soil ecotoxicology

“…Salanitro et al (1997) concluded that bioremediation of crude oil-spiked soil was effective in alleviating all toxicity to earthworms, despite high residual oil concentrations of 4500-10 000 mg kg 21 . However, Wong et al (1999) found that earthworm toxicity was correlated with hydrocarbon concentrations; TPH explained 65% of the variance in the earthworm toxicity data.…”

The Use of Acute and Chronic Bioassays to Determine the Ecological Risk and Bioremediation Efficiency of Oil-Polluted Soils

“…The effect values found here are lower than the ones reported by other authors [10,40], which could be due to differences in oil types or soils characteristics (e.g., organic matter contents). Based on work by Salanitro et al [8], Dorn et al [10], Saterbak et al [2], and Wong et al [1], Dorn and Salanitro [9] concluded that oil levels Ͻ4,000 mg/kg dry soil will have little effect on plants and earthworms. Their studies, however, mainly focused on acute effects and used shorter exposure periods than applied here.…”

“…Chemical analysis usually is insufficient to provide insight into the potential ecological risk of polluted soils since it does not allow for an integration of the combined effects of the mixture of all chemicals present at a polluted site, including their bioavailability [1,2]. Bioassays do integrate these effects and are therefore recommended for the ecological risk assessment of polluted soils [3].…”

“…To date, little data are available on the toxicity of oil pollution in soils [2]. Most information has been obtained from bioassays on field-polluted or remediated soils, applying less standardized conditions [1,2,8,9]. Most available toxicity data are restricted to acute toxicity tests on a limited number of organisms, mainly earthworms, plants, and microorganisms [10].…”