Evaluation of a new battery of toxicity tests for boreal forest soils: Assessment of the impact of hydrocarbons and salts

Abstract

The ability to assess the toxic potential of soil contamination within boreal regions is currently limited to test species representative of arable lands. This study evaluated the use of six boreal plant species (Pinus banksiana, Picea glauca, Picea mariana, Populus tremuloides, Calamagrostis Canadensis, and Solidago canadensis) and four invertebrate species (Dendrodrilus rubidus, Folsomia nivalis, Proisotoma minuta, and Oppia nitens) and compared their performance to a suite of standard agronomic soil test species using site soils impacted by petroleum hydrocarbon (PHC) and salt contamination. To maintain horizon-specific differences, individual soil horizons were collected from impacted sites and relayered within the test vessels. Use of the boreal species was directly applicable to the assessment of the contaminated forest soils and, in the case of the hydrocarbon-impacted soil, demonstrated greater overall sensitivity (25th percentile of estimated species sensitivity distribution [ESSD25] = 5.6% contamination: 10,600 mg/kg fraction 3 [F3; equivalent hydrocarbon range of >C16 to C34] Of/Oh horizon, and 270 mg/kg F3 Ahg horizon) relative to the standard test species (ESSD25 = 23% contamination: 44,000 mg/kg F3 Of/Oh horizon, and 1,100 mg/kg F3 Ahg horizon). For salinity, there was no difference between boreal and standard species with a combined ESSD25 = 2.3%, equating to 0.24 and 0.25 dS/m for the Ah and Ck horizons. The unequal distribution of soil invertebrates within the layered test vessels can confound test results and the interpretation of the toxic potential of a site. The use of test species relevant to boreal eco-zones strengthens the applicability of the data in support of realistic ecological risk assessments applicable to the boreal regions.

Petroleum hydrocarbon mixture toxicity and a trait‐based approach to soil invertebrate species for site‐specific risk assessments

“…With a maximum life span of 140 d and a large average clutch size per adult, F. candida represents an opportunistic species that invests energy into reproduction rather than survival, as is apparent by their relatively tolerant reproductive response to petroleum hydrocarbon–contaminated soils (van Straalen ; Rubach et al ; Environment Canada ). Based on our findings and other studies on earthworm reproduction (Cermak et al ; Agnell et al ; Princz et al ), the reproduction of mites and earthworms was sensitive to petroleum hydrocarbon–contaminated soils. Their life history traits reflect the fact that they allocate more energy to survival than reproduction (Murphy and Sardar ; Environment Canada 2004; Norton and Behan‐Pelletier ; Princz et al ).…”

Oppia nitensC.L. Koch, 1836 (Acari: Oribatida): Current Status of Its Bionomics and Relevance as a Model Invertebrate in Soil Ecotoxicology

“…In a study with petroleum hydrocarbon‐contaminated soil (~250 000 mg/kg total petroleum hydrocarbon), Princz et al () found no mortality of O. nitens ; however, they observed that reproduction was substantially impacted relative to control. Gainer et al () assessed the toxicity of lubricating oil, a 50/50 mixture of F2/F3 petroleum hydrocarbons, to O. nitens in OECD artificial soil (10% peat) and reported a reproduction EC50 value of 1210 mg/kg.…”

Selective biostimulation of cold‐ and salt‐tolerant hydrocarbon‐degrading Dietzia maris in petroleum‐contaminated sub‐Arctic soils with high salinity

“…This study focuses on the isolation, characterization and selective stimulation of cold‐ and salt‐tolerant hydrocarbon‐degrading bacteria particularly for the biostimulation of petroleum‐contaminated sub‐Arctic soils abruptly impacted by sources of high salinity (such as saline industrial effluents). Hydrocarbon‐ and salt‐contaminated soils often exist at drilling waste disposal sites and abandoned flare pits in oil and gas fields located in cold, remote areas of northern Canada and other cold‐region countries …”