Assessment of the bioavailability and toxicity of lead polluted soils using a combination of chemical approaches and bioassays with the collembolan Folsomia candida

Abstract

h i g h l i g h t s• Soils from different landscapes of a shooting range are examined.• Bioavailability of Pb varies with soil properties especially, pH and OM.• Collembolan reproduction was more sensitive to pH than to Pb in soils.• Collembolans avoided acid Pb contaminated soils. a r t i c l e i n f o a b s t r a c tUnderstanding bioavailability and toxicity is essential for effective ecological assessment of contaminated soils. Total, water and 0.01 M CaCl 2 extractable and porewater Pb concentrations and soil properties in different shooting field soils were investigated. Three artificial soils containing different pH and organic matter contents and two natural soils were included as controls. Survival, reproduction and avoidance responses of Folsomia candida exposed to these soils as well as internal Pb concentrations were measured. In the shooting range soils, total Pb concentrations were 47-2398 mg/kg dw, pH CaCl 2 3.2-6.8 and organic matter content 3.8-7.0%. Pb concentrations in F. candida linearly increased with increasing Pb concentrations in the soils. Acid forest soils caused significantly higher collembolan mortality and avoidance responses and significantly lower reproduction than the neutral grassland soils, which could be attributed to differences in pH and especially CaCl 2 extractable Pb concentrations. Soil properties significantly affected bioavailability and toxicity of Pb, but overall the collembolans seemed more sensitive to pH than to Pb in soils. This study shows the importance of selecting proper reference soils for assessing the effects of field soils.

The toxicity of different lead salts to Enchytraeus crypticus in relation to bioavailability in soil

“…In the present study, the BAFs for Pb uptake in E. crypticus were more or less constant at low exposure concentrations but showed a slightly decreasing trend at the higher test concentrations of lead nitrate and lead chloride (Supplemental Data, Figure S1), which [30]. The BAFs for E. crypticus were much higher than those for F. candida reported by Fountain and Hopkin [29], but comparable to those for Pb uptake in E. andrei or F. candida exposed to field-contaminated soils [31,32]. This might be attributed to species differences, soil properties, and consequent differences in Pb availability in soil.…”

“…For Pb accumulation in the springtail F. candida, fairly constant BAFs of 0.04 to 0.06 were calculated at total soil concentrations of 406 to 49 200 mg Pb/kg dry soil [29]. The BAFs for E. crypticus were much higher than those for F. candida reported by Fountain and Hopkin [29], but comparable to those for Pb uptake in E. andrei or F. candida exposed to field-contaminated soils [31,32]. The BAFs for E. crypticus were much higher than those for F. candida reported by Fountain and Hopkin [29], but comparable to those for Pb uptake in E. andrei or F. candida exposed to field-contaminated soils [31,32].…”

Ecotoxicity of cadmium in a soil collembolan-predatory mite food chain: Can we use the 15N labeled litter addition method to assess soil functional change?

“…bioavailability is typically estimated using the soil solution or extraction with water or CaCl 2 (Hobbelen et al, 2004). Recent studies also show that CaCl 2 -extractable Pb concentrations in combination with soil properties could best explain the effect on F. candida reproduction in a single species test (R 2 ¼ 0.82) (Luo et al, 2014a). We also carried out a standard single species test of F. candida in the present soil two days after Cd addition (data not published) and the EC50 value (6.12 mg Cd kg À1 ) of F. candida reproduction based on CaCl 2 extraction was clearly lower than that (29.4 mg Cd kg À1 ) in the present study (t-test, P < 0.05).…”

Short-Term Biochemical Impacts in &lt;i&gt;Cyphoderus javanus&lt;/i&gt; Borner (Collembola) as Potential Biomarkers of Fly Ash and Heavy Metal Pollution in Tropical Lateritic Soil

“…In Orchesella cincta (Collembola) the assimilation efficiency of Pb and Cd from a contaminated algal diet was 0.4% and 8.3%, respectively, but the rate of excretion by moulting was 48% of Pb and 30% of Cd, which led to higher levels of Cd in tissues [42]. Some scientists observed Pb concentrations in F. candida linearly increased with increasing Pb concentrations in the soils [43]. Dissipation of heavy metals in soil depends mostly on the physicochemical properties of the matrix, like organic matter content, clay fraction, mineralogical composition, pH and more, all of which collectively determine the binding ability of soil to the metals [44].…”