Dendrodrilus rubidus

[ref. ID; 3580]

Test system

Strains

Toxicants

Test design

• Earthworm burrowing rates: The methods of Robinson et al. (1991). The soil was placed into Petri dishes (210 mm i.d.) with one half containing the uncontaminated soil and the other containing the same soil treated with 0, 12, 25, 123, 247, 494 or 1235 mg As kg-1 as sodium arsenate, with a divider separating the two soils. Earthworms (n=3) introduced onto the soil in each side of the dish. Six replicates. The time taken by earthworms to burrow entirely into the soil (15 mm depth) was recorded at 1, 3, 5, 10, 15, 20, 25 and 30 min.
• Soil discrimination: Soil was placed in Petri dishes with no divider separating the two soils. Earthworm (n=3) were introduced to each side of the dish. Replicates (n=3) for each species at each site and each concentration of sodium arsenate were stored in the dark at 9 degrees C.
• Arsenate toxicity: The uncontaminated soil was treated with sodium arsenate heptahydrate (494 mg As kg-1). Moistened soil (69 g) was weighed into the each of a series of 20x25 cm polythene bags. One earthworm was weighed and introduced in to each bag.
• Lethal concentration of As (LC50): The uncontaminated soil and Devon Great Consols were weighed and 55 g placed into a series of 20x25 cm polythene bags. Solutions of sodium arsenate were added to soil, setting the moisture content of the soil to 45%. Six concentrations of sodium arsenate were used for each site: Devon Grate Consols 247, 494, 988, 1235, 1976 and 2350 mg As kg-1 and 12, 25, 37, 74, 123 and 180 mg As kg-1, for the uncontaminated site. One earthworm was weighed and introduced into each bag. The bags were sealed and kept in the dark at 9 degrees C. Six replicates. Exposure period 14 days.

Measurements/observations

• Soil discrimination: Earthworms that had burrowed into each siil were recorded after 3 hr.
• Arsenate toxicity: Specimens were examined at weekly intervals and assigned a conditions index (C.I.) score: 0 = dead, 1 = moribund (flaccid and/or unresponsible to tactile stimulation) and 2 = responsive (active and responsive to tactile stimulation).
• Lethal concentration of As (LC50): Conditions of alive or dead.

Evaluations

• Soil discrimination: A three factor ANOVA was carried out with species, concentration and site as factors, and a GLM model was constructed using Minitab.
• Lethal concentration of As (LC50): LC50.

[ref. ID; 4481]

Test system

Toxicants

Sample

• Contaminated site; From arsenic-contaminated sites at Devon Great Consols, an abandoned copper and arsenic mine near Tavistock, Devon, UK.
• Uncontaminated site; From a mixed deciduous woodland soil at Lancaster University campus (Lancaster, UK).

Measurements/observations

[ref. ID; 5991]

Test systems

Collection site

Measurements/observations

• Soil: pH, organic carbon, CEC, conc. nitric acid extractable Cd, Cu, Pb and Zn concentration.
• Worms: dry-weight, Metal (Cd, Cu, Pb and Zn) concentration in worm tissue.

[ref. ID; 5996]

Test system

Sample

• Site 1. Near an old lead smelter in Tikkurila (The soil there is heavily contaminated with Pb from the smelter, which was in operation for nearly 60 years, until it was closed in the early 1980s and finally demolished in 1991).
• Site 2. Pornainen (less Pb contaminated situated ‘control’ soil) about 25 km to the north-east of Tikkurila.

Sampling method

Test design

• Experiment 1. Identification, counting and weighting of collecting earthworms.
• Experiment 2. Rearing experiments. Blocks of highly Pb contaminated soil were thawed and vertically cut into smaller units without destroying their structure, and the units were fitted into cylindrical plastic pots (diameter 8.5 cm, height 15 cm) to be used for rearing. The pots were fitted with caps of fine nylon net. During the rearing period the pots were kept inside a dark, ventilated chamber at temperature of +10 degrees C.

Measurements/observations

[ref. ID; 5998]

Test system

Collection site

Measurements/observations