A Comparison of Biomarker Responses in the Earthworm Aporrectodea Caliginosa to the Organophosphorus Insecticides Diazinon and Chlorpyrifos

Abstract

Three biomarkers in Aporrectodea caliginosa Savigny were evaluated for their ability to detect exposure to organophosphorus insecticides, and these physiological responses were related to effects on growth and life-table parameters. Adult and juvenile earthworms were exposed to a laboratory-simulated field rate (low concentration) and a higher sublethal concentration of diazinon and chlorpyrifos. After a four-week exposure, juveniles were evaluated for cholinesterase activity, glutathione S-transferase activity, and growth, and adults were evaluated for the lysosomal neutral red retention assay (NRRA) and growth. Cholinesterase activity and the NRRA were more sensitive than growth in each age group for detecting exposure to the pesticides. Life-table parameters were evaluated in earthworms exposed as juveniles and as adults. Maturation was less sensitive to pesticides than was cocoon production. Growth and cocoon production in earthworms exposed as juveniles appeared to be more sensitive to organophosphorus insecticides than earthworms exposed as adults. Life-table responses in juveniles may, therefore, be more predictive of long-term impacts of organophosphorus insecticide applications on populations than responses in adults. Biomarker responses occurred at similar or lower concentrations than those causing an adverse effect on cocoon production and cocoon viability, indicating their usefulness in risk assessment for predicting ecologically relevant assessment end points.

Enzymes of Earthworm as Indicators of Pesticide Pollution in Soil

“…ChE depression of 35% and 70% was observed w. r. t. control when exposed to 4 and 28 mg/kg, respectively [69] Eisenia fetida Monocrotophos AChE AChE inhibition was observed Dose-dependent. AChE activity co-related with morphological damage [70] Eisenia andrei Carbaryl AChE Dose-dependent AChE activity was observed [71] Drawida willsi…”

Effects of Pesticides on the Growth and Reproduction of Earthworm: A Review

“…Zhou et al [45] assessed and found chlorpyrifos had adverse effect on growth in earthworm exposed to 5 mg/kg chlorpyrifos after eight weeks. Some studies have shown that growth of earthworms appeared to be more severely affected at juvenile stage than at adult stage [46,47].…”

Toxicity Assessment of Buprofezin, Lufenuron, and Triflumuron to the EarthwormAporrectodea caliginosa

“…Stenersen [39] observed a depression of activity by OP compounds, with a recovery to normal levels taking more than 50 days. In study by Booth and O'Halloran [19] who also found the enzyme to be continuously depressed with time and any recovery to be prolonged. It can be said that the toxicity test may be helpful for screening of pesticides especially sublethal effects on AChE and GST activities of earthworms and may aid in understanding ecotoxicological impacts on earthworms.…”

“…A number of researchers have used biomarkers effectively to determine pesticide effects on earthworms [16][17][18]. Biomarkers, measuring effects on suborganism levels, can provide links between a chemical and its toxic effect and are generally more sensitive than the more traditional measures of contamination, such as mortality and abundance [19][20][21][22].…”

“…Biochemical reaction studies mostly focus on the evaluation of possible adverse effects of chemicals on aquatic organisms [19,22]. The severity of soil contamination caused by persistent organic pollutants is commonly assessed with standard acute and reproduction tests.…”