Ecology, Environment and Conservation Paper


Vol.30, Issue 3, 2024

Page Number: 1395-1399

RISK ASSESSMENT OF CHLORPYRIFOS 50% EC ON NONTARGET BENEFICIAL SPECIES OF TERRESTRIAL INHABITANT: EARTHWORM (EISENIA FETIDA) AND HONEY BEE (APIS MELLIFERA)

V.E. Narke, S.R. Bhonglae, S.N. Shegar4 and U.V. Khisti

Abstract

Chlorpyrifos 50% EC was found to be hazardous when evaluated with a terrestrial test system, i.e., in earthworms and honey bees. In earthworms, at concentrations 40, 64, 102.4, 163.8, and 262.1 mg/kg (dry weight of artificial soil) on day 14, 0/40, 0/40, 4/40, 9/40, 16/40, and 40/40 cumulative mortality was observed when treated with 0, 40, 64, 102.4, 163.8 and 262.1 mg/kg (dry weight of artificial soil) respectively. Behavioural or pathological signs were observed such as dullness in the worms treated with 64, 102.4, 163.8, and 262.1 mg/kg (dry weight of artificial soil) on day 7. The LC50 of Chlorpyrifos 50% EC for earthworms observed for a period of 14 days was found to be 240.443 mg/kg (dry weight of artificial soil) with lower confidence limits of 155.014 mg/kg (dry weight of artificial soil) and the upper confidence limits of 372.951 mg/kg (dry weight of artificial soil). The Chlorpyrifos 50% EC is classified under “Category 3” as per the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) (Mariyadas et al., 2018; Nöel, 2015). When the bees were exposed to Chlorpyrifos 50% EC at 0.1, 0.2, 0.4, and 0.8 μg a.i./bee mortalities were observed at 0.2 μg, 0.4, and 0.8 μg a.i./bee concentration at 4h and 24 h. The signs of intoxication were observed 4th h onwards. The signs observed were lethargy, and dullness till 48 h. The LD50 of Chlorpyrifos 50% EC in Honey bees by oral route for a period of 24 h was found to be 0.400 μg a.i./bee with confidence limits of 0.263 μg a.i./bee to 0.609 μg a.i./bee.