Environ Toxicol Chem 2021 Apr 6. Epub 2021 Apr 6.
Laboratory of Toxicology, Department of Environmental Veterinary Sciences, Faculty of Veterinary Medicine, Hokkaido University, Sapporo, Japan.
Neonicotinoid insecticides (NNIs) are now popular in many agricultural systems across Africa; however, the extent of human exposures to NNIs in African countries are scarcely reported. The present study sought to evaluate neonicotinoid exposures in the consumer population of Kumasi, a cosmopolitan city in Ghana. A total of 75 human urine samples were collected from healthy volunteers (non-farmers; age 13-80 years old); and analyzed with LC-ESI/MS/MS system. Seven NNIs and three NNI metabolites were detected in the following pattern (frequency, median concentration, maximum concentration): N-dm-acetamiprid (94.7%, 0.41 µg/L, 8.79 µg/L) > imidacloprid (70.7%, 0.15 µg/L, 211.62 µg/L) > CPMF (62.2%, 0.43 µg/L, 53.85 µg/L) > CPMA (56.8%, 0.10 µg/L, 3.53 µg/L) > clothianidin (40%, >LOQ, 0.45 µg/L) > nitenpyram (18.7%, >LOQ, 0.14 µg/L) ≈ thiamethoxam (18.7%, >LOQ, 0.21 µg/L) > dinotefuran (12.0%, >LOQ, 1.01 µg/L) > acetamiprid (2.7%, >LOQ, 0.08 µg/L) ≈ thiacloprid (2.7%, >LOQ, 0.14 µg/L). About 92% of the subjects were found to be exposed to multiple neonicotinoids simultaneously. The mean, median and maximum IMIeq (imidacloprid equivalence of the relative potency factor of NNIs) were found to be 1.6, 0.5, 22.52 respectively. The median estimated daily intakes of acetamiprid, imidacloprid and nitenpyram were 0.47, 1.27 and 0.02 µg/kg/day for females: and 0.91, 0.66 and 0.08 µg/kg/day for males, respectively. The maximum daily intakes (DI) of all the NNIs were below 1% of their chronic reference doses (cRfDs), except for imidacloprid and thiacloprid which recorded a maximum DIs corresponding to 17.97% and 8.28% of cRfDs respectively. To the best of our knowledge, the present study is the first biomonitoring report on neonicotinoid insecticides in Africa. This article is protected by copyright. All rights reserved.