Human Exposures to Neonicotinoids in Kumasi, Ghana

• Published in: Environmental toxicology and chemistry Vol. 40; no. 8; pp. 2306 - 2318
• Main Authors: Nimako, Collins, Ikenaka, Yoshinori, Akoto, Osei, Bortey‐Sam, Nesta, Ichise, Takahiro, Nakayama, Shouta M.M., Asante, Kwadwo A., Fujioka, Kazutoshi, Taira, Kumiko, Ishizuka, Mayumi
• Format: Journal Article
• Language: English
• Published: United States Blackwell Publishing Ltd 01.08.2021
• Subjects: acetamiprid; Acetic acid; Biomonitoring; chemistry; Chronic reference dose; clothianidin; dinotefuran; ecotoxicology; electrospray ionization mass spectrometry; environmental monitoring; Exposure; Farming systems; Female; Ghana; Humans; Imidacloprid; Imidacloprid equivalent; Insecticides; Insecticides - analysis; Ionization; Ions; Liquid chromatography; Male; Mass spectrometry; Mass spectroscopy; Metabolites; Neonicotinoid; Neonicotinoid insecticides; Neonicotinoids - analysis; nitenpyram; Nitro Compounds; Pesticide risk assessment; Pesticides; Thiacloprid; Thiamethoxam; urine; Ghana; Africa; Neonicotinoid; Biomonitoring; Imidacloprid equivalent; Chronic reference dose; Pesticide risk assessment; Pesticides
• ISSN: 0730-7268; 1552-8618; 1552-8618
• DOI: 10.1002/etc.5065

Neonicotinoid insecticides (NNIs) are now popular in many agricultural systems across Africa; however, the extent of human exposures to NNIs in African countries is scarcely reported. The present study evaluates 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 (nonfarmers, aged 13–80 yr) and analyzed with a liquid chromatography electrospray ionization tandem mass spectrometry system. Seven NNIs and 3 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) > N‐(6‐chloro‐3‐pyridylmethyl)‐N‐ethyl‐N′‐methylformamidine (62.2%, 0.43 µg/L, 53.85 µg/L) > 2‐[N‐(6‐chloro‐3‐pyridylmethyl)‐N‐ethylamino]‐2‐(methylimino)acetic acid (56.8%, 0.10 µg/L, 3.53 µg/L) > clothianidin (40%, >limit of quantification [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). Approximately 92% of the subjects were found to be exposed to multiple neonicotinoids simultaneously. The mean, median, and maximum imidacloprid equivalent of the relative potency factor of NNIs were found to be 1.6, 0.5, and 22.52, respectively. The median estimated daily intakes of acetamiprid, imidacloprid, and nitenpyram were 0.47, 1.27, and 0.02 µg/kg/d for females and 0.91, 0.66, and 0.08 µg/kg/d for males, respectively. The maximum daily intakes of all the NNIs were <1% of their chronic reference doses (cRfDs), except for imidacloprid and thiacloprid which recorded maximum daily intakes 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. Environ Toxicol Chem 2021;40:2306–2318. © 2021 SETAC