title: Concentrations of neonicotinoid insecticides in honey, pollen and honey bees (Apis mellifera L.) in central Saskatchewan, Canada.
abstract: Neonicotinoid insecticides (NIs) and their transformation products were detected in honey, pollen and honey bees, (Apis mellifera) from hives located within 30 km of the City of Saskatoon, Saskatchewan, Canada. Clothianidin and thiamethoxam were the most frequently detected NIs, found in 68 and 75% of honey samples at mean concentrations of 8.2 and 17.2 ng g(-1) wet mass, (wm), respectively. Clothianidin was also found in >50% of samples of bees and pollen. Concentrations of clothianidin in bees exceed the LD50 in 2 of 28 samples, while for other NIs concentrations were typically 10-100-fold less than the oral LD50. Imidaclorpid was detected in ∼30% of samples of honey, but only 5% of pollen and concentrations were <LOD in bees. Transformation products of Imidaclorpid, imidaclorpid-Olefin and imidacloprid-5-Hydroxy were detected with greater frequency and at greater mean concentrations indicating a need for more focus on potential effects of these transformation products than the untransformed, active ingredient NIs. Results of an assessment of the potential dietary uptake of NIs from honey and pollen by bees over winter, during which worker bees live longer than in summer, suggested that, in some hives, consumption of honey and pollen during over-wintering might have adverse effects on bees.
authors.affiliation: Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, Saskatchewan, S7N 5B3, Canada. Electronic address: garrycodling@yahoo.co.uk.
authors.forename: Garry
authors.initials: G
authors.lastname: Codling
authors.affiliation: Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, Saskatchewan, S7N 5B3, Canada; Department of Zoology, Faculty of Science, Tanta University, 31527, Tanta, Egypt.
authors.forename: Yahya
authors.initials: Y
authors.lastname: Al Naggar
authors.affiliation: Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, Saskatchewan, S7N 5B3, Canada; Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; Department of Zoology, and Center for Integrative Toxicology, Michigan State University, East Lansing, MI, USA; School of Biological Sciences, University of Hong Kong, Hong Kong, SAR, China; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, China; Biology Department, Hong Kong Baptist University, Kowloon, Hong Kong, SAR, China.
authors.forename: John P
authors.initials: JP
authors.lastname: Giesy
authors.affiliation: Meadow Ridge Enterprises LTD, Saskatoon, Saskatchewan, S7K 3J9, Canada.
authors.forename: Albert J
authors.initials: AJ
authors.lastname: Robertson
mesh_terms: D000818:Animals; D001516:Bees / Q000737:chemistry* / Q000254:growth & development; D006146:Guanidines / Q000032:analysis* / Q000378:metabolism; D006722:Honey / Q000032:analysis*; D007093:Imidazoles / Q000032:analysis* / Q000378:metabolism; D007306:Insecticides / Q000032:analysis*; D057230:Limit of Detection; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000032:analysis* / Q000378:metabolism; D010078:Oxazines / Q000032:analysis* / Q000378:metabolism; D011058:Pollen / Q000737:chemistry*; D012525:Saskatchewan; D012621:Seasons; D000077922:Thiamethoxam; D013844:Thiazoles / Q000032:analysis* / Q000378:metabolism
chemical_list: D006146:Guanidines; D007093:Imidazoles; D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; D010078:Oxazines; D013844:Thiazoles; C480342:clothianidin; C082359:imidacloprid; D000077922:Thiamethoxam
keywords: Agriculture; Honey bees; Imidaclorpid; LD(50); Metabolites; Risk assessment