© Benaki Phytopathological Institute
        
        
          Hellenic Plant Protection Journal
        
        
          
            8:
          
        
        
          33-45, 2015
        
        
          DOI 10.1515/hppj-2015-0006
        
        
          Laboratory of Pesticides Toxicology, Department of
        
        
          Pesticides Control and Phytopharmacy, Benaki Phy-
        
        
          topathological Institute, 8 St. Delta Str., GR-145 61 Ki-
        
        
          fissia, Attica, Greece
        
        
          * Corresponding authors: 
        
        
        
        
          icance of NNDs for plant protection; never-
        
        
          theless they imply their ubiquitous presence
        
        
          in the environment.
        
        
          NNDs are systemic insecticides with
        
        
          chemical structures based on nicotine moi-
        
        
          ety (Figure 1). Consequently, their mode of
        
        
          action is similar to that of nicotine. Research
        
        
          studies have shown that NNDs bind in sev-
        
        
          eral and sometimes different domains in the
        
        
          insect nicotinic acetylcholine receptors [for
        
        
          the description of these receptors see the
        
        
          chapter by Jones and Sattelle, 2010] that re-
        
        
          sults in differentiation of their bioactivity
        
        
          (Matsuda
        
        
          et al
        
        
          ., 2005; Tomizawa
        
        
          et al
        
        
          ., 2007a;
        
        
          Tomizawa
        
        
          et al.
        
        
          , 2007b). Briefly, NNDs target
        
        
          the nicotinic receptors and provoke excita-
        
        
          tion of the nerve cells, causing trembling
        
        
          and shaking and eventually paralysis. The
        
        
          latter can lead to the death of the insects,
        
        
          depending on dose and exposure duration.
        
        
          Active substances of NNDs have been al-
        
        
          leged as one of the factors that lead to the
        
        
          development of the honeybee colony col-
        
        
          lapse disorder (CCD) syndrome (Vanengels-
        
        
          dorp
        
        
          et al
        
        
          ., 2009). NNDs in particular seem
        
        
          to interplay in CCD (Lu
        
        
          et al
        
        
          ., 2014), howev-
        
        
          er further research is needed to elucidate
        
        
          CCD causality, since combined stress that
        
        
          REVIEW ARTICLE
        
        
          
            Neonicotinoids and their Metabolites in Human
          
        
        
          
            Biomonitoring: A Review
          
        
        
          K.M. Kasiotis* and K. Machera*
        
        
          
            Summary
          
        
        
          Neonicotinoids (NNDs) constitute a major class of insecticides with a broad and versatile
        
        
          spectrum of applications in agriculture. Hence, their residues are found in several environmental com-
        
        
          partments and can be transferred
        
        
          via
        
        
          several pathways to numerous organisms. Despite their pro-
        
        
          found impact on honeybees and wild bees (impairment of memory, impact on immune system), their
        
        
          presence in humans is far less reported, possibly due to the low to moderate toxicological effects that
        
        
          they elicit. The aim of the present review is to emphasize on developments in the biomonitoring of
        
        
          NNDs. It focuses mainly on chromatographic analysis of NNDs and their metabolites in human biologi-
        
        
          cal fluids, discussing key features, such as sample preparation and analytical method validation. None-
        
        
          theless, case reports regarding intoxication incidents are presented, highlighting the significance of
        
        
          such cases especially in the developing world.
        
        
          Additional Keywords:
        
        
          LC-MS, urine, Imidacloprid
        
        
          
            Introduction
          
        
        
          Insecticides are substances of chemi-
        
        
          cal or biological origin that are used to con-
        
        
          trol insects. Amongst the plethora of insec-
        
        
          ticides, neonicotinoids (NNDs) comprise
        
        
          a significant class of insecticides with nu-
        
        
          merous applications in agriculture. NNDs
        
        
          family includes, imidacloprid (IMI), thiame-
        
        
          thoxam (THIAM), clothianidin (CLOTH), thi-
        
        
          acloprid (THIAC), acetamiprid (ACET), di-
        
        
          notefuran (DINOT), nitenpyram (NITEN),
        
        
          nithiazine (NITH), imidaclothiz (IMCL), flonic-
        
        
          amid (FLON), the fourth generation member
        
        
          sulfoxaflor (SULF) and cycloxaprid (CCLX).
        
        
          Exemplary compound of NNDs is IMI, whose
        
        
          sales in 2008 were estimated to ca. 5,450
        
        
          tones in 2010 (Pollack, 2011) and its produc-
        
        
          tion was estimated at ca. 20,000 tones [see
        
        
          (Simon-Delso
        
        
          et al
        
        
          ., 2015) and references
        
        
          therein]. The above data indicate the signif-