PMID- 15260290
OWN - NLM
STAT- MEDLINE
DCOM- 20041018
LR  - 20051116
IS  - 1526-498X (Print)
IS  - 1526-498X (Linking)
VI  - 60
IP  - 7
DP  - 2004 Jul
TI  - Bound and unextractable pesticidal plant residues: chemical characterization and 
      consumer exposure.
PG  - 613-23
AB  - Plants are well known to incorporate pesticides into bound and unextractable 
      residues that resist solubilization in common laboratory solvents and are 
      therefore not accessible to standard residue analysis. A characterization of such 
      residues has been proposed for incorporation rates above trigger values of 0.05 
      mg kg(-1) parent pesticide equivalents, or percentage values of 10% (United 
      States Environmental Protection Agency, 1995) or 25% (Commission of the European 
      Communities, 1997) of the total radioactive residue. These trigger values are 
      often exceeded. The present review describes the current status of the chemical 
      characterization and animal bioavailability of bound and unextractable residues 
      that may be xenobiotic in nature or result from natural recycling of simple 
      degradation products. The latter case represents a mechanism of detoxification. 
      Bound residues have been shown to be covalent or non-covalent in nature. With 
      regard to the plant matrix molecules involved, incorporation into proteins, 
      lignins, pectins, hemicelluloses and cutins has been demonstrated, and four 
      covalent linkage types are known. Animal feeding experiments have revealed cases 
      of low as well as high bioavailability. Many of the studies are limited by 
      experimental uncertainties and by results only being reported as relative 
      percentage values rather than absolute exposure. A preliminary value of absolute 
      exposure from bound and unextractable residues is derived here for the first time 
      from eight case studies. The mean exposure (ca 1.5 mg kg(-1) pesticidal 
      equivalents) exceeds some of the existing maximum residue levels (MRLs) of 
      residual free pesticides that are typically in the range of 0.05-1 mg kg(-1). A 
      mathematical framework for the correction of current maximum residue levels is 
      presented for cases of highly bioavailable bound residues. As bound pesticidal 
      residues in food plants could represent a source of significant consumer 
      exposure, an experimental test scheme is proposed here. It consists of basic 
      chemical characterization, model digestibility tests and, in exceptional cases, 
      animal bioavailability and additional toxicological studies.
FAU - Sandermann, Heinrich Jr
AU  - Sandermann H Jr
AD  - GSF - National Research Centre for Environment and Health, Institute for 
      Biochemical Plant Pathology, D-85764 Neuherberg, Germany. sandermann@gsf.de
LA  - eng
PT  - Journal Article
PT  - Review
PL  - England
TA  - Pest Manag Sci
JT  - Pest management science
JID - 100898744
RN  - 0 (Pesticide Residues)
RN  - 0 (Pesticides)
SB  - IM
MH  - Animals
MH  - Binding Sites/drug effects
MH  - Biological Availability
MH  - Environmental Exposure/*analysis
MH  - Humans
MH  - Models, Biological
MH  - Pesticide Residues/chemistry/*metabolism/pharmacology
MH  - Pesticides/chemistry/*metabolism/pharmacology
MH  - Plants/*metabolism
RF  - 83
EDAT- 2004/07/21 05:00
MHDA- 2004/10/19 09:00
CRDT- 2004/07/21 05:00
PHST- 2004/07/21 05:00 [pubmed]
PHST- 2004/10/19 09:00 [medline]
PHST- 2004/07/21 05:00 [entrez]
AID - 10.1002/ps.888 [doi]
PST - ppublish
SO  - Pest Manag Sci. 2004 Jul;60(7):613-23. doi: 10.1002/ps.888.