title: Pooled biological specimens for human biomonitoring of environmental chemicals: opportunities and limitations.
abstract: Biomonitoring has become the "gold standard" in assessing chemical exposures, and has an important role in risk assessment. The pooling of biological specimens-combining multiple individual specimens into a single sample-can be used in biomonitoring studies to monitor levels of exposure and identify exposure trends or to identify susceptible populations in a cost-effective manner. Pooled samples provide an estimate of central tendency and may also reveal information about variation within the population. The development of a pooling strategy requires careful consideration of the type and number of samples collected, the number of pools required and the number of specimens to combine per pool in order to maximise the type and robustness of the data. Creative pooling strategies can be used to explore exposure-outcome associations, and extrapolation from other larger studies can be useful in identifying elevated exposures in specific individuals. The use of pooled specimens is advantageous as it saves significantly on analytical costs, may reduce the time and resources required for recruitment and, in certain circumstances, allows quantification of samples approaching the limit of detection. In addition, the use of pooled samples can provide population estimates while avoiding ethical difficulties that may be associated with reporting individual results.
authors.affiliation: National Research Centre for Environmental Toxicology (Entox), University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Amy L
authors.initials: AL
authors.lastname: Heffernan
authors.affiliation: Summit Toxicology, LLP, Falls Church, Virginia, USA.
authors.forename: Lesa L
authors.initials: LL
authors.lastname: Aylward
authors.affiliation: School of Clinical Sciences and Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Queensland, Australia.
authors.forename: Leisa-Maree L
authors.initials: LM
authors.lastname: Toms
authors.affiliation: Children's Health and Environment Program, Queensland Children's Medical Research Institute, University of Queensland, Herston, Queensland, Australia.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Sly
authors.affiliation: Department of Applied Environmental Science, Stockholm University, Stockholm, Sweden.
authors.forename: Matthew
authors.initials: M
authors.lastname: Macleod
authors.affiliation: National Research Centre for Environmental Toxicology (Entox), University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Jochen F
authors.initials: JF
authors.lastname: Mueller
mesh_terms: D004781:Environmental Exposure; D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants / Q000633:toxicity*; D006801:Humans
chemical_list: D004785:Environmental Pollutants