The California biomonitoring program: persistent organic pollutants in archived and contemporary serum

Abstract

In 2006, California passed legislation establishing the first State Biomonitoring Program in the USA. The main goals are to: 1) Determine levels of environmental chemical contaminants in a representative sample of Californians; 2) Establish trends in the levels of these chemicals over time; 3) Assess the effectiveness of public health efforts and regulatory programs to decrease exposures to specific chemicals. As part of the Biomonitoring Program, our laboratory will be conducting analyses for Persistent Organic Pollutants (POPs) such as organochlorine pesticides (OCPs), PCBs, polybrominated diphenyl ethers (PBDEs), perfluorinated chemicals (PFCs), triclosan, phenols, OH-PCBs and OHPBDEs. Prior to this program, we had conducted a number of epidemiologic studies using specimens collected from the 1960s to the present and analysing them for POPs. Serum, milk and adipose samples were extracted and the neutral fractions were cleaned up using deactivated Florisil column chromatography, and analyzed for PCBs, OCPs and PBDEs by dual column GC-ECD and/or High Resolution Mass Spectrometry. Online Solid Phase Extraction - HPLC- Turbo ion Spray - Tandem Mass Spectrometry was used to analyze PFCs. Following standard conventions, results are expressed on a lipid basis (PCBs, PBDEs, OCPs), or on a volume basis (PFCs, Triclosan, Phenols, OH-PCBs, OH-PBDEs). A Quality Management system tracks all laboratory work. We had first reported the absence of PBDEs in serum samples from 1960s California populations as opposed to their presence in samples collected in the 1990s. We confirmed this observation with the analysis of over 1500 samples from the 1960s. In contemporary serum, the abundance of PBDE congeners was in the order of BDE-47>153>99>100, while BDE-209 was measurable in only a few of the samples. We could trace the increase of PFOA from the1960s to the 1980s, followed by a slight decrease in 2009. On the other hand, PFOS and PFHxS were highest in the 1960s, with similar decreasing trends from the1980s to 2009. In addition to addressing the research hypotheses of each epidemiologic study, data compiled across studies can show trends such as the emergence of PBDEs, and the decline in PCBs, phenols, OCPs and some PFCs over time. In addition, determinants of exposures (age, country of birth, ethnicity and reproductive history) can be identified, allowing for optimal sampling designs to account for the population diversity in California and can also be used in questionnaires to assess exposures. These data help establish a baseline before the new Biomonitoring Program launches its state-wide surveys.