Acetaminophen, pesticide, and diethylhexyl phthalate metabolites, anandamide, and fatty acids in deciduous molars: potential biomarkers of perinatal exposure.

The developing fetus is particularly vulnerable to adverse effects from pharmaceutical and exogenous chemical exposure. Deciduous teeth primarily form over specific periods from the second trimester in utero through the months after birth. We hypothesized that organic chemicals or their metabolites circulating in the bloodstream may sorb into forming dental tissues and remain stored in the tooth thereafter. Our aims were to devise analytical and preparation methods for potentially toxic or beneficial organic chemicals or metabolites in deciduous teeth and to estimate their detection frequencies. The analgesic acetaminophen was stored at greater concentration in a child's second molar than a first molar, consistent with intake, suggesting that acetaminophen concentration in molars may be a biomarker of acetaminophen exposure during molar formation. Chemicals detected by liquid chromatography/tandem mass spectrometry in molars of 21 typically developing children include the endocannabinoid anandamide (86% of children), acetaminophen (43%), and specific metabolites mono-2-ethylhexyl phthalate (MEHP, of plasticizer di-2-ethylhexyl phthalate, 29%), 3,5,6-trichloro-2-pyridinol (TCPy, of organophosphate (OP) insecticide chlorpyrifos, 10%), and 2-isopropyl-6-methyl-4-pyrimidinol (IMPy, of OP insecticide diazinon, 10%). None of these chemicals has previously been detected in human teeth. Molars from the two oldest subjects contained the largest concentrations of MEHP, TCPy, and IMPy. Potentially protective fatty acids detected by gas chromatography/mass spectrometry after derivatization include docosahexaenoic (19%), arachidonic (100%), and linoleic (100%). Validation studies are necessary to verify that each detected chemical in molars provides a biomarker of perinatal exposure.

Semivolatile endocrine-disrupting compounds in paired indoor and outdoor air in two northern California communities.

Interest in the health effects of potential endocrine-disrupting compounds (EDCs) that are high production volume chemicals used in consumer products has made exposure assessment and source identification a priority. We collected paired indoor and outdoor air samples in 40 nonsmoking homes in urban, industrial Richmond, CA, and 10 in rural Bolinas, CA. Samples were analyzed by GC-MS for 104 analytes, including phthalates (11), alkylphenols (3), parabens (3), polybrominated diphenyl ether (PBDE) flame retardants (3), polychlorinated biphenyls (PCBs) (3), polycyclic aromatic hydrocarbons (PAHs) (24), pesticides (38), and phenolic compounds (19). We detected 39 analytes in outdoor air and 63 in indoor air. For many of the phenolic compounds, alkylphenols, phthalates, and PBDEs, these represent some of the first outdoor measures and the first analysis of the relative importance of indoor and outdoor sources in paired samples. Data demonstrate higher indoor concentrations for 32 analytes, suggesting primarily indoor sources, as compared with only 2 that were higher outdoors. Outdoor air concentrations were higher in Richmond than Bolinas for 3 phthalates, 10 PAHs, and o-phenylphenol, while indoor air levels were more similar between communities, except that differences observed outdoors were also seen indoors. Indoor concentrations of the most ubiquitous chemicals were generally correlated with each other (4-t-butylphenol, o-phenylphenol, nonylphenol, several phthalates, and methyl phenanthrenes; Kendall correlation coefficients 0.2-0.6, p<0.05), indicating possible shared sources and highlighting the importance of considering mixtures in health studies.

Development of a personal dual-phase air sampling method for phthalate diesters.

Phthalates are used as plasticizers in many industrial and consumer products. Urinary biomonitoring has shown widespread human exposure to phthalates, with workers having especially high exposures. Phthalates can be present in workplace air as either aerosols or vapors depending on source materials, vapor pressure, and processing temperatures. We sought to develop a dual-phase air sampling method for 6 phthalates, dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), benzyl butyl phthalate (BzBP), di(2-ethylhexyl) phthalate (DEHP), and di-n-octyl phthalate (DnOP), adaptable to aerosol inlets with known particle collection characteristics. Collection media consisted of a quartz fiber filter and XAD-2 resin. Limit of detection (LOD) and limit of quantification (LOQ) were determined for each phthalate. Phthalate recoveries were evaluated at 3x, 10x and 30x the LOQ, and after storage at -21 degrees C and 21 degrees C. Media were Soxhlet extracted in 10% diethyl ether in hexanes along with an extraction surrogate, di-n-pentyl phthalate-d(4). Gas chromatography/mass spectrometry was performed to quantify the phthalate diesters using di(2-ethylhexyl) phthalate-d(4) as an internal standard. Estimated LODs were 1 microg per sample (BzBP, DEHP, and DnOP), 2 microg per sample (DMP and DBP), and 5 microg per sample (DEP). Mean recoveries under static conditions were 85-104% for DBP, BzBP, DEHP, and DnOP; but <70% for DMP and DEP at 3x and 10x the LOQ. After air was pulled through spiked samples, DMP and DEP recoveries improved to 74-81%. After storage for 62 days, phthalate recovery was better at -21 degrees C than at 21 degrees C. Method accuracy was best for DBP, BzBP, DEHP, and DnOP (range 11-18%), and less so for DMP (28%) and DEP (29%).