Comparative Exposure Assessment Using Silicone Passive Samplers Indicates That Domestic Dogs Are Sentinels To Support Human Health Research

Abstract

Silicone wristbands are promising passive samplers to support epidemiological studies in characterizing exposure to organic contaminants; however, investigating associated health risks remains challenging because of the latency period for many chronic diseases that take years to manifest. Dogs provide valuable insights as sentinels for exposure-related human disease because they share similar exposures in the home, have shorter life spans, share many clinical/biological features, and have closely related genomes. Here, we evaluated exposures among pet dogs and their owners using silicone dog tags and wristbands to determine if contaminant levels were correlated with validated exposure biomarkers. Significant correlations between measures on dog tags and wristbands were observed (r s = 0.38–0.90; p < 0.05). Correlations with their respective urinary biomarkers were stronger in dog tags compared to that in human wristbands (r s = 0.50–0.71; p < 0.01) for several organophosphate esters. This supports the value of using silicone bands with dogs to investigate health impacts on humans from shared exposures.

Operationalizing the Exposome Using Passive Silicone Samplers

“…Since the use of silicone PSDs is a new approach for passive exposure monitoring, 38 of the 44 reviewed studies combined PSDs with validated approaches for assessing exposures, including comparison to biomarker levels and established sampling devices. These include quantification of known exposure biomarkers in blood and urine [45,68,81,87,88], hand wipes [64,75,87], active air sampling [45,46,89,90], and low-density polyethylene PSDs [67,91], as well as using questionnaires to estimate past exposures [60,61,77,78,81,82,84,87,88,92,93]. Findings include a significant correlation between the PSD chemical concentrations and accepted biomarker measurements in urine [45,87], demonstrating usability of silicone PSDs to evaluate personal exposures.…”

“…Most exposures included volatile and semi-volatile compounds measured using gas-chromatography (GC), including single-and triple-quadrupole mass spectrometers, with some studies leveraging electron capture detectors for increasing specificity towards halogenated compounds [60,67,71,72]. Only a few studies combined GC with HRMS, including time of flight (TOF) and Orbitrap mass spectrometers [61][62][63][73][74][75][76][77][78][79]. Of the studies using HRMS technologies, only 50% were untargeted, defined as methods that used data-driven approaches for signal detection, filtering, and annotation.…”

Silicone Wristbands in Exposure Assessment: Analytical Considerations and Comparison with Other Approaches

“…This stage of sample preparation had been carried out in the reviewed research papers by washing post-exposure wristbands in a solvent. Most commonly a cycle (or series of cycles) of agitated WB wash(es) were performed, with the use of either an orbital shaker [ 18 , 20 , 36 , 45 , 48 , 59 , 67 , 68 , 69 , 75 , 77 ], an overhead shaker [ 24 , 71 ], a magnetic stir plate [ 65 ], Soxhlet extraction [ 51 ], or sonication [ 21 , 28 , 47 , 58 , 63 , 70 , 72 , 74 , 76 , 78 ]. The most frequently applied solvent of choice was ethyl acetate [ 20 , 24 , 55 ].…”

“…Moreover, discrepancies in presentation of quantitative results exist. Some researchers use analyte mass per entire wristband (e.g., Dixon et al [ 48 ], Xie et al [ 78 ]), whereas others share results as analyte mass per unit mass of the wristband (usually per one gram; e.g., Hammel et al [ 72 ], Wise et al [ 74 ]). These differences may hinder comparisons between the studies [ 51 ].…”

“…Inconsistent results were obtained in studies investigating silicone WBs–urine relationship while assessing exposure to OPEs. For instance, low and statistically insignificant correlations were observed between triphenyl phosphate (TPHP) in WBs and its metabolite, diphenyl phosphate (DPHP), in urine [ 49 , 51 , 72 , 78 ], except for Wise et al [ 74 ] ( Table S2 ). DPHP, however, is not a specific (unique) metabolite of TPHP, so concurrent exposure to other OPEs possibly overshadowed the true link.…”