Preparation and performance features of wristband samplers and considerations for chemical exposure assessment

Abstract

Wristbands are increasingly used for assessing personal chemical exposures. Unlike some exposure assessment tools, guidelines for wristbands, such as preparation, applicable chemicals, and transport and storage logistics, are lacking. We tested the wristband's capacity to capture and retain 148 chemicals including polychlorinated biphenyls (PCBs), pesticides, flame retardants, polycyclic aromatic hydrocarbons (PAHs), and volatile organic chemicals (VOCs). The chemicals span a wide range of physical-chemical properties, with log octanol-air partitioning coefficients from 2.1 to 13.7. All chemicals were quantitatively and precisely recovered from initial exposures, averaging 102% recovery with relative SD ≤21%. In simulated transport conditions at +30 °C, SVOCs were stable up to 1 month (average: 104%) and VOC levels were unchanged (average: 99%) for 7 days. During long-term storage at -20 °C up to 3 (VOCs) or 6 months (SVOCs), all chemical levels were stable from chemical degradation or diffusional losses, averaging 110%. Applying a paired wristband/active sampler study with human participants, the first estimates of wristband-air partitioning coefficients for PAHs are presented to aid in environmental air concentration estimates. Extrapolation of these stability results to other chemicals within the same physical-chemical parameters is expected to yield similar results. As we better define wristband characteristics, wristbands can be better integrated in exposure science and epidemiological studies.

Figure 1

Recovery, transport, and storage stability experimental design. Dashed blue line represents long-term storage, dotted orange line represents accelerated storage stability, and dash–dot line represents transport stability. The cleaning step was only used for wristbands deployed outside the laboratory.

Figure 2

Conditioned wristband in orange shown in the total ion chromatogram (TIC) below, compared with an improperly prepared wristband (gray trace). Note that a wristband without any cleaning would be even further off scale.

Figure 3

Select chemicals from five broad classes of chemicals. Sets include stability at 4, 7, 28, 82, and 182 (or 183) days (x axis) and −20 °C, 4 °C, and +30 °C are organized as three groups on the y axis. The percentage recovery for each chemical is given by the y axis (scale on left). Stability out to 183 days is reported for −20 °C for all SVOC chemical classes. Recoveries at 2–4, 7, and 28 days at both 4 °C and +30 °C are given for all chemical classes. Each bar represents n=4 for each chemical at each time and temperature, with error bars representing standard error. The gray bar across each graph bounds ±30% of the true value (100%). Within pesticides are representative chemicals from insecticides, herbicides, and fungicides. Within the flame retardants are both an organophosphate and PBDEs. PCBs include tetra-to hepta-chlorinated congeners, and PAHs include 2–6-ring chemicals. VOCs include aromatic, chlorinated, and alkane chemicals.

Figure 4

Linear regression plot of log Koa and estimated log Ksa for 12 PAHs in participants who wore paired wristbands and active air-monitoring backpacks. Values in gray circles were generally expected to fall below the line of best fit since they were not at equilibrium at the end of deployment. PAH, polycyclic aromatic hydrocarbon.