Silicone Wristbands Research Articles

Determining personal exposure to high production volume chemicals (HPVCs) and polycyclic aromatic hydrocarbons (PAHs) with silicone wristbands: A pilot study

High production volume chemicals (HPVCs) and polycyclic aromatic hydrocarbons (PAHs) are semi-volatile organic compounds (semi-VOCs) of great environmental concern because of their presence worldwide and health problems resulting from long-term exposure to some of them. It is essential to have robust analytical methods to monitor the concentrations of these compounds not only in environmental samples but also individual exposure. In this pilot study we develop and validate a multiresidue analytical method based on ultrasound-assisted extraction and gas-chromatography mass spectrometry for the simultaneous determination of 56 semi-VOCs using silicone wristbands (SWBs) as personal passive samplers. The developed method provided recoveries between 43% and 114% on sampled SWBs and method detection and quantification limits in the range of 0.1–35 ng/g and 0.3–119 ng/g, respectively. A preliminary study was performed with a small group of adults living in the industrial city of Tarragona (north-eastern Spain) to evaluate the applicability of SWBs for monitoring individual exposure to the studied HPVCs and PAHs. Benzothiazoles, benzenesulfonamides, UV stabilisers and phenolic antioxidants were determined for the first time in SWBs. Phthalates (PAEs), stood out above the rest, accounting for 52% of the total concentrations. Diethylhexyl phthalate was the compound found at the highest concentrations with values between 1.1 and 82 μg/g. Carcinogenic and non-carcinogenic dermal risk assessment was performed for adults and considering two scenarios (low and high). PAHs were the compounds with the highest carcinogenic and non-carcinogenic dermal risk regardless of the exposure scenario. The second family of compounds that contributed the most to the total risk were PAEs but high punctual concentrations of these compounds caused significant differences between exposure scenarios.

Occurrence of legacy and emerging organophosphate flame retardants (OPFRs) on silicone wristbands: Comparison within couples

Novel organophosphate flame retardants (OPFRs) are recently identified and highly detected in indoor dusts, but their personal exposure was not clear. Here, wristband was used to estimate non-dietary exposure to emerging OPFRs in comparison with legacy OPFRs in 93 adults in Beijing, China. Comparison of studies in wristband monitoring data showed a clear difference in profiles of legacy OPFRs between China and United States, where tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) was usually the dominant OPFR in the United States, but triphenyl phosphate has the highest contribution to total OPFRs in China. Five emerging OPFRs, including diethylene glycol bis(bis(2-chloroisopropyl) phosphate) (DEGBBCPP) and bis(2-ethylhexyl) phenyl phosphate (BEHPP), were detected in above 45 % of wristbands. The median concentration of DEGBBCPP (2.2 ng/g) was about three times higher than TDCIPP (0.76 ng/g), a legacy chloro-OPFR. Both emerging and legacy OPFRs were significantly correlated within 40 pairs of couples, suggesting major exposure in their homes. Wristbands from husbands had significantly higher tris(2-butoxyethyl) phosphate (TBOEP) and DEGBBCPP, while 2-ethylhexyl diphenyl phosphate (EHDPP) was significantly higher in wives' bands, suggesting gender-related exposure sources for these OPFRs.

Children’s exposure to chemical contaminants: Demographic disparities and associations with the developing basal ganglia

Children are regularly exposed to chemical contaminants that may influence brain development. However, relatively little is known about how these contaminants impact the developing human brain. Here, we combined silicone wristband exposure assessments with neuroimaging for the first time to examine how chemical contaminant mixtures are associated with the developing basal ganglia—a brain region key for the healthy development of emotion, reward, and motor processing, and which may be particularly susceptible to contaminant harm. Further, we examined demographic disparities in exposures to clarify which children were at highest risk for any contaminant-associated neurobiological changes. Participants included 62 community children (average age 7.00 years, 53% female, 66% White) who underwent structural neuroimaging to provide data on their basal ganglia structure and wore a silicone wristband for seven days to track their chemical contaminant exposure. 45 chemical contaminants—including phthalates and their alternatives, brominated flame retardants, organophosphate esters, pesticides, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls—were detected in over 75% of wristbands. Notable demographic disparities in exposure were present, such that Non-White and lower-income children were more exposed to several contaminants. Exposure to chemical contaminant mixtures was not associated with overall basal ganglia volume; however, two organophosphate esters (2IPPDPP and 4IPPDPP) were both associated with a larger globus pallidus, a basal ganglia sub-region. Results highlight demographic disparities in exposure and suggest possible risks to a brain region key for healthy emotional development.

Occupational Exposure of On-Shift Ottawa Firefighters to Flame Retardants and Polycyclic Aromatic Hydrocarbons.

Firefighters can be exposed to complex mixtures of airborne substances, including hazardous substances released during structural fires. This study employed silicone wristbands (SWBs) as passive samplers to investigate potential exposure to polycyclic aromatic hydrocarbons (PAHs) and flame retardants (FRs). SWBs were deployed at different areas of four fire stations, in four truck cabins, and at an office control location; they were also donned outside the jackets of 18 firefighters who responded to fire calls. Overall, office areas had significantly lower PAHs than fire station areas. Vehicle bays and truck cabins had significantly higher concentrations of low molecular weight (LMW) PAHs than sleeping and living room areas. For organophosphate ester flame retardants (OPFRs), tri-n-butyl phosphate (TnBP) and tris(1-chloro-2-propyl) phosphate (TCPP) were detected in all the samples; 2-ethylhexyl diphenyl phosphate (EHDPP) was more frequently detected in the fire station areas. Triphenyl phosphate (TPP) concentrations were highest in the truck cabin and office areas, and tris(1,3-dichloro-2-propyl)phosphate (TDCPP) was highest in truck cabins. Thirteen of 16 PAHs and nine of 36 OPFRs were detected in all the SWBs worn by firefighters, and tris (2-butoxyethyl) phosphate (TBEP) was the predominant OPFR. Levels of LMW PAHs were significantly lower when firefighters did not enter the fire. LMW PAHs, HMW (high molecular weight) PAHs, and EHDPP were significantly elevated when heavy smoke was reported. This work highlights the potential for occupational exposure to PAHs and flame retardants in some fire station areas; moreover, factors that may influence exposure during fire suppression. Whilst firefighters' occupational exposure to PAHs is likely related to fire suppression and exposure to contaminated gear and trucks, exposure to OPFRs may be more related to their presence in truck interiors and electronics.

Silicone Wristbands as a Personal Passive Sampler to Evaluate Indoor Exposure to Volatile and Non-volatile PFASs.

Exposure to per- and polyfluoroalkyl substances (PFASs) primarily occurs via consumption of contaminated drinking water and food; however, individuals can also be exposed dermally and via inhalation indoors. This study developed an analytical method for measuring volatile PFASs in silicone wristbands and used them to assess personal exposure in a Midwestern community (n = 87). Paired samples of blood and wristbands were analyzed for PFASs using LC-MS/MS and GC-HRMS to monitor both non-volatile and volatile PFASs. The most frequently detected PFASs in wristbands were: 6:2 diPAP, 6:2 FTOH, MeFOSE and EtFOSE. Females had a 4-fold higher exposure to 6:2 diPAP compared to males and age-dependent differences in exposure to 6:2 FTOH, MeFOSE and EtFOSE were observed. Exposure to MeFOSE and EtFOSE differed based on the average time spent in the home. Frequently detected PFASs in blood were: PFOA, PFOS, PFHxS, PFHpS, and N-MeFOSAA. A strong correlation was found between MeFOSE in the wristbands and N-MeFOSAA in serum (rs = 0.90, p-value <0.001), suggesting exposure to this PFAS was primarily via inhalation and dermal exposure. These results demonstrate that wristbands can provide individual level data on exposure to some polyfluoroalkyl precursors present indoors that reflect serum levels of their suspected biotransformation products.

Chemical and non-chemical stressors in a postpartum cohort through wristband and self report data: Links between increased chemical burden, economic, and racial stress

Multiple external stressors are known to have adverse impacts on health and development. Certain groups are more vulnerable and/or more likely to be exposed toenvironmental, psychological, and social stressors simultaneously. Yet, few studies have examined combined exposure to environmental toxicants and psychosocial stress. Here, we integrated environmental chemical exposure data collected using silicone wristbands and self-report social stressor data within the Brain and Early Experience (BEE) perinatal cohort to understand co-exposure to environmental chemicals and social stress. Silicone wristbands were worn for one week by mothers throughout central North Carolina who were 6 months postpartum (n = 97). Exposure to 110 environmental chemicals across eight chemical classes was quantified on silicone wristbands using gas chromatography mass spectrometry. Social stress was evaluated using eight established self-report questionnaires (e.g., Brief Symptom Inventory, Perceived Stress Scale), quantifying experiences such as race-related stress, economic strain, and relationship conflict. Hair cortisol levels were measured as an additional metric of stress. The chemical exposure landscape and associations among chemical exposure, demographic characteristics, and social stress were characterized through individual variable analyses, cluster and data reduction, and compiled scoring approaches to comprehensively evaluate chemical and social stress burdens. We found that chemicals contain co-occurring patterns largely based on chemical class, with phthalates representing the chemical class with highest exposure and polychlorinated biphenyls the lowest. Chemicals showed differential exposure across racial groups, with diethyl phthalate, triphenyl phosphate, and tris(3,5-dimethyl phenyl) phosphate at higher levels in Black participants compared with White participants. Integrating social stressor profiling with chemical exposure data identified one particularly vulnerable subset of participants in which high chemical exposure burden coincided with high experiences of racism and economic stress. These findings demonstrate co-occurring chemical and social stress, warranting further investigation to better understand how these combined stressors may contribute to disparities in maternal and child health.

Evaluating the use of silicone wristbands and urine biomarkers for assessment of phthalate exposure

Evaluating the use of silicone wristbands and urine biomarkers for assessment of phthalate exposure

Associations of environmental chemical exposures measured in personal silicone wristbands with sociodemographic factors, COVID-19 restrictions, and child respiratory health

BackgroundAlthough human biomonitoring of environmental chemicals has been considered a gold standard, these methods can be costly, burdensome, and prone to unwanted sources of variability that may cause confounding. Silicone wristbands have recently emerged as innovative passive samplers for measuring personal exposures. MethodsIn a pilot study from 2019 to 2021 involving 55 children aged 5–9 years in Seattle and Yakima, Washington, we utilized silicone wristbands to explore associations of sociodemographic variables and COVID-19-related restrictions, including school closures, with exposures to numerous chemicals including brominated and organophosphate ester (OPE) flame retardants, polychlorinated biphenyls, polycyclic aromatic hydrocarbons (PAHs), phthalates, and pesticides. We additionally conducted the first analysis testing silicone wristband chemicals as predictors of child wheeze, individually and in mixtures via logistic weighted quantile sum regression (WQS). ResultsAmong 109 semi-volatile organic compounds measured, we detected 40 in >60% of wristbands worn by children continuously for an average of 5 days. Chemicals were generally positively correlated, especially within the same class. Male sex and increasing age were linked with higher exposures across several chemical classes; Hispanic/Latino ethnicity was linked with higher exposures to some phthalates and OPEs. COVID-19 restrictions were associated with lower wristband concentrations of brominated and triaryl OPE flame retardants. Each one-decile higher WQS exposure index was suggestively associated with 2.11-fold [95% CI: 0.93–4.80] higher odds of child wheeze. Risk of child wheeze was higher per 10-fold increase in the PAH chrysene (RR = 1.93[1.07–3.49]), the pesticide cis-permethrin (3.31[1.23–8.91]), and di-isononyl phthalate (DINP) (5.40[1.22–24.0]) ConclusionsOur identification of demographic factors including sex, age, and ethnicity associated with chemical exposures may aid efforts to mitigate exposure disparities. Lower exposures to flame retardants during pandemic restrictions corroborates prior evidence of higher levels of these chemicals in school versus home environments. Future research in larger cohorts is needed to validate these findings.

Silicone wristbands reveal ubiquitous human exposure to ortho-phthalates and non-ortho-phthalate plasticizers in Southern California

In the United States and abroad, ortho-phthalates and non-ortho-phthalate plasticizers continue to be used within a diverse array of consumer products. Prior California-specific biomonitoring programs for ortho-phthalates have focused on rural, agricultural communities and, to our knowledge, these programs have not measured the potential for exposure to non-ortho-phthalate plasticizers. Therefore, the potential for human exposure to ortho-phthalates and non-ortho-phthalate plasticizers have not been adequately addressed in regions of California that have higher population density. Since there are numerous sources of ortho-phthalates and non-ortho-phthalate plasticizers in population-dense, urban regions, the objective of this study was to leverage silicone wristbands to quantify aggregate ortho-phthalate and non-ortho-phthalate plasticizer exposure over a 5-day period across two different cohorts (2019 and 2020) of undergraduate students at the University of California, Riverside (UCR) that commute from all over Southern California. Based on 5 d of aggregate exposure across two different cohorts, total ortho-phthalate plus non-ortho-phthalate plasticizer concentrations ranged, on average, from ∼100,000–1,000,000 ng/g. Based on the distribution of individual ortho-phthalate and non-ortho-phthalate plasticizer concentrations, the concentrations of di-isononyl phthalate (DiNP, a high molecular weight ortho-phthalate), di (2-ethylhexyl) phthalate (DEHP, a high molecular weight ortho-phthalate), and di-2-ethylhexyl terephthalate (DEHT, a non-ortho-phthalate plasticizer) detected within wristbands were higher than the remaining seven ortho-phthalates and non-ortho-phthalate plasticizers measured, accounting for approximately 94–97% of the total mass depending on the cohort. Overall, our findings raise concerns about chronic DiNP, DEHP, and DEHT exposure in urban, population-dense regions throughout California.

Children's exposure to brominated flame retardants in the home: The TESIE study

Due to differences in chemical properties and half-lives, best practices for exposure assessment may differ for legacy versus novel brominated flame retardants (BFRs). Our objective was to identify the environment matrix that best predicted biomarkers of children's BFR exposures. Paired samples were collected from children aged 3–6 years and their homes, including dust, a small piece of polyurethane foam from the furniture, and a handwipe and wristband from each child. Biological samples collected included serum, which was analyzed for 11 polybrominated diphenyl ethers (PBDEs), and urine, which was analyzed for tetrabromobenzoic acid (TBBA), a metabolite of 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (EH-TBB). Significant positive correlations were typically observed between BFRs measured in dust, handwipes and wristbands, though wristbands and handwipes tended to be more strongly correlated with one another than with dust. PBDEs, EH-TBB and BEH-TEBP were detected in 30% of the sofa foam samples, suggesting that the foam was treated with PentaBDE or Firemaster® 550/600 (FM 550/600). PBDEs were detected in all serum samples and TBBA was detected in 43% of urine samples. Statistically significant positive correlations were observed between the environmental samples and serum for PBDEs. Urinary TBBA was 6.86 and 6.58 times more likely to be detected among children in the highest tertile of EH-TBB exposure for handwipes and wristbands, respectively (95 % CI: 2.61, 18.06 and 1.43, 30.05 with p < 0.001 and 0.02, respectively). The presence of either PentaBDE or FM 550/600 in furniture was also associated with significantly higher levels of these chemicals in dust, handwipes and serum (for PBDEs) and more frequent detection of TBBA in urine (p = 0.13). Our results suggest that children are exposed to a range of BFRs in the home, some of which likely originate from residential furniture, and that silicone wristbands are a practical tool for evaluating external exposure to both legacy and novel BFRs.

Characterization of fire investigators’ polyaromatic hydrocarbon exposures using silicone wristbands

BackgroundExposures to polyaromatic hydrocarbons (PAHs) contribute to cancer in the fire service. Fire investigators are involved in evaluations of post-fire scenes. In the US, it is estimated that there are up to 9000 fire investigators, compared to approximately 1.1 million total firefighting personnel. This exploratory study contributes initial evidence of PAH exposures sustained by this understudied group using worn silicone passive samplers. ObjectivesEvaluate PAH exposures sustained by fire investigators at post-fire scenes using worn silicone passive samplers. Assess explanatory factors and health risks of PAH exposure at post-fire scenes. MethodsAs part of a cross-sectional study design, silicone wristbands were distributed to 16 North Carolina fire investigators, including eight public, seven private, and one public and private. Wristbands were worn during 46 post-fire scene investigations. Fire investigators completed pre- and post-surveys providing sociodemographic, occupational, and post-fire scene characteristics. Solvent extracts from wristbands were analyzed via gas chromatography-mass spectrometry (GC-MS). Results were used to estimate vapor-phase PAH concentration in the air at post-fire scenes. ResultsFire investigations lasted an average of 148 minutes, standard deviation ± 93 minutes. A significant positive correlation (r=0.455, p<.001) was found between investigation duration and PAH concentrations on wristbands. Significantly greater time-normalized PAH exposures (p=0.039) were observed for investigations of newer post-fire scenes compared to older post-fire scenes. Regulatory airborne PAH exposure limits were exceeded in six investigations, based on exposure to estimated vapor-phase PAH concentrations in the air at post-fire scenes. DiscussionHigher levels of off-gassing and suspended particulates at younger post-fire scenes may explain greater PAH exposure. Weaker correlations are found between wristband PAH concentration and investigation duration at older post-fire scenes, suggesting reduction of off-gassing PAHs over time. Exceedances of regulatory PAH limits indicate a need for protection against vapor-phase contaminants, especially at more recent post-fire scenes.

Monitoring human exposure to four parabens and triclosan: comparing silicone wristbands with spot urine samples as predictors of internal dose

BackgroundPeople are exposed to a variety of chemicals each day as a result of their personal care product (PCP) use.ObjectiveThis study was designed to determine if silicone wristbands provide a quantitative estimate of internal dose for phenols commonly associated with PCPs, with a focus on triclosan and four parabens: methyl-, ethyl-, propyl-, and butylparaben. Uptake of these compounds into wristbands and correlations with internal dose were assessed.MethodsTen adults from central North Carolina wore five silicone wristbands, with one wristband removed each day for 5 days. Each participant provided a 24 h urine sample and a random spot urine sample each day, in which paraben and triclosan metabolites were evaluated.ResultsAll parabens and triclosan were detected frequently in wristbands and, except for butylparaben, in urine samples. Wristband and spot urine concentrations of parabens and triclosan were both compared to a measurement of internal dose (i.e., the total metabolite mass excreted over 5 days as a measurement of internal dose).Impact statementThe two most hydrophobic compounds investigated, butylparaben and triclosan, displayed significant linear uptake in wristbands over 5 days, whereas concentrations of methyl- and ethylparaben displayed a steady state concentration. In general, wristbands and spot urine samples were similarly correlated to internal dose for frequently detected parabens and triclosan. However, wristbands have additional advantages including higher detection rates and reduced participant burden that may make them more suitable tools for assessing exposure to PCPs.

Personal environmental exposure to plasticizers and organophosphate flame retardants using silicone wristbands and urine: Patterns, comparisons, and correlations

Plasticizers (PLs) and organophosphate flame retardants (OPFRs) are ubiquitous in the environment due to their widespread use and potential for leaching from consumer products. Environmental exposure is a critical aspect of the human exposome, revealing complex interactions between environmental contaminants and potential health effects. Silicone wristbands (SWBs) have emerged as a novel and non-invasive sampling device for assessing personal external exposure. In this study, SWBs were used as a proxy to estimate personal dermal adsorption (EDdermal) to PLs and OPFRs in Belgian participants for one week; four morning urine samples were also collected and analyzed for estimated daily intake (EDI). The results of the SWBs samples showed that all the participants were exposed to these chemicals, and the exposure was found to be highest for the legacy and alternative plasticizers (LP and AP), followed by the legacy and emerging OPFRs (LOPFR and EOPFR). In urine samples, the highest levels were observed for metabolites of diethyl phthalate (DEP), di-isobutyl phthalate (DiBP) and di-n-butyl phthalate (DnBP) among LPs and di(2-ethylhexyl) terephthalate (DEHT) for APs. Outliers among the participants indicated that there were other sources of exposure that were not identified. Results showed a significant correlation between EDdermal and EDI for DiBP, tris (2-butoxyethyl) phosphate (TBOEP) and triphenyl phosphate (TPhP). These correlations indicated their suitability for predicting exposure via SWB monitoring for total chemical exposure. The results of this pilot study advance our understanding of SWB sampling and its relevance for predicting aggregate environmental chemical exposures, while highlighting the potential of SWBs as low-cost, non-invasive personal samplers for future research. This innovative approach has the potential to advance the assessment of environmental exposures and their impact on public health.

Quantifying 209 Polychlorinated Biphenyl Congeners in Silicone Wristbands to Evaluate Differences in Exposure among Demolition Workers.

A social housing estate in Denmark was designated for demolition due to exceedance of guidance values for polychlorinated biphenyls (PCBs) in indoor air. Here, we deployed precleaned silicone wristbands (n = 46) among demolition workers of these contaminated buildings during single workdays while conducting various work tasks. We established a method to analyze all 209 PCBs in wristbands to identify prominent congeners of exposure and evaluate differences between tasks. Wristbands were extracted using microwave-assisted extraction and then concentrated for gas chromatography-tandem mass spectrometry (GC-MS/MS) analysis. Twenty-nine chromatographic peaks representing 37 congeners were detected in every wristband, and tetra-CBs were the dominant homologue group. PCB-66, -44, and -70 were the most abundant congeners measured in worker wristbands, none of which are included within the typical seven indicator or WHO 12 PCBs. Workers who cut PCB-containing sealants had wristbands with the highest PCB concentrations (geometric mean ∑209PCBs = 1963 ng/g wristband), which were followed by those handling concrete elements on the building roof. Additionally, wristbands captured a broader range of PCBs than has been previously measured in air and serum samples. Taken together, our results highlight the importance of total congener analysis in assessing current PCB exposure in demolition work and the utility of wristbands for assessing these exposures.

Occupational exposures among women beedi workers in Mysore District, India: A mixed-methods study protocol.

Beedi is the most common smoking form of tobacco used in India. The rolling of beedis is performed primarily by women in settings that lack occupational safeguards. The aims of this protocol are to establish methods for the study of occupational exposures among women beedi workers and their experiences and challenges working with unburnt tobacco. This protocol employs a convergent parallel mixed-methods approach. Qualitatively, we plan to explore the experiences and challenges faced by women beedi workers using photovoice, a community based participatory method. Occupational exposures to pesticides will be assessed through the use of silicone wristbands worn for seven days by workers, and exposure to toxic metals and metalloids will be assessed in dust samples collected in the homes of workers. The outcomes will be analyzed to form policy recommendations to improve the occupational health of women beedi workers.

Chemical uptake into silicone wristbands over a five day period

Silicone wristbands are a noninvasive personal exposure assessment tool. However, despite their utility, questions remain about the rate at which chemicals accumulate on wristbands when worn, as validation studies utilizing wristbands worn by human participants are limited. This study evaluated the chemical uptake rates of 113 organic pollutants from several chemical classes (i.e., polychlorinated biphenyls (PCB), organophosphate esters (OPEs), alkyl OPEs, polybrominated diphenyl ethers (PBDEs), brominated flame retardants (BFR), phthalates, pesticides, and polycyclic aromatic hydrocarbons (PAHs) over a five-day period. Adult participants (n = 10) were asked to wear five silicone wristbands and then remove one wristband each day. Several compounds were detected in all participants' wristbands after only one day. The number of chemicals detected frequently (i.e. in at least seven participants wristbands) increased from 20% of target compounds to 26% after three days and more substantially increased to 34% of target compounds after four days of wear. Chemicals detected in at least seven participants’ day five wristbands (n = 24 chemicals) underwent further statistical analysis, including estimating the chemical uptake rates over time. Some chemicals, including pesticides and phthalates, had postive and significant correlations between concentrations on wristbands worn five days and concentrations of wristbands worn fewer days suggesting chronic exposure. For 23 of the 24 compounds evaluated there was a statistically significant and positive linear association between the length of time wristbands were worn and chemical concentrations in wristbands. Despite the differences that exist between laboratory studies using polydimethylsiloxane (PDMS) environmental samplers and worn wristbands, these results indicate that worn wristbands are primarily acting as first-order kinetic samplers. These results suggest that studies using different deployment lengths should be comparable when results are normalized to the length of the deployment period. In addition, a shorter deployment period could be utilized for compounds that were commonly detected in as little as one day.

Development of Nontargeted Workflow of Occupational Exposure by Infrared Ion Spectroscopy and Silicone Wristbands' Passive Sampling.

A new approach using orthogonal analytical techniques is developed for chemical identification. High resolution mass spectrometry and infrared ion spectroscopy are applied through a 5-level confidence paradigm to demonstrate the effectiveness of nontargeted workflow for the identification of hazardous organophosphates. Triphenyl phosphate is used as a surrogate organophosphate for occupational exposure, and silicone wristbands are used to represent personal samplers. Spectral data of a target compound is combined with spectral data of the sodium adduct and quantum chemical calculations to achieve a confirmed identification. Here, we demonstrate a nontargeted workflow that identifies organophosphate exposure and provides a mechanism for selecting validated methods for quantitative analyses.

HBM4EU E-waste study: Assessing persistent organic pollutants in blood, silicone wristbands, and settled dust among E-waste recycling workers in Europe

E-waste recycling is an increasingly important activity that contributes to reducing the burden of end-of-life electronic and electrical apparatus and allows for the EU's transition to a circular economy. This study investigated the exposure levels of selected persistent organic pollutants (POPs) in workers from e-waste recycling facilities across Europe.The concentrations of seven polychlorinated biphenyls (PCBs) and eight polybrominated diphenyl ethers (PBDEs) congeners were measured by GC-MS. Workers were categorized into five groups based on the type of e-waste handled and two control groups. Generalized linear models were used to assess the determinants of exposure levels among workers. POPs levels were also assessed in dust and silicone wristbands (SWB) and compared with serum.Four PCB congeners (CB 118, 138, 153, and 180) were frequently detected in serum regardless of worker's category. With the exception of CB 118, all tested PCBs were significantly higher in workers compared to the control group. Controls working in the same company as occupationally exposed (Within control group), also displayed higher levels of serum CB 180 than non-industrial controls with no known exposures to these chemicals (Outwith controls) (p < 0.05). BDE 209 was the most prevalent POP in settled dust (16 μg/g) and SWB (220 ng/WB). Spearman correlation revealed moderate to strong positive correlations between SWB and dust. Increased age and the number of years smoked cigarettes were key determinants for workers exposure. Estimated daily intake through dust ingestion revealed that ΣPCB was higher for both the 50th (0.03 ng/kg bw/day) and 95th (0.09 ng/kg bw/day) percentile exposure scenarios compared to values reported for the general population.This study is one of the first to address the occupational exposure to PCBs and PBDEs in Europe among e-waste workers through biomonitoring combined with analysis of settled dust and SWB. Our findings suggest that e-waste workers may face elevated PCB exposure and that appropriate exposure assessments are needed to establish effective mitigation strategies.

Arachidonic Acid Metabolites in Self-collected Biospecimens Following Campfire Exposure: Exploring Non-invasive Biomarkers of Wildfire Health Effects.

Climate change has contributed to increased frequency and intensity of wildfire. Studying its acute effects is limited due to unpredictable nature of wildfire occurrence, which necessitates readily deployable techniques to collect biospecimens. To identify biomarkers of wildfire's acute effects, we conducted this exploratory study in eight healthy campers (four men and four women) who self-collected nasal fluid, urine, saliva, and skin wipes at different time points before, during, and after 4-hour exposure to wood smoke in a camping event. Concentrations of black carbon in the air and polycyclic aromatic hydrocarbons in participants' silicone wristbands were significantly elevated during the exposure session. Among 30 arachidonic acid metabolites measured, lipoxygenase metabolites were more abundant in nasal fluid and saliva, whereas cyclooxygenase and non-enzymatic metabolites were more abundant in urine. We observed drastic increases, at 8 hours following the exposure, in urinary levels of PGE2 (398%) and 15-keto-PGF2α (191%) (FDR<10%), with greater increases in men (FDR < 0.01%) than in women. No significant changes were observed for other metabolites in urine or the other biospecimens. Our results suggest urinary PGE2 and 15-keto-PGF2α as promising biomarkers reflecting pathophysiologic (likely sex-dependent) changes induced by short-term exposure to wildfire.

PM2.5 Is Insufficient to Explain Personal PAH Exposure.

To understand how chemical exposure can impact health, researchers need tools that capture the complexities of personal chemical exposure. In practice, fine particulate matter (PM2.5) air quality index (AQI) data from outdoor stationary monitors and Hazard Mapping System (HMS) smoke density data from satellites are often used as proxies for personal chemical exposure, but do not capture total chemical exposure. Silicone wristbands can quantify more individualized exposure data than stationary air monitors or smoke satellites. However, it is not understood how these proxy measurements compare to chemical data measured from wristbands. In this study, participants wore daily wristbands, carried a phone that recorded locations, and answered daily questionnaires for a 7-day period in multiple seasons. We gathered publicly available daily PM2.5 AQI data and HMS data. We analyzed wristbands for 94 organic chemicals, including 53 polycyclic aromatic hydrocarbons. Wristband chemical detections and concentrations, behavioral variables (e.g., time spent indoors), and environmental conditions (e.g., PM2.5 AQI) significantly differed between seasons. Machine learning models were fit to predict personal chemical exposure using PM2.5 AQI only, HMS only, and a multivariate feature set including PM2.5 AQI, HMS, and other environmental and behavioral information. On average, the multivariate models increased predictive accuracy by approximately 70% compared to either the AQI model or the HMS model for all chemicals modeled. This study provides evidence that PM2.5 AQI data alone or HMS data alone is insufficient to explain personal chemical exposures. Our results identify additional key predictors of personal chemical exposure.