Nicotine levels in silicone wristband samplers worn by children exposed to secondhand smoke and electronic cigarette vapor are highly correlated with child's urinary cotinine

Low levels of nicotine and cotinine but not benzo[a]pyrene induce human trophoblast cell proliferation

E-cigarettes use constitutes a source of thirdhand nicotine exposure. The increasing use of electronic cigarettes in homes and public places increases the risk of exposure of pregnant women to thirdhand nicotine. The effects of exposure of pregnant women to very low levels of nicotine have not been studied in humans but detrimental in experimental animals. The objective of this study is to investigate the effect of nanomolar concentrations of nicotine and its metabolite cotinine on the proliferation of JEG-3, a human trophoblast cell line. We also studied the proliferative effect of nanomolar concentrations of benzo[a]pyrene (B[a]P), a polycyclic hydrocarbon in tobacco smoke, for comparison. We treated JEG-3 cells in culture with nanomolar concentrations of nicotine, cotinine, and B[a]P. Their effect on cell proliferation was determined, relative to untreated cells, by MTT assay. Western blotting was used to assess the mitogenic signaling pathways affected by nicotine and cotinine. In contrast to the inhibitory effects reported with higher concentrations, we showed that nanomolar concentrations of nicotine and cotinine resulted in significant JEG-3 cell proliferation and a rapid but transient increase in levels of phosphorylated ERK and AKT, but not STAT3. Biphasic, non-monotonic effect on cell growth is characteristic of endocrine disruptive chemicals like nicotine. The mitogenic effects of nicotine and cotinine potentially contribute to increased villous epithelial thickness, seen in placentas of some smoking mothers. This increases the diffusion distance for oxygen and nutrients between mother and fetus, contributing to intrauterine growth restriction in infants of smoking mothers.

Influence of tobacco product wastes in a protected coastal reserve adjacent to urbanization

The present study, conducted at the Kendall-Frost Mission Bay Marsh Reserve in San Diego, California, aimed to assess tobacco-related pollutants in urban waters, a topic with limited prior research. Across 26 events occurring between November 2019 and February 2022, encompassing both wet and dry seasons at two outfall sites (Noyes St. and Olney St.), water and sediment samples were subjected to analysis for nicotine and cotinine levels, with Noyes St. displaying wide variation in nicotine concentrations, reaching a peak of 50.75 ng/L in water samples, whereas Olney St. recorded a peak of 1.46 ng/L. Wet seasons consistently had higher nicotine levels in water, suggesting the possibility of tobacco litter entering the reserve through stormwater runoff. Cotinine was detected in both sites in both water and sediment samples; however, these levels were considerably lower in comparison to nicotine concentrations. Limited research assesses aquatic environmental pollution from tobacco use and disposal, especially in protected areas like urban natural reserves. This study was conducted at the Kendall-Frost Mission Bay Marsh Reserve in San Diego, California, to evaluate tobacco-related pollutants in San Diego's urban waters. Twenty-six sampling events between November 2019 and February 2022, spanning wet and dry seasons at two outfall sites, were conducted. Nicotine and cotinine, a major ingredient of tobacco and its metabolite, were analyzed in the collected water and sediment samples. Nicotine concentrations differed substantially between the outfall locations (Noyes St. and Olney St.), with Noyes St. displaying wide variations, averaging at 9.31 (±13.24) ng/L with a maximum concentration of 50.75 ng/L, and Olney St. at 0.53 (±0.41) ng/L with a maximum concentration of 1.46 ng/L in water samples. In both locations, the nicotine concentrations in water samples were higher during wet seasons than dry seasons, and this pattern was more significant at Noyes St. outfall than at Olney St. outfall, which received not only stormwater runoff but also was connected to Mission Bay. Although this pattern did not directly align with sediment nicotine levels at both sites, maximum nicotine concentration in Noyes St. sediments during wet seasons was approximately 120 times higher than in Olney St. sediments. Regarding cotinine, Noyes St. outfall water averaged 3.17 ng/L (±1.88), and Olney St. water averaged 1.09 ng/L (±1.06). Similar to nicotine, the cotinine concentrations were higher in Noyes St. water and sediment compared to Olney St., but overall, the cotinine concentrations in both water and sediment were much lower than the corresponding nicotine concentrations. The study identifies urban stormwater runoff as a potential source of nicotine and cotinine pollution in a protected reserve, implicating tobacco product litter and human tobacco use as contributing factors.

Changes and stability of hand nicotine levels in children of smokers: Associations with urinary biomarkers, reported child tobacco smoke exposure, and home smoking bans

BACKGROUND

Exposure to thirdhand smoke (THS) residue takes place through inhalation, ingestion, and dermal transfer. Hand nicotine levels have been proposed to measure THS pollution in the environment of children, but little is known about its variability and stability over time and correlates of change.

OBJECTIVES

The goal was to determine the stability of hand nicotine in comparison to urinary biomarkers and to explore factors that influence changes in hand nicotine.

METHODS

Data were collected from 0 to 11-year-old children (Mean age = 5.9) who lived with ≥1 tobacco smokers (N = 129). At a 6-week interval, we collected repeated measures of hand nicotine, four urinary biomarkers (cotinine, trans-3'-hydroxycotinine, nicotelline N-oxides, and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol), and parent-reported child tobacco smoke exposure (TSE). Dependent sample t-tests, correlations, and multivariable regression analyses were conducted to examine the changes in child TSE.

RESULTS

Hand nicotine levels (r = 0.63, p < 0.001) showed similar correlations between repeated measures to urinary biomarkers (r = 0.58-0.71; p < 0.001). Different from urinary biomarkers, mean hand nicotine levels increased over time (t(113) = 3.37, p < 0.001) being significantly higher in children from homes without smoking bans at Time 2 (p = 0.016) compared to Time 1 (p = 0.003). Changes in hand nicotine correlated with changes in cotinine and trans-3'-hydroxycotinine (r = 0.30 and r = 0.19, respectively, p < 0.05). Children with home smoking bans at Time 1 and 2 showed significantly lower hand nicotine levels compared to children without home smoking bans.

DISCUSSION

Findings indicate that hand nicotine levels provide additional insights into children's exposure to tobacco smoke pollutants than reported child TSE and urinary biomarkers. Changes in hand nicotine levels show that consistent home smoking bans in homes of children of smokers can lower THS exposure. Hand nicotine levels may be influenced by the environmental settings in which they are collected.

Expanding the access of wearable silicone wristbands in community-engaged research through best practices in data analysis and integration

Wearable silicone wristbands are a rapidly growing exposure assessment technology that offer researchers the ability to study previously inaccessible cohorts and have the potential to provide a more comprehensive picture of chemical exposure within diverse communities. However, there are no established best practices for analyzing the data within a study or across multiple studies, thereby limiting impact and access of these data for larger meta-analyses. We utilize data from three studies, from over 600 wristbands worn by participants in New York City and Eugene, Oregon, to present a first-of-its-kind manuscript detailing wristband data properties. We further discuss and provide concrete examples of key areas and considerations in common statistical modeling methods where best practices must be established to enable meta-analyses and integration of data from multiple studies. Finally, we detail important and challenging aspects of machine learning, meta-analysis, and data integration that researchers will face in order to extend beyond the limited scope of individual studies focused on specific populations.

The Incidence of the XRCC1 rs25487 and PON1 rs662 Polymorphisms in a Population from Central Brazil: Patterns in an Area with a High Level of Agricultural Activity

In Brazil, high levels of agricultural activity are reflected in the consumption of enormous amounts of pesticides. The production of grain in Brazil has been estimated at 289.8 million tons in the 2022 harvest, an expansion of 14.7% compared with 2021. These advances are likely associated with a progressive increase in the occupational exposure of a population to pesticides. The Paraoxonase 1 gene (PON1) is involved in liver detoxification; the rs662 variant of this gene modifies the activity of the enzyme. The repair of pesticide-induced genetic damage depends on the protein produced by the X-Ray Repair Cross-Complementing Group 1 gene (XRCC). Its function is impaired due to an rs25487 variant. The present study describes the frequencies of the rs662 and rs25487 and their haplotypes in a sample population from Goiás, Brazil. It compares the frequencies with other populations worldwide to verify the variation in the distribution of these SNPs, with 494 unrelated individuals in the state of Goiás. The A allele of the rs25487 variant had a frequency of 26% in the Goiás population, and the modified rs662 G allele had a frequency of 42.8%. Four haplotypes were recorded for the rs25487 (G > A) and rs662 (A > G) markers, with a frequency of 11.9% being recorded for the A-G haplotype (both modified alleles), 30.8% for the G-G haplotype, 14.3% for the A-A haplotype, and 42.8% for the G-A haplotype (both wild-type alleles). We demonstrated the distribution of important SNPs associated with pesticide exposure in an area with a high agricultural activity level, Central Brazil.

Switching people who smoke to unfiltered cigarettes: perceptions, addiction and behavioural effects in a cross-over randomised controlled trial

BACKGROUND

Behavioural research is needed to inform a ban on sales of filtered cigarettes that could reduce plastic waste due to discarded filters. This study reports on differences in perceptions, nicotine dependence and behaviour among participants in a cross-over randomised trial of filtered compared with unfiltered cigarettes.

METHOD

This proof-of-concept study involved 43 people who smoke filtered cigarettes (41.9% women, mean age 36.7 years). Participants were provided 2 weeks' supply of filtered cigarettes, 2 weeks of the same brand of unfiltered cigarettes and randomly assigned to starting conditions. Measures included the Modified Cigarette Evaluation Questionnaire; single-item cigarette perception questions; Fagerström Test of Nicotine Dependence; 7-day cigarette consumption, urinary cotinine and intention to quit. Analyses included linear and ordinal repeated measures mixed-effects models and paired t-tests.

RESULTS

Filtered cigarettes were perceived as better tasting, more satisfying, more enjoyable, less aversive, less harsh, less potent and less negatively reinforcing than unfiltered cigarettes. Filtered cigarettes were smoked at a higher rate during the trial than unfiltered cigarettes (p<0.05). There was no difference in cotinine, dependence or intention to quit between filtered versus unfiltered cigarette conditions (p>0.05).

CONCLUSION

People who smoke perceived unfiltered cigarettes as having greater nicotine effects and less desirable sensory effects than filtered cigarettes, and they smoked fewer of these during the trial. Although cotinine, dependence and intention to quit were similar for smoking unfiltered and filtered cigarettes in this small trial, results suggest that banning the sale of filtered cigarettes might make smoking less attractive overall to people who smoke.

TRIAL REGISTRATION NUMBER

NCT03749876.

High density polyethylene (HDPE) and thermoplastic polyurethane (TPU) wristbands as personal passive samplers monitoring per- and polyfluoroalkyl substances (PFASs) exposure to postgraduate students

Per- and polyfluoroalkyl substances (PFASs) present adverse effects for human health, which result in strong needs for reliable tools monitoring personal exposure to PFASs. This study manufactured two wristbands of high density polyethylene (HDPE) and thermoplastic polyurethane (TPU), and used the wristbands to monitor PFASs personal exposure. The analytical method was developed to measure 32 PFASs in the paired HDPE and TPU wristbands worn by 60 postgraduates. Twenty-nine of 32 PFASs were detected and hexafluoropropylene oxide dimer acid (HFPO-DA) was predominant individual PFASs with median concentrations of 337 and 554 pg/g for HDPE and TPU wristbands respectively. The gender and grade of students had moderate effects on PFASs distribution in the wristbands. Higher PFASs levels were determined in the two wristbands worn by the male students compared to the females, and the greatest PFASs concentration was observed in the wristbands worn by the first-year postgraduates, follow by second- and third-year postgraduates. Additionally, significant correlations between paired HDPE and TPU wristbands were observed for perfluorobutanoic acid (PFBA), perfluorohexane sulfonic acid (PFHxS), perfluoroheptane sulfonic acid (PFHpS), perfluorooctane sulfonic acid (PFOS), and HFPO-DA. These results suggest that HDPE and TPU wristbands can be used as effective tools for monitoring personal PFAS exposure.

Wearable Passive Samplers for Assessing Environmental Exposure to Organic Chemicals: Current Approaches and Future Directions

PURPOSE OF REVIEW

We are continuously exposed to dynamic mixtures of airborne contaminants that vary by location. Understanding the compositional diversity of these complex mixtures and the levels to which we are each exposed requires comprehensive exposure assessment. This comprehensive analysis is often lacking in population-based studies due to logistic and analytical challenges associated with traditional measurement approaches involving active air sampling and chemical-by-chemical analysis. The objective of this review is to provide an overview of wearable passive samplers as alternative tools to active samplers in environmental health research. The review highlights the advances and challenges in using wearable passive samplers for assessing personal exposure to organic chemicals and further presents a framework to enable quantitative measurements of exposure and expanded use of this monitoring approach to the population scale.

RECENT FINDINGS

Overall, wearable passive samplers are promising tools for assessing personal exposure to environmental contaminants, evident by the increased adoption and use of silicone-based devices in recent years. When combined with high throughput chemical analysis, these exposure assessment tools present opportunities for advancing our ability to assess personal exposures to complex mixtures. Most designs of wearable passive samplers used for assessing exposure to semi-volatile organic chemicals are currently uncalibrated, thus, are mostly used for qualitative research. The challenge with using wearable samplers for quantitative exposure assessment mostly lies with the inherent complexity in calibrating these wearable devices. Questions remain regarding how they perform under various conditions and the uncertainty of exposure estimates. As popularity of these samplers grows, it is critical to understand the uptake kinetics of chemicals and the different environmental and meteorological conditions that can introduce variability. Wearable passive samplers enable evaluation of exposure to hundreds of chemicals. The review presents the state-of-the-art of technology for assessing personal exposure to environmental chemicals. As more studies calibrate wearable samplers, these tools present promise for quantitatively assessing exposure at both the individual and population levels.

Personal air pollutant exposure monitoring in South African children in the VHEMBE birth cohort

The burden of disease associated with environmental exposures disproportionately impacts residents of low- and middle-income countries. Children living in rural regions of these countries may experience higher exposure to insecticides from indoor residual spraying used for malaria control and household air pollution. This study evaluated environmental exposures of children living in a rural region of South Africa. Quantifying exposure levels and identifying characteristics that are associated with exposure in this geographic region has been challenging due to limitations with available monitoring techniques. Wearable passive samplers have recently been shown to be a convenient and reliable tool for assessing personal exposures. In this study, a passive sampler wristband, known as Fresh Air wristband, was worn by 49 children (five-years of age) residing in the Limpopo province of South Africa. The study leveraged ongoing research within the Venda Health Examination of Mothers, Babies, and their Environment (VHEMBE) birth cohort. A wide range of chemicals (35 in total) were detected using the wristbands, including polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides, phthalates, and organophosphate esters (OPEs) flame retardants. Higher concentrations of PAHs were observed among children from households that fell below the food poverty threshold, did not have access to electric cookstoves/burners, or reported longer times of cooking or burning materials during the sampling period. Concentrations of p,p'-DDD and p,p'-DDT were also found to be elevated for children from households falling below the food poverty threshold as well as for children whose households were sprayed for malaria control within the previous 1.5 years. This study demonstrates the feasibility of using passive sampler wristbands as a non-invasive method for personal exposure assessment of children in rural regions of South Africa to complex mixtures environmental contaminants derived from a combination of sources. Future studies are needed to further identify and understand the effects of airborne environmental contaminants on childhood development and strategies to mitigate exposures.

Silicone wristbands as personal passive sampling devices: Current knowledge, recommendations for use, and future directions

Personal chemical exposure assessment is necessary to determine the frequency and magnitude of individual chemical exposures, especially since chemicals present in everyday environments may lead to adverse health outcomes. In the last decade, silicone wristbands have emerged as a new chemical exposure assessment tool and have since been utilized for assessing personal exposure to a wide range of chemicals in a variety of populations. Silicone wristbands can be powerful tools for quantifying personal exposure to chemical mixtures in a single sample, associating exposure with health outcomes, and potentially overcoming some of the challenges associated with quantifying the chemical exposome. However, as their popularity grows, it is crucial that they are used in the appropriate context and within the limits of the technology. This review serves as a guide for researchers interested in utilizing silicone wristbands as a personal exposure assessment tool. Along with briefly discussing the passive sampling theory behind silicone wristbands, this review performs an in-depth comparison of wristbands to other common exposure assessment tools, including biomarkers of exposure measured in biospecimens, and evaluates their utility in exposure assessments and epidemiological studies. Finally, this review includes recommendations for utilizing silicone wristbands to evaluate personal chemical exposure and provides suggestions on what research is needed to recognize silicone wristbands as a premier chemical exposure assessment tool.

Inter-method reliability of silicone exposome wristbands and urinary biomarker assays in a pregnancy cohort

Silicone wristbands act as passive environmental samplers capable of detecting and measuring concentrations of a variety of chemicals. They offer a noninvasive method to collect complex exposure data in large-scale epidemiological studies. We evaluated the inter-method reliability of silicone wristbands and urinary biomarkers in the New Hampshire Birth Cohort Study. A subset of study participants (n = 96) provided a urine sample and wore a silicone wristband for 7 days at approximately 12 gestational weeks. Women were instructed to wear the wristbands during all their normal activities. Concentrations of urinary compounds and metabolites in the urine and parent compounds in wristbands were compared. High detection rates were observed for triphenyl phosphate (76.0%) and benzophenone (78.1%) in wristbands, although the distribution of corresponding urinary concentrations of chemicals did not differ according to whether chemicals were detected or not detected in wristbands. While detected among only 8.3% of wristbands, median urinary triclosan concentrations were higher among those with triclosan detected in wristbands (9.04 ng/mL) than without (0.16 ng/mL). For most chemicals slight to fair agreement was observed across exposure assessment methods, potentially due to low rates of detection in the wristbands for chemicals where observed urinary concentrations were relatively low as compared to background concentrations in the general population. Our findings support the growing body of research in support of deploying silicone wristbands as an important exposure assessment tool.

Handwashing Results in Incomplete Nicotine Removal from Fingers of Individuals who Smoke: A Randomized Controlled Experiment

OBJECTIVE

Tobacco residue, also known as third-hand smoke (THS), contains toxicants and lingers in dust and on surfaces and clothes. THS also remains on hands of individuals who smoke, with potential transfer to infants during visitation while infants are hospitalized in neonatal intensive care units (NICUs), raising concerns (e.g., hindered respiratory development) for vulnerable infants. Previously unexplored, this study tested handwashing (HW) and sanitization efficacy for finger-nicotine removal in a sample of adults who smoked and were visiting infants in an NICU.

STUDY DESIGN

A cross-sectional sample was recruited to complete an interview, carbon monoxide breath samples, and three nicotine wipes of separate fingers (thumb, index, and middle). Eligible participants (n = 14) reported current smoking (verified with breath samples) and were randomly assigned to 30 seconds of HW (n = 7) or alcohol-based sanitization (n = 7), with the order of finger wipes both counterbalanced and randomly assigned. After randomization, the first finger was wiped for nicotine. Participants then washed or sanitized their hands and finger two was wiped 5 minutes later. An interview assessing tobacco/nicotine use and exposure was then administered, followed by a second breath sample and the final finger wipe (40-60 minutes after washing/sanitizing).

RESULTS

Generalized linear mixed models found that HW was more effective than sanitizer for nicotine removal but failed to completely remove nicotine.

CONCLUSIONS

Without proper protections (e.g., wearing gloves and gowns), NICU visitors who smoke may inadvertently expose infants to THS. Research on cleaning protocols are needed to protect vulnerable medical populations from THS and associated risks.

KEY POINTS

· NICU infants may be exposed to THS via visitors.. · THS is not eliminated by HW or sanitizing.. · THS removal protections for NICU infants are needed..

İdrar kotinin ve kotinin/kreatinin oranının çevresel tütün dumanı maruziyetinin bir biyolojik belirteci olarak kullanımı

Purpose: Exposure to Environmental Tobacco Smoke (ETS) remains a worldwide public health problem. The purpose of this study was to investigate the relationship between parents' smoking habits at home and children's exposure to environmental tobacco smoke by measuring urinary cotinine levels and urine cotinine/creatinine ratios in children. Materials and Methods: This case-control typed analytical study was conducted with 357 children in the 0-18 age group. The case group consisted of 180 children exposed to environmental cigarette smoke. As the control group, it consisted of 177 healthy children and non-smoking in their family. The levels of cotinine and creatinine in spot urinary were analyzed in both groups. Results: The urinary cotinine level of the children was found to be statistically higher in those whose parents were smokers, female gender, fathers with a low educational level, and those with 3 or fewer rooms in the house. The urinary cotinine/creatinine ratio of the children was found to be statistically higher in those whose parents were smokers (15.91 pg/mg (1.54-147.54) vs 7.90 pg/mg (1.29-68.52)), female gender (13.19 pg/mg (1.79-115.07) vs 10.45 pg/mg (1.29-147.54)). Urinary cotinine levels in the ETS exposed group were affected 1042 times more than in the ETS unexposed group [OR:1042,462, 95% CI (139.821.839-7772.246)]. Conclusion: In the present study, urinary cotinine levels were found to be higher in children exposed to tobacco smoke than in children not exposed to tobacco smoke. In the light of these results, urinary cotinine can be used as a biomarker to evaluate exposure to ETS in children. Educating parents is essential to raising their awareness of exposure to ETS and teaching the right behaviors to protect children's health, especially in the home environment.

Silicone wristbands as personal passive samplers of exposure to polychlorinated biphenyls in contaminated buildings

Polychlorinated biphenyls (PCBs) were used in a number of industrial products from 1950 to 80s, including building materials. As a result, some buildings exhibit high levels of PCBs in the indoor environment. The aim of this study was to test silicone wristbands as a method for estimating personal exposure to PCBs in buildings both in controlled experiments and field settings. In the controlled study, the sampling kinetics of silicone wristbands were investigated in a 31-day uptake study. The field study focused on the application of wristbands as a personal exposure measure. It included 71 persons in a contaminated housing estate and 23 persons in a reference group. The linear uptake of PCBs ranged from 2 to 24 days for PCB-8, 18, 28, 31, 40, 44, 49, 52, 66, 99, and 101 under controlled conditions. A generic sampling rate (R_k) of 2.3 m³ d^-1 corresponding to a mass transfer coefficient of 17 m h^-1 was found in the controlled kinetic study. Partitioning coefficients were also determined for the nine congeners. In the field study, an apparent generic field sampling rate (R_f) of 2.6 m³ d^-1 was found; when adjusted to reported hours exposed, it increased to 3.5 m³ d^-1. The wristbands were shown to be a good tool for predicting airborne exposure, as there was a highly significant difference between the exposed and reference group as well as a clear trend when used for ranking of exposure. In correlation analyses, highly significant correlations were observed between air and wristband levels, though adjusting by self-reported exposure time only increased the correlation marginally in the field study. The obtained kinetic data can be used for estimating the magnitude of external exposure. The advantages provided by the wristbands in the form of easy use and handling are significant, though the limitations should also be acknowledged.

Comparing impact of pesticide exposure on cognitive abilities of Latinx children from rural farmworker and urban non-farmworker families in North Carolina

Pesticide exposure remains a health hazard despite extensive study into adverse effects. Children in vulnerable populations, such as Latinx children in farmworker families, are particularly at risk for exposure. Several studies have demonstrated the detrimental cognitive effects of prenatal exposure to pesticides, particularly organophosphates (OPs) within this high-risk group. However, results from studies investigating the cognitive effects of early childhood pesticide exposure are equivocal. Most studies examining the effects of pesticide exposure have used correlative analyses rather than examining populations with expected high and low exposure. The current study compares 8-year-old children from rural families of farmworkers and urban, non-farmworker families. We used the Weschler Intelligence Scale for Children - Fifth Edition (WISC-V) to assess cognitive performance in these children. We designed this study with the expectation that children from farmworker families would have greater exposure to agricultural pesticides than urban, non-farmworker children. This assumption of exposure to agricultural pesticides was confirmed in a recent report that assessed exposure probabilities using life history calendars. However, data from passive wristband sampling of acute (1-week) pesticide exposure from these same children indicate that both study populations have considerable pesticide exposure but to different chemicals. As expected the children of farmworkers had greater OP exposure than non-farmworker children, but the non-farmworker children had greater exposure to two other classes of insecticides (organochlorines [OCs] and pyrethroids). Our analyses considered these findings. A comparison of the cognitive scores between groups revealed that children from farmworker families had slightly higher performance on the Visual-Spatial Index (VSI) and Verbal Comprehension Index (VCI) when compared to children from non-farmworker families. Regression analyses where pesticide exposure was included as covariates revealed that OC exposure accounted for the largest portion of the group differences for both VSI and VCI. However, a post-hoc moderation analysis did not find significant interactions. The main study outcome was that the non-farmworker children exhibited lower WISC-V scores than the children from farmworker families, and the analyses incorporating pesticide exposure measures raise the hypothesis the that pervasive and persistent nature of a variety of pesticides may have adverse effects on the neurodevelopment of young Latinx children whether living in rural or non-farmworker environments.

Evaluating predictive relationships between wristbands and urine for assessment of personal PAH exposure

During events like the COVID-19 pandemic or a disaster, researchers may need to switch from collecting biological samples to personal exposure samplers that are easy and safe to transport and wear, such as silicone wristbands. Previous studies have demonstrated significant correlations between urine biomarker concentrations and chemical levels in wristbands. We build upon those studies and use a novel combination of descriptive statistics and supervised statistical learning to evaluate the relationship between polycyclic aromatic hydrocarbon (PAH) concentrations in silicone wristbands and hydroxy-PAH (OH-PAH) concentrations in urine. In New York City, 109 participants in a longitudinal birth cohort wore one wristband for 48 h and provided a spot urine sample at the end of the 48-hour period during their third trimester of pregnancy. We compared four PAHs with the corresponding seven OH-PAHs using descriptive statistics, a linear regression model, and a linear discriminant analysis model. Five of the seven PAH and OH-PAH pairs had significant correlations (Pearson's r = 0.35-0.64, p ≤ 0.003) and significant chi-square tests of independence for exposure categories (p ≤ 0.009). For these five comparisons, the observed PAH or OH-PAH concentration could predict the other concentration within a factor of 1.47 for 50-80% of the measurements (depending on the pair). Prediction accuracies for high exposure categories were at least 1.5 times higher compared to accuracies based on random chance. These results demonstrate that wristbands and urine provide similar PAH exposure assessment information, which is critical for environmental health researchers looking for the flexibility to switch between biological sample and wristband collection.

A systematic review of the use of silicone wristbands for environmental exposure assessment, with a focus on polycyclic aromatic hydrocarbons (PAHs)

BACKGROUND

Exposure assessment is critical for connecting environmental pollutants to health outcomes and evaluating impacts of interventions or environmental policies. Silicone wristbands (SWBs) show promise for multi-pollutant exposure assessment, including polycyclic aromatic hydrocarbons (PAHs), a ubiquitous class of toxic environmental pollutants.

OBJECTIVE

To review published studies where SWBs were worn on the wrist for human environmental exposure assessments and evaluate the ability of SWBs to capture personal exposures, identify gaps which need to be addressed to implement this tool, and make recommendations for future studies to advance the field of exposure science through utilization of SWBs.

METHODS

We performed a systematic search and a cited reference search in Scopus and extracted key study descriptions.

RESULTS

Thirty-nine unique studies were identified, with analytes including PAHs, pesticides, flame retardants, and tobacco products. SWBs were shipped under ambient conditions without apparent analyte loss, indicating utility for global exposure and health studies. Nineteen articles detected a total of 60 PAHs in at least one SWB. Correlations with other concurrent biological and air measurements indicate the SWB captures exposure to flame retardants, tobacco products, and PAHs.

SIGNIFICANCE

SWBs show promise as a simple-to-deploy tool to estimate environmental and occupational exposures to chemical mixtures, including PAHs.

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

Humans are exposed to numerous potentially harmful chemicals throughout their lifetime. Although many studies have addressed this issue, the data on chronic exposure is still lacking. Hence, there is a growing interest in methods and tools allowing to longitudinally track personal exposure to multiple chemicals via different routes. Since the seminal work, silicone wristbands (WBs) have been increasingly used to facilitate human exposure assessment, as using WBs as a wearable sampler offers new insights into measuring chemical risks involved in many ambient and occupational scenarios. However, the literature lacks a detailed overview regarding methodologies being used; a comprehensive comparison with other approaches of personal exposure assessment is needed as well. Therefore, the aim of this review is fourfold. First, we summarize hitherto conducted research that employed silicone WBs as personal passive samplers. Second, all pre-analytical and analytical steps used to obtain exposure data are discussed. Third, we compare main characteristics of WBs with key features of selected matrices used in exposure assessment, namely urine, blood, hand wipes, active air sampling, and settled dust. Finally, we discuss future needs of research employing silicone WBs. Our work shows a variety of possibilities, advantages, and caveats associated with employment of silicone WBs as personal passive samplers. Although further research is necessary, silicone WBs have already been proven valuable as a tool for longitudinal assessment of personal exposure.

Review of HPLC-MS methods for the analysis of nicotine and its active metabolite cotinine in various biological matrices

In recent years, tobacco smoking is a risk factor for a series of diseases including cardiovascular diseases, cerebrovascular diseases, and cancers. Nicotine, the primary component of tobacco smoke, is mainly transformed to its active metabolite cotinine, which is often used as biomarker for tobacco exposure for its higher blood concentration and longer residence time than nicotine. Various analytical methods have been developed for the determination of nicotine and cotinine in biological matrices. This article reviewed the HPLC-MS based methods for nicotine and/or cotinine analysis in various biological matrices. The sample preparation, mass and chromatographic conditions and method validation results of these methods have been summarized and analyzed. Sample was mainly pretreated by protein precipitation and/or extraction. Separation was achieved using methanol and/or acetonitrile:water (with or without ammonium acetate) on C18 columns, and acetonitrile:water (with formic acid, ammonium acetate/formate) on HILIC columns. Nicotine-d3, nicotine-d4 and cotinine-d3 were commonly used internal standards. Other non-deuterated IS were also used such as ritonavir, N-ethylnorcotinine, and milrinone. For both nicotine and cotinine, the calibration range was 0.005-35000 ng/mL, the matrix effect was 75.96% - 126.8% and the recovery was 53% - 124.5%. The two analytes were stable at room temperature for 1-10 days, at -80 °C for up to 6 months, and after 3-6 freeze-thaw cycles. Comedications did not affect nicotine and cotinine analysis.

Comparative Assessment of Pesticide Exposures in Domestic Dogs and Their Owners Using Silicone Passive Samplers and Biomonitoring

Pesticides are used extensively in residential settings for lawn maintenance and in homes to control household pests including application directly on pets to deter fleas and ticks. Pesticides are commonly detected in the home environment where people and pets can be subject to chronic exposure. Due to increased interest in using companion animals as sentinels for human environmental health studies, we conducted a comparative pesticide exposure assessment in 30 people and their pet dogs to determine how well silicone wristbands and silicone dog tags can predict urinary pesticide biomarkers of exposure. Using targeted gas chromatography-mass spectrometry analyses, we quantified eight pesticides in silicone samplers and used a suspect screening approach for additional pesticides. Urine samples were analyzed for 15 pesticide metabolite biomarkers. Several pesticides were detected in >70% of silicone samplers including permethrin, N,N-diethyl-meta-toluamide (DEET), and chlorpyrifos. Significant and positive correlations were observed between silicone sampler levels of permethrin and DEET with their corresponding urinary metabolites (r_s = 0.50-0.96, p < 0.05) in both species. Significantly higher levels of fipronil were observed in silicone samplers from participants who reported using flea and tick products containing fipronil on their dog. This study suggests that people and their dogs have similar pesticide exposures in a home environment.

Operationalizing the Exposome Using Passive Silicone Samplers

The exposome, which is defined as the cumulative effect of environmental exposures and corresponding biological responses, aims to provide a comprehensive measure for evaluating non-genetic causes of disease. Operationalization of the exposome for environmental health and precision medicine has been limited by the lack of a universal approach for characterizing complex exposures, particularly as they vary temporally and geographically. To overcome these challenges, passive sampling devices (PSDs) provide a key measurement strategy for deep exposome phenotyping, which aims to provide comprehensive chemical assessment using untargeted high-resolution mass spectrometry for exposome-wide association studies. To highlight the advantages of silicone PSDs, we review their use in population studies and evaluate the broad range of applications and chemical classes characterized using these samplers. We assess key aspects of incorporating PSDs within observational studies, including the need to preclean samplers prior to use to remove impurities that interfere with compound detection, analytical considerations, and cost. We close with strategies on how to incorporate measures of the external exposome using PSDs, and their advantages for reducing variability in exposure measures and providing a more thorough accounting of the exposome. Continued development and application of silicone PSDs will facilitate greater understanding of how environmental exposures drive disease risk, while providing a feasible strategy for incorporating untargeted, high-resolution characterization of the external exposome in human studies.

Investigating the association between smoking, environmental tobacco smoke exposure and reward-related brain activity in adolescent experimental smokers

Reduced anticipatory reward‐related activity, especially in the ventral striatum (VS), may underly adolescent vulnerability to develop nicotine dependence. It remains unclear whether nicotine uptake caused by environmental tobacco smoke (ETS) exposure, known to be associated with future smoking, might prompt similar changes in the brain's reward system, rendering adolescents vulnerable for development of nicotine dependence. To address this question, we tested whether current ETS exposure and monthly smoking are associated with VS hypoactivity for non‐drug rewards in experimental smoking adolescents. One‐hundred adolescents performed a monetary incentive delay task while brain activity was measured using fMRI. To test the hypothesized relationship, we used a variety of approaches: (1) a whole‐brain voxel‐wise approach, (2) an region‐of‐interest approach in the VS using frequentist and Bayesian statistics and (3) a small volume voxel‐wise approach across the complete striatum. The results converged in revealing no significant relationships between monthly smoking, ETS exposure and reward‐related brain activation across the brain or in the (ventral) striatum specifically. However, Bayesian statistics showed only anecdotal evidence for the null hypothesis in the VS, providing limited insight into the (non‐)existence of the hypothesized relationship. Based on these results, we speculate that blunted VS reward‐related activity might only occur after relatively high levels of exposure or might be associated with more long term effects of smoking. Future studies would benefit from even larger sample sizes to reliably distinguish between the null and alternative models, as well as more objective measures of (environmental) smoking via using devices such as silicone wristbands.

Altered microbiomes in thirdhand smoke-exposed children and their home environments

INTRODUCTION

Tobacco smoke contains numerous toxic chemicals that accumulate in indoor environments creating thirdhand smoke (THS). We investigated if THS-polluted homes differed in children's human and built-environment microbiomes as compared to THS-free homes.

METHODS

Participants were n = 19 THS-exposed children and n = 10 unexposed children (≤5 years) and their caregivers. Environmental and biological samples were analyzed for THS pollutants and exposure. Swab samples were collected from the built-environment (floor, table, armrest, bed frame) and child (finger, nose, mouth, and ear canal), and 16S ribosomal RNA genes were analyzed for bacterial taxa using high-throughput DNA sequencing.

RESULTS

Phylogenetic α-diversity was significantly higher for the built-environment microbiomes in THS-polluted homes compared to THS-free homes (p < 0.014). Log2-fold comparison found differences between THS-polluted and THS-free homes for specific genera in samples from the built-environment (e.g., Acinetobacter, Bradyrhizobium, Corynebacterium, Gemella, Neisseria, Staphylococcus, Streptococcus, and Veillonella) and in samples from children (esp. Corynebacterium, Gemella, Lautropia, Neisseria, Rothia, Staphylococcus, and Veillonella).

CONCLUSION

When exposed to THS, indoor and children microbiomes are altered in an environment-specific manner. Changes are similar to those reported in previous studies for smokers and secondhand smoke-exposed persons. THS-induced changes in child and built-environmental microbiomes may play a role in clinical outcomes in children.

IMPACT

Despite smoking bans, children can be exposed to tobacco smoke residue (i.e., thirdhand smoke) that lingers on surfaces and in settled house dust. Thirdhand smoke exposure is associated with changes in the microbiomes of the home environment and of the children living in these homes. Thirdhand smoke is associated with increased phylogenetic diversity of the home environment and changes in the abundances of several genera of the child microbiome known to be affected by active smoking and secondhand smoke (e.g., Corynebacterium, Staphylococcus, Streptococcus). Thirdhand smoke exposure by itself may induce alterations in the microbiome that play a role in childhood pathologies.

E-Cigarette Toxicology

Since the spread of tobacco from the Americas hundreds of years ago, tobacco cigarettes and, more recently, alternative tobacco products have become global products of nicotine addiction. Within the evolving alternative tobacco product space, electronic cigarette (e-cigarette) vaping has surpassed conventional cigarette smoking among adolescents and young adults in the United States and beyond. This review describes the experimental and clinical evidence of e-cigarette toxicity and deleterious health effects. Adverse health effects related to e-cigarette aerosols are influenced by several factors, including e-liquid components, physical device factors, chemical changes related to heating, and health of the e-cigarette user (e.g., asthmatic). Federal, state, and local regulations have attempted to govern e-cigarette flavors, manufacturing, distribution, and availability, particularly to underaged youths. However, the evolving e-cigarette landscape continues to impede timely toxicological studies and hinder progress made toward our understanding of the long-term health consequence of e-cigarettes. Expected final online publication date for the Annual Review of Pharmacology and Toxicology, Volume 62 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Exposure of children and mothers to organophosphate esters: Prediction by house dust and silicone wristbands

Ubiquitous human exposure to organophosphorus tri-esters (tri-OPEs) has been reported worldwide. Previous studies investigated the feasibility of using house dust and wristbands to assess human OPE exposure. We hypothesized that these two approaches could differ in relative effectiveness in the characterization of children and adult exposure. In the participants recruited from Guangzhou, South China, urinary levels of major OPE metabolites, including diphenyl phosphate (DPHP) and bis(butoxyethyl) phosphate (BBOEP), were significantly higher in children than their mothers (median 6.6 versus 3.7 ng/mL and 0.11 versus 0.06 ng/mL, respectively). The associations of dust or wristband-associated OPEs with urinary metabolites exhibited chemical-specific patterns, which also differed between children and mothers. Significant and marginally significant associations were determined between dust concentrations of triphenyl phosphate (TPHP), tris(2-butoxyethyl) phosphate (TBOEP), trimethylphenyl phosphate (TMPP), or tris(1-chloro-2-propyl) phosphate (TCIPP) and their metabolites in children urine and between dust tris(1,3-dichloroisopropyl) phosphate (TDCIPP), TPHP or TMPP and urinary metabolites in mothers. By contrast, wristbands exhibited better efficiency of predicting internal exposure to TDCIPP. While both house dust and wristbands exhibited the potential as a convenient approach for assessing long-term OPE exposure, their feasibility requires better investigations via larger-scale studies and standardized sampling protocols.

Thirdhand smoke associations with the gut microbiomes of infants admitted to a neonatal intensive care unit: An observational study

INTRODUCTION

Microbiome differences have been found in adults who smoke cigarettes compared to non-smoking adults, but the impact of thirdhand smoke (THS; post-combustion tobacco residue) on hospitalized infants' rapidly developing gut microbiomes is unexplored. Our aim was to explore gut microbiome differences in infants admitted to a neonatal ICU (NICU) with varying THS-related exposure.

METHODS

Forty-three mother-infant dyads (household member[s] smoke cigarettes, n = 32; no household smoking, n = 11) consented to a carbon monoxide-breath sample, bedside furniture nicotine wipes, infant-urine samples (for cotinine [nicotine's primary metabolite] assays), and stool collection (for 16S rRNA V4 gene sequencing). Negative binomial regression modeled relative abundances of 8 bacterial genera with THS exposure-related variables (i.e., household cigarette use, surface nicotine, and infant urine cotinine), controlling for gestational age, postnatal age, antibiotic use, and breastmilk feeding. Microbiome-diversity outcomes were modeled similarly. Bayesian posterior probabilities (PP) ≥75.0% were considered meaningful.

RESULTS

A majority of infants (78%) were born pre-term. Infants from non-smoking homes and/or with lower NICU-furniture surface nicotine had greater microbiome alpha-diversity compared to infants from smoking households (PP ≥ 75.0%). Associations (with PP ≥ 75.0%) of selected bacterial genera with urine cotinine, surface nicotine, and/or household cigarette use were evidenced for 7 (of 8) modeled genera. For example, lower Bifidobacterium relative abundance associated with greater furniture nicotine (IRR<0.01 [<0.01, 64.02]; PP = 87.1%), urine cotinine (IRR = 0.08 [<0.01,2.84]; PP = 86.9%), and household smoking (IRR<0.01 [<0.01, 7.38]; PP = 96.0%; FDR p < 0.05).

CONCLUSIONS

THS-related exposure was associated with microbiome differences in NICU-admitted infants. Additional research on effects of tobacco-related exposures on healthy infant gut-microbiome development is warranted.

Optimized workflow for unknown screening using gas chromatography high-resolution mass spectrometry expands identification of contaminants in silicone personal passive samplers

RATIONALE

Silicone wristbands have emerged as valuable passive samplers for monitoring of personal exposure to environmental contaminants in the rapidly developing field of exposomics. Once deployed, silicone wristbands collect and hold a wealth of chemical information that can be interrogated using high-resolution mass spectrometry (HRMS) to provide a broad coverage of chemical mixtures.

METHODS

Gas chromatography coupled to Orbitrap™ mass spectrometry (GC/Orbitrap™ MS) was used to simultaneously perform suspect screening (using in-house database) and unknown screening (using vendor databases) of extracts from wristbands worn by volunteers. The goal of this study was to optimize a workflow that allows detection of low levels of priority pollutants, with high reliability. In this regard, a data processing workflow for GC/Orbitrap™ MS was developed using a mixture of 123 environmentally relevant standards consisting of pesticides, flame retardants, organophosphate esters, and polycyclic aromatic hydrocarbons as test compounds.

RESULTS

The optimized unknown screening workflow using a search index threshold of 750 resulted in positive identification of 70 analytes in validation samples, and a reduction in the number of false positives by over 50%. An average of 26 compounds with high confidence identification, 7 level 1 compounds and 19 level 2 compounds, were observed in worn wristbands. The data were further analyzed via suspect screening and retrospective suspect screening to identify an additional 36 compounds.

CONCLUSIONS

This study provides three important findings: (1) a clear evidence of the importance of sample cleanup in addressing complex sample matrices for unknown analysis, (2) a valuable workflow for the identification of unknown contaminants in silicone wristband samplers using electron ionization HRMS data, and (3) a novel application of GC/Orbitrap™ MS for the unknown analysis of organic contaminants that can be used in exposomics studies.

Pesticide exposure among Latinx children: Comparison of children in rural, farmworker and urban, non-farmworker communities

Personal pesticide exposure is not well characterized among children in vulnerable, immigrant communities. We used silicone wristbands in 2018-2019 to assess pesticide exposure in 8 year old Latinx boys and girls in rural, farmworker families (n = 73) and urban, non-farmworker families (n = 60) living in North Carolina who were enrolled in the PACE5 Study, a community-based participatory research study. We determined the detection and concentrations (ng/g) of 75 pesticides and pesticide degradation products in the silicone wristbands worn for one week using gas chromatography electron capture detection and employed gas chromatography mass spectrometry. Differences by personal and family characteristics were tested using analysis of variance or Wilcoxon Rank Sum tests when necessary. Pesticide concentrations above the limit of detection were analyzed, and reported as geometric means and 95% confidence intervals (CI). The most frequently detected pesticide classes were organochlorines (85.7%), pyrethroids (65.4%), and organophosphates (59.4%), with the most frequently detected specific pesticides being alpha-chlordane (69.2%), trans-nonachlor (67.7%), gamma-chlordane (66.2%), chlorpyrifos (54.9%), cypermethrin (49.6%), and trans-permethrin (39.1%). More of those children in urban, non-farmworker families had detections of organochlorines (93.3% vs. 79.5, p = 0.0228) and pyrethroids (75.0% vs. 57.5%, p = 0.0351) than did those in rural, farmworker families; more children in rural, farmworker families had detections for organophosphates (71.2% vs. 45.0%, p= 0.0022). Children in urban, non-farmworker families had greater concentrations of alpha-chlordane (geometric mean (GM) 18.98, 95% CI 14.14, 25.47 vs. 10.25, 95% CI 7.49, 14.03; p= 0.0055) and dieldrin (GM 17.38, 95% CI 12.78 23.62 vs. 8.10, 95% CI 5.47, 12.00; p= 0.0034) than did children in rural, farmworker families. These results support the position that pesticides are ubiquitous in the living environment for children in vulnerable, immigrant communities, and argue for greater effort in documenting the widespread nature of pesticide exposure among children, with greater effort to reduce pesticide exposure.

Nicotine, Cotinine, and Tobacco-Specific Nitrosamines Measured in Children's Silicone Wristbands in Relation to Secondhand Smoke and E-cigarette Vapor Exposure

INTRODUCTION

Simple silicone wristbands (WB) hold promise for exposure assessment in children. We previously reported strong correlations between nicotine in WB worn by children and urinary cotinine (UC). Here, we investigated differences in WB chemical concentrations among children exposed to secondhand smoke from conventional cigarettes (CC) or secondhand vapor from electronic cigarettes (EC), and children living with nonusers of either product (NS).

METHODS

Children (n = 53) wore three WB and a passive nicotine air sampler for 7 days and one WB for 2 days, and gave a urine sample on day 7. Caregivers reported daily exposures during the 7-day period. We determined nicotine, cotinine, and tobacco-specific nitrosamines (TSNAs) concentrations in WB, nicotine in air samplers, and UC through isotope-dilution liquid chromatography with triple-quadrupole mass spectrometry.

RESULTS

Nicotine and cotinine levels in WB in children differentiated between groups of children recruited into NS, EC exposed, and CC exposed groups in a similar manner to UC. WB levels were significantly higher in the CC group (WB nicotine median 233.8 ng/g silicone, UC median 3.6 ng/mL, n = 15) than the EC group (WB nicotine median: 28.9 ng/g, UC 0.5 ng/mL, n = 19), and both CC and EC group levels were higher than the NS group (WB nicotine median: 3.7 ng/g, UC 0.1 ng/mL, n = 19). TSNAs, including the known carcinogen NNK, were detected in 39% of WB.

CONCLUSIONS

Silicone WB show promise for sensitive detection of exposure to tobacco-related contaminants from traditional and electronic cigarettes and have potential for tobacco control efforts.

IMPLICATIONS

Silicone WB worn by children can absorb nicotine, cotinine, and tobacco-specific nitrosamines, and amounts of these compounds are closely related to the child's urinary cotinine. Levels of tobacco-specific compounds in the silicone WB can distinguish patterns of children's exposure to secondhand smoke and e-cigarette vapor. Silicone WB are simple to use and acceptable to children and, therefore, may be useful for tobacco control activities such as parental awareness and behavior change, and effects of smoke-free policy implementation.

Environmental Tobacco Smoke Exposure and Brain Functioning Associated with Smoking Cue-Reactivity and Inhibitory Control in Nonsmoking Adolescents

INTRODUCTION

Despite its well-established negative effects, environmental tobacco smoke (ETS) exposure remains highly prevalent worldwide. ETS exposure is associated with a wide range of physical and mental health-related problems among youth, including an increased likelihood to develop nicotine dependence. Up till now, neurocognitive effects of ETS exposure are largely unknown, while such effects could explain the role of ETS exposure in the development of nicotine dependence. Therefore, this preregistered study investigated the role of current ETS exposure in brain functioning associated with smoking cue-reactivity and inhibitory control.

METHOD

Concurrent with functional magnetic resonance imaging, nonsmoking adolescents aged 14-18 years (N = 51) performed a smoking cue-reactivity task, assessing brain functioning to smoking cues, and a Go/NoGo task measuring inhibitory control. ETS exposure was measured using a self-report questionnaire and biochemically verified.

RESULTS

No significant associations were observed between current ETS exposure and brain functioning associated with smoking cue-reactivity and inhibitory control.

CONCLUSION

These findings suggest that low-to-moderate levels of current ETS exposure are not associated with increased salience of smoking cues or deficits in inhibitory control in nonsmoking adolescents. Longitudinal research is needed to further clarify the exact effect of lifetime ETS exposure on brain functioning, as well as research focusing on the effects of higher levels of ETS exposure.

The use of silicone wristbands to evaluate personal exposure to semi-volatile organic chemicals (SVOCs) in France and Italy

In this exploratory study, we measured for the first-time human exposure to about 90 semi-volatile organic chemicals (SVOCs) in France and Italy using silicone wristbands. Participants in France (n = 40) and in Italy (n = 31) wore a silicone wristband for five days during 2018 and 2019. Samples were analyzed for 39 polybrominated diphenyl ethers (PBDEs), 10 novel brominated flame retardants (nBFRs), 25 organophosphate esters (OPEs), and 18 polycyclic aromatic hydrocarbons (PAHs). In both groups, the most commonly detected chemicals were BDE-209, BEHTBP, tris[(2R)-1-chloro-2-propyl] phosphate (TCIPP), and phenanthrene among PBDEs, nBFRs, OPEs, and PAHs, respectively. The concentrations of ∑₃₉ PBDEs, ∑₁₀ nBFRs, ∑₂₅ OPEs, ∑₁₈ PAHs, and of most individual chemicals were generally significantly higher in samples from France than in those from Italy, except for BDE-209 and TCIPP. On a broader scale, the chemical concentrations were generally significantly lower in this study than those measured in the United States in previous studies using the same type of wristbands. Efforts to standardize the protocols for the use of silicone wristbands are still needed but this study shows that wristbands are capable of capturing regional differences in human exposure to a large variety of SVOCs and, therefore, can be used as personal exposure monitor for studies with global coverage.

Catching flame retardants and pesticides in silicone wristbands: Evidence of exposure to current and legacy pollutants in Uruguayan children

Children are exposed to many potentially toxic compounds in their daily lives and are vulnerable to the harmful effects. To date, very few non-invasive methods are available to quantify children's exposure to environmental chemicals. Due to their ease of implementation, silicone wristbands have emerged as passive samplers to study personal environmental exposures and have the potential to greatly increase our knowledge of chemical exposures in vulnerable population groups. Nevertheless, there is a limited number of studies monitoring children's exposures via silicone wristbands. In this study, we implemented this sampling technique in ongoing research activities in Montevideo, Uruguay which aim to monitor chemical exposures in a cohort of elementary school children. The silicone wristbands were worn by 24 children for 7 days; they were quantitatively analyzed using gas chromatography with tandem mass spectrometry for 45 chemical pollutants, including polychlorinated biphenyls (PCBs), pesticides, polybrominated diphenyl ethers (PBDEs), organophosphorus flame retardants (OPFRs), and novel halogenated flame-retardant chemicals (NHFRs). All classes of chemicals, except NHFRs, were identified in the passive samplers. The average number of analytes detected in each wristband was 13 ±3. OPFRs were consistently the most abundant class of analytes detected. Median concentrations of ΣOPFRs, ΣPBDEs, ΣPCBs, and dichlorodiphenyltrichloroethane (DDT) and its metabolites (dichlorodiphenyldichloroethylene (DDE) and dichlorodiphenyldichloroethane (DDD)) were 1020, 3.00, 0.52 and 3.79 ng/g wristband, respectively. Two major findings result from this research; differences in trends of two OPFRs (TCPP and TDCPP) are observed between studies in Uruguay and the United States, and the detection of DDT, a chemical banned in several countries, suggests that children's exposure profiles in these settings may differ from other parts of the world. This was the first study to examine children's exposome in South America using silicone wristbands and clearly points to a need for further studies.

Urinary metabolites of furan in waterpipe tobacco smokers compared to non-smokers in home settings in the US

OBJECTIVES

Determine uptake of furan, a potential human carcinogen, in waterpipe tobacco (WPT) smokers in home settings.

METHODS

We analysed data from a US convenience sample of 50 exclusive WPT smokers, mean age 25.3 years, and 25 non-smokers, mean age 25.5 years. For WPT smokers, data were collected at a home visit by research assistants during which participants smoked one WPT head of one brand for a mean of 33.1 min in their homes. Research assistants provided and prepared a WP for participants by weighing and loading 10 g of WPT in the WP head. At the completion of the smoking session, research assistants measured the remaining WPT. Cotinine and six furan metabolites were quantified in first morning urine samples provided on 2 consecutive days for non-smokers, and on the morning of a WPT smoking session and on the following morning for smokers.

RESULTS

WPT smokers consumed a mean of 2.99 g WPT. In WPT smokers, urinary cotinine levels increased significantly 26.1 times the following morning; however, urinary metabolites of furan did not increase significantly. Compared to non-smokers, 2 furan metabolites, N-acetyl-S-[1-(5-acetylamino-5-carboxylpentyl)-1H-pyrrol-3-yl]-L-cysteine and N-acetyl-S-[1-(5-amino-5-carboxypentyl)-1H-pyrrol-3-yl]-L-cysteine sulfoxide, were significantly higher in WPT smokers in pre and in post WPT smoking levels.

CONCLUSIONS

To enable a more rigorous assessment of furan exposure from WPT smoking, future research should determine furan concentrations in WPT smoke, quantify furan metabolites from users of various WPT brands; and extend the investigation to social settings where WPT smoking is habitually practiced.

Assessment of Multipollutant Exposures During Pregnancy Using Silicone Wristbands

Silicone wristbands can assess multipollutant exposures in a non-invasive and minimally burdensome manner, which may be suitable for use among pregnant women. We investigated silicone wristbands as passive environmental samplers in the New Hampshire Birth Cohort Study, a prospective pregnancy cohort. We used wristbands to assess exposure to a broad range of organic chemicals, identified multipollutant exposure profiles using self-organizing maps (SOMs), and assessed temporal consistency and determinants of exposures during pregnancy. Participants (n = 255) wore wristbands for 1 week at 12 gestational weeks. Of 1,530 chemicals assayed, 199 were detected in at least one wristband and 16 were detected in >60% of wristbands. A median of 23 (range: 12,37) chemicals were detected in each wristband, and chemicals in commerce and personal care products were most frequently detected. A subset of participants (n=20) wore a second wristband at 24 gestational weeks, and concentrations of frequently detected chemicals were moderately correlated between time points (median intraclass correlation: 0.22; range: 0.00,0.69). Women with higher educational attainment had fewer chemicals detected in their wristbands and the total number of chemicals detected varied seasonally. Triphenyl phosphate concentrations were positively associated with nail polish use, and benzophenone concentrations were highest in summer. No clear associations were observed with other a priori relations, including certain behaviors, season, and socioeconomic factors. SOM analyses revealed 12 profiles, ranging from 2 to 149 participants, captured multipollutant exposure profiles observed in this cohort. The most common profile (n = 149) indicated that 58% of participants experienced relatively low exposures to frequently detected chemicals. Less common (n ≥ 10) and rare (n < 10) profiles were characterized by low to moderate exposures to most chemicals and very high and/or very low exposure to a subset of chemicals. Certain covariates varied across SOM profile membership; for example, relative to women in the most common profile who had low exposures to most chemicals, women in the profile with elevated exposure to galaxolide and benzyl benzoate were younger, more likely to be single, and more likely to report nail polish use. Our study illustrates the utility of silicone wristbands for measurement of multipollutant exposures in sensitive populations, including pregnant women.

Comparing the Use of Silicone Wristbands, Hand Wipes, And Dust to Evaluate Children's Exposure to Flame Retardants and Plasticizers

Organophosphate esters (OPEs) are applied as additive flame retardants, and along with phthalates, are also used as plasticizers in consumer products. As such, human exposure is common and chronic. Deployed as personal passive samplers, silicone wristbands have been shown to detect over a thousand industrial and consumer product chemicals; however, few studies have evaluated chemical concentrations with their corresponding biomarkers of exposure, especially in children. Further, little is known about how well the wristbands predict individual exposure compared to existing validated external exposure tools such as indoor air, dust, and hand wipes. Here, we analyzed wristbands worn by children (ages 3-6) for 18 OPEs and 10 phthalates and compared them to corresponding urinary biomarkers. In wristbands, 13 of 18 OPEs and all phthalates were detected in >80% of wristbands, and 6 OPEs and 4 phthalates were significantly associated with corresponding urinary metabolites (r_s = 0.2-0.6, p < 0.05). When compared to paired hand wipes and house dust, wristbands were found to have similar or greater correlation coefficients with respective urinary biomarkers. These results suggest that wristbands can serve as effective and quantitative assessment tools for evaluating personal exposure to some OPEs and phthalates, and for certain chemicals, may provide a better exposure estimate than indoor dust.

The Effects of Nicotine on Development

Recently, there has been a significant increase in the use of noncombustible nicotine-containing products, including electronic cigarettes (e-cigarettes). Of increasing popularity are e-cigarettes that can deliver high doses of nicotine over short periods of time. These devices have led to a rise in nicotine addiction in adolescent users who were nonsmokers. Use of noncombustible nicotine products by pregnant mothers is also increasing and can expose the developing fetus to nicotine, a known teratogen. In addition, young children are frequently exposed to secondhand and thirdhand nicotine aerosols generated by e-cigarettes, with little understanding of the effects these exposures can have on health. With the advent of these new nicotine-delivery systems, many concerns have arisen regarding the short- and long-term health effects of nicotine on childhood health during all stages of development. Although health studies on nicotine exposure alone are limited, educating policy makers and health care providers on the potential health effects of noncombustible nicotine is needed because public acceptance of these products has become so widespread. Most studies evaluating the effects of nicotine on health have been undertaken in the context of smoke exposure. Nevertheless, in vitro and in vivo preclinical studies strongly indicate that nicotine exposure alone can adversely affect the nervous, respiratory, immune, and cardiovascular systems, particularly when exposure occurs during critical developmental periods. In this review, we have included both preclinical and clinical studies to identify age-related health effects of nicotine exposure alone, examining the mechanisms underlying these effects.

Pharmaceuticals residues and xenobiotics contaminants: Occurrence, analytical techniques and sustainable alternatives for wastewater treatment

Emerging contaminants are increasingly present in the environment, and their appearance on both the environment and health of living beings are still poorly understood by society. Conventional sewage treatment facilities that are under validity and were designed years ago are not developed to remove pharmaceutical compounds, their main focus is organic and bacteriological removal. Pharmaceutical residues are associated directly with quantitative production aspects as well as inadequate waste management policies. Persistent classes of emerging compounds such as xenobiotics present molecules whose physicochemical properties such as small molecular size, ionizability, water solubility, lipophilicity, polarity and volatility make degradability, identification and quantification of these complex compounds difficult. Based on research results showing that there is a possibility of risk to human and environmental health the presence of these compounds in the environment this article aimed to review the main pharmaceutical and xenobiotic residues present in the environment, as well as to present the most common methodologies used. The most commonly used analytical methods for identifying these compounds were HPLC and Gas Chromatography coupled with mass spectrometry with potential for characterize complex substances in the environment with low concentrations. An alternative and low-cost technology for emerging compound treatment demonstrated in the literature with a satisfactory performance for several types of sewage such as domestic sewage, wastewater and agroindustrial, was the Wetlands Constructed. The study was able to identify the main compounds that are being found in the environment and identify the most used analytical methods to identify and quantify these compounds, bringing some alternatives combining technologies for the treatment of compounds. Environmental contamination is eminent, since the production of emerging compounds aims to increase along with technological development. This demonstrates the need to explore and aggregate sewage treatment technologies to reduce or prevent the deposition of these compounds into the environment.

Association between Thyroid Function and Exposures to Brominated and Organophosphate Flame Retardants in Rural Central Appalachia

Exposure to flame retardants (FRs) is associated with adverse effects on human health. Focusing on three FR groups, including polybrominated diphenyl ethers (PBDEs), organophosphate FRs (OPFRs), and novel brominated FRs (nBFRs), we determined the levels of these chemicals in indoor air in homes in rural Central Appalachia using passive air samplers and personal exposures in the residents of these homes using silicone wristbands. We also investigated the relationships between the FR levels in wristbands and the thyroid function. The median total concentrations of PBDEs, OPFRs, and nBFRs were 210, 25 000, and 69 pg/m³ in indoor air, and 49, 670, and 110 ng/g in wristbands, respectively. The most abundant chemicals in both air and wristbands were BDE-47 and -99 among PBDEs, tris[(2R)-1-chloro-2-propyl] phosphate among OPFRs, and 2-ethylhexyl 2,3,4,5-tetrabromobenzoate and bis(2-ethylhexyl) tetrabromophthalate among nBFRs. In gender-specific regression models that were controlled for age and smoking, significant associations were observed between BDE-99, BDE-197, and 2-ethylhexyldiphenyl phosphate (EHDP) and free thyroxine (FT₄), between BDE-100 and free triiodothyronine (FT₃), and between anti-Dechlorane Plus (DP) and thyroid-stimulating hormone (TSH). In particular, most penta-BDE congeners were significantly or marginally significantly associated with FT₄ and FT₃ for both females and males. Our results suggest that wristbands can be used as suitable exposure monitors for evaluating human exposure to FRs.

Silicone wristbands integrate dermal and inhalation exposures to semi-volatile organic compounds (SVOCs)

Silicone wristbands are being increasingly used to assess human exposure to semi-volatile organic compounds (SVOCs). However, it is unclear what exposure pathways wristbands integrate. To test the hypothesis that wristbands integrate inhalation and dermal exposures, we measured 38 chemicals from four compound groups (PAHs, PBDEs, nBFRs, and OPEs) in silicone wristbands and brooches, active air samples (Occupational Safety and Health Administration Versatile Sampler or OVS cartridge), and hand wipes from 10 adults during a 72-hour period. Phenanthrene, BDE-47, 2‑ethylhexyl 2,3,4,5‑tetrabromobenzoate (EHTBB), tris[(2R)‑1‑chloro‑2‑propyl] phosphate (TCIPP), and tris(1,3‑dichloro‑2‑propyl) phosphate (TDCIPP) were the predominant compounds in all four matrices. In a linear regression analysis, the compound levels in OVS were positively associated with those in wristbands and brooches for nBFRs and OPEs, but not for PAHs and PBDEs. The compound levels in wristbands were positively associated with those in hand wipes and brooches for all chemicals. The regressions between the levels in wristbands and OVS or brooches combined with the levels in hand wipes showed stronger, supporting the hypothesis that wristbands captured inhalation and dermal exposure pathways.

Development of an environmental health tool linking chemical exposures, physical location and lung function

BACKGROUND

A challenge in environmental health research is collecting robust data sets to facilitate comparisons between personal chemical exposures, the environment and health outcomes. To address this challenge, the Exposure, Location and lung Function (ELF) tool was designed in collaboration with communities that share environmental health concerns. These concerns centered on respiratory health and ambient air quality. The ELF collects exposure to polycyclic aromatic hydrocarbons (PAHs), given their association with diminished lung function. Here, we describe the ELF as a novel environmental health assessment tool.

METHODS

The ELF tool collects chemical exposure for 62 PAHs using passive sampling silicone wristbands, geospatial location data and respiratory lung function measures using a paired hand-held spirometer. The ELF was tested by 10 individuals with mild to moderate asthma for 7 days. Participants wore a wristband each day to collect PAH exposure, carried a cell phone, and performed spirometry daily to collect respiratory health measures. Location data was gathered using the geospatial positioning system technology in an Android cell-phone.

RESULTS

We detected and quantified 31 PAHs across the study population. PAH exposure data showed spatial and temporal sensitivity within and between participants. Location data was used with existing datasets such as the Toxics Release Inventory and the National Oceanic and Atmospheric Administration (NOAA) Hazard Mapping System. Respiratory health outcomes were validated using criteria from the American Thoracic Society with 94% of participant data meeting standards. Finally, the ELF was used with a high degree of compliance (> 90%) by community members.

CONCLUSIONS

The ELF is a novel environmental health assessment tool that allows for personal data collection spanning chemical exposures, location and lung function measures as well as self-reported information.