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.
Phthalates and their potential replacements, including non-phthalate plasticizers, are ubiquitous in home environments due to their presence in building materials, plastics, and personal care ...products. As a result, exposure to these compounds is universal. However, the primary pathways of exposure and understanding which products in the home are associated most strongly with particular exposures are unclear.
We sought to investigate the relationships between phthalates and non-phthalate plasticizers in paired samples of house dust, hand wipes, and their corresponding metabolites in children's urine samples (n = 180). In addition, we compared product use or presence of materials in the household against all compounds to investigate the relationship between product use or presence and exposure.
Children aged 3–6 years provided hand wipe and urine samples. Questionnaires were completed by mothers or legal guardians to capture product use and housing characteristics, and house dust samples were collected from the main living area during home visits.
Phthalates and non-phthalate replacements were detected frequently in the environmental matrices. All urine samples had at least 13 of 19 phthalate or non-phthalate replacement metabolites present. Hand wipe mass and dust concentrations of diisobutyl phthalate, benzyl butyl phthalate (BBP), bis(2-ethylhexyl) phthalate, and di-isononyl phthalate were significantly associated with their corresponding urinary metabolites (rs = 0.18–0.56, p < 0.05). Bis(2-ethylhexyl) terephthalate (DEHTP) in dust was also significantly and positively correlated with its urinary metabolites (rs = 0.33, p < 0.001). Vinyl flooring was most significantly and positively associated with particular phthalate exposures (indicated by concentrations in environmental matrices and urinary biomarkers). In particular, children who lived in homes with 100% vinyl flooring had urinary concentrations of monobenzyl phthalate, a BBP metabolite, that were 15 times higher than those of children who lived in homes with no vinyl flooring (p < 0.0001). Levels of BBP in hand wipes and dust were 3.5 and 4.5 times higher, respectively, in those homes with 100% vinyl flooring (p < 0.0001 for both).
This paper summarizes one of the most comprehensive phthalate and non-phthalate plasticizer investigation of potential residential exposure sources conducted in North America to date. The data presented herein provide evidence that dermal contact and hand-to-mouth behaviors are important sources of exposure to phthalates and non-phthalate plasticizers. In addition, the percentage of vinyl flooring is an important consideration when examining residential exposures to these compounds.
•Plasticizers were frequently detected in children’s hand wipes, dust, and urine.•Phthalates in hand wipes and house dust were correlated with metabolites in urine.•The metabolite of BBP was higher in children who lived in homes with 100% vinyl floors.•DEHTP was more abundant than DEHP in house dust and child hand wipes.
•Paired hand wipe, wristband, house dust and urine samples were analyzed for phenols.•Exposure matrices and urinary biomarkers were positively correlated.•Triclosan in dust, wristbands and hand wipes ...was correlated with urinary biomarkers.•Lotion use was associated with ethyl, methyl, and propylparaben biomarkers.
Environmental phenols, such as parabens, bisphenol A, and triclosan, are ubiquitous in indoor environments because of their use in packaging, plastics, personal care products, and as anti-microbials. The primary pathways of exposure, as well as habits and behaviors that may lead to greater exposure, are still unclear.
Herein, we investigate the relationships between phenols found in residential environments by comparing levels in paired samples of house dust and hand wipes with children’s urine. In addition, phenols were analyzed in a novel exposure tool, the silicone wristbands, to investigate which external matrix best correlates with individual exposure based on urinary phenol biomarkers.
Children aged 3–6 years in central North Carolina, United States, provided paired hand wipe (n = 202), wristband (n = 76), and spot urine samples (n = 180), while legal guardians completed questionnaires on habits and behaviors. House dust samples (n = 186) were collected from the main living area during home visits completed between 2014 and 2016.
Environmental phenols were detected frequently in all matrices investigated. Ethyl, methyl, and propylparaben levels observed in hand wipes, dust, and on wristbands were significantly correlated to their associated urinary biomarkers. In addition, intra-paraben correlations were noted, with biomarkers of ethyl, methyl, and propylparabens generally positively and significantly correlated, which suggests co-application of parabens in products. Triclosan levels in dust were positive and significantly correlated with levels in hand wipes and wristbands and with urinary concentrations, suggesting non-personal care product sources may be important in children’s overall triclosan exposure. Generally, chemicals on wristbands were more highly correlated with urinary biomarkers than with chemicals in hand wipes or house dust. In addition, more frequent lotion use was positively associated with urinary concentrations of paraben biomarkers.
Our results suggest that the home environment is an important source of exposure which has been under-investigated for some environmental phenols (e.g., triclosan in house dust). Associations between wristbands and biomarkers of exposure, which were stronger than for hand wipes and house dust, suggest that silicone wristbands may provide a suitable exposure assessment tool for some phenols.
Firefighters are occupationally exposed to an array of hazardous chemicals, and these exposures have been linked to the higher rates of some cancer in firefighters. However, additional research that ...characterizes firefighters' exposure is needed to fully elucidate the impacts on health risks. In this pilot study, we used silicone wristbands to quantify off-duty and on-duty chemical exposures experienced by 20 firefighters in Durham, North Carolina. By using each firefighter's off-duty wristband to represent individual baseline exposures, we assessed occupation-related exposures (i.e. on-duty exposures). We also investigated the influence of responding to a fire event while on-duty. In total, 134 chemicals were quantified using both GC-MS and LC-MS/MS targeted methods. Seventy-one chemicals were detected in at least 50% of all silicone wristbands, including 7 PFAS, which to our knowledge, have not been reported in wristbands previously. Of these, phthalates were generally measured at the highest concentrations, followed by brominated flame retardants (BFRs) and organophosphate esters (OPEs). PFAS were measured at lower concentrations overall, but firefighter PFOS exposures while on-duty and responding to fires were 2.5 times higher than off-duty exposures. Exposure to polycyclic aromatic hydrocarbons (PAH), BFRs, and some OPEs were occupationally associated, with firefighters experiencing 0.5 to 8.5 times higher exposure while on-duty as compared to off-duty. PAH exposures were also higher for firefighters who respond to a fire than those who did not while on-duty. Additional research with a larger population of firefighters that builds upon this pilot investigation may further pinpoint exposure sources that may contribute to firefighters' risk for cancer, such as those from firefighter gear or directly from fires. This research demonstrates the utility of using silicone wristbands to quantify occupational exposure in firefighters and the ability to disentangle exposures that may be specific to fire events as opposed to other sources that firefighters might experience.
Display omitted
•Firefighters' exposure to 134 chemicals was investigated with silicone wristbands.•Exposures to flame retardants and PAHs were associated with firefighting.•Responding to a fire event while on-duty increased PAH exposure.•PFAS were quantified on silicone wristbands for the first time, with higher exposure to PFOS observed while responding to fires.•On-duty exposure to phthalates and pesticides were generally lower than off-duty exposures.
Silicone wristbands present a noninvasive exposure assessment tool and an alternative to traditional biomonitoring; however, questions about their utility remain as validation studies are limited. We ...sought to determine if wristbands provide quantitative estimates of internal organophosphate ester (OPE) exposure. We evaluated internal dose by measuring metabolite masses excreted in 24-h urine samples collected over five days among 10 adults. We compared internal dose to OPE concentrations in paired wristbands worn during collection and, as a comparison, evaluated metabolite levels in spot urine samples. Three of six OPE metabolites evaluated were detected in greater than 98% of urine samples, and 24 of 34 assessed OPEs were detected in at least one wristband. OPE uptake in wristbands was linear over time (range = 0.54–61.8 ng/g/day). OPE concentrations in spot urine and wristbands were not correlated with total diphenyl phosphate (DPHP) excreted in urine, which may be due to the range of possible DPHP parent compounds or dietary exposure. However, for tris(1,3-dichloro-2-propyl)phosphate (TDCIPP) and tris(2-chloroisopropyl)phosphate (TCIPP), wristbands and spot urine samples were both moderately to strongly correlated with internal dose (all r s > 0.56 and p < 0.1), suggesting both perform well as integrated exposure estimates. Given the potential advantages of silicone wristbands, further studies investigating additional compounds are warranted.
Place is a social determinant of health, as recently evidenced by COVID-19. Previous literature surrounding health disparities in the United States often fails to acknowledge the role of structural ...racism on place-based health disparities for historically marginalized communities (i.e., Black and African American communities, Hispanic/Latinx communities, Indigenous communities i.e., First Nations, Native American, Alaskan Native, and Native Hawaiian, and Pacific Islanders). This narrative review summarizes the intersection between structural racism and place as contributors to COVID-19 health disparities.
This narrative review accounts for the unique place-based health care experiences influenced by structural racism, including health systems and services and physical environment. We searched online databases for peer-reviewed and governmental sources, published in English between 2000 and 2021, related to place-based U.S. health inequities in historically marginalized communities. We then narrate the link between the historical trajectory of structural racism and current COVID-19 health outcomes for historically marginalized communities.
Structural racism has infrequently been named as a contributor to place as a social determinant of health. This narrative review details how place is intricately intertwined with the results of structural racism, focusing on one's access to health systems and services and physical environment, including the outdoor air and drinking water. The role of place, health disparities, and structural racism has been starkly displayed during the COVID-19 pandemic, where historically marginalized communities have been subject to greater rates of COVID-19 incidence and mortality.
As COVID-19 becomes endemic, it is crucial to understand how place-based inequities and structural racism contributed to the COVID-19 racial disparities in incidence and mortality. Addressing structurally racist place-based health inequities through anti-racist policy strategies is one way to move the United States toward achieving health equity.
Evidence from different chickadee species (Poecile genus) indicates that birds can modify the note composition of their “chick-a-dee” calls in the presence of predator stimuli. Here, we tested the ...effects of predator models and the distance of those models on calls of three species foraging together at feeding stations: Carolina chickadees (Poecile carolinensis) and tufted titmice (Baeolophus bicolor), both members of the Paridae family, and white-breasted nuthatches (Sitta carolinensis), a member of the Sittidae family. Model and distance affected seed-taking rates in all three species. “Chick-a-dee” calling rates were higher in the predator context for both chickadees and titmice, but we detected no predator context effects on “quank” call rates for nuthatches. Predator and distance contexts affected acoustic parameters of notes of the “chick-a-dee” calls of chickadees and titmice; no such effects were detected for nuthatch “quank” calls. These results suggest species differences in encoding of information in the primary social calls of these three species that commonly occur in multi-species flocks. Chickadees and titmice are “nuclear” species and nuthatches are “satellite” species, and these different roles might be related to the differences in vocal signaling that we detected.
Cassiferaldehyde, a recently discovered naturally occurring tyrosinase inhibitor, and six of its analogs, in which the aldehyde group has been replaced by various other functionalities, have been ...synthesized by a short and simple sequence starting from 2,3-dihydroxybenzaldehyde. Single-crystal x-ray structures of cassiferaldehyde as well as its methyl ketone, nitrile, and carboxylic acid analogs are reported.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The United States Environmental Protection Agency (USEPA) is in the process of developing a high throughput (HT) model for exposure-based prioritization to inform toxicity testing and chemical risk ...assessment within its ExpoCast program. This mechanistic modeling approach is adapted from the prior Stochastic Human Exposure and Dose Simulation (SHEDS) framework, which was implemented in SAS. SHEDS-HT, written in R, reduces user burden and input demands by linking chemicals to particular exposure scenarios based on consumer product categories or food groups. SHEDS-HT rapidly generates probabilistic population distribution estimates of pathway-specific exposures, overall exposures, and intake doses. These predictions are based on specific exposure scenarios, a fugacity-based indoor environmental media model, and information from human activity databases. The predictive ability of SHEDS-HT is best evaluated by comparison to available biomarker measurements or to alternative predictions from prior measurement-intensive exposure studies. A key example of the latter is the USEPA’s Children’s Total Exposure to Persistent Pesticides and Other Persistent Organic Pollutants (CTEPP) study, which was conducted in Ohio and North Carolina. CTEPP provides both environmental and corresponding urinary biomarker data for a relatively large sample of commonly encountered commercial chemicals. The National Health and Nutrition Examination Survey (NHANES) also provides representative urinary biomarker data for some of the same compounds on a whole US population basis. However, biomarker data can reflect exposure to both a parent compound and its metabolite(s). Absence of environmental measurements for most biomarkers greatly reduces the number of compounds for which complete accounting of inputs and outputs can be conducted. In this evaluation of SHEDS-HT, focus is placed on 2,4-dichlorophenoxyacetic acid (2,4-D) and three parent compounds of the urinary biomarker 3,5,6-trichloro-2-pyridinol (TCPy), chlorpyrifos, chlorpyrifos methyl, and triclopyr.
PDF
