Uptake of Typical Hydrophobic Organic Contaminants in Vegetables: Evidence From Passive Samplers.

Quantifying the root uptake of hydrophobic organic contaminants (HOCs) by plants remains challenging due to the lack of data on the freely available fractions of HOCs in soil porewater. We therefore hypothesized that a passive sampler could act as a useful tool to evaluate the root uptake potential and pathways of HOCs by plants in soil. We tested this hypothesis by exploring the uptake of polybrominated diphenyl ethers (PBDEs) and organophosphate esters (OPEs) by carrot and lettuce with the codeployment of passive samplers in a contaminated soil system.

Effects of polymer matrix and temperature on pyrolysis of tetrabromobisphenol A: Product profiles and transformation pathways.

Plastics are crucial constituents in electronic waste (e-waste) and part of the issue in e-waste recycling and environmental protection. However, previous studies have mostly focused on plastic recovery or thermal behavior of flame retardants, but not both simultaneously. The present study simulated the process of e-waste thermal treatment to explore tetrabromobisphenol A (TBBPA) pyrolysis at various temperatures using polystyrene (PS), polyvinyl chloride (PVC), and e-waste plastics as polymer matrices.

Per- and polyfluoroalkyl substances (PFAS) exposure in plasma and their blood-brain barrier transmission efficiency-A pilot study.

Per- and polyfluoroalkyl substances (PFAS) have been shown to penetrate the blood-brain barrier (BBB) and accumulate in human brain. The BBB transmission and accumulation efficiency of PFAS, as well as the potential health risks from human co-exposure to legacy and emerging PFAS due to differences in transport efficiency, need to be further elucidated. In the present pilot study, 23 plasma samples from glioma patients were analyzed for 17 PFAS.

Utility of a modified o-DGT passive sampler for measurement of bisphenol analogues in freshwater and coastal waters.

Bisphenol analogues (BPs) are commonly found in riverine and coastal waters. However, the lack of a reliable and robust passive sampling method has hindered our ability to monitor these compounds in aquatic systems. The study developed a novel organic-diffusive gradients in thin film (o-DGT) sampler based on stainless steel mesh membrane, polyacrylamide diffusive gel, and hydrophilic-lipophilic balance (HLB) binding gel.

Use of machine learning to identify key factors regulating volatilization of semi-volatile organic chemicals from soil to air.

Volatilization from soil to air is a key process driving the distribution and fate of semi-volatile organic contaminants. However, quantifying this process and the key environmental governing factors remains difficult. To address this issue, the volatilization fluxes of polybrominated diphenyl ethers (PBDEs) and organophosphate esters (OPEs) from soil were determined in 16 batch experiments orthogonally with six variables (chemical property, soil concentration, air velocity, ambient temperature, soil porosity, and soil moisture) and analyzed with machine learning methods.

Fluorescent Visualization of Chemical Profiles across the Air-Water Interface.

Chemical transfer across the air-water interface is one of the most important geochemical processes of global significance. Quantifying such a process has remained extremely challenging due to the lack of suitable technologies to measure chemical diffusion across the air-water microlayer. Herein, we present a fluorescence optical system capable of visualizing the formation of the air-water microlayer with a spatial resolution of 10 μm and quantifying air-water diffusion fluxes using pyrene as a target chemical.

Particle transfer mediates dermal exposure of consumers to plasticizers in eraser and pen accessories.

Dermal exposure to chemicals released from daily consumer products is a rising concern, particularly for children who are susceptible to unintentional hand-to-mouth transfer and related chemical exposure risk. However, chemical transfer induced by tiny particles of intact products has yet to be adequately addressed. The objective of the present study was to determine the potentiality of particles release from intact erasers and pen grips upon dermal contact by measuring the migration rates of the embedded plasticizers (phthalates and its alternatives).

Hydrophobic organic contaminants affiliated with polymer-specific microplastics in urban river tributaries and estuaries.

Exposure to microplastics (MPs) and hydrophobic organic contaminants (HOCs) combined at high concentrations may induce adverse effects to aquatic organisms in laboratory-scale studies. To determine environmentally relevant concentrations of HOCs in MPs, it is essential to understand the occurrence of MP-affiliated HOCs in the aquatic environment. Here we report the occurrences of HOCs affiliated with polymer-specific floating MPs from 12 tributaries and three estuaries in the Pearl River Delta, South China.

Effects of organic carbon/elemental carbon and particle size on inhalation bioaccessibility of particle-bound PAHs.

Bioaccessible fractions of particle-bound hydrophobic organic compounds (HOCs) are critical to evaluating human inhalation exposure risk. However, the key factors for controlling the release of HOCs into the lung fluid are not adequately examined. To address this issue, eight particle size fractions (0.

Size-resolved gas-particle partitioning characteristics of typical semi-volatile organic compounds in urban atmosphere.

Understanding particle size distribution and size-resolved gas-particle partitioning of semi-volatile organic compounds (SVOCs) is important for characterizing their fate in atmosphere. However, the size-resolved gas-particle partitioning characteristics of SVOCs has not been adequately considered. To address this issue, the present study collected gaseous and size-fractioned particulate samples both in and outside of schools, offices, and residences in three districts of different urbanization levels in a megacity, Guangzhou, South China during two seasons.

Insufficient evidence to link human exposure to heavy metals with biomarkers of glioma.

Information on molecular mechanisms has implicated potential association between the concentrations of heavy metals and incidences of glioma, but experimental data on human brain tissue remain sparse. To address this data gap, 13 heavy metals were measured in 137 glioma and 35 non-glioma samples collected from 161 alive patients in Guangdong Province, China in 2019 - 2020. All target heavy metals were detected, suggesting they could cross the blood-brain barrier.

Glioma is associated with exposure to legacy and alternative per- and polyfluoroalkyl substances.

Data on the occurrences of legacy and alternative per- and polyfluoroalkyl substances (PFASs) in glioma are scarce. It remains unclear if PFASs exposure is related to the prevalence of glioma. A total of 137 glioma and 40 non-glioma brain tissue samples from patients recruited from the Nanfang Hospital, South China were analyzed for 17 PFAS compounds.

Transfer of Frictional Contact Derived Phthalates from Pad Surface Enhances Dermal Exposure.

Dermal exposure to chemicals derived from object surface contact is an important contributor to increased health risk. However, chemical transfer induced by mechanical friction between dermal and object surface has yet to be adequately addressed. To fill this knowledge gap, rubbing fabrics were used as surrogate skins to stimulate dermal mechanical friction with pad products with phthalates as target analytes.

Distribution profiles of bisphenols in school supplies and implications for human exposure.

Bisphenol compounds (BPs) are usually applied in the production of school supplies, however, little is known on the occurrence of BPs in school supplies. In this study, 15 BPs were detected in 121 samples of school supplies collected from commercial market. Among all compounds studied, BPA, BPF, and BPS were the dominant compounds in school supplies with the detection frequency of 93.

Utility of benzothiazoles as markers of tire-derived inputs to estuarine waters assessed by polyethylene sheets.

Tire-derived particles and polyethylene (PE) debris co-exist in estuaries and potentially deteriorate water quality. Chemicals can be emitted from tire-derived particles and resorb to PE debris. However, there was lack of information about the interaction (e.

A Novel Personal Passive Sampler for Collecting Gaseous Phthalates.

Dermal absorption of gaseous chemicals is an important contributor to increased health risk and has yet to be adequately addressed due to the lack of available sampling techniques. In the present study, a novel personal passive sampler consisting of a housing (embracing a polydimethylsiloxane (PDMS) disk as the sorbent phase, a membrane filter, and a stainless-steel mesh) and a watchband (traditional wristband) was constructed and used to characterize gaseous phthalates (PAEs) near the air-skin interface. In a real-life setting, the utility of the passive sampler was validated by comparing the composition profiles of PAEs in the PDMS disks and in active samples and watchbands.

Use of glioma to assess the distribution patterns of perfluoroalkyl and polyfluoroalkyl substances in human brain.

Human brain has a complex structure and is able to perform powerful functions. Blood-brain barrier blocks the entry of foreign substances and maintains the homeostasis of the brain. However, some exogenous substances are still able to pass through the blood-brain barrier, with distribution patterns yet to be clarified.

Development of an in vitro model to simulate migration of organic contaminants from pad products to human sweat and enhance dermal exposure risk assessment.

Dermal sorption is an important route for human exposure to organic chemicals embedded in consumer products, but the related chemical migration from consumer products to sweats was often overlooked in assessing skin exposure risk. To address this issue, the present study selected polycyclic aromatic hydrocarbons (PAHs), phthalic acid esters (PAEs), and benzothiazoles (BTs) as the target compounds and developed an in vitro simulation model with two artificial sweats (i.e.

Determination of low-density polyethylene-water partition coefficients for novel halogenated flame retardants with the large volume model and co-solvent model.

The partition coefficient (K) of an analyte between low-density polyethylene (LDPE) film and water is a critical parameter for measuring freely dissolved concentrations of the analyte with PE passive sampling devices. Measuring log K for super hydrophobic organic chemicals (HOCs) have been proven extremely difficult. The present study developed a large volume model for measuring log K of super HOCs, i.

Effects of cooking on oral bioaccessibility of PBDEs, MeO-PBDEs, and OH-PBDEs in fish (tilapia) and chicken egg.

Human health concerns are rising with polybrominated diphenyl ethers' (PBDEs) analogues, methoxylated and hydroxylated PBDEs (MeO-PBDEs and OH-PBDEs), due to their occurrences in foods and greater potential toxicological effects than PBDEs. While the oral bioaccessibilities (BA%) of PBDEs in foods are available, such information on MeO-PBDEs and OH-PBDEs, and the effects of cooking on them have not been adequately addressed. The present study was conducted with fish and chicken egg as typical foods to assess the bioaccessibility (BA%) of PBDEs, MeO-PBDEs, and OH-PBDEs using the colon extended physiologically based extraction test and examine the effects of cooking processes (boiling, frying, and steaming) on them.

Impact of passive sampler protection apparatus on sediment porewater profiles of hydrophobic organic compounds.

Passive sampling techniques have been widely used to determine the dissolved concentration profiles of hydrophobic organic compounds (HOCs) in sediment porewater. However, the effects of having a protection for the passive sampler on profiling HOCs concentrations in sediment porewater, especially in deep sediment, have remained unclear. To address this issue, low density polyethylene passive samplers with and without protectors, which consisted of glass fiber filter and porous stainless steel shield, were simultaneously deployed in sediment of the Dongjiang River, South China.

Polybrominated diphenyl ethers and organophosphate esters flame retardants in play mats from China and the exposure risks for children.

A total of 41 play mats made from different raw materials, such as polyethylene (PE), ethylene-vinyl acetate copolymer (EVA), chemical crosslinked polyethylene (XPE), and polyvinyl chloride (PVC), were obtained from Chinese markets and analyzed for flame retardants. Polybrominated diphenyl ethers (PBDEs) and their replacements, organophosphate esters (OPEs), were measured and the associated exposure risks for children were evaluated. The levels (range; median) of OPEs (6.

Low Tar Level Does Not Reduce Human Exposure to Polycyclic Aromatic Hydrocarbons in Environmental Tobacco Smoke.

Environmental tobacco smoke (ETS) is known to pose potential risk to human health, but the effects of tar level remain to be clarified. In the present study, ETS samples from two cigarette types with different tar levels in a 72.5 m room were collected for measurement of 16 polycyclic aromatic hydrocarbons (PAHs).

Emissions and Occupational Exposure Risk of Halogenated Flame Retardants from Primitive Recycling of E-Waste.

The production and usage of non-polybrominated diphenyl ether (PBDE) halogenated flame retardants (HFRs) have substantially increased after the ban of several PBDEs. This has resulted in widespread environmental occurrence of non-PBDE HFRs, further amplified by emissions from primitive recycling of obsolete electronics (e-waste). The present study conducted chamber experiments to characterize 15 HFRs (∑HFR) from thermal treatment and open burning of typical e-waste.

Hydroxylated polycyclic aromatic hydrocarbons in surface soil in an emerging urban conurbation in South China.

To investigate the effects of human activity on contaminants in regional soil, hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) were measured in 187 surface soil samples of different land-use types collected from the Pearl River Delta (PRD), South China. The concentrations of ΣOH-PAH (sum of nine target analytes) ranged from 0.36 to 252ng/g (median: 5.