Quality characterization of tobacco flavor and tobacco leaf position identification based on homemade electronic nose.

A set of nine unique tobacco extract samples was analyzed using a self-developed electronic nose (E-nose) system, a commercial E-nose, and gas chromatography-mass spectrometry (GC-MS). The evaluation employed principal component analysis, statistical quality control, and soft independent modeling of class analogies (SIMCA). These multifaceted statistical methods scrutinized the collected data. Subsequently, a quality control model was devised to assess the stability of the sample quality. The results showed that the custom E-nose system could successfully distinguish between tobacco extracts with similar odors. After further training and the development of a quality control model for accepted tobacco extracts, it was possible to identify samples with normal and abnormal quality. To further validate our E-nose and extend its use within the tobacco industry, we collected and accurately classified the flavors of different tobacco leaf positions, with a remarkable accuracy rate of 0.9744. This finding facilitates the practical application of our E-nose system for the efficient identification of tobacco leaf positions.

Exposure to polycyclic aromatic hydrocarbons (PAHs) from domestic heating and cooking combustion of different fuel types for elders in rural China.

Solid fuel combustion emitted abundant pollutants, especially polycyclic aromatic hydrocarbons (PAHs) which had significant minus impact on human health in rural China. PAHs in PM2.5 emitted from different fuels combustion and hydroxylated metabolites of PAHs (OH-PAHs) in urine samples of different fuel users were detected in this study. The indoor PAHs were higher than that in outdoors for solid fuel use households, and the concentration of PAHs in the indoor of liquefied petroleum gas (LPG) use household was not much lower than solid fuel use households. Biogas-use household produced the lowest PAHs, which significantly reduced 64-82% compared with those emitted by solid fuel combustion. The different combustion conditions influenced the gaseous PAHs in indoors between two sampling sites. The gas/particle partition indicated that PAHs tended to occur in the particle phase with increased molecular weight, and the absorption was the main mechanism. The relative higher contribution of high molecular weight PAHs (HMW-PAHs) in solid fuel use households than in clean fuel use households, induced more health risks of PAHs. The concentration of Σ10OH-PAHs in the urine samples for elders of different fuel-use households displayed the trend of coal (83.27 ng/mL) > wood (79.32 ng/mL) > LPG (51.61 ng/mL) > biogas (28.96 ng/mL), and OH-NaPs was the predominant metabolites, which accounted for more than 90% of the total concentration. The carcinogenic risk of PAHs based on internal exposure was greater than or close to 10-4, with serious carcinogenic risks. This was different with the incremental lifetime cancer risk based on the atmospheric concentrations. The exposure of PAHs from solid fuel combustion for human being especially for the elders in this region should be concerned, and more data should be done for the internal exposure of PAHs.

Coking-Produced Aromatic Compounds in Urine of Exposed and Nonexposed Populations: Exposure Levels, Source Identification, and Model-Based Health Implications.

Coking contamination in China is complex and poses potential health risks to humans. In this study, we collected urine samples from coking plant workers, nearby residents, and control individuals to analyze 25 coking-produced aromatic compounds (ACs), including metabolites of polycyclic aromatic hydrocarbons (PAHs) and their derivatives, chlorophenols, and nitrophenols. The median concentration of total ACs in urine of workers was 102 µg·g-1 creatinine, significantly higher than that in the other two groups. Hydroxy-PAHs and hydroxy hetero-PAHs were the dominant ACs. Workers directly exposed from coking industrial processes, i.e., coking, coal preparation, and chemical production processes, showed higher concentrations of hydroxy-PAHs and hydroxy hetero-PAHs (excluding 5-hydroxyisoquinoline), while those from indirect exposure workshops had higher levels of other ACs, indicating different sources in the coking plant. The AC mixture in workers demonstrated positive effects on DNA damage and lipid peroxidation with 5-hydroxyisoquinoline and 3-hydroxycarbazole playing a significant role using a quantile g-computation model. Monte Carlo simulation revealed that coking contamination elevated the carcinogenic risk for exposed workers by 5-fold compared to controls with pyrene, pentachlorophenol, and carbazole contributing the most, and workers from coking process are at the highest risk. This study enhances understanding of coking-produced AC levels and provides valuable insights into coking contamination control.

Nontarget Screening of Novel Urinary Biomarkers for Occupational Exposure to Toxic Chemicals from Coking Industry Using HPLC-QTOF-MS.

High-resolution mass spectrometry is an advanced technique for comprehensive screening of toxic chemicals. In this study, urine samples were collected from both an occupationally exposed population at a coking site and normal inhabitants to identify novel urinary biomarkers for occupational exposure to coking contaminants. A coking-site-appropriate analytical method was developed for unknown chemical screening. Through nontarget screening, 515 differential features were identified, and finally, 32 differential compounds were confirmed as candidates for the current study, including 13 polycyclic aromatic hydrocarbon (PAH) metabolites. Besides monohydroxy-PAHs (such as 1-&2-naphthol, 2-&9-hydroxyfluorene, 2-&4-phenanthrol, and 1-&2-hydroxypyrene), many other PAH metabolites including dihydroxy metabolites, PAH oxide, and sulfate conjugate were detected, suggesting that the quantification based solely on monohydroxy-PAHs significantly underestimated the human exposure to PAHs. Furthermore, several novel compounds were recognized that could be considered as biomarkers for the exposure to coking contaminants, including quinolin-2-ol (1.10 ± 0.44 ng/mL), naphthylmethanols (11.4 ± 5.47 ng/mL), N-hydroxy-1-aminonaphthalene (0.78 ± 0.43 ng/mL), hydroxydibenzofurans (17.4 ± 7.85 ng/mL), hydroxyanthraquinone (0.13 ± 0.053 ng/mL), and hydroxybiphenyl (2.70 ± 1.03 ng/mL). Despite their lower levels compared with hydroxy-PAHs (95.1 ± 30.8 ng/mL), their severe toxicities should not be overlooked. The study provides a nontarget screening approach to identify chemicals in human urine, which is crucial for accurately assessing the health risks of toxic chemicals in the coking industry.

Internal exposure risk based on urinary metabolites of PAHs of occupation and non-occupation populations around a non-ferrous metal smelting plant.

The emission of various metals from non-ferrous metal smelting activities is well known. However, relative investigations on potential occupational exposure of organic pollutants are still limited. Herein, total of 619 human urine samples were collected from workers engaged in smelting activities and residents living near and/or far from the smelting sites, and ten mono-hydroxylated metabolites of polycyclic aromatic hydrocarbons (OH-PAHs) in human urine were determined. The median levels of Σ10OH-PAHs in smelting workers (25.6 ng/mL) were significantly higher (p < 0.01) than that of surrounding residents (9.00 ng/mL) and rural residents as the control (8.17 ng/mL), indicating an increase in occupational PAH exposure in non-ferrous metal smelting activities. The composition profiles of OH-PAH congeners were similar in three groups, in which naphthalene metabolites accounted for 76-82% of the total. The effects of smoking, drinking, gender, BMI, and occupational categories on urinary OH-PAHs were considered. The partial correlation analysis showed an insignificant effect of non-ferrous metal smelting activities on PAH exposure for surrounding residents. In the health risk assessments, almost all smelting workers had cancer risks exceeded the acceptable level of 10-6. This study provides a reference to occupational PAH exposure and reinforce the necessary of health monitoring among smelting workers.

Co-exposure health risk of benzo[a]pyrene with aromatic VOCs: Monoaromatic hydrocarbons inhibit the glucuronidation of benzo[a]pyrene.

Occupational workers and residents near petrochemical industry facilities are exposed to multiple contaminants on a daily basis. However, little is known about the co-exposure effects of different pollutants based on biotransformation. The study examined benzo[a]pyrene (BaP), a representative polycyclic aromatic hydrocarbon related to the petrochemical industry, to investigate changes in toxicity and co-exposure mechanism associated with different monoaromatic hydrocarbons (MAHs). A central composite design method was used to simulate site co-exposure scenarios to reveal biotransformation of BaP when co-exposed with benzene, toluene, chlorobenzene, or nitrobenzene in microsome systems. BaP metabolism depended on MAH concentration, and association of MAH with microsome concentration/incubation time. Particularly, MAH co-exposure negatively affected BaP glucuronidation, an important phase Ⅱ detoxification process. BaP metabolite intensities decreased to 43%-80% for OH-BaP-G, and 32%-71% for diOH-BaP-G in co-exposure system with MAHs, compared with control group. Furthermore, glucuronidation was affected by competitive and time-dependent inhibition. Co-exposure significantly decreased gene expression of UGT 1A10 and BCRP/ABCG2 in HepG2 cells, which are involved in BaP detoxification through metabolism and transmembrane transportation. Therefore, human co-exposure to multiple contaminants may deteriorate toxic effects of these chemicals by disturbing metabolic pathways. This study provides a reference for assessing toxic effects and co-exposure risks of pollutants.

Spatial distribution, source identification, and human health risk assessment of PAHs and their derivatives in soils nearby the coke plants.

The coking industry can generate large amounts of polycyclic aromatic hydrocarbons (PAHs) and their derivatives, which may negatively impact the environment and human health. In this study, soils nearby a typical coking plant were sampled to assess the impact of coke production on the surrounding residential areas and human health. The mean concentration of PAHs and their derivatives in residential area soils nearby the coke plant was 4270 ng/g dw, which was 1 order of magnitude higher than that observed in areas far from the coke plant and approximately 4 times lower than that revealed the coke plant. In addition, the results showed that coking processing area was the most contaminant area of the coke plant (mean: 74.4 µg/g dw), where was also the main source of pollutants in residential areas. In terms of vertical soils in coking plant, the maximum levels of chemicals (mean: 205 µg/g dw) were presented at the leakage of underground pipelines, where were much higher than those in surface soils, and decreased with the increase of depth. The analysis of variance (ANOVA) results showed obvious differences in the concentrations of 6-nitrochrysene between the plant, residential areas and control areas. Meanwhile, 6-nitrochrysene had potential cancer risk (CR) for human in the coking site. Thus, 6-nitrochrysene was the most noteworthy PAH derivatives. Furthermore, the CR (mean: 5.94 × 10-5) and toxic equivalent quantities (TEQs) (mean: 14.8 µg·TEQ/g) of PAHs and their derivatives was assessed in this study. This finding suggested that PAHs and their derivatives especially those extremely toxic chemicals (Nitro-PAHs (NPAHs) and Br/Cl-PAHs (XPAHs)) might pose a potential health risk to residents nearby the coke plant. The current study provides further insights into the pollution characteristics of PAHs and their derivatives in coke plants and potential risks to the workers and surrounding residents.

Associations between urinary monohydroxylated polycyclic aromatic hydrocarbons and unexplained recurrent spontaneous abortion and health risk assessment in a large case-control study in China.

Polycyclic aromatic hydrocarbons (PAHs) are a group of environmental endocrine disruptors with known carcinogenic, reproductive, and developmental toxicity. Important knowledge gaps remain regarding the relationship between PAH exposure and unexplained recurrent spontaneous abortion (URSA). In the present study, twelve monohydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) were measured in the urine of 413 URSA cases and 434 controls. The main OH-PAHs measured in this study were monohydroxy metabolites of naphthalene, followed by fluorene and phenanthrene. After the creatinine correction, the median concentration of urinary OH-PAHs in the control group (17.4 µg/g Creatinine) was higher than that in the case group (14.2 µg/g Creatinine). There was no positive relationship between PAH exposure and URSA using binary logistic regression analysis. Among 847 Chinese women of childbearing age, residential environment, type of drinking water, and education level were the influencing factors of PAH exposure. The health risk assessment showed that over 98% of women had a carcinogenic risk with carcinogenic risk values above the acceptable level (10-6). Although this large-scale case-control study did not observe an association between PAH exposure and URSA, more attention should be paid to the high carcinogenic risk due to PAH exposure in women of reproductive age.

Handwipes as indicators to assess organophosphate flame retardants exposure and thyroid hormone effects in e-waste dismantlers.

Dermal exposure is increasingly recognized as an important pathway for organic pollutant exposure. However, data on dermal exposure are limited, particularly with respect to the health effects. This study evaluated association between organophosphorus flame retardants (OPFRs) in handwipes and internal body burden on workers and adult residents in an electronic waste (e-waste) dismantling area. The impact of dermal exposure to OPFRs on thyroid hormones (THs) served as a biomarker for early effects. Triphenyl phosphate (TPhP) was the most detected compound in handwipes, with median levels of 1180, 200, and 24.0 ng in people identified as e-waste bakers, e-waste dismantlers, and adult residents. Among e-waste dismantlers, TPhP levels in handwipes were positively correlated with paired serum TPhP and urinary diphenyl phosphate (DPhP) levels. In multiple linear regression models controlling for sex, age and smoking, TPhP levels in handwipes of e-waste dismantlers were significantly negatively correlated with three THs used to evaluate thyroid function: serum reverse 3,3',5-triiodo-L-thyronine (rT3), 3,3'-diiodo-L-thyronine (3,3'-T2), and 3,5-diiodo-L-thyronine (3,5-T2). These findings suggest that handwipes can act as non-invasive exposure indicators to assess body burden of dermal exposure to TPhP and health effects on THs of e-waste dismantlers. This study highlights importance of OPFR effect on human THs through dermal exposure.

Preparation of tobacco pyrolysis liquids in subcritical/supercritical ethanol and their application in the aroma enhancement of heated cigarettes.

For the aroma enhancement research of heated cigarettes, it is worth exploring whether tobacco can be pyrolyzed into pyrolysis liquids containing a large number of volatile aroma components. In this study, tobacco pyrolysis liquids were prepared in subcritical/supercritical ethanol, and their applications in the aroma enhancement of heated cigarettes were investigated. The optimal conditions of supercritical liquefaction reactions were determined by optimizing the reaction time, liquid/solid mass ratio and temperature conditions. Moreover, the effect of supercritical liquefaction conditions on volatile aroma components in tobacco pyrolysis liquids was investigated by GC-MS. The results indicated that the reaction temperature had the most significant impact on the tobacco pyrolysis reaction, and higher reaction temperature promoted the pyrolysis conversion of tobacco, resulting in enhanced tobacco conversion and a high content of volatile components in the tobacco pyrolysis liquid. The optimal reaction conditions for the preparation of tobacco pyrolysis liquid were found to be a temperature of 220°C, a liquid/solid mass ratio = 15, and a 2-h reaction time. Meanwhile, the content of ester compounds and nicotine in the tobacco pyrolysis liquid increased significantly with the increase of reaction temperature. Sub/supercritical ethanol treatment significantly destroyed the surface structure of tobacco, and the degree of tobacco depolymerization increased when temperature rised. The analysis of aroma compounds in the smoke of heated cigarettes indicated that the tobacco pyrolysis liquid could significantly increase the release of aromatic substances and has a significant aroma-enhancing effect. This article proposed and prepared tobacco pyrolysis liquid in subcritical/supercritical ethanol and explored its potential application in the aroma enhancement of heated cigarettes, offering a new route for flavor enhancement technology for this type of product.

Atmospheric occurrences of nitrated and hydroxylated polycyclic aromatic hydrocarbons from typical e-waste dismantling sites.

Primitive electronic waste (e-waste) dismantling activities have been shown to be an important emissions source for a variety of toxic organic compounds, including carcinogenic polycyclic aromatic hydrocarbons (PAHs). Previous studies have found that some nitrated PAHs (NPAHs) are more toxic than their parent PAHs, however, little attention has been paid to the formation of PAH derivatives during e-waste processing and there is a lack of comprehensive data from field observations. In this study, the spatial distribution, temporal trends and atmospheric fate of NPAHs and hydroxylated PAHs (OH-PAHs) were investigated at typical e-waste dismantling sites, with monitoring data collected over three consecutive years. Compared to background levels, higher levels of NPAHs and OH-PAHs were found in air samples from an e-waste dismantling industrial park, with their seasonal and annual changes shown to be affected by e-waste dismantling activities. Atmospheric PM2.5 particles were found to have high relative abundances of NPAHs (76.9%-95.1%) and OH-PAHs (73.3%-91.6%), with particle-bound concentrations ranging from 20.1 to 88.8 and 37.1 to 107 pg m-3, respectively. The most abundant NPAH isomers were found to be 9-Nitroanthracene and 2-Nitrofluoranthene, while OH-PAH isomers containing 2-4 rings were predominant. Source identification was performed based on the specific diagnostic ratios of NPAH isomers, confirming that NPAH and OH-PAH emissions have multiple sources, including emissions related to the e-waste dismantling process, atmospheric photochemical reactions and traffic emissions. Further research on the fate of such derivatives and their potential use as markers for source identification, is urgently required.

Human exposure to BTEX emitted from a typical e-waste recycling industrial park: External and internal exposure levels, sources, and probabilistic risk implications.

Benzene, toluene, ethylbenzene, and xylene (BTEX) can be released during extensive activities associated with the disposal of electronic waste (e-waste), which might pose deleterious health effects on workers. In this study, pollution profiles of BTEX in air and their urinary excretive profiles in occupational workers were investigated in a typical e-waste recycling industrial park. The results showed that the workers in the park were generally exposed to high levels of BTEX. The median levels of urinary metabolites were approximately 6-orders of magnitude higher than those of unmetabolized BTEX, indicating that pollutants efficiently metabolize at those occupational levels. The analytes presented differential profiles in external and internal exposure. Among the metabolites, significant correlation (p < 0.05) was observed between N-acetyl-S-benzyl-L-cysteine (S-BMA) concentration and atmospheric individual BTEX derived from the e-waste recycling area, suggesting that S-BMA is a potential marker for BTEX exposure to e-waste occupational workers. Notably, 95.2 % of all the workers showed a cumulative carcinogenic risk induced by BTEX exposure via inhalation, with 99.9 % of the carcinogenic risk distribution based on concentration of benzene metabolite (N-acetyl-S-(phenyl)-L-cysteine) exceeding 1.0E-6. This study holds potential in providing valuable inferences for the development of remediation strategies focusing on BTEX exposure reduction to protect workers' health at e-waste recycling industries.

Levels and health risks of urinary phthalate metabolites and the association between phthalate exposure and unexplained recurrent spontaneous abortion: a large case-control study from China.

Phthalate acid esters (PAEs) are environmental endocrine disruptors that can interfere with endocrine processes and cause adverse reproductive outcomes. The link between PAE exposure and unexplained recurrent spontaneous abortion (URSA) remains unknown. In this study, nine urinary metabolites of PAEs (mPAEs) were measured in 594 URSA cases and 569 healthy controls. The measured mPAEs were ubiquitously detected and present at higher levels (median: 203 ng/mL) in the URSA cases than in the controls (median: 161 ng/mL). Multiple logistic regression analysis showed that URSA was associated with higher concentrations of mono (2-ethyl-5-hydroxyhexyl) phthalate (mEHHP), mono (2-ethylhexyl) phthalate (mEHP), and mono-ethyl phthalate (mEP) and lower concentrations of mono-isobutyl phthalate (miBP). Moreover, a quantile-based g-computation (QGC) model revealed a positive association between mPAEs mixture and URSA. The URSA cases showed significantly higher concentrations of di-(2-ethylhexyl) phthalate (DEHP) than the controls. This was consistent with the health risk assessment, which suggested that DEHP is the main contributors to potential non-carcinogenic risk. DEHP accounted for over 80% of total risk. The large case-control study results suggest that PAE exposure may increase the risk of URSA, and that policy-makers and public health experts should pay more attention to DEHP exposure.

National-scale urinary phthalate metabolites in the general urban residents involving 26 provincial capital cities in China and the influencing factors as well as non-carcinogenic risks.

Phthalates (PAEs) are widely used in daily products but can cause a variety of adverse effects in humans. Few studies have been carried out on human internal exposure levels of PAEs on a large-scale, especially in developing countries. In the present study, 1161 urine samples collected from residents of 26 provincial capitals in China were analyzed for nine phthalate metabolites (mPAEs). The chemicals were widely detected, and the median specific gravity adjusted urinary concentration of Σ9mPAEs was 278 µg/L. Di-(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP) were the main parent PAEs that the residents were exposed to. Demographic characteristics, such as age and educational level, were significantly associated with PAE exposure. Children and the elderly had higher mPAE levels. Subjects with lower educational levels were more frequently exposed to DnBP and DEHP. However, mono-ethyl phthalate showed the opposite trend, i.e., higher concentrations in subjects aged 18-59 years and with higher educational levels. Geographic differences were detected at the national scale. Residents in northeastern and western China had higher levels of mPAEs than those in central China, most likely because of different industrial usage of the chemicals and different living habits and living conditions of the residents. Health risk assessment showed that hazard indices of PAEs ranged from 0.07 to 9.34, with 20.0% of the subjects being concern for potential non-carcinogenic risk as assessed by Monte Carlo simulation. DEHP and DnBP were the primary contributors, representing 96.7% of total risk. This first large-scale study on PAE human internal exposure in China provides useful information on residents' health in a developing country, which could be used for chemical management and health protection.

Urinary monohydroxylated polycyclic aromatic hydrocarbons in the general population from 26 provincial capital cities in China: Levels, influencing factors, and health risks.

Polycyclic aromatic hydrocarbons (PAHs) derived from the incomplete combustion of organic materials are associated with adverse health effects. However, little is known about PAH exposure levels and their influencing factors on a large scale in developing countries. In this study, urinary monohydroxylated metabolites of PAHs (OH-PAHs), including the metabolites of naphthalene, fluorene, phenanthrene, pyrene, chrysene, and benzo[a]pyrene, were measured in 1154 samples in the general population nationwide from 26 provincial capitals in China. Concentrations of OH-PAHs ranged from 1.39 to 228 µg/L. OH-Nap, metabolite of naphthalene, was the predominant compound, accounting for 65.1% of totals. People in eastern, southwest and northeast China, such as Shanghai, Kunming, Nanning, and Changchun, suffered more PAH exposure than other regions which might associate with sampling time, living habits of the subjects, and the imbalance of economic development and energy consumption across regions. Urinary OH-PAH concentrations were associated with body mass index, gender, and age, and smoking was the main correlating factor. Inhalation and diet might be the main exposure route of human exposure to PAHs, especially for smokers by inhalation. Hazard indices showed that no subject was exposed to PAHs with potential non-carcinogenic risk. Furthermore, the carcinogenic risk was the most significant health effects, with almost all subjects having carcinogenic risk values higher than the acceptable level of 10-6. Naphthalene and phenanthrene were the main contributors. The results also suggested a possible relationship between PAH exposure and lung cancer in the Chinese population. This first nationwide study on human internal exposure to PAHs provides a large body of scientific information for governmental decision-making about associated human health and the prevention of human exposure to PAHs.

Liquid-liquid extraction combined with online cleanup for the simultaneous determination of PAHs by GC-MS/MS and their hydroxylated metabolites by LC-MS/MS in human fingernails.

A method was developed for the simultaneous determination of polycyclic aromatic hydrocarbons (PAHs) and their hydroxylated metabolites (OH-PAHs) in human fingernails using liquid-liquid extraction and online purification. After surface decontamination by rinsing with acetone, the fingernails were digested with sodium hydroxide and subjected to liquid-liquid extraction with a mixture of n-hexane and methyl tertbutyl ether. The organic extract was then fractionated using a silica-based solid-phase extraction (SPE) cartridge to obtain a PAH fraction eluted with n-hexane/dichloromethane (v/v, 95:5) and an OH-PAH fraction eluted with dichloromethane/ethyl acetate (v/v, 50:50). The PAH fraction was directly injected into an online gel permeation chromatography-gas chromatography-triple quadrupole tandem mass spectrometry (GPC-GC-MS/MS) system, enabling rapid determination of 16 PAHs. A parallel online SPE liquid chromatography tandem mass spectrometry (LC-MS/MS) method was used to determine 12 OH-PAHs. Validation experiments showed that the recovery of PAH and OH-PAH were within range of 67.4%-105.1% (RSD ≤ 10.1%) and 72.8%-102.3% (RSD ≤ 10.9%), respectively, with limits of quantitation (LOQ) of 0.06-0.8 ng/g and 0.15-3.1 ng/g, respectively. Forty-two human fingernail samples from residents of Southern China were analyzed to establish background PAH and OH-PAH levels in this region. Several PAHs and OH-PAHs were detected, at concentrations of 97.5 to 3,687 ng/g for PAHs and 24.2 to 767 ng/g for OH-PAHs. The dominant homologues were two- and three-ring PAH isomers, notably naphthalene (Nap), fluorene (Flu), and phenanthrene (Phe), as well as the corresponding hydroxylated metabolites 2-OH-Nap, OH-Flu, and OH-Phe. Smoking, consuming barbecued food, and age had no significant effects on PAH exposure, but a larger sample would be required to confirm this finding. The online purification strategy presented here expedites cleanup and purification during analysis of human fingernails and should facilitate non-invasive biomonitoring of PAHs in humans, particularly when analyzing large numbers of samples.

Pollution profiles and human health risk assessment of atmospheric organophosphorus esters in an e-waste dismantling park and its surrounding area.

Recycling e-waste has been recognized as an important emission source of organophosphate triesters (tri-OPEs) and organophosphate diesters (di-OPEs), but the presence of di-OPEs in atmosphere has not been studied. Herein, tri-OPEs and di-OPEs in atmosphere of an e-waste dismantling park and surrounding area in South China were monitored for three consecutive years. Thirteen tri-OPEs and seven di-OPEs were identified. In 2017, 2018, and 2019, tri-OPE concentrations in e-waste dismantling park were 1.30 × 108, 4.60 × 106, and 4.01 × 107 pg/m3, while di-OPE concentrations were 1.14 × 103, 1.10 × 103, and 0.35 × 103 pg/m3, respectively, which were much higher than the surrounding area. Tri-OPEs and di-OPEs generated during e-waste dismantling affected surrounding area through diffusion. Triphenyl phosphate (TPhP) and diphenyl phosphate (DPhP) were the predominant congeners of tri-OPEs and di-OPEs, respectively. Additionally, TPhP concentration was extremely higher than other tri-OPEs, so TPhP could be used as an indicator of e-waste dismantling. Spearman correlation analysis showed significant correlations between DPhP and TPhP (R2 = 0.53, p < 0.01), bis-(1-chloro-2-propyl) phosphate (BCIPP) and tris(2-chloropropyl) phosphate (TCIPP) (R2 = 0.49, p < 0.01), as well as dibutyl phosphate (DBP) and tributyl phosphate (TBP) (R2 = 0.53, p < 0.01), indicating that they had the same source. Further, non-carcinogenic risk of them to people via inhalation was acceptable and non-carcinogenic risk of tri-OPEs decreased year by year in surrounding area.

Development and validation of a multi-residue method for the simultaneous analysis of brominated and organophosphate flame retardants, organochlorine pesticides, and polycyclic aromatic compounds in household dust.

Household dust is a sink for multiple toxic chemicals with known or suspected potential health effects. However, most dust exposure studies focus on a few chemicals, which may limit overall understanding of human exposure characteristics because people spend most of their time indoors. This paper describes the development and evaluation of a multi-residue analysis of 20 organochlorine pesticides (OCPs), 15 polycyclic aromatic hydrocarbons (PAHs), 8 polybrominated diphenyl ether congeners (PBDEs), 3 hexabromocyclododecane (HBCDs), 8 synthetic musks (Musks), and 7 organophosphate esters (OPEs) in indoor dusts. After extraction with acetone/hexane (v/v, 1 : 1), all target compounds were fractionated with a Florisil solid-phase extraction (SPE) cartridge into two fractions: PAHs, PBDEs, HBCDs, OCPs and Musks, which were eluted with hexane/dichloromethane, and OPEs eluted with ethyl acetate. Further clean-up using acidified silica 44% cartridges was then performed to enable determination of PBDEs and HBCDs. Instrumental analysis of the target chemicals was performed using gas chromatography (GC) or liquid chromatography (LC) coupled with mass spectrometry (MS) or tandem mass spectrometry (MS/MS). A newly-optimized GC-MS/MS method was employed for the simultaneous determination of PAHs, OCPs, and Musks. The lower limit of quantification (LOQ) values of PAHs, OCPs, and Musks were 0.14-0.92 ng g-1, 0.06-0.38 ng g-1 and 0.07-0.40 ng g-1, respectively. PBDEs were quantified by GC-MS with electron capture negative ionization, and HBCDs and OPEs by LC-MS/MS with electrospray ionization (ESI) in negative and positive ion mode, respectively. Recovery experiments showed that the average recoveries and relative standard deviations were 99-113% and 1-14% for PBDEs, 89-105% and 1-6% for HBCDs, 71-120% and 3-17% for PAHs, 71-112% and 2-17% for OCPs, 77-120% and 2-13% for Musks, and 80-127% and 1-14% for OPEs. Validation experiments showed that the method achieved good accuracy. The developed method was used to analyze SRM 2585 and real indoor dust samples to demonstrate its suitability for routine analysis. The target contaminants were widely detected in SRM 2585 and indoor dust collected from Wuhan of Central China, with PAHs the major species, followed by OPEs, OCPs, and PBDEs.

Adenosine triphosphate (ATP) and zinc(II) ions responsive pyrene based turn-on fluorescent probe and its application in live cell imaging.

A novel highly selective and sensitive turn-on fluorescent chemosensor PCE to recognize Zn2+ has been developed. The sensor PCE displays a remarkable fluorescent enhancement at 456 nm (λex = 340 nm) with Zn2+ without the interference of other biologically important relevant metal ions in aqueous acetonitrile solution. Job's plot and mass spectral studies divulge such the interaction of PCE by Zn2+ was 1:1 binding stoichiometry. The association constant and detection limit of PCE to recognize Zn2+ was found to be 0.948 × 104 M-1 and 4.82 × 10-7 M respectively. The nature of turn-on fluorescence sensor was supported by TD-DFT calculations. And the synthesized probe PCE was able to image intracellular Zn2+ in living cells using confocal imaging techniques. PCE-Zn ensemble showed the remarkable fluorescence enhancement with ATP selectively among other biologically important phosphates. 31P NMR experiments suggesting that the triphosphates unit of ATP is intact with the PCEZn. PCE-Zn ensemble can be utilized for monitoring ATP in live cells.

Human health risks estimations from polycyclic aromatic hydrocarbons in serum and their hydroxylated metabolites in paired urine samples.

Polycyclic aromatic hydrocarbons (PAHs) are compounds with two or more benzene rings whose hydroxylated metabolites (OH-PAHs) are excreted in urine. Human PAH exposure is therefore commonly estimated based on urinary OH-PAH concentrations. However, no study has compared PAH exposure estimates based on urinary OH-PAHs to measurements of PAH levels in blood samples. Estimates of PAH exposure based solely on urinary OH-PAHs may thus be subject to substantial error. To test this hypothesis, paired measurements of parent PAHs in serum and OH-PAHs in urine samples from 480 participants in Guangzhou, a typical developed city in southern China, were used to investigate differences in the estimates of human PAH exposure obtained by sampling different biological matrices. The median PAH concentration in serum was 4.05 ng mL-1, which was lower than that of OH-PAHs in urine (8.33 ng mL-1). However, serum pyrene levels were significantly higher than urinary levels of its metabolite 1-hydroxypyrene. Concentrations of parent PAHs in serum were not significantly correlated with those of their metabolites in urine with the exception of phenanthrene, which exhibited a significant negative correlation. Over 28% of the participants had carcinogenic risk values above the acceptable cancer risk level of 10-6. Overall, estimated human exposure and health risks based on urinary 1-hydroxypyrene levels were only 13.6% of those based on serum pyrene measurements, indicating that estimates based solely on urine sampling may substantially understate health risks due to PAH exposure.