Urinary Metabolites of Polycyclic Aromatic Hydrocarbons of Rural Population in Northwestern China: Oxidative Stress and Health Risk Assessment.

Polycyclic aromatic hydrocarbon (PAH) exposure is suspected to be linked to oxidative damage. Herein, ten PAH human exposure biomarkers [hydroxylated PAH metabolites (OH-PAHs)] and five oxidative stress biomarkers (OSBs) were detected in urine samples collected from participants living in a rural area (n = 181) in Northwestern China. The median molar concentration of ΣOH-PAHs in urine was 47.0 pmol mL-1. The 2-hydroxynaphthalene (2-OHNap; median: 2.21 ng mL-1) was the dominant OH-PAH. The risk assessment of PAH exposure found that hazard index (HI) values were <1, indicating that the PAH exposure of rural people in Jingyuan would not generate significant cumulative risks. Smokers (median: 0.033) obtained higher HI values than nonsmokers (median: 0.015, p < 0.01), suggesting that smokers face a higher health risk from PAH exposure than nonsmokers. Pearson correlation and multivariate linear regression analysis revealed that ΣOH-PAH concentrations were significant factors in increasing the oxidative damage to deoxyribonucleic acid (DNA) (8-hydroxy-2'-deoxyguanosine, 8-OHdG), ribonucleic acid (RNA) (8-oxo-7,8-dihydroguanine, 8-oxoGua), and protein (o, o'-dityrosine, diY) (p < 0.05). Among all PAH metabolites, only 1-hydroxypyrene (1-OHPyr) could positively affect the expression of all five OSBs (p < 0.05), suggesting that urinary 1-OHPyr might be a reliable biomarker for PAH exposure and a useful indicator for assessing the impacts of PAH exposure on oxidative stress. This study is focused on the relation between PAH exposure and oxidative damage and lays a foundation for the study of the health effect mechanism of PAHs.

A fast method for the determination of personal care product chemicals in human urine using dispersive liquid-liquid extraction and ultra high-performance liquid chromatography-tandem mass spectrometry.

RATIONALE: Personal care product chemicals (PCPCs) are the chemicals used in personal care products. Many of them are endocrine disruptors and have potential adverse effects on humans. The concentrations of PCPCs in urine are the main biomarker for assessing human exposure. METHODS: A method was developed for the simultaneous determination of 14 PCPCs in human urine using dispersive liquid-liquid extraction combined with ultra high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). RESULTS: Compared with liquid-liquid extraction, this method had the advantages of time efficiency, sensitivity, and limited organic solvent consumption. It produced good linearity (0.9965-0.9996), limits of detection (2.82-36.36 pg mL-1 ), limits of quantitation (9.39-121.08 pg mL-1 ), matrix effect (-0.90%-2.55%), intra-day precision (relative standard deviations [RSDs] <15%), and inter-day precision (RSDs <19.9%). The method had satisfactory relative recovery at three concentration levels. CONCLUSIONS: A rapid method was developed for the simultaneous quantification of 14 PCPCs in human urine. The practicability of the method was verified with 21 urine from university students. It is expected that this method will provide a powerful reference for the assessment of exposure to PCPCs in large populations.

Urinary Levels of 14 Metal Elements in General Population: A Region-Based Exploratory Study in China.

Metal pollution may lead to a variety of diseases; for this reason, it has become a matter of public concern worldwide. However, it is necessary to use biomonitoring approaches to assess the risks posed to human health by metals. In this study, the concentrations of 14 metal elements in 181 urine samples obtained from the general population of Gansu Province, China, were analyzed using inductively coupled plasma mass spectrometry. Eleven out of fourteen target elements had detection frequencies above 85%, namely, Cr, Ni, As, Se, Cd, Al, Fe, Cu and Rb. The concentrations of most metal elements in the urine of our subjects corresponded to the medium levels of subjects in other regional studies. Gender exerted a significant influence (p < 0.05) on the concentrations of Tl, Rb and Zn. The concentrations of Ni, As, Pb, Sr, Tl, Zn, Cu and Se showed significant differences among different age groups and the age-related concentration trends varied among these elements. There were significant differences in the urine concentrations of Zn and Sr between those subjects in the group who were frequently exposed to soil (exposed soil > 20 min/day) and those in the group who were not, indicating that people in regular contact with soil may be more exposed to metals. This study provides useful information for evaluating the levels of metal exposure among general populations.

Multiple metal exposure and metabolic syndrome in elderly individuals: A case-control study in an active mining district, Northwest China.

The prevalence of metabolic syndrome (MetS) is increasing at an alarming rate worldwide, particularly among elderly individuals. Exposure to various metals has been linked to the development of MetS. However, limited studies have focused attention on the elderly population living in active mining districts. Participants with MetS (N = 292) were matched for age (±2 years old) and sex with a healthy subject (N = 292). We measured the serum levels of 14 metals in older people aged 65-85 years. Conditional logistic regression, restricted cubic spline model, multiple linear regression, and Bayesian Kernel Machine Regression (BKMR) were applied to estimate potential associations between multiple metals and the risk of MetS. Serum levels of Sb and Fe were significantly higher than the controls (0.58 µg/L vs 0.46 µg/L, 2167 µg/L vs 2042 µg/L, p < 0.05), while Mg was significantly lower (20035 µg/L vs 20,394 µg/L, p < 0.05). An increased risk of MetS was associated with higher serum Sb levels (adjusted odds ratio (OR) = 1.61 for the highest tertile vs. the lowest tertile, 95% CI = 1.08-2.40, p-trend = 0.018) and serum Fe levels (adjusted OR = 1.55 for the highest tertile, 95% CI = 1.04-2.33, p-trend = 0.032). Higher Mg levels in serum may have potential protective effects on the development of MetS (adjusted OR = 0.61 for the highest tertile, 95% CI = 0.41-0.91, p-trend = 0.013). A joint exposure analysis by the BKMR model revealed that the mixture of 12 metals (except Tl and Cd) was associated with increased risk of MetS. Our results indicated that exposure to Sb and Fe might increase the risk of MetS in an elderly population living in mining-intensive areas. Further work is needed to confirm the protective effect of Mg on MetS.

Occurrence and profile characteristics of environmental phenols in human urine from a rural area in Northwestern China.

Many environmental phenols, such as bisphenols, benzophenones and parabens, are known as endocrine disruptors and can adversely affect human health. However, the knowledge of human exposure to common environmental phenols in Chinese rural areas is insufficient. In this context, 181 urine samples were collected from participants in a rural area in Northwest China and were analyzed for nine bisphenols, three benzophenones and four parabens. Bisphenol A (BPA), bisphenol S, benzophenone-1 (BP-1), benzophenone-3 (BP-3), 4-hydroxybenzophenone, methylparaben (MeP), ethylparaben and propylparaben (PrP) were detected in more than 50% of the urine samples, with median concentrations of 0.938 ng/mL, 0.0111 ng/mL, 0.191 ng/mL, 1.30 ng/mL, 0.0320 ng/mL, 25.9 ng/mL, 4.31 ng/mL and 1.94 ng/mL, respectively. A significant positive correlation was observed between BP-1 and BP-3, as well as between MeP and PrP, indicating metabolic transformation and combined use, respectively. The concentrations of MeP and PrP in females were significantly higher than those in males, suggesting that females were exposed to more MeP and PrP than males. Urinary concentrations of BPA, BP-3, MeP and PrP could be influenced by age. Other demographic information, such as annual household income, education and occupation was not associated with the exposure level of the targeted phenols in adults. The estimated daily intakes of the analytes except BPA were all below their respective tolerable/acceptable daily intake levels. This study profiles the demographic differences in the exposure to environmental phenols in general populations from rural areas and provides information on risk assessments.

Wide occurrence of seven phthalate plasticizers and two typical microplastics in pig feed.

Plastics are widely used as packaging and engineering materials in feed processing, which leads to the potential contamination of plasticizers and microplastics (MPs) in animal feeds. In this study, the concentrations of two typical MPs, i.e., polyethylene terephthalate (PET) and polycarbonate (PC), and seven phthalates (PAEs) as well as their corresponding monoester metabolites (mPAEs) in 45 pig feed samples in China were analyzed by mass spectrometers. Among PAEs, dibutyl phthalate (DBP) and bis(2-ethylhexyl) phthalate (DEHP) were detected in all samples, and DEHP showed the highest concentrations of 8.26-2464 µg/kg, which accounted for 65.6% of the total detected PAEs. PET MPs (

Phthalates in dormitory dust and human urine: A study of exposure characteristics and risk assessments of university students.

Phthalate diesters (PAEs) are prevalent and potentially toxic to human health. The university dormitory represents a typical and relatively uniform indoor environment. This study evaluated the concentrations of phthalate monoesters (mPAEs) in urine samples from 101 residents of university status, and the concentrations of PAEs in dust collected from 36 corresponding dormitories. Di-(2-ethylhexyl) phthalate (DEHP, median: 68.0 µg/g) was the major PAE in dust, and mono-ethyl phthalate (47.9 %) was the most abundant mPAE in urine. The levels of both PAEs in dormitory dust and mPAEs in urine were higher in females than in males, indicating higher PAE exposure in females. Differences in lifestyles (dormitory time and plastic product use frequency) may also affect human exposure to PAEs. Moreover, there were significant positive correlations between the estimated daily intakes of PAEs calculated by using concentrations of PAEs in dust (EDID) and mPAEs in urine (EDIU), suggesting that PAEs in dust could be a significant source of human exposure to PAEs. The value of EDID/EDIU for low molecular weight PAEs (3-6 carbon atoms in their backbone) was lower than that of high molecular weight PAEs. The contribution rate of various pathways to PAE exposure illustrated that non-dietary ingestion (87.8 %) was the major pathway of human exposure to PAEs in dust. Approximately 4.95 % of university students' hazard quotients of DEHP were >1, indicating that there may be some health risks associated with DEHP exposure among PAEs. Furthermore, it is recommended that some measures be taken to reduce the production and application of DEHP.

Simultaneous determination of multiple isomeric hydroxylated polycyclic aromatic hydrocarbons in urine by using ultra-high performance liquid chromatography tandem mass spectrometry.

Monitoring the level of hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) in urine is the key to exploring human metabolic changes and comprehensive potential toxicity of PAHs. The OH-PAHs with isomeric structure have different biological functions, indicating that their quantification is indispensable. However, the quantitation method is still dissatisfactory due to the poor separation of these isomeric OH-PAHs. The current study established a ultra-high performance liquid chromatography (UHPLC) tandem mass spectrometry (MS) method to complete the simultaneous determination of 17 OH-PAHs, including two naphthalene metabolites (1-hydroxynaphthalene, 2-hydroxynaphthalene), two fluorene metabolites (2-hydroxyfluorene, 3-hydroxyfluorene), five phenanthrene metabolites (1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 3-hydroxyphenanthrene, 4-hydroxyphenanthrene, 9-hydroxyphenanthrene), a pyrene metabolite (1-hydroxypyrene), five chrysene metabolites (1-hydroxychrysene, 2-hydroxychrysene, 3-hydroxychrysene, 4-hydroxychrysene, 6-hydroxychrysene) and two benzo[a]pyrene metabolites (3-hydroxybenzo[a]pyrene, 9-hydroxybenzo[a]pyrene). The method validation results showed good selectivity, linearity (r2 > 0.999), inter-day and intra-day precision (relative standard deviation (RSD) < 5.5% and RSD < 6.3%), stability (RSD < 19.3%), matrix effect (-8.3%-11.5%) and recovery (65.9%-116.2%). This method is convenient, sensitive and efficient, saving expensive materials and complicated derivatization procedures. The practical applicability of developed approach was also tested in urine samples to identify potential biomarkers of PAHs exposure in humans, and a great compromise was obtained between recoveries and extract convenience. The developed approach may be widely utilized for specific determination of OH-PAHs with isomer structure in urine samples. It is expected that the application of this method may provide powerful references for PAHs exposure assessment.