Associations between blood volatile organic compounds, and changes in hematologic and biochemical profiles, in a population-based study

Depressive symptoms mediate the relationship between blood volatile organic compounds exposure and short sleep duration among US adults

The associations of volatile organic compounds (VOCs) exposure with short sleep duration (SSD) have rarely been studied. We aimed to evaluate the correlation between VOC exposure and SSD risk, while also exploring the potential mediating influence of depressive symptoms. Blood concentrations of seven VOCs, namely benzene, toluene, ethylbenzene, m-/p-xylene, o-xylene, styrene (collectively known as BTEXS), and 1,4-dichlorobenzene, were analyzed in 2905 U.S. adults. Weighted logistic regression, quantile-based g-computation (QGC), and weighted quantile sum (WQS) regression were employed to investigate associations between selected VOCs and SSD risk. Mediation analyses were conducted to explore the potential mediating effects of depressive symptoms on these relationships. Increased blood levels of BTEXS were positively correlated with SSD risk, with odds ratios (OR) ranging from 1.130 to 1.212 (all P < 0.05). A nonlinear association between toluene concentration and SSD risk was observed (P for nonlinearity = 0.028). Both QGC and WQS analyses indicated a positive association between co-exposure to VOCs and SSD, with styrene showing the highest positive weights (QGC: OR = 1.313, 95 % confidence interval (CI): 1.038-1.660; WQS: OR = 1.386, 95 % CI: 1.111-1.731). Furthermore, BTEXS exposure was positively linked to depressive symptoms, which in turn were significantly associated with SSD risk. Mediation analyses revealed that depressive symptoms partially mediated the relationships between individual and mixed VOCs and SSD risk, with mediation proportions ranging from 15.87 % to 20.54 % (all P < 0.05). These findings indicated that exposure to VOCs increased SSD risk, with depressive symptoms playing a partial mediating role.

Individual and mixture effects of BTEX occupational exposure with hematologic and hepatic profiles in petrochemical workers and the metabolic mechanism

Evidence on the association of occupational exposure to benzene, toluene, ethylbenzene, and xylene (BTEX) with hematologic and hepatic profiles were equivocal, and few studies have investigated overall effect of BTEX mixtures. Herein, significant higher concentrations (p < 0.05) of hippuric acid, 1,2-dihydroxybenzene, mandelic acid, trans, trans-muconic acid and phenylglyoxylic acid were found in petrochemical workers than the controls, in accordance with higher levels of hematologic and hepatic profiles found in petrochemical workers (p < 0.05). Occupational exposure to individual BTEX was associated with elevated levels of white blood cell (WBC), lymphocyte (LYMPH), alanine aminotransferase (ALT), and gamma-glutamyl transferase (GGT). Further, the Weighted Quantile Sum Regression model and Bayesian Kernel Machine Regression model consistently identified a positive association between BTEX mixture exposure and WBC, LYMPH, and GGT. Xylene was the primary contributor to increased WBC, LYMPH, and GGT levels. Furthermore, BTEX exposure resulting in the increased inflammation indices were mainly related to perturbations of sphingolipid metabolism, biosynthesis of unsaturated fatty acids, and primary bile acid biosynthesis. Whereas metabolites mediated the correlation between BTEX exposure and liver function indices were related to the perturbations of biosynthesis of unsaturated fatty acids, arachidonic acid metabolism, sphingolipid metabolism, primary bile acid biosynthesis, etc. Our findings revealed potential health risk of occupational exposure to BTEX and might help one to understand the link between BTEX exposure and hematologic and hepatic profiles.

Oil spill cleanup related exposures to benzene, toluene, ethylbenzene, xylenes, and n-hexane and incident diabetes mellitus

BACKGROUND AND OBJECTIVES

Exposure to benzene, toluene, ethylbenzene, xylenes, and n-hexane (BTEX-H) may contribute to the development of diabetes. Oil spill response and cleanup (OSRC) workers are exposed to BTEX-H but there are few relevant studies. We studied incident diabetes over 10 years of follow-up among OSRC workers.

METHODS

This analysis includes 21,726 participants (82.2 % male, mean age 39.9 years; 66.5 % White race) in the Gulf Long-term Follow-up Study - a prospective cohort of Deepwater Horizon (DWH) oil spill OSRC workers followed from 2011 to 2013 through 2021. Individual estimates of cumulative work-related exposures to specific BTEX-H chemicals and an aggregate sum (total BTEX-H) were derived from a job-exposure matrix that linked exposure group estimates derived from exposure measurements to self-reported DWH work histories. We used Cox models to estimate associations of quartiles of exposure to individual BTEX-H chemicals and total BTEX-H with diabetes incidence. We used quantile-based g-computation, quantifying associations with exposure to the BTEX-H chemicals, treating them as separate components in a mixture. We examined differences in associations by neighborhood disadvantage using the Area Deprivation Index (ADI) and by self-classified race in stratified analyses.

RESULTS

Exposure to the BTEX-H chemicals was associated with diabetes, with elevated hazard ratios for third and fourth quartiles of exposure compared to the first quartile. For example, total BTEX-H, Q3 and Q4 HRs were 1.10 95 %CI (0.91, 1.33) and 1.27 95 %CI (1.05, 1.53), respectively. The HR associated with a three-quartile increase in the BTEX-H mixture was 1.31 95 %CI (1.07, 1.59). Stratified analyses showed little variation by race and suggestions of variation by ADI.

CONCLUSION

Exposures to BTEX-H chemicals were associated with incident diabetes among OSRC workers for the individual BTEX-H chemicals, total BTEX-H, and the BTEX-H mixture. The range of exposures in this study make these findings relevant to other low to moderate exposure settings.

Simulated occupational exposure to volatile organic compounds from industrial printing ink alter behavioral, neurological, oxidative, hepatic, and kidney indices in mice

Industrial printing inks are major sources of occupational exposure to volatile organic compounds (VOCs) with potential adverse effects. The behavioral, neurological, oxidative, hepatic, and kidney function effects of simulated occupational exposure to VOCs emitted from an industrial printing ink were investigated in laboratory mice, Mus musculus for 4 weeks. Average TVOCs value of 0.5 mg/m3 measured at 10 printing presses was the exposure level utilized in this study. There were significant duration-dependent and sex-disaggregated differences in the behavioral responses; acetylcholinesterase (neurological biomarker) and MDA (lipid peroxidation biomarker) activities significantly increased while SOD and CAT (antioxidants) activities significantly decreased in the brain; ALT, AST, and ALP (liver) as well as bilirubin, urea, and creatinine (kidney) were significantly elevated in exposed mice correlating with histopathologies compared to control. The results showed that long term inhalation of VOCs emitted from industrial printing inks may pose multiple sub-lethal effects in occupationally exposed persons, especially females.

Trimester-specific associations of exposure to epoxide alkanes, alkenals, and 1,3-butadiene with preschool children's intellectual development: A birth cohort study in Wuhan, China

The impact of prenatal exposure to contaminants with neurotoxicity like epoxide alkanes (ethylene oxide, propylene oxide), alkenals (acrolein, crotonaldehyde), and 1,3-butadiene on children's intellectual development remains underreported, and related sensitive window is of interest. In this cohort study, metabolites of these contaminants were measured in 3,081 urine samples from 1,027 pregnant women across three trimesters. Children's intelligence quotient was evaluated at 4-6 years old. Generalized estimating equation models showed that higher urinary concentrations of 2-hydroxypropyl mercapturic acid (a metabolite of propylene oxide), 3-hydroxypropyl mercapturic acid (HPMMA, a metabolite of crotonaldehyde), and the sum of acrolein metabolites in the first trimester were associated with lower visual spatial index (VSI), working memory index (WMI), or processing speed index scores. Quantile g-computation models revealed that co-exposure to these contaminants in the first trimester were associated with lower VSI (β = -0.98, 95 % CI: -1.94, -0.03) and WMI (β = -0.86, 95 % CI: -1.66, -0.06) scores, with HPMMA as the major contributor. These results suggested that early pregnancy could be a sensitive window during which exposure to propylene oxide, crotonaldehyde, and acrolein may impair offspring's intellectual development.

Ambient low-level benzene, genetic factors, and heart failure incidence among urban adults

Ambient benzene, a representative volatile organic compound (VOC) primarily resulting from rapid industrialization and urbanization, is also of great concern as an urban air toxic. The global benzene market is experiencing steady growth, driven by its use in industrial manufacturing. Currently, population epidemiological evidence about the effects of ambient benzene on heart failure (HF) incidence is still inadequate, especially at low levels of long-term exposure. Leveraging data from 277,585 urban residents in the UK Biobank, the study utilized Cox regression models adjusted for potential confounders to evaluate the association between low-concentration benzene exposure and HF risk. The investigation also assessed potential interactions between genetic predisposition and ambient benzene by applying relative excess risk due to interaction (RERI) metrics and interaction significance testing. Furthermore, the effect of ambient benzene on cardiac functional parameters was estimated using multiple linear regression models. This study demonstrated that per interquartile range increment of ambient benzene was related to the elevated HF risk (hazard ratios = 1.22, 95 % confidence interval (CI): 1.07-1.39] from the time-dependent Cox model. An additive interaction between ambient benzene and genetic risk was observed (RERI = 0.18, 95 % CI: 0.01-0.36). Ambient benzene exposure demonstrated significant correlations with modifications in cardiac functional parameters, such as ventricular end-diastolic and end-systolic volumes. Prolonged exposure to low-concentration ambient benzene may elevate the likelihood of developing HF, which provides the necessary evidence for the systematic risk assessment of ambient benzene and promotes the formulation and updating of air quality guidelines worldwide.

Environmental Pollutants, Occupational Exposures, and Liver Disease

Environmental pollutants significantly impact liver disease development, progression, and outcomes. This review examines the complex relationship between environmental exposures and liver pathology, from malignant conditions like hepatocellular carcinoma to steatotic and cholestatic liver diseases. Key environmental factors include air pollutants, volatile organic compounds, persistent organic pollutants, heavy metals, and per- and polyfluoroalkyl substances. These compounds can act through multiple mechanisms, including endocrine disruption, metabolic perturbation, oxidative stress, and direct hepatotoxicity. The impact of these exposures is often modified by factors such as sex, diet, and genetic predisposition. Recent research has revealed that even low-level exposures to certain chemicals can significantly affect liver health, particularly when combined with other risk factors. The emergence of exposomics as a research tool promises to enhance our understanding of how environmental factors influence liver disease. Importantly, exposure effects can vary by demographic and socioeconomic factors, highlighting environmental justice concerns. Implementation of this knowledge in clinical practice requires new diagnostic approaches, healthcare system adaptations, and increased awareness among medical professionals. In conclusion, this review provides a comprehensive examination of current evidence linking environmental exposures to liver disease and discusses implications for clinical practice and public health policy.

The association analysis between exposure to volatile organic compounds and fatty liver disease in US Adults

BACKGROUND

Limited epidemiological research has explored the associations between ambient volatile organic compounds (VOCs) and fatty liver disease (FLD). This study aimed to explore the associations between VOCs and FLD and liver function biomarkers. We obtained urinary concentrations of VOCs metabolites from NHANES.

METHODS

Weighted logistic regression models were employed to investigate the relationships between VOCs and FLD risk, including alcoholic FLD (AFLD) and non-alcoholic FLD (NAFLD). The associations of VOCs and liver function biomarkers were also investigated using weighted linear regression.

RESULTS

Among the 2050 participants, 774 were classified as having FLD. After adjustment, each log-transformed SD increase in N-Acetyl-S-(2-carboxyethyl)-l-cysteine (CEMA), 2-Aminothiazoline-4-carboxylicacid (ATCA), and trans-trans-muconic-acid (MUCA) had a OR (95%CI) of 1.30 (1.06-1.61; P-trend=0.014), 1.34 (1.12-1.61; P-trend=0.002), and 1.22 (1.01-1.47; P-trend=0.035), respectively. ATCA and MUCA were associated with higher risks of NAFLD (OR=1.47, 95%CI: 1.20-1.79, and OR=1.26, 95%CI: 1.02-1.56, respectively). VOCs were positively associated with gamma glutamyl transaminase (GGT) and C-reactive protein (CRP), while inversely associated with albumin, total protein and alanine aminotransferase (ALT) (P < 0.05).

CONCLUSIONS

Urinary metabolites of VOCs have been found to be strongly correlated with a higher risk of FLD and NFALD, and impaired liver function. These novel findings merit further prospective studies to comprehend the effect of VOCs on liver diseases.

Relation of volatile organic compounds to renal function in American adolescents: three statistical models

This study was conducted to evaluate the relationship between 17 urinary metabolites of volatile organic compounds (mVOCs) in adolescents and renal function parameters (estimated glomerular filtration rate (eGFR), albumin-to-creatinine ratio (ACR), urinary albumin, serum uric acid (SUA), and blood urea nitrogen (BUN)). In adjusted generalised linear models (GLM), mVOCs were positively correlated with eGFR, urinary albumin, and BUN, and mVOCs were negatively correlated with ACR and SUA. Weighted Quartile Sum (WQS) index correlated with eGFR [β(95%CI): 0.040 (0.028, 0.052)], urine albumin [β(95%CI): 0.275 (0.203, 0.622)], SUA [β(95%CI): 0.040 (0.025, 0.055)] and BUN [β(95%CI): 0.102 (0.082, 0.122)]. In Bayesian Kernel Machine Regression (BKMR) model, total compound effect was positively correlated with eGFR, positive associations were observed in high concentration of the mixture with urine albumin and ACR. Findings suggest that single and mixed exposures to mVOCs may affect renal parameters in adolescents.

Association between occupational exposure to gasoline and anemia: a retrospective cohort study in China

BACKGROUND

Anemia is a major global burden, and occupational gasoline exposure is a common occupational hazard factor. Although previous studies have shown that there is a potential relationship between occupational gasoline exposure and the increase of anemia prevalence, this relationship has not been fully explored. The current cohort study aimed to investigate the association between occupational exposure to gasoline and anemia, and the effect of gasoline concentration on hemoglobin (Hb) levels.

METHODS

This retrospective cohort study collected baseline data from 1451 workers, including 605 exposed to gasoline and 846 not exposed to gasoline. Participants were enrolled in 2013-2015, and follow-up in 2019. Anemia was diagnosed according to WHO guidelines on hemoglobin cutoffs to define anemia in individuals and populations. Occupational exposure concentration of gasoline was measured based on the Chinese national standard (GBZ-T300.62-2017). Logistic regression was conducted to analyze the associations of occupational exposure to gasoline and anemia.

RESULTS

The incidence of anemia among workers exposed to gasoline was significantly higher than that among non-exposed workers (relative risk [RR] = 11.03, 95% confidence interval [CI]: 9.45-12.53). The risks of anemia were significantly higher among participants exposed to gasoline concentrations ≥ 43.20 mg/m³ (RR = 13.92, 95%CI: 12.25-15.28), 18.01-43.19 mg/m³ (RR = 12.93, 95%CI: 11.07-14.51), and 0.01-18.00 mg/m³ (RR = 5.49, 95%CI: 3.96-7.32) compared with the control non-exposed group. The risk of anemia was significantly higher among exposed workers, after adjusting for all confounding factors. There was also a significant negative correlation between gasoline exposure concentration and hemoglobin level.

CONCLUSIONS

Occupational exposure to gasoline is associated with an increased incidence of anemia, with a positive correlation between occupational gasoline exposure levels and the severity of anemia. The incidence and severity of anemia increase while hemoglobin levels decrease in line with increasing gasoline exposure concentrations. These findings emphasize the importance of assessing anemia in workers exposed to gasoline.

Association of exposure to multiple volatile organic compounds with ultrasound-defined hepatic steatosis and fibrosis in the adult US population: NHANES 2017-2020

Objective

Volatile organic compounds (VOCs) are pervasive environmental pollutants known to impact human health, but their role in liver steatosis or fibrosis is not fully understood. This study investigates the association of urinary VOC mixtures with the risk of liver steatosis and fibrosis in U.S. adult population.

Methods

Data of 1854 adults from the National Health and Nutrition Examination Survey (NHANES) from 2017.01 to 2020.03 were collected. Vibration Controlled Transient Elastography (VCTE) assessed hepatic steatosis and liver fibrosis via the controlled attenuation parameter (CAP) and liver stiffness measurement (LSM), respectively. The study examined the relationship between urinary exposure biomarkers for 20 VOCs and liver health outcomes using multivariate logistic regression and Bayesian Kernel Machine Regression (BKMR) to evaluate the effects of both individual and mixed VOC exposures.

Results

Multivariate logistic regression analysis revealed that exposure biomarkers for acrolein and crotonaldehyde were positively associated with hepatic steatosis. Conversely, biomarkers for styrene, ethylbenzene, and propylene oxide were negatively associated with hepatic steatosis. Furthermore, biomarkers for 1,3-butadiene and xylene were positively associated with liver fibrosis, while ethylbenzene was negatively associated with this condition. BKMR analysis identified a significant positive joint effect of VOC biomarkers on CAP. Notably, when other VOC-EBs were held at median levels, biomarkers for acrolein and 1,3-butadiene exhibited linear correlations with Ln CAP and hepatic Ln LSM, respectively.

Conclusion

The study highlights the potential hepatotoxic effects of VOC mixtures, particularly noting the roles of acrolein and 1,3-butadiene in exacerbating liver steatosis and fibrosis. These findings advocate for further research to explore the mechanistic pathways and conduct longitudinal studies to establish causality and enhance understanding of VOCs' impact on liver health.

Styrene and ethylbenzene exposure and type 2 diabetes mellitus: A longitudinal gene-environment interaction study

Styrene and ethylbenzene (S/EB) are identified as hazardous air contaminants that raise significant concerns. The association between S/EB exposure and the incidence of type 2 diabetes mellitus (T2DM), and the interaction between genes and environment, remains poorly understood. Our study consisted of 2219 Chinese adults who were part of the Wuhan-Zhuhai cohort. A follow-up assessment was conducted after six years. Exposure to S/EB was quantified by determining the concentrations of urinary biomarkers of exposure to S/EB (UBE-S/EB; urinary phenylglyoxylic acid level plus urinary mandelic acid level). Logistic regression models were constructed to investigate the relations of UBE-S/EB and genetic risk score (GRS) with T2DM prevalence and incidence. The interaction effects of UBE-S/EB and GRS on T2DM were investigated on multiplicative and additive scales. UBE-S/EB was dose-dependently and positively related to T2DM prevalence and incidence. Participants with high levels of UBE-S/EB [relative risk (RR) = 1.930, 95% confidence interval (CI): 1.157-3.309] or GRS (1.943, 1.110-3.462) demonstrated the highest risk of incident T2DM, in comparison to those with low levels of UBE-S/EB or GRS. Significant additive interaction between UBE-S/EB and GRS on T2DM incidence was discovered with relative excess risk due to interaction (95% CI) of 0.178 (0.065-0.292). The RR (95% CI) of T2DM incidence was 2.602 (1.238-6.140) for individuals with high UBE-S/EB and high GRS, compared to those with low UBE-S/EB and low GRS. This study presented the initial evidence that S/EB exposure was significantly related to increased risk of T2DM incidence, and the relationship was interactively aggravated by genetic predisposition.

Microglia Mediate Metabolic Dysfunction From Common Air Pollutants Through NF-κB Signaling

The prevalence of type 2 diabetes (T2D) poses a significant health challenge, yet the contribution of air pollutants to T2D epidemics remains under-studied. Several studies demonstrated a correlation between exposure to volatile organic compounds (VOCs) in indoor/outdoor environments and T2D. Here, we conducted the first meta-analysis, establishing a robust association between exposure to benzene, a prevalent airborne VOC, and insulin resistance in humans across all ages. We used a controlled benzene exposure system, continuous glucose monitoring approach, and indirect calorimetry in mice, to investigate the underlying mechanisms. Following exposure, disruptions in energy homeostasis, accompanied by modifications in the hypothalamic transcriptome and alterations in insulin and immune signaling, were observed exclusively in males, leading to a surge in blood glucose levels. In agreement, RNA sequencing of microglia revealed increased expression of genes associated with immune response and NF-κB signaling. Selective ablation of IKKβ in immune cells (Cx3cr1GFPΔIKK) or exclusively in microglia (Tmem119ERΔIKK) in adult mice alleviated benzene-induced gliosis, restored energy homeostasis and hypothalamic gene expression, and protected against hyperglycemia. We conclude that the microglial NF-κB pathway plays a critical role in chemical-induced metabolic disturbances, revealing a vital pathophysiological mechanism linking exposure to airborne toxicants and the onset of metabolic diseases.

ARTICLE HIGHLIGHTS

Application and interpretation of immunophenotyping data in safety and risk assessment

The use of immunophenotyping during immunotoxicity investigations was first popularized in the 1980 s and has since become more integrated into diagnostic and non-clinical assessments. The data provided from immunophenotyping can serve as an initial source of information to guide decisions for additional, more advanced, immunotoxicity testing as well as for human health safety and risk assessment of drugs and chemicals. However, comprehensive guidance describing applications of immunophenotyping data in immunotoxicity investigations is lacking, particularly among regulatory bodies. Therefore, a critical examination is needed for the appropriate interpretations and potential misinterpretations of such data during the assessment of drug safety and chemical risk. As such, the current uses and implications of immunophenotyping data in human health safety and risk assessments has been evaluated to provide additional context for the application of current methodologies and guidelines. In addition, case studies are presented to highlight the challenges of interpreting immunophenotyping results along with incorporating the findings into immunotoxicity investigations. Based on the analyses of current approaches and methodologies, a decision flow is presented for use of immunophenotyping data during risk informed decision making.

Combined association of urinary volatile organic compounds with chronic bronchitis and emphysema among adults in NHANES 2011-2014: The mediating role of inflammation

Evidence on the association of volatile organic compounds (VOCs) with chronic bronchitis (CB) and emphysema is spare and defective. To evaluate the relationship between urinary metabolites of VOCs (mVOCs) with CB and emphysema, and to identify the potential mVOC of paramount importance, data from NHANES 2011-2014 waves were utilized. Logistic regression was conducted to estimate the independent association of mVOCs with respiratory outcomes. Least absolute shrinkage and selection operator (LASSO) regression was performed to screen a parsimonious set of CB- and emphysema-relevant mVOCs that were used for further co-exposure analyses of weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR). Mediation analysis was employed to detect the mediating role of inflammatory makers in such associations. In single exposure analytic model, nine mVOCs were individually and positively associated with CB, while four mVOCs were with emphysema. In WQS regression, positive association between LASSO selected mVOCs and CB was identified (OR = 1.82, 95% CI: 1.25 to 2.69), and N-acetyl-S-(4-hydroxy-2-butenyl)-l-cysteine (MHBMA3) weighted the highest. Results from BKMR further validated such combined association and the significance of MHBMA3. As for emphysema, significantly positive overall trend of mVOCs was only observed in BKMR model and N-acetyl-S-(N-methylcarbamoyl)-l-cysteine (AMCC) contributed most to the mixed effect. White blood cell count (WBC) and lymphocyte number (LYM) were mediators in the positive pattern of mVOCs mixture with CB, while association between mVOCs mixture and emphysema was significantly mediated by LYM and segmented neutrophils num (NEO). This study demonstrated that exposure to VOCs was associated with CB and emphysema independently and combinedly, which might be partly speculated that VOCs were linked to activated inflammations. Our findings shed novel light on VOCs related respiratory illness, and provide a new basis for the contribution of certain VOCs to the risk of CB and emphysema, which has potential public health implications.

A review of disrupted biological response associated with volatile organic compound exposure: Insight into identification of biomarkers

Volatile organic compounds (VOCs) are widespread harmful atmospheric pollutants, which have long been concerned and elucidated to be one of the risks of acute and chronic diseases for human, such as leukemia and cancer. Although numerous scientific studies have documented the potential adverse outcomes caused by VOC exposure, the mechanisms which biological response pathways of these VOC disruption remain poorly understood. Therefore, the identification of biochemical markers associated with metabolism, health effects and diseases orientation can be an effective means of screening biological targets for VOC exposure, which provide evidences to the toxicity assessment of compounds. The current review aims to understand the mechanisms underlying VOCs-elicited adverse outcomes by charactering various types of biomarkers. VOCs-related biomarkers from three aspects were summarized through in vitro, animal and epidemiological studies. i) Unmetabolized and metabolized VOC biomarkers in human samples for assessing exposure characteristics in different communities; ii) Adverse endpoint effects related biomarkers, mainly including (anti)oxidative stress, inflammation response and DNA damage; iii) Omics-based molecular biomarkers alteration in gene, protein, lipid and metabolite aspects associated with biological signaling pathway disorders response to VOC exposure. Further research, advanced machine learning and bioinformation approaches combined with experimental results are urgently needed to ascertain the selection of biomarkers and further illuminate toxic mechanisms of VOC exposure. Finally, VOCs-induced disease causes can be predicted with proven results.

Association between Volatile Organic Compound Exposure and Sex Hormones in Adolescents: The Mediating Role of Serum Albumin

The associations between VOCs and sex hormones in adolescents remain unclear, and the role of serum albumin in these associations deserves to be explored. We conducted cross-sectional analyses using generalized linear models (GLMs), weighted quantile sum (WQS) regression, and mediation analysis, based on data from 584 adolescents from the National Health and Nutrition Examination Survey (NHANES). The GLM analyses revealed that seven kinds of mVOCs potentially affected sex hormone levels. According to the WQS regression results, 2-aminothiazoline-4-carboxylic acid (ATCA) was the major contributor to the significant associations of mixed mVOC exposure with testosterone, estradiol, and free androgen index in males; N-acetyl-S-(N-methylcarbamoyl)-L-cysteine (AMCC) was the major contributor to the significant associations of mixed mVOC exposure with sex hormone-binding globulin in males; and N-acetyl-S-(benzyl)-L-cysteine (BMA) was the major contributor to the significant associations of mixed mVOC exposure with the ratio of testosterone to estradiol in females. Moreover, serum albumin could mediate up to 9.2% of the associations between mixed exposure to mVOCs and sex hormones. Our findings could provide a reference for studies on the mechanisms underlying the effects of VOCs on sex hormones in adolescents and emphasize the necessity of reducing exposure to ATCA, AMCC, BMA, and their parent compounds.

Sexual dimorphism association of combined exposure to volatile organic compounds (VOC) with kidney damage

BACKGROUND

Epidemiological evidence emphasizes air pollutants' role in chronic kidney disease (CKD). Volatile organic compounds (VOCs) contribute to air pollution, yet research on VOCs and kidney damage, especially gender disparities, is limited.

METHODS

This study analyzed NHANES data to explore associations between urinary VOC metabolite mixtures (VOCMs) and key kidney-related parameters: estimated glomerular filtration rate (eGFR), albumin-to-creatinine ratio (ACR), chronic kidney disease (CKD), and albuminuria. Mediation analyses assessed the potential mediating roles of biological aging (BA) and serum albumin in VOCM mixtures' effects on kidney damage. Sensitivity analyses were also conducted.

RESULTS

The mixture analysis unveiled a noteworthy positive association between VOCM mixtures and the risk of developing CKD, coupled with a significant negative correlation with eGFR within the overall participant cohort. These findings remained consistent when examining the female subgroup. However, among male participants, no significant link emerged between VOCM mixtures and CKD or eGFR. Furthermore, in both the overall and female participant groups, there was an absence of a significant correlation between VOCM mixtures and either ACR or albuminuria. On the other hand, in male participants, while no significant correlation was detected with albuminuria, a significant positive correlation was observed with ACR. Pollutant analysis identified potential links between kidney damage and 1,3-butadiene, toluene, ethylbenzene, styrene, xylene, acrolein, crotonaldehyde and propylene oxide. Mediation analyses suggested that BA might partially mediate the relationship between VOCM mixtures and kidney damage.

CONCLUSION

The current findings highlight the widespread exposure to VOCs among the general U.S. adult population and indicate a potential correlation between exposure to VOC mixtures and compromised renal function parameters, with notable gender disparities. Females appear to exhibit greater sensitivity to impaired renal function resulting from VOCs exposure. Anti-aging treatments may offer some mitigation against kidney damage due to VOCs exposure.

Single and mixed effects of multiple volatile organic compounds exposure on hematological parameters in the U.S. adult population

BACKGROUND

Most research exploring the correlation between volatile organic compounds (VOCs) and hematological parameters have focused on single VOCs. Our study aimed to explore the single and combined effects of VOCs on hematological parameters through three statistical models.

METHODS

Data from 4 cycles of the National Health and Nutrition Examination Survey (NHANES) were used in this study. The correlations between single exposure to 16 VOCs and hematological parameters in the general population were assessed by weighted multiple linear regression. Weighted quantile sum (WQS) and Bayesian kernel machine regression (BKMR) models were used to explore the relationship between the combined important VOCs selected by the least absolute shrinkage and selection operator (LASSO) and hematological parameters, as well as the effects of smoking status on them.

RESULTS

A total of 4089 adults were included in the study. We found that a variety of VOCs were significantly associated with hematological parameters. Among them, N-acetyl-S-(benzyl)-l-cysteine (BMA) was significantly negatively correlated with white blood cell (WBC), red blood cell (RBC), lymphocyte, and neutrophil counts. N-acetyl-S-(3-hydroxypropyl-1-methyl)-l-cysteine (HPMMA) was significantly positively correlated with WBC, monocyte, lymphocyte, and neutrophil counts. In the WQS analysis, the WQS index of the VOCs mixtures was positively correlated with WBC (β: 0.031; P < 0.001), monocyte (0.023; P = 0.021), and neutrophil (0.040; P = 0.001) counts, while negatively associated with RBC (-0.013; P < 0.001) counts. The BKMR model revealed that combined exposure to VOCs levels ≥70th percentile was significantly associated with lower RBC counts, and BMA was identified as the dominant contributor. Smoking significantly influenced the relationship between VOCs and hematological parameters.

CONCLUSIONS

Our study indicated the effects of single and overall VOCs exposure on hematological parameters and suggested the hematotoxicity as well as pro-inflammatory effects of VOCs, which had strong public health implications for reducing the potential health hazards of VOCs exposure to the hematologic system.

Exposure to BTEX is associated with cardiovascular disease, dyslipidemia and leukocytosis in national US population

BACKGROUND

Comprehensive research on the effects of individual benzene, toluene, ethylbenzene, and xylenes (BTEX) and their mixture measured in blood samples, on cardiovascular diseases (CVD) and related risk factors among the general population is limited.

OBJECTIVES

To investigate the effects of blood individual and mixed BTEX on total CVD and its subtypes, lipid profiles, and white blood cell (WBC) count.

METHODS

Survey-weighted multivariate logistic regression was used to examine the associations between blood individual and mixed BTEX with CVD and its subtypes in 17,007 participants from NHANES 1999-2018. The combined effect of BTEX mixture on CVD was estimated using weighted quantile sum modeling and quantile g-computation. Weighted multivariate linear regression assessed the effects of BTEX on lipid profiles and WBC, including its five-part differential count.

RESULTS

In comparison to the reference quartile of BTEX mixture, individuals in the highest quartile had a significantly increased adjusted odds ratio of CVD risk (1.64, 95 % CI: 1.23 to 2.19, P for trend = 0.008). Positive associations were observed for benzene, toluene, ethylbenzene, and m-/p-xylene, demonstrating a monotonically increasing exposure-response relationship. Mixed BTEX was associated with congestive heart failure (CHF), angina pectoris, and heart attack. Individual benzene, toluene, and ethylbenzene were associated with CHF, while toluene, ethylbenzene, and all xylene isomers were linked to angina pectoris. Benzene, toluene, and o-xylene were associated with heart attack. Both mixed and individual BTEX showed positive associations with triglycerides, cholesterol, low-density lipoprotein, and WBC, including its five-part differential count, but a negative relationship with high-density lipoprotein. Subgroup analyses identified modifying effects of smoking, drinking, exercise, BMI, hypertension, and diabetes on the associations between specific toxicants and CVD risk.

CONCLUSIONS

Exposure to BTEX was associated with cardiovascular diseases and cardiovascular risk factors. These findings emphasize the importance of considering blood BTEX levels when assessing cardiovascular health risks.

Co-exposure of petrochemical workers to noise and mixture of benzene, toluene, ethylbenzene, xylene, and styrene: Impact on mild renal impairment and interaction

Epidemiological evidence concerning effects of simultaneous exposure to noise and benzene, toluene, ethylbenzene, xylene, and styrene (BTEXS) on renal function remains uncertain. In 2020, a cross-sectional study was conducted among 1160 petrochemical workers in southern China to investigate effects of their co-exposure on estimated glomerular filtration rate (eGFR) and mild renal impairment (MRI). Noise levels were assessed using cumulative noise exposure (CNE). Urinary biomarkers for BTEXS were quantified. We found the majority of workers had exposure levels to noise and BTEXS below China's occupational exposure limits. CNE, trans, trans-muconic acid (tt-MA), and the sum of mandelic acid and phenylglyoxylic acid (PGMA) were linearly associated with decreased eGFR and increased MRI risk. We observed U-shaped associations for both N-acetyl-S-phenyl-L-cysteine (SPMA) and o-methylhippuric acid (2-MHA) with MRI. In further assessing the joint effect of BTEXS (β, -0.164 [95% CI, -0.296 to -0.033]) per quartile increase in all BTEXS metabolites on eGFR using quantile g-computation models, we found SPMA, tt-MA, 2-MHA, and PGMA played pivotal roles. Additionally, the risk of MRI associated with tt-MA was more pronounced in workers with lower CNE levels (P = 0.004). Multiplicative interaction analysis revealed antagonisms of CNE and PGMA on MRI risk (P = 0.034). Thus, our findings reveal negative dose-effect associations between noise and BTEXS mixture exposure and renal function in petrochemical workers. With the exception of toluene, benzene, xylene, ethylbenzene, and styrene are all concerning pollutants for renal dysfunction. Effects of benzene, ethylbenzene, and styrene exposure on renal dysfunction were more pronounced in workers with lower CNE.

Increased oxidative stress in shoe industry workers with low-level exposure to a mixture of volatile organic compounds

This study aimed to assess the redox status and trace metal levels in 49 shoe industry workers (11 men and 38 women) occupationally exposed to a mixture of volatile organic compounds (VOCs), which includes aliphatic hydrocarbons, aromatic hydrocarbons, ketones, esters, ethers, and carboxylic acids. All measured VOCs were below the permitted occupational exposure limits. The control group included 50 unexposed participants (25 men and 25 women). The following plasma parameters were analysed: superoxide anion (O2 •-), advanced oxidation protein products (AOPP), total oxidative status (TOS), prooxidant-antioxidant balance (PAB), oxidative stress index (OSI), superoxide dismutase (SOD) and paraoxonase-1 (PON1) enzyme activity, total SH group content (SHG), and total antioxidant status (TAS). Trace metal levels (copper, zinc, iron, magnesium, and manganese) were analysed in whole blood. All oxidative stress and antioxidative defence parameters were higher in the exposed workers than controls, except for PON1 activity. Higher Fe, Mg, and Zn, and lower Cu were observed in the exposed vs control men, while the exposed women had higher Fe and lower Mg, Zn, and Cu than their controls. Our findings confirm that combined exposure to a mixture of VOCs, even at permitted levels, may result in additive or synergistic adverse health effects and related disorders. This raises concern about current risk assessments, which mainly rely on the effects of individual chemicals, and calls for risk assessment approaches that can explain combined exposure to multiple chemicals.

Increased Levels of Urine Volatile Organic Compounds Are Associated With Diabetes Risk and Impaired Glucose Homeostasis

CONTEXT

Volatile organic compounds (VOCs) are pervasive environmental pollutants that have been linked to various adverse health effects. However, the effect of ambient VOCs, whether individually or in mixtures, on diabetes remains uncertain and requires further investigation.

OBJECTIVE

This study investigates the effects of ambient VOCs exposure, whether single or mixed, on diabetes mellitus and glucose homeostasis in the general population.

METHODS

Urinary concentrations of VOC metabolites were obtained from the National Health and Nutrition Examination Survey. Survey-weighted logistic regression and generalized linear regression were used to explore the associations between individual VOC exposure and diabetes risk and glucose homeostasis indicators, respectively. Weighted quantile sum (WQS) regression models were applied to assess the combined effects of VOC mixtures.

RESULTS

Out of 8468 participants, 1504 had diabetes mellitus. Eight VOC metabolites showed positive associations with diabetes mellitus (OR, 1.15-1.43; all P < .05), insulin resistance (IR) (OR, 1.02-1.06; P < .05), and other glucose homeostasis indicators (β, 0.04-2.32; all P < .05). Mixed VOC models revealed positive correlations between the WQS indices and diabetes risk (OR = 1.52; 95% CI, 1.29-1.81), IR (OR = 1.36; 95% CI, 1.14-1.62), and other glucose homeostasis indicators (β, 0.17-2.22; all P < .05).

CONCLUSION

Urinary metabolites of ambient VOCs are significantly associated with an increased diabetes risk and impaired glucose homeostasis. Thus, primary prevention policies aimed at reducing ambient VOCs could attenuate diabetes burden.

Microglial NF-κB Signaling Deficiency Protects Against Metabolic Disruptions Caused by Volatile Organic Compound via Modulating the Hypothalamic Transcriptome

Prolonged exposure to benzene, a prevalent volatile organic compound (VOC), at concentrations found in smoke, triggers hyperglycemia, and inflammation in mice. Corroborating this with existing epidemiological data, we show a strong correlation between environmental benzene exposure and metabolic impairments in humans. To uncover the underlying mechanisms, we employed a controlled exposure system and continuous glucose monitoring (CGM), revealing rapid blood glucose surges and disturbances in energy homeostasis in mice. These effects were attributed to alterations in the hypothalamic transcriptome, specifically impacting insulin and immune response genes, leading to hypothalamic insulin resistance and neuroinflammation. Moreover, benzene exposure activated microglial transcription characterized by heightened expression of IKKβ/NF-κB-related genes. Remarkably, selective removal of IKKβ in immune cells or adult microglia in mice alleviated benzene-induced hypothalamic gliosis, and protected against hyperglycemia. In summary, our study uncovers a crucial pathophysiological mechanism, establishing a clear link between airborne toxicant exposure and the onset of metabolic diseases.

Single-chemical and mixture effects of multiple volatile organic compounds exposure on liver injury and risk of non-alcoholic fatty liver disease in a representative general adult population

Evidence on liver injury and non-alcoholic fatty liver disease (NAFLD) from volatile organic compounds (VOCs) exposure is insufficient. A cross-sectional study including 3011 US adults from the National Health and Nutrition Examination Survey was conducted to explore the associations of urinary exposure biomarkers (EBs) for 13 VOCs (toluene, xylene, ethylbenzene, styrene, acrylamide, N,N-dimethylformamide, acrolein, crotonaldehyde, 1,3-butadiene, acrylonitrile, cyanide, propylene oxide, and 1-bromopropane) with liver injury biomarkers and the risk of NAFLD by performing single-chemical (survey weight regression) and mixture (Bayesian kernel machine regression [BKMR] and weighted quantile sum [WQS]) analyses. We found significant positive associations of EBs for toluene and 1-bromopropane with alanine aminotransferase (ALT), EBs for toluene, crotonaldehyde, and 1,3-butadiene with asparate aminotransferase (AST), EBs for 1,3-butadiene and cyanide with alkaline phosphatase (ALP), EBs for xylene and cyanide with hepamet fibrosis score (HFS), EBs for the total 13 VOCs (except propylene oxide) with United States fatty liver index (USFLI), and EBs for xylene, N,N-dimethylformamide, acrolein, crotonaldehyde, and acrylonitrile with NALFD; and significant inverse associations of EBs for ethylbenzene, styrene, acrylamide, acrolein, crotonaldehyde, 1,3-butadiene, acrylonitrile, cyanide, and propylene oxide with total bilirubin, EBs for ethylbenzene, styrene, acrylamide, acrolein, 1,3-butadiene, acrylonitrile, and cyanide with albumin (ALB), EBs for ethylbenzene, styrene, acrylamide, N,N-dimethylformamide, acrolein, crotonaldehyde, 1,3-butadiene, acrylonitrile, cyanide, and propylene oxide with total protein (TP), and EB for 1-bromopropane with AST/ALT (all P-FDR<0.05). In BKMR and WQS, the mixture of VOC-EBs was significantly positively associated with ALT, AST, ALP, HFS, USFLI, and the risk of NAFLD, while significantly inversely associated with TBIL, ALB, TP, and AST/ALT. VOCs exposure was associated with liver injury and increased risk of NAFLD in US adults. These findings highlight that great attention should be paid to the potential risk of liver health damage from VOCs exposure.

Do blood metals influence lipid profiles? Findings of a cross-sectional population-based survey

Dyslipidemia, an imbalance of lipids and a major risk factor for cardiovascular disease, has been associated with elevated blood and urine levels of several heavy metals. Using data from a Canadian Health Measures Survey (CHMS), we tested associations between blood levels of cadmium, copper, mercury, lead, manganese, molybdenum, nickel, selenium, and zinc, and the lipids triglycerides (TG), total cholesterol (TC), low density lipoproteins (LDL), high density lipoproteins (HDL) and apolipoproteins A1 (APO A1), and B (APO B). All adjusted associations between single metals and lipids were positive and significant, except for APO A1 and HDL. The joint effect of an interquartile range increase in heavy metals was positively associated with percentage increases of TC, LDL and APO B of 8.82% (95%CI: 7.06, 10.57), 7.01% (95%CI: 2.51, 11.51) and 7.15% (95%CI: 0.51, 13.78), respectively. Future studies are warranted to determine if reducing environmental exposure to heavy metals favorably influences lipid profiles and the risk of cardiovascular disease.

Long-term effect of styrene and ethylbenzene exposure on fasting plasma glucose: A gene-environment interaction study

Styrene and ethylbenzene (S/EB) are hazardous pollutants that have attracted worldwide concern. In this prospective cohort study, S/EB exposure biomarker (the sum of mandelic acid and phenylglyoxylic acid [MA+PGA]) and fasting plasma glucose (FPG) were repeatedly measured three times. The polygenic risk score (PRS) based on 137 single nucleotide polymorphisms for type 2 diabetes mellitus (T2DM) was calculated to evaluate cumulative genetic effect. In repeated-measures cross-sectional analyses, MA+PGA (β [95% confidence interval]: 0.106 [0.022, 0.189]) and PRS (0.111 [0.047, 0.176]) were significantly related to FPG. For long-term effect assessment, participants with sustained high MA+PGA or with high PRS had 0.021 (95% CI: -0.398, 0.441) or 0.465 (0.064, 0.866) mmol/L increase in FPG, respectively, over 3 years follow-up, and had 0.256 (0.017, 0.494) or 0.265 (0.004, 0.527) mmol/L increase in FPG, respectively, over 6 years follow-up. We further detected a significant interaction effect between MA+PGA and PRS on FPG change, compared with participants with sustained low MA+PGA and low PRS, those with sustained high MA+PGA and high PRS had 0.778 (0.319, 1.258) mmol/L increase in FPG (P for interaction=0.028) over 6 years follow-up. Our study provides the first evidence that long-term exposure to S/EB potentially increases FPG, which might be aggravated by genetic susceptibility.

Urinary metabolites of multiple volatile organic compounds, oxidative stress biomarkers, and gestational diabetes mellitus: Association analyses

Volatile organic compounds are ubiquitous in the environment, which may cause various adverse health effects. The objectives of this study were to investigate associations of single and mixture of urinary metabolites of volatile organic compounds (mVOCs) with gestational diabetes mellitus (GDM) risk, and examine the possible role of oxidative stress in the associations. This nested case-control study included 454 GDM cases and 454 healthy controls matched by maternal age and infant sex. Urinary concentrations of twenty-one mVOCs and three oxidative stress biomarkers (including 8-OHdG, 8-OHG, and HNEMA), in early pregnancy were measured. Analyses using logistic regression model showed that an interquartile range increase in urinary concentrations of six individual mVOCs (ATCA, BPMA, CEMA, 3HPMA, MU, and TGA) were significantly associated with increased odds of GDM by 19-27%. Weighted quantile sum regression analyses showed that in each quartile increment of the mixture of mVOCs, the odds of GDM increased by 39% (95% CI: 16%, 67%), with 2-aminothiazoline-4-carboxylic acid weighted the most in the associations (weight: 25%). Furthermore, significant associations of the oxidative stress biomarkers with both GDM and certain mVOCs were observed. These results suggested that certain urinary mVOCs (correspondingly, the parent VOCs such as 1-bromopropane, cyanide, and benzene should be concerned as priority ones for regulation and policy making) in early pregnancy were significantly associated with elevated GDM incidence, and the associations were potentially related with oxidative stress biomarkers.

Associations between residential volatile organic compound exposures and liver injury markers: The role of biological sex and race

While occupational exposures to volatile organic compounds (VOCs) have been linked to steatohepatitis and liver cancer in industrial workers, recent findings have also positively correlated low-dose, residential VOC exposures with liver injury markers. VOC sources are numerous; factors including biological make up (sex), socio-cultural constructs (gender, race) and lifestyle (smoking) can influence both VOC exposure levels and disease outcomes. Therefore, the current study's objective is to investigate how sex and race influence associations between residential VOC exposures and liver injury markers particularly in smokers vs. nonsmokers. Subjects (n = 663) were recruited from residential neighborhoods; informed consent was obtained. Exposure biomarkers included 16 urinary VOC metabolites. Serological disease biomarkers included liver enzymes, direct bilirubin, and hepatocyte death markers (cytokeratin K18). Pearson correlations and generalized linear models were conducted. Models were adjusted for common liver-related confounders and interaction terms. The study population constituted approximately 60% females (n = 401) and 40% males (n = 262), and a higher percent of males were smokers and/or frequent drinkers. Both sexes had a higher percent of White (75% females, 82% males) vs. Black individuals. Positive associations were identified for metabolites of acrolein, acrylamide, acrylonitrile, butadiene, crotonaldehyde, and styrene with alkaline phosphatase (ALP), a biomarker for cholestatic injury; and for the benzene metabolite with bilirubin; only in females. These associations were retained in female smokers. Similar associations were also observed between these metabolites and ALP only in White individuals (n = 514). In Black individuals (n = 114), the styrene metabolite was positively associated with aspartate transaminase. Interaction models indicated that positive associations for acrylamide/crotonaldehyde metabolites with ALP in females were dose-dependent. Most VOC associations with K18 markers were negative in this residential population. Overall, the findings demonstrated that biological sex, race, and smoking status influence VOC effects on liver injury and underscored the role of biological-social-lifestyle factor(s) interactions when addressing air pollution-related health disparities.

Urinary metabolites of multiple volatile organic compounds among pregnant women across pregnancy: Variability, exposure characteristics, and associations with selected oxidative stress biomarkers

Volatile organic compounds (VOCs) are a group of pollutants pervasive in daily life with identified adverse health effects. However, no study has investigated the variability in VOC metabolites during pregnancy and their relationships with oxidative stress biomarkers in pregnant women. In the present study, the variability of 21 selected VOC metabolites was examined and their relationships with three selected oxidative stress biomarkers measured in spot urine samples at three trimesters of 1094 pregnant women were analyzed. Nineteen VOC metabolites were ubiquitous in the urine samples with detection rates ranging from 75.9% to 100%. Monohydroxybutenyl mercapturic acid (MHBMA) and s-phenyl mercapturic acid (PMA) had detection rates lower than 1.00%. Intraclass correlation coefficients (ICCs) of the detected analytes at three trimesters ranged 0.07-0.24, and the concentrations were highest in the first trimester. Higher concentrations of some VOC metabolites were related with participant characteristics including higher pre-pregnancy body mass index (BMI), lower education level, unemployment during pregnancy, multiparity, and sampling season of summer or winter. In repeated cross-sectional analyses, interquartile range (IQR) increases in the 19 detected VOC metabolites were positively related with 8-hydroxy-2'-deoxyguanosine (8-OHdG), 8-hydroxyguanosine (8-OHG), and 4-hydroxy nonenal mercapturic acid (HNEMA) with the estimates ranging from 9.00% to 204%. The mixture effect of the VOC metabolites on the oxidative stress biomarkers was further assessed using weighted quantile sum regression (WQS) models and the results showed that the WQS index of VOC metabolite mixture was significantly associated with 8-OHdG (β: 0.37, 0,32, and 0.39 at the 1st, 2nd, and 3rd trimester, respectively), 8-OHG (0.38, 0.32, and 0.39) and HNEMA (1.21, 1.08, and 1.10). Glycidamide mercapturic acid (GAMA), and trans,trans-muconic acid (MU) were the strongest contributors of the mixture effect on 8-OHdG, 8-OHG, and HNEMA, respectively. Overall, urinary concentrations of the VOC metabolites during pregnancy were strongly associated with the oxidative stress biomarkers.

Latent Trajectories of Haematological, Hepatic, and Renal Profiles after Oil Spill Exposure: A Longitudinal Analysis

Exposure to polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs) in crude oil has carcinogenic effects on various organ systems. This longitudinal cohort study examined the effects of oil spill exposure on the haematological, hepatic, and renal profiles of Rayong oil spill clean-up workers. The sample included 869 clean-up workers from the Rayong oil spill. Latent class mixture models were used to investigate and classify the longitudinal trajectories and trends of the haematological, hepatic, and renal indices. Subgroup analysis was used to evaluate the association between the urinary metabolites of PAHs and VOCs and haematological, hepatic, and renal parameters. Most clean-up workers (97.6%) had increasing levels of white blood cells (WBCs) (0.03 × 103 cells/µL), 94.90% of the workers had a significantly increasing trend of blood urea nitrogen (0.31 mg/dL per year), and 87.20% had a significantly increasing trend of serum creatinine (0.01 mg/dL per year). A high-decreasing trend of WBCs was seen in 2.42% (-0.73 × 103 per year). Post-exposure changes in haematological, renal, and hepatic profiles are present in workers exposed to the Rayong oil spill. This indicates possible long-term health complications and worsening renal function after exposure to PAHs and VOCs in crude oil.

Exposures to volatile organic compounds, serum vitamin D, and kidney function: association and interaction assessment in the US adult population

The relationships of exposures to volatile organic compounds (VOCs) with vitamin D and kidney function remain unclear. Our analyses included 6070 adults from 2003 to 2010 survey cycles of the National Health and Nutrition Examination Survey to explore associations of six VOCs with serum vitamin D, albumin-to-creatinine ratio (ACR), and estimated glomerular filtration rate (eGFR). The results suggested that dibromochloromethane was positively associated with ACR, and chloroform was inversely associated with ACR. U-shaped associations of toluene, m-/p-xylene, bromodichloromethane, and 1,4-dichlorobenzene with ACR were observed. Toluene, m-/p-xylene, and 1,4-dichlorobenzene were associated with eGFR in U-shaped manners, while bromodichloromethane and chloroform were inversely associated with eGFR. Elevation in 1,4-dichlorobenzene was associated with decrease in vitamin D, while chloroform and m-/p-xylene were in U-shaped associations with vitamin D. VOCs mixture was U-shaped associated with ACR, inversely associated with eGFR, and inversely associated with vitamin D. Vitamin D was in a U-shaped association with ACR. Vitamin D significantly interacted with VOCs on the two kidney parameters. In the US adult population, exposures to VOCs were associated with kidney function and serum vitamin D level decline, and the serum vitamin D may have interaction effects with VOCs exposures on kidney function.

Urinary volatile organic compound metabolites and reduced lung function in U.S. adults

BACKGROUND

Volatile organic compounds (VOCs) are associated with adverse respiratory outcomes at high occupational exposures. However, whether exposure levels found in the general population have similar effects is unknown.

METHODS

We analyzed data on 1342 adult participants in the 2011-2012 National Health and Nutrition Examination Survey aged ≥18 years old who had urinary VOC metabolites and spirometry measurements available. Linear regression models adjusting for covariates were fitted to estimate the associations of VOC exposures levels and spirometry outcomes, while accounting for survey design and sampling weights to generate nationally representative estimates.

RESULTS

The urinary metabolites for xylene, acrylamide, acrolein, 1,3-butadiene, cyanide, toluene, 1-bromopropane, acrylonitrile, propylene oxide, styrene, ethylbenzene, and crotonaldehyde in our analysis were all detected in >75% of participants. Forced expiratory volume in 1 s (FEV1) to forced vital capacity (FVC) ratio % was lower with urinary metabolites of acrylamide (β: -2.65, 95% CI: -4.32, -0.98), acrylonitrile (β: -1.02, 95% CI: -2.01, -0.03), and styrene (β: -3.13, 95% CI: -5.35, -0.90). FEV1% predicted was lower with the urinary metabolites of acrolein (β: -7.77, 95% CI: -13.29, -2.25), acrylonitrile (β: -2.05, 95% CI: -3.77, -0.34), propylene oxide (β: -2.90, 95% CI: -5.50, -0.32), and styrene (β: -4.41, 95% CI: -6.97, -1.85).

CONCLUSIONS

This is the first study of a representative sample of the U.S. adult population to reveal associations of acrylonitrile, propylene oxide, and styrene urinary metabolites with reduced lung function at non-occupational exposures. Results also support previous evidence of acrylamide and acrolein's association with adverse respiratory outcomes.

Hematological Effects and Benchmark Doses of Long-Term Co-Exposure to Benzene, Toluene, and Xylenes in a Follow-Up Study on Petrochemical Workers

Benzene, toluene, and xylenes (BTX) commonly co-exist. Exposure to individual components and BTX-rich mixtures can induce hematological effects. However, the hematological effects of long-term exposure to BTX are still unclear, and respective reference levels based on empirical evidence should be developed. We conducted a follow-up study in BTX-exposed petrochemical workers. Long-term exposure levels were quantified by measuring cumulative exposure (CE). Generalized weighted quantile sum (WQS) regression models and Benchmark Dose (BMD) Software were used to evaluate their combined effects and calculate their BMDs, respectively. Many hematologic parameters were significantly decreased at the four-year follow-up (p < 0.05). We found positive associations of CE levels of benzene, toluene, and xylene with the decline in monocyte counts, lymphocyte counts, and hematocrit, respectively (β > 0.010, Ptrend < 0.05). These associations were stronger in subjects with higher baseline parameters, males, drinkers, or overweight subjects (Pinteraction < 0.05). BTX had positive combined effects on the decline in monocyte counts, red-blood-cell counts, and hemoglobin concentrations (Ptrend for WQS indices < 0.05). The estimated BMDs for CE levels of benzene, toluene, and xylene were 2.138, 1.449, and 2.937 mg/m3 × year, respectively. Our study demonstrated the hematological effects of long-term BTX co-exposure and developed 8h-RELs of about 0.01 ppm based on their hematological effects.

Volatile organic compounds: A proinflammatory activator in autoimmune diseases

The etiopathogenesis of inflammatory and autoimmune diseases, including pulmonary disease, atherosclerosis, and rheumatoid arthritis, has been linked to human exposure to volatile organic compounds (VOC) present in the environment. Chronic inflammation due to immune breakdown and malfunctioning of the immune system has been projected to play a major role in the initiation and progression of autoimmune disorders. Macrophages, major phagocytes involved in the regulation of chronic inflammation, are a major target of VOC. Excessive and prolonged activation of immune cells (T and B lymphocytes) and overexpression of the master pro-inflammatory constituents [cytokine and tumor necrosis factor-alpha, together with other mediators (interleukin-6, interleukin-1, and interferon-gamma)] have been shown to play a central role in the pathogenesis of autoimmune inflammatory responses. The function and efficiency of the immune system resulting in immunostimulation and immunosuppression are a result of exogenous and endogenous factors. An autoimmune disorder is a by-product of the overproduction of these inflammatory mediators. Additionally, an excess of these toxicants helps in promoting autoimmunity through alterations in DNA methylation in CD4 T cells. The purpose of this review is to shed light on the possible role of VOC exposure in the onset and progression of autoimmune diseases.

The association between blood PFAS concentrations and clinical biochemical measures of organ function and metabolism in participants of the Canadian Health Measures Survey (CHMS)

Per- and poly-fluoroalkyl substances (PFAS) are ubiquitous and may persist in human tissue for several years. Only a small proportion of PFAS have been studied for human health effects. We tested the association between human blood levels of six PFAS and several clinical measures of organ and metabolic function in a nationally representative sample of 6768 participants aged 3-79 years old who participated in the Canadian Health Measures Survey. Cross-sectional associations were assessed by generalized linear mixed models incorporating survey-specific sampling weights. An increase in perfluorooctanoic acid (PFOA) equivalent to the magnitude of its geometric mean (GM) of 2.0 μg/L was associated with percentage (95% CI) increases in serum enzymes reflecting liver function: aspartate aminotransferase (AST) 3.7 (1.1, 6.4), gamma-glutamyl transferase (GGT) 11.8 (2.5, 21.8), alanine aminotransferase (ALT) 3.2 (0.5, 5.9), and bilirubin 3.6 (2.7, 4.5). A GM increase in perfluorodecanoic acid (PFDA) of 0.2 μg/L was positively associated with percentage increases in GGT, triglycerides, low-density lipoprotein (LDL) cholesterol, total cholesterol, and calcium with respective increases of 15.5 (2.2, 30.4), 7.0 (1.0, 13.2), 10.7 (5.5, 16.1), 2.8 (0.2, 5.3), and 0.8 (0.3, 1.3). PFOA, perfluorooctane sulfonate (PFOS), PFDA and perfluorononanoic acid (PFNA) were positively associated with GGT. All six congeners were positively associated with at least one biomarker of lipid metabolism, and 5 of 6, PFOA, PFOS, PFDA, perfluorohexane sulfonate (PFHxS) and PFNA were positively associated with serum calcium. Exposure to selected PFAS is associated with clinical blood tests reflecting metabolism and the function of several organ systems. These relatively small changes may possibly indicate early pathology that is clinically inapparent and may possibly be of significance in a general population or in individuals exposed to very high levels of PFAS.

Associations Between Residential Exposure to Volatile Organic Compounds and Liver Injury Markers

Occupational exposures to volatile organic compounds (VOCs) have been associated with numerous health complications including steatohepatitis and liver cancer. However, the potential impact of environmental/residential VOC exposures on liver health and function is largely unknown. To address this knowledge gap, the objective of this cross-sectional study is to investigate associations between VOCs and liver injury biomarkers in community residents. Subjects were recruited from six Louisville neighborhoods, and informed consent was obtained. Exposure biomarkers included 16 creatinine-adjusted urinary metabolites corresponding to 12 parent VOCs. Serological disease biomarkers measured included cytokertain-18 (K18 M65 and M30), liver enzymes, and direct bilirubin. Associations between exposure and disease biomarkers were assessed using generalized linear models. Smoking status was confirmed through urinary cotinine levels. The population comprised of approximately 60% females and 40% males; White persons accounted 78% of the population; with more nonsmokers (n = 413) than smokers (n = 250). When compared with nonsmokers, males (45%) and Black persons (26%) were more likely to be smokers. In the overall population, metabolites of acrolein, acrylonitrile, acrylamide, 1,3-butadiene, crotonaldehyde, styrene, and xylene were positively associated with alkaline phosphatase. These associations persisted in smokers, with the exception of crotonaldehyde, and addition of N,N-dimethylformamide and propylene oxide metabolites. Although no positive associations were observed for K18 M30, the benzene metabolite was positively associated with bilirubin, irrespective of smoking status. Taken together, the results demonstrated that selected VOCs were positively associated with liver injury biomarkers. These findings will enable better risk assessment and identification of populations vulnerable to liver disease.

Liver function alterations among workers in the shoe industry due to combined low-level exposure to organic solvents

This study aimed to investigate the potential hepatotoxicity, nephrotoxic, and hematotoxic effects of simultaneous occupational low-level exposure of shoe workers to a mixture of organic solvents. The study included 16 male and 55 female workers and non-exposed subjects (n = 60) in the control group. Along with a standard sets of hematological, liver enzymes (aspartate aminotransferase (AST), alanine aminotransferase (ALT) and gamma-glutamyl transpeptidase (GGT), bilirubin total, bilirubin direct, blood glucose, urea, and creatinine were analyzed in all participants. Indoor air quality was monitored using a Gasmet Dx - 4000 multi-component analyzer. Despite the concentration levels of individual chemicals in shoe production units were below the permissible limits, the equivalent exposure (Em) values calculated based on the American Conference of Governmental Industrial Hygienists (ACGIH) and National Institute of Occupational Safety and Health (NIOSH) occupational exposure limits were higher than 1. Statistically significant increase of biochemical parameters (aspartate aminotransferase (AST), gamma-glutamyl transpeptidase (GGT), total bilirubin, and direct bilirubin) was obtained in exposed workers of both genders compared with controls (p < 0.001). Calculated liver damage risk scores were significantly higher in both females and males compared with controls (p < 0.001). The multivariate logistic regression analysis showed that direct bilirubin was the most important predictor of organic solvent mixture exposure in the studied group of workers. These results suggest that combined exposure to organic solvents even at low concentrations may lead to hepatotoxicity.