Acute exposure to crotonaldehyde induces dysfunction of immune system in male Wistar rats

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.

Urinary Volatile Organic Compound Metabolites Are Associated with Reduced Lung Function in U.S. Children and Adolescents

(1) Background: Volatile organic compounds (VOCs) are indoor pollutants absorbed by inhalation. The association of several VOCs with lung function in children and adolescents is unknown. (2) Methods: We analyzed 505 participants, 6-17-year-olds from the 2011-2012 National Health and Nutrition Examination Survey. Multiple linear regression models were fitted to estimate the associations of VOC metabolites with spirometry outcomes adjusting for covariates. (3) Results: Urinary metabolites of xylene, acrylamide, acrolein, 1,3-butadiene, cyanide, toluene, 1-bromopropane, acrylonitrile, propylene oxide, styrene, ethylbenzene, and crotonaldehyde were all detected in ≥64.5% of participants. Forced expiratory volume in 1 s (FEV1) % predicted was lower in participants with higher levels of metabolites of acrylamide (β: -7.95, 95% CI: -13.69, -2.21) and styrene (β: -6.33, 95% CI: -11.60, -1.07), whereas the FEV1 to forced vital capacity (FVC) ratio % was lower in children with higher propylene oxide metabolite levels (β: -2.05, 95% CI: -3.49, -0.61). FEV1 % predicted was lower with higher crotonaldehyde metabolite levels only in overweight/obese participants (β: -15.42, 95% CI: -26.76, -4.08) (Pinteraction < 0.001) and with higher 1-bromopropane metabolite levels only in those with serum cotinine > 1 ng/mL (β: -6.26, 95% CI: -9.69, -2.82) (Pinteraction < 0.001). (4) Conclusions: We found novel associations of metabolites for acrylamide, propylene oxide, styrene, 1-bromopropane and crotonaldehyde with lower lung function in children and adolescents.

Changes in biomarkers of exposure and withdrawal symptom among Chinese adult smokers after completely or partially switching from combustible cigarettes to an electronic nicotine delivery system

This study assessed changes in biomarkers of exposure (BoE) after 5 days of completely or partially switching to an electronic nicotine delivery system (ENDS) use, compared with continued use of combustible cigarettes and smoking abstinence among Chinese adult smokers. A randomized, open-label, parallel-arm study was conducted among Chinese adult smokers who were naive ENDS users. Forty-six subjects were randomized to 4 study groups (n = 11-12 per group): exclusive ENDS use, dual use of ENDS and cigarettes, exclusive cigarettes use, and smoking abstinence. Subjects were confined in clinic for 5 consecutive days and product use was ad libitum. Nicotine and its metabolites (cotinine and 3-hydroxycotinine), and BoEs (AAMA, CEMA, HEMA, HMPMA, 3-HPMA, SPMA, exhaled CO, and exhaled NO) were measured. Withdrawal symptom was measured using MNWS throughout the 5-day period. Six urine BoEs of volatile organic compounds decreased by 55.1-84.1% in the exclusive ENDS use group, which is similar to the smoking abstinence group (67.2-87.4%). The level of decrease was 56.8-70.4% in the dual use group and 10.7-39.0% in the cigarettes group. Urine total nicotine exposure had a non-significant increase in the exclusive ENDS use group, and plasma nicotine and cotinine showed a trend of increasing day by day. After completely or partially switching to ENDS use among Chinese smokers, exposure to selected toxicants were significantly decreased. The results of this study add to the body of evidence that exposure to toxic substance decreased among smokers after complete or partial switch from combustible cigarettes to ENDS use. As part of transition to experienced ENDS use, this study found that smokers of the initial stage who have no prior ENDS experience may increase nicotine intake after switching to ENDS use.

Exposure to volatile organic compounds is a risk factor for diabetes: A cross-sectional study

Currently, more studies showed that environmental chemicals were associated with the development of diabetes. However, the effect of volatile organic compounds (VOCs) on diabetes remained uncertain and needed to be studied. This cross-sectional study examined whether exposure to low levels of VOCs was associated with diabetes, insulin resistance (TyG index) and glucose-related indicators (FPG,HbA1c, insulin) in the general population by using the NHANES dataset (2013-2014 and 2015-2016). We analyzed the association between urinary VOC metabolism (mVOCs) and these indicators in 1409 adults by multiple linear regression models or logistic regression models, further Bayesian kernel machine regression (BKMR) models were performed for mixture exposure analysis. The results showed positive associations between multiple mVOCs and diabetes, TyG index, FPG, HbA1c and insulin, respectively. Among them, HPMMA concentration in urine was significantly positively correlated with diabetes and related indicators (TyG index, FPG and HbA1c), and the concentration of CEMA was significantly positively correlated with insulin. The positive association of mVOCs with diabetes and its related indicators was more significant in the female group and in the 40-59 years group. Thus, our study suggested that exposure to VOCs affected insulin resistance and glucose homeostasis, further affecting diabetes levels, which had important public health implications.

Acute and chronic vascular effects of inhaled crotonaldehyde in mice: Role of TRPA1

Although crotonaldehyde (CR) is an abundant α,β-unsaturated aldehyde in mainstream cigarette smoke (MCS), the cardiovascular toxicity of inhaled CR is largely unexplored. Thus, male C57BL/6 J mice were exposed acutely (1 h, 6 h, and 4d) and chronically (12 weeks) to CR (at levels relevant to MCS; 1 and 3 ppm), and cardiovascular and systemic outcomes were measured in vivo and in vitro. Diastolic blood pressure was decreased (hypotension) by both acute and chronic CR exposure. Vascular toxicity of inhaled CR was quantified in isolated aorta in response to agonists of contraction (phenylephrine, PE) and relaxation (acetylcholine, ACh; sodium nitroprusside, SNP). Although no change in contractility was observed, ACh-induced relaxations were augmented after both acute and chronic CR exposures whereas SNP-induced relaxation was enhanced only following 3 ppm CR exposure. Because CR is a known agonist of the transient receptor potential ankyrin 1 (TRPA1) channel, male TRPA1-null mice were exposed to air or CR (4d, 1 ppm) and aortic function assessed in vitro. CR exposure had no effect on TRPA1-null aortic function indicating a role of TRPA1 in CR effects in C57BL/6 J mice. Notably, CR exposure (4d, 1 ppm) had no effect on aortic function in female C57BL/6 J mice. This study shows that CR inhalation exposure induces real-time and persistent vascular changes that promote hypotension-a known risk factor for stroke. Because of continued widespread exposures of humans to combustion-derived CR (environmental and tobacco products), CR may be an important cardiovascular disease risk factor.