Effects of long-term solvent exposure on blood cytokine levels and antioxidant enzyme activities in house painters

Altered oxidative stress and antioxidant biomarkers concentrations in pregnant individuals exposed to oil and gas sites in Northeastern British Columbia

Northeastern British Columbia is a region of prolific unconventional oil and gas (UOG) activity. UOG activity can release volatile organic compounds (VOCs) which can elevate oxidative stress and disrupt antioxidant activity in exposed pregnant individuals, potentially increasing the risk of adverse pregnancy outcomes. This study measured biomarkers of oxidative stress and antioxidant activity in pooled urine samples of 85 pregnant individuals living in Northeastern British Columbia, to analyze associations between indoor air VOCs, oil and gas well density and proximity metrics, and biomarker concentrations. Concentrations of catalase, superoxide dismutase (SOD), glutathione S-transferase, total antioxidant capacity, 6-hydroxymelatonin sulfate (aMT6s), malondialdehyde (MDA), 8-hydroxy-2'-deoxyguanosine (8-OHdG), and 8-isoprostane were measured using assay kits. Associations between exposure metrics and biomarker concentrations were determined using multiple linear regression models adjusted for biomarker-specific covariables. UOG proximity was associated with decreased SOD and 8-OHdG. Decreased 8-OHdG was associated with increased proximity to all wells. Decreased aMT6s were observed with increased indoor air hexanal concentrations. MDA was negatively associated with indoor air 1,4-dioxane concentrations. No statistically significant associations were found between other biomarkers and exposure metrics. Although some associations linked oil and gas activity to altered oxidative stress and antioxidant activity, the possibility of chance findings due to the large number of tests cannot be discounted. This study shows that living near UOG wells may alter oxidative stress and antioxidant activity in pregnant individuals. More research is needed to elucidate underlying mechanisms and to what degree UOG activity affects oxidative stress and antioxidant activity.

Perturbations in indices of oxidative stress, oxidative DNA damage and lung function in chronic exposure to wood dust in Southern Nigeria

OBJECTIVES

Oxidative stress (OS) and oxidative DNA damage accruing from chronic exposure to wood dust have been implicated in the development of chronic lung conditions among woodworkers. Indices of OS, inflammation, oxidative DNA damage and lung function in relation to duration of exposure to wood dust were assessed in woodworkers to determine their possible utility as risk evaluation indices for chronic lung conditions.

METHODS

Ninety participants comprising 30 active woodworkers, 30 passive woodworkers, and 30 controls were enrolled into this cross-sectional study. The total plasma peroxides, total antioxidant capacity (TAC), oxidative stress index (OSI), malondialdehyde (MDA), reduced glutathione, nitric oxide, high sensitivity C-reactive protein (hs-CRP), 8-hydroxy-2'-deoxyguanosine (8-OHdG) and peak expiratory flow rate (PEFR) were determined in all participants.

RESULTS

Woodworkers had lower PEFR, TAC, and higher malondialdehyde, OSI, hs-CRP, and 8-OHdG compared to controls (p < 0.05). Active woodworkers had higher malondialdehyde, 8-OHdG, and hs-CRP compared to passive woodworkers (p < 0.05). Increasing duration of exposure to wood dust is associated with higher malondialdehyde, hs-CRP, and 8-OHdG in active woodworkers (p < 0.05) and higher 8-OHdG and hs-CRP in passive woodworkers (p < 0.05). Negative correlation was observed between hs-CRP and TAC (r=-0.367, p = 0.048) in active workers.

CONCLUSION

The association of exposure to wood dust with elevated indices of inflammation, OS, lipid peroxidation, oxidative DNA damage, and reduction in antioxidants and peak expiratory flow rate; and the concomitant increase in oxidative DNA damage and inflammation with increasing duration of exposure suggest that these indices may be useful in predicting woodworkers at risk of development of chronic lung conditions.

The association between wood dust exposure and respiratory disorders and oxidative stress among furniture workers

BACKGROUND

This study was undertaken to determine the effect of wood dust on the respiratory system and oxidative stress in furniture workers and to determine whether any associations exist between respiratory parameters and oxidative stress.

METHODS

This cross-sectional study was performed on 45 furniture workers and 45 office workers as a reference group in Iran. The NIOSH method 0600 was used to determine the concentration of particulates. The prevalence of respiratory symptoms was estimated via the European Community Respiratory Health Survey (ECRHS) questionnaire. Oxidative stress biomarkers and respiratory parameters were also measured.

RESULTS

The mean concentrations of respirable and non-respirable dust were found to be 1.51 mg/m³ and 1.23 mg/m³, respectively. Pulmonary function parameters, including forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), FEV1/FVC, and antioxidant capacity biomarkers such as total antioxidant capacity (TAC) and superoxide dismutase (SOD) were significantly lower, while the prevalence of respiratory symptoms, and malondialdehyde (MDA) levels, were significantly higher in the furniture workers than in the reference group. There were significant positive associations between FVC and FEV1 with SOD and TAC.

CONCLUSION

The present study results indicated that exposure to wood dust significantly increased respiratory disorders and confirmed the association between lung function parameters and oxidative stress.

Hepatotoxicity of aflatoxin B1 and its oxidative effects in wood dust Egyptian exposed workers

The goal of the present study is to estimate the oxidative effects of AFB1 induced hepatotoxicity in furniture wood dust exposed workers. A cross-sectional comparative study was designed for comparing AFB1/albumin (AFB1/alb) levels and liver functions [alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP)], malondialdehyde (MDA), glutathione peroxidase (GPx), catalase (CAT) and superoxide dismutase (SOD) in 88 furniture workers and 78 controls not occupationally exposed to wood dust. The AFB1/Alb, AST, ALT, MDA, and GPx were significantly higher; while, CAT significantly reduced in workers compared with controls. There was a significant correlation between AFB1/Alb and MDA level with the liver enzymes among both groups. CAT was inversely correlated with AFB1/Alb and the liver enzymes, and GPx was inversely correlated with AST in the workers. It was concluded that wood dust exposure is associated with raised serum levels of AFB1 and oxidative stress.

Lifestyle and environmental contributions to ovulatory dysfunction in women of polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common reason of anovulatory infertility. Environmental factor is one of the main causes of PCOS, but its contribution to ovulatory dysfunction in PCOS remains unknown.

METHODS

A total of 2217 infertile women diagnosed as PCOS according to Rotterdam criteria were recruited, including 1979 women with oligo-anovulation (OA group) and 238 women with normal -anovulation (non OA group). Besides, 279 healthy control women of reproductive age were enrolled as controls.

RESULTS

Frequencies of snoring (PCOS-OA group, PCOS-non-OA group, control group: 29.30% vs 18.10% vs 11.50%, P < 0.01), smoking (37.70% vs 28.10% vs 12.20%, P < 0.01), plastic tableware usage (38.30% vs 28.10% vs 25.40%, P < 0.01) and indoor decoration (32.10% vs 24.80% vs 16.80%, P < 0.01) were highest in PCOS-OA group. After adjusted for multivariable, difference remained significant between PCOS-OA group and the other two groups. PCOS-OA women preferred a meat favorable diet compared to PCOS-non-OA group (54.60% vs 41.30%, P < 0.01). There was no difference between three groups in exercise, frequency of insomnia, and alcohol consumption.

CONCLUSIONS

Smoking, snoring, hyper-caloric diet, plastic tableware usage and indoor decoration were found to be associated with an increased risk for ovulatory dysfunction in women suffering from PCOS.

TNF-α and IL-6 as Biomarkers of Impaired Lung Functions in Dimethylacetamide Exposure

Background

Tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) are well-known biomarkers of systemic inflammation that have been associated with many diseases in the past. In this study, we aimed to determine the relationship between impaired lung functions and the levels of these biomarkers in DMAc exposed people.

Methods

101 non-exposed control subjects (Group 1) and 109 DMAc-exposed workers from the polyvinyl chloride (PVC) industry were included in the study. In the next step, the exposed group was divided into two groups according to the level of exposure (Group 2 and 3). DMAc, TNF-α, IL-6, creatinine, ALT, AST, GFR and standard spirometry measurements were carried out in all subjects.

Results

When compared to the control group, TNF-α and IL-6 levels were significantly high compatible with the increase of DMAc levels, in the exposed groups. Urinary DMAc Levels were 0.06 mg/L in the control group. This level is significantly low when compared to exposed and severely exposed group (2.43 mg/L and 3.17 mg/L). TNF-α levels were 56.86 pg/mL, 145.52 pg/mL and 230.52 pg/mL in control, exposed and severely exposed groups. IL-6 levels were found to be 38.08 pg/mL, 89.19 pg/mL and 116 pg/mL for control, exposed and severely exposed groups, respectively. Similarly, the FEV1/FVC ratio decreased especially in the severely exposed group (p 0.001).

Conclusions

In our study, results have revealed that TNF-and IL-6 levels are promising biomarkers in the early diagnosis of lung function impairment in inhalational DMAc exposure.

Correlation between preconception maternal non-occupational exposure to interior decoration or oil paint odour and average birth weight of neonates: findings from a nationwide cohort study in China's rural areas

BACKGROUND

Birth weight is a critical indicator of neonatal health and foretells people's health in adolescence and even adulthood. Some researchers have warned against the adverse effects on babies' birth weight of exposure to pollutants in interior decoration or oil paint by odour intake. This study evaluated the effects of maternal exposure to such factors before conception on the birth weights of neonates.

METHODS

Data on 213 461 cases in this study were from the database of the free National Pre-pregnancy Checkups Project. Defined as 'exposed' were those women exposed to oil paint odour or interior decoration at home or in the workplace within 6 months before their pregnancy. The study focused on revealing the correlation between such exposure and the birth weight of the neonates of these women, especially the incidence of macrosomia and low birth weight (LBW). Statistical analysis was conducted using the Kruskal-Wallis H test, the Mann-Whitney U test and logistic regression.

RESULTS

The birth weight of babies from mothers non-occupationally exposed to such settings averaged 3465 g (range 3150-3650 g), whereas the birth weight of those from mothers free of such exposure averaged 3300 g (range 3000-3600g). Maternal exposure preconception to interior decoration or oil paint odour reduced the incidence of LBW in their babies (p=0.003, OR 0.749, 95% CI 0.617 to 0.909). Such exposure may also augment the probability of macrosomia (p<0.001, OR 1.297, 95% CI 1.133 to 1.484).

CONCLUSION

Maternal exposure to interior decoration or oil paint odour preconception may increase the average birth weight of neonates, as well as the incidence of macrosomia.

Increased oxidative stress and plasma Hsp70 levels among gasoline filling station attendants

OBJECTIVES

Methylcyclopentadienyl manganese tricarbonyl (MMT) is an organic derivative of manganese (Mn) and is used as an antiknock agent and octane enhancer in gasoline. In this article, we tested the oxidative stress and heat stress protein (Hsp) 70 levels of gasoline station attendants to explore potential plasma biomarkers. Furthermore, the dose-response relationship was also identified.

METHODS

A total of 144 workers, including 96 petrol fillers and 48 cashiers, participated in the study. Ambient concentrations of benzene, toluene, ethylbenzene, and xylene (BTEX) and Mn were monitored at nine filling stations. During the measuring process, the individual cumulative exposure index was calculated. Plasma oxidative stress and Hsp70 levels were also analysed using enzyme-linked immunosorbent assay.

RESULTS

The BTEX time-weighted average in office areas was significantly lower than in refuelling areas ( p < 0.05). In refuelling areas, the content of Mn ranged from 6.44 μg/m³ to 127.34 μg/m³, which was much higher than that in office areas (3.16-7.22 μg/m³; p < 0.05). Exposed workers had significantly different plasma oxidative stress indicators compared with the control group, respectively: superoxide dismutase (SOD), 39.18 ± 6.05 U/mL versus 52.84 ± 3.87 U/mL; glutathione peroxidase (GSH-Px), 186.07 ± 15.63 U versus 194.38 ± 10.42 U; and malondialdehyde (MDA), 1.68 ± 0.52 nmol/L versus 1.43 ± 0.64 nmol/L (in all comparisons, p < 0.05). Plasma Hsp70 level in the exposed group (2.77 ± 0.64 ng/mL) was significantly higher than in the control group (2.32 ± 0.87 ng/mL; p < 0.05). Furthermore, Hsp70 levels were inversely correlated with the activities of SOD ( r = -0.305) and GSH-Px ( r = -0.302) in the exposed group ( p < 0.05). Moreover, a positive correlation ( r = 0.653) was found between plasma Hsp70 levels and plasma MDA levels ( p < 0.05).

CONCLUSION

Exposure to MMT-containing gasoline may result in increasing reactive oxygen stress among filling station attendants. Plasma Hsp70 levels could be used as a sensitive responsive biomarker for exposed workers.

Elevated red blood cell distribution width and inflammation in printing workers

BACKGROUND

The aim of this study was to estimate the effects of exposure to chemical compounds on systemic biochemical inflammatory markers in printing industry workers.

MATERIAL/METHODS

Fifty-eight printing workers from 19 different small- and medium-sized enterprises in the printing sector were investigated. For comparison, 80 healthy workers not subjected to workplace chemicals served as control subjects.

RESULTS

No significant differences were observed between the printing workers and control subjects with respect to age, BMI, waist circumference/hip circumference ratio, smoking, and alcohol consumption. Printing workers had significantly higher serum TNF-alpha levels (11.02 ± 5.34 vs. 9.26 ± 3.87 pg/ml, p=0.039), plasma fibrinogen levels (1.74 ± 0.49 vs. 1.38 ± 0.5 mg/dl, p=0.012), and red blood cell distribution width (RDW-SD) (49.77 ± 3.09 vs. 47.3 ± 2.88 p<0.01) compared to control subjects.

CONCLUSIONS

Elevation of RDW, serum TNF-alpha, and plasma fibrinogen levels in printing workers may be due to systemic toxic effects of chemical compounds used in this sector. TNF-alpha is an inflammatory cytokine that has a wide spectrum of biological activities, and fibrinogen plays an important role in pathological processes. Some compounds may be carcinogenic or mutagenic. Better designed workplaces and working conditions will help to reduce the hazardous effects of chemical compounds.

Immunotoxicity and pulmonary toxicity induced by paints in Egyptian painters

Associations between painting, sensitization, and respiratory disease have received little attention, despite the extensive use of paint and paint removal products. The objectives of this study were to investigate the possible immunotoxicity and pulmonary toxicity induced by paints in Egyptian painter workers. This study was carried out on 60 adult males. Subjects were designated as controls (n = 30 healthy persons) or paint-exposed workers (n = 30). The controls and workers were then divided into four equal groups (15 individuals/group): Group I, Control group-never smoked; Group II, Smoker controls; Groups III, paint-exposed non-smoking workers; and Group IV, paint-exposed smoker workers. A complete physical examination, chest radiograph, and pulmonary function test (PFT) were performed with each subject. Serum levels of immunoglobulin (Ig) E and interleukin (IL)-4, -6, and -10, WBC sub-set counts, total numbers of WBC, and leukocyte differentials were also assessed. The pulmonary toxicity due to the paint exposures appeared in the form of allergic manifestations in the respiratory tract, significant reductions in FVC, FEV1, FEV1/FVC ratio and PEF parameters, and a reticular pattern in both lung fields. Immunotoxicity was evidenced by increases in total leukocyte levels, total lymphocytes, CD8(+) T-lymphocytes, B (CD19(+))-lymphocytes, NK (CD3(+)CD16(+)CD56(+)) cells, and eosinophils, as well as a significant decrease in CD4+ T-lymphocyte; there were also significant elevations in serum IgE, IL-4, and IL-6, and a significant reduction in IL-10, levels in these hosts. Based on these results, we assert that repeated paint exposure is associated with pulmonary and immune system toxicities that may lead to an augmentation of allergic diseases.

Evaluation of genotoxicity and oxidative damage in painters exposed to low levels of toluene

Toluene is an organic solvent used in numerous processes and products, including industrial paints. Toluene neurotoxicity and reproductive toxicity are well recognized; however, its genotoxicity is still under discussion, and toluene is not classified as a carcinogenic solvent. Using the comet assay and the micronucleus test for detection of possible genotoxic effects of toluene, we monitored industrial painters from Rio Grande do Sul, Brazil. The putative involvement of oxidative stress in genetic damage and the influences of age, smoking, alcohol consumption, and exposure time were also assessed. Although all biomarkers of toluene exposure were below the biological exposure limits, painters presented significantly higher DNA damage (comet assay) than the control group; however, in the micronucleus assay, no significant difference was observed. Painters also showed alterations in hepatic enzymes and albumin levels, as well as oxidative damage, suggesting the involvement of oxidative stress. According to multiple linear regression analysis, blood toluene levels may account for the increased DNA damage in painters. In summary, this study showed that low levels of toluene exposure can cause genetic damage, and this is related to oxidative stress, age, and time of exposure.

A change in CD3γ, CD3δ, CD3ϵ, and CD3ζ gene expression in T-lymphocytes from benzene-exposed and benzene-poisoned workers

Benzene is known to be highly toxic to a variety of cell types, including lymphocytes. A previous study showed that T-lymphocyte immune function disorder might be related to benzene exposure. To elucidate characteristics of TCR signal transduction in benzene-exposed workers, expression levels of CD3γ, CD3δ, CD3ϵ, and CD3ζ genes in peripheral blood mononuclear cells (PBMC) were analyzed. Real-time RT-PCR using SYBR Green I was used to detect CD3 gene expression levels in PBMC from 20 benzene-exposed workers, seven workers with chronic mild benzene poisoning, five workers with chronic severe benzene poisoning and 14 healthy individuals (controls). The relative mRNA expression level was analyzed by the 2(-Δct) × 100% method. In benzene-exposed worker cells, significantly higher CD3δ, CD3ϵ, and CD3ζ, expression levels were observed as compared with values for cells from the healthy controls. In the workers with chronic severe benzene poisoning, lymphocyte CD3γ, CD3ϵ, and CD3ζ gene expression levels were significantly lower than in control cells. Lymphocytes from chronic mildly benzene- poisoned workers evinced two different gene expression patterns, i.e., CD3γ and CD3ϵ levels were similar to those in the benzene-exposed worker cells, but CD3δ and CD3ζ expression levels were significantly lower relative to those in cells from chronic severely-benzene-poisoned counterparts. It remained to be determined if these reductions in expression of these genes presage or are indicative of deficiencies in the activities of T-lymphocytes in these workers. For now, it is hoped that this study may contribute to a better understanding of the disorders in cellular immunity frequently found with benzene-exposed workers.

The Effects of Long-Term, Low-Level Exposure to Monocyclic Aromatic Hydrocarbons on Worker's Insulin Resistance

Objectives

This study was designed to investigate whether long-term, low-level exposure to monocyclic aromatic hydrocarbons (MAHs) induced insulin resistance.

Methods

The subjects were 110 male workers who were occupationally exposed to styrene, toluene, and xylene. One hundred and ten age-matched male workers who had never been occupationally exposed to organic solvents were selected as a control group. Cytokines, which have played a key role in the pathogenesis of insulin resistance, and oxidative stress indices were measured. Assessment of exposure to MAHs was performed by measuring their ambient levels and their urinary metabolites in exposed workers, and the resulting parameters between the exposed group and non-exposed control groups were compared.

Results

There was no significant difference in general characteristics and anthropometric parameters between the two groups; however, total cholesterol, fasting glucose, fasting insulin, and homeostasis model assessment of insulin resistance levels were significantly higher in the exposed group. Phenylglyoxylic acid levels showed significant association with tumor necrosis factor-α, total oxidative status, and oxidative stress index via multiple linear regression analysis. Further, there was a negative correlation between methylhippuric acid levels and total anti-oxidative capacity, and there was a significant relationship between MAHs exposure and fasting glucose levels, as found by multiple logistic regression analysis (odds ratio = 3.95, 95% confidence interval = 1.074-14.530).

Conclusion

This study indicated that MAHs increase fasting glucose level and insulin resistance. Furthermore, these results suggested that absorbing the organic solvent itself and active metabolic intermediates can increase oxidative stress and cytokine levels, resulting in the changes in glucose metabolism and the induction of insulin resistance.

Exposure to benzene induces oxidative stress, alters the immune response and expression of p53 in gasoline filling workers

BACKGROUND

Chronic exposure to benzene can lead to deleterious effects on many biological systems including blood and blood-forming organs. We investigated the adverse effects of benzene among workers occupationally exposed to benzene in India.

METHODS

Four hundred twenty-eight gasoline filling workers occupationally exposed to benzene and 78 unexposed individuals were recruited for this study. Benzene concentration was determined by gas chromatography, reactive oxygen species (ROS) by dichlorofluorescin diacetate (DCFH-DA) method, malondialdehyde (MDA) by thiobarbituric acid reactive substances assay (TBARS), total superoxide dismutase (T-SOD) by RANSOD kit and glutathione (GSH) by 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB) reaction, respectively. CD4, CD8, IgG were carried out by using fluorescence activated cell sorter (FACS Calibur) and mRNA expression of p53 by reverse transcriptase PCR (RT-PCR).

RESULTS

A significant increase in the concentration of benzene and its byproducts in both blood and urine were found in the workers compared with the controls. The levels of ROS and MDA were significantly elevated, and GSH and total T-SOD were decreased in the workers compared with the controls. A statistically significant decrease in the immunoglobulin levels, CD4T cells, CD4/CD8 ratio was observed in workers (vs. controls), whereas no significant difference was observed in CD8T cells. p53 gene expression was markedly higher in workers than in controls.

CONCLUSION

Occupational exposure to benzene causes oxidative stress, immune suppression and increases the expression of tumor-suppressing gene p53 in gasoline filling workers. These bio-functional markers might be useful in screening and surveillance for occupational hazard.