Urinary Metals, Arsenic, and Polycyclic Aromatic Hydrocarbon Exposure and Risk of Self-reported Emphysema in the US Adult Population

Comprehensive analysis of environmental exposure to hazardous trace elements and lung function: a national cross-sectional study

BACKGROUND

There is growing interest in the joint effects of hazardous trace elements (HTEs) on lung function deficits, but the data are limited. This is a critical research gap given increased global industrialisation.

METHODS

A national cross-sectional study including spirometry was performed among 2112 adults across 11 provinces in China between 2020 and 2021. A total of 27 HTEs were quantified from urine samples. Generalised linear models and quantile-based g-computation were used to explore the individual and joint effects of urinary HTEs on lung function, respectively.

RESULTS

Overall, there were negative associations between forced expiratory volume in 1 s (FEV1) and urinary arsenic (As) (z-score coefficient, -0.150; 95% CI, -0.262 to -0.038 per 1 ln-unit increase), barium (Ba) (-0.148, 95% CI: -0.258 to -0.039), cadmium (Cd) (-0.132, 95% CI: -0.236 to -0.028), thallium (Tl) (-0.137, 95% CI: -0.257 to -0.018), strontium (Sr) (-0.147, 95% CI: -0.273 to -0.022) and lead (Pb) (-0.121, 95% CI: -0.219 to -0.023). Similar results were observed for forced vital capacity (FVC) with urinary As, Ba and Pb and FEV1/FVC with titanium (Ti), As, Sr, Cd, Tl and Pb. We found borderline associations between the ln-quartile of joint HTEs and decreased FEV1 (-20 mL, 95% CI: -48 to +8) and FVC (-14 mL, 95% CI: -49 to+2). Ba and Ti were assigned the largest negative weights for FEV1 and FVC within the model, respectively.

CONCLUSION

Our study investigating a wide range of HTEs in a highly polluted setting suggests that higher urinary HTE concentrations are associated with lower lung function, especially for emerging Ti and Ba, which need to be monitored or regulated to improve lung health.

Oral arsenite exposure induces inflammation and apoptosis in pulmonary tissue: acute and chronic evaluation in young and adult mice

Inorganic arsenic is a well-known environmental toxicant, and exposure to this metalloid is strongly linked with severe and extensive toxic effects in various organs including the lungs. In the present study, we aimed to investigate the acute and chronic effects of arsenite exposure on pulmonary tissue in young and adult mice. In brief, young and adult female Balb/C mice were exposed to 3 and 30 ppm arsenite daily via drinking water for 30 and 90 days. Subsequently, the animals were sacrificed and various histological and immunohistochemistry (IHC) analyses were performed using lung tissues. Our findings showed arsenite was found to cause dose-dependent pathological changes such as thickening of the alveolar septum, inflammatory cell infiltrations and lung fibrosis in young and adult mice. In addition, arsenite exposure significantly increased the expression of inflammatory markers NF-κB and TNF-α, indicating that arsenite-exposed mice suffered from severe lung inflammation. Moreover, the IHC analysis of fibrotic proteins demonstrated an increased expression of TGF-β1, α-SMA, vimentin and collagen-I in the arsenite-exposed mice compared to the control mice. This was accompanied by apoptosis, which was indicated by the upregulated expression of caspase-3 in arsenite-exposed mice compared to the control. Adult mice were generally found to be more prone to arsenite toxicity during chronic exposure relative to their younger counterparts. Overall, our findings suggest that arsenite in drinking water may induce dose-dependent and age-dependent structural and functional impairment in the lungs through elevating inflammation and fibrotic proteins.

A review on the potential risks and mechanisms of heavy metal exposure to Chronic Obstructive Pulmonary Disease

Chronic Obstructive Pulmonary Disease (COPD) is a chronic disease that affects patients as well as the health and economic stability of society as a whole. At the same time, heavy metal pollution is widely recognized as having a possible impact on the environment and human health. Therefore, these diseases have become important global public health issues. In recent years, researchers have shown great interest in the potential association between heavy metal exposure and the development of COPD, and there has been a substantial increase in the number of related studies. However, we still face the challenge of developing a comprehensive and integrated understanding of this complex association. Therefore, this review aimed to evaluate the existing epidemiological studies to clarify the association between heavy metal exposure and COPD. In addition, we will discuss the biological mechanisms between the two to better understand the multiple molecular pathways and possible mechanisms of action involved, and provide additional insights for the subsequent identification of potential strategies to prevent and control the effects of heavy metal exposure on the development of COPD in individuals and populations.

Association of urinary arsenic, polycyclic aromatic hydrocarbons, and metals with cancers among the female population in the US

BACKGROUND

Cancers that primarily affect women in the US include breast, uterine, and cervical cancers. There may be associations between these different types of cancer in women and environmental pollutant exposure.

PURPOSE

This study aimed to assess seven species of arsenic, six polycyclic aromatic hydrocarbon (PAH) compounds, and fourteen different metal concentrations in urine and their correlation with cancer among women.

METHODS

We conducted a cross-sectional analysis using 2011--2012 to 2015-2016 National Health and Nutrition Examination Survey data (n = 4,956) and logistic regression modeling of the complex weighted survey design.

RESULTS

Breast cancer was inversely correlated with arsenocholine (3rd quantile), monomethylarsonic acid (4th quantile), manganese (4th quantile), and antimony (3rd, 4th quantiles). Cervical cancer was inversely correlated with 3-hydroxyfluorene (3rd quantile), molybdenum (2nd, 4th quantiles), antimony (3rd quantile), tin (4th quantile), and thallium (4th quantile) exposure and positively associated with arsenic acid (3rd quantile), arsenobetaine (2nd, 4th quantiles). Uterine cancer was correlated with 1-hydroxynaphthalene (3rd, 4th quantiles), 2-hydroxynaphthalene (4th quantile), 1-hydroxyphenathrene (2nd, 4th quantiles), 1-hydroxypyrene (3rd quantile), cobalt (2nd, 3rd quantiles) and inversely with mercury (4th quantile).

CONCLUSION

This study determined breast cancer and arsenic and some metal species exposure, indicating an inverse association. Arsenic acid and arsenobetaine exposure showed a positive correlation with cervical cancer. For uterine cancer, the correlations for the PAH compounds and cobalt showed a positive correlation, and the arsenic species and mercury were inversely associated. Further research is required to establish or refute the findings.

MicroRNAs as Potential Biomarkers of Environmental Exposure to Polycyclic Aromatic Hydrocarbons and Their Link with Inflammation and Lung Cancer

Exposure to atmospheric air pollution containing volatile organic compounds such as polycyclic aromatic hydrocarbons (PAHs) has been shown to be a risk factor in the induction of lung inflammation and the initiation and progression of lung cancer. MicroRNAs (miRNAs) are small single-stranded non-coding RNA molecules of ~20-22 nucleotides that regulate different physiological processes, and their altered expression is implicated in various pathophysiological conditions. Recent studies have shown that the regulation of gene expression of miRNAs can be affected in diseases associated with outdoor air pollution, meaning they could also be useful as biomarkers of exposure to environmental pollution. In this article, we review the published evidence on miRNAs in relation to exposure to PAH pollution and discuss the possible mechanisms that may link these compounds with the expression of miRNAs.

Systemic inflammation mediates environmental polycyclic aromatic hydrocarbons to increase chronic obstructive pulmonary disease risk in United States adults: a cross-sectional NHANES study

Introduction

This study explored the relationship between environmental polycyclic aromatic hydrocarbons (PAHs) and Chronic obstructive pulmonary disease (COPD), and identified systemic inflammation as a mediator of the increased risk of COPD from PAHs.

Methods

Data were obtained from 60,936 middle-aged and older Americans recruited in the National Health and Nutrition Examination Survey 2005-2016. Environmental PAHs were measured in terms of urinary concentrations of PAHs metabolites (NAP: 1-hydroxynaphthalene, FLU: 2-hydroxyfluorene, PA: 1-hydroxyphenanthrene, and PYR: 1-hydroxypyrene). We used multifactor logical analysis to figure out the link between PAHs and COPD, and the non-linear relationship was examined using Restricted cubic spline. Spearman correlation analysis was utilized to analyze the connection between PAHs and systemic immune-inflammation index (SII).

Results

The results showed that the COPD population had higher NAP (3.550 vs. 3.282, p < 0.001), FLU (2.501 vs. 2.307, p < 0.001), PA (2.155 vs. 2.082, p = 0.005), and PYR (2.013 vs. 1.959, p = 0.008) levels than non-COPD population. In unadjusted logistics analysis, the risk of COPD with log NAP was higher [OR = 1.461, 95% CI (1.258-1.698), p < 0.001]. Upon taking into account, confounders like sex, age, race, and log NAP still increased a possible COPD risk [OR = 1.429, 95% CI (1.224-1.669), p < 0.001]. Similarly, FLU, PA, and PYR significantly increased the risk of COPD (all OR > 1, p < 0.05), both unadjusted and adjusted. Furthermore, Restricted cubic spline demonstrated a strong link between PAHs levels and COPD risk (p < 0.05). Additionally, a Spearman correlation analysis revealed a favorable association between log FLU and log SII (R = 0.43, p = 0.006), while NAP, PA, and PYR levels were not associated with log SII (all p > 0.05). Ultimately, the mediating effect analysis revealed a mediating effect capacity of 5.34% for the SII-mediated association between FLU and COPD.

Conclusion

The findings suggest that the risk of COPD is significantly increased when environmental PAHs exposure is at high levels, and that systemic inflammation may be involved in the process.

Exposure to arsenic, polycyclic aromatic hydrocarbons, metals, and association with skin cancers in the US adults

Worldwide, skin cancer affects millions of people yearly and is broadly classified into melanoma and nonmelanoma types of skin cancer. The toxicity of metals to human health is a public and clinical health problem due to their widespread use in tools, machinery, and appliances as well as their widespread distribution in the air, water, and soil. Arsenic is a carcinogenic metalloid and available in the Earth's crust. Polycyclic aromatic hydrocarbons (PAHs) are toxic to humans, and incomplete combustion of fossil fuels is the main source of PAHs. Human populations exposed to metals from various sources can lead to various diseases including cancer. Limited studies are conducted to simultaneously assess the correlation of multiple arsenic, PAHs, metals with the occurrence of skin cancer. This study aimed to analyze the association between six PAHs compounds, seven types of arsenic, and fourteen metals from urine specimen with skin cancer in US adults. We performed a cross-sectional analysis using data from a total of 14,716 adults from the National Health Examination and Nutrition Survey (NHANES) database for three cycles ranging from 2011-2012 to 2015-2016. Specialized weighted complex survey logit regressions were conducted. Linear logit regression models using only main effects were performed first to identify the correlation between the selected demographic and lifestyle variables and melanoma, nonmelanoma, and unknown types of skin cancer. A second set of linear, main-effects logit regression models were constructed to examine the correlation between melanoma, nonmelanoma, and other types of skin cancers and seven types of arsenic (arsenous acid, arsenic acid, arsenobetaine, arsenocholine, dimethylarsinic acid, monomethylacrsonic acid, and total arsenic), six PAHs (1-hydroxynaphthalene, 2-hydroxynaphthalene, 3-hydroxyfluorene, 2-hydroxyfluorene, 1-hydroxyphenathrene, and 1-hydroxypyrene), and fourteen metals (barium, cadmium, cobalt, cesium, molybdenum, manganese, lead, antimony, tin, strontium, thallium, tungsten, uranium, and mercury) when adjusted for the selected covariates. The statistical analysis was conducted using R software, version 4.0.4. A marginal positive significant correlation between total arsenic and nonmelanoma was observed. This study identified a significant positive association between barium, cadmium, cesium, mercury, tin, and melanoma development. Cesium showed a significant positive statistical association for nonmelanoma, and thallium showed a borderline significant statistical association for nonmelanoma. A statistically significant positive association was found between cadmium and an unknown type of skin cancer. The findings of this study indicated a statistically significant positive association between skin cancer and barium, cadmium, cesium, tin, mercury, and thallium. Further studies are recommended in humans to refute or confirm these findings.

Arsenic, polycyclic aromatic hydrocarbons, and metal exposure and risk assessment of stroke

Globally, stroke is one of the primary causes of morbidity and mortality. In the USA, stroke is a major cause of death and disability. Limited studies assessed the impact of polycyclic aromatic hydrocarbons, arsenic, and other metal exposure and their association with the risk of stroke. This study aimed to assess different arsenic species, including total arsenic; two types of organic arsenic, i.e., arsenobetaine and arsenocholine; four types of inorganic arsenic, i.e., arsenic acid, arsenous acid, dimethylarsinic acid (DMA), and monomethylarsonic acid (MMA); six types of urinary polycyclic aromatic hydrocarbon (PAH) compounds, i.e., 1-hydroxynaphthalene, 1-hydroxyphenanthrene, 1-hydroxypyrene, 2-hydroxynaphthalene, 2-hydroxyfluorene, and 3-hydroxyfluorene; and fourteen types of metals from urine specimen, i.e., manganese, cadmium, lead, mercury, barium, cobalt, strontium, molybdenum, cesium, thallium, antimony, tin, tungsten, and uranium and their association with those who reported having been told they had had a stroke by a medical professional. The National Health and Nutrition Examination Survey (NHANES) data used in this study include three data cycles from 2011-2016. In this study, data from a total of 5537 males and females who are aged 20 years and older were analyzed using logistic modeling of the complex weighted survey design. R version 3.6.3 software was used to conduct the analyses. Four species of urinary PAHs, including the third quantiles of 1-hydroxynaphthalene [odds ratio (OR): 2.327, 95% confidence interval (CI): 0.961-5.632], 2-hydroxynaphthalene [OR: 2.449, 95% CI: 1.067-5.622], and 3-hydroxyfluorene [OR: 2.289, 95% CI: 1.077-4.861] and the second quantiles of 3-hydroxyfluorene [OR: 2.201, 95% CI: 1.115, 4.346] and 1-hydroxypyrene [OR: 2.066, 95% CI: 1.037, 4.114], showed a positive correlation with increased odds of stroke. Among metals, the third (3rd) [OR: 3.566, 95% CI: 1.370, 9.280] and fourth (4th) [OR: 2.844, 95% CI: 0.947, 8.543] quantiles of urinary manganese showed a positive correlation with increased odds of stroke.

Polycyclic aromatic hydrocarbon exposure burden: Individual and mixture analyses of associations with chronic obstructive pulmonary disease risk

Accumulating data demonstrate that polycyclic aromatic hydrocarbons (PAH) exposure is linked to compromised respiratory diseases. This study aimed to analyze urinary PAH metabolites and their associations with chronic obstructive pulmonary disease (COPD) in a sample size of 3015 subjects from a total population of 50,588 from the National Health and Nutrition Examination Survey (NHANES) in 2007-2016. Results showed that the most predominant metabolite was 1-Hydroxynaphthalene (1-NAP, 84%) with a geometric mean concentration of 50,265 ng/L, followed by its homologue 2-NAP (10%), both of which arose from sources including road emission, smoking and cooking. Multiple logistic regression showed that seven of the ten major PAH metabolites were correlated with increased COPD risk: including 1-NAP (OR: 1.83, 95%CI: 1.25, 2.69), 2-Hydroxyfluorene (2-FLU, OR: 2.29, 95%CI: 1.42, 3.68) and 1-Hydroxyphenanthrene (1-PHE, OR: 2.79, 95%CI: 1.85, 4.21), when compared to the lowest tertile after adjusted for covariates. Total exposure burden per PAH congener sub-group demonstrated persistent positive correlation with COPD for ∑PHE (OR: 1.80, 95%CI: 1.34, 2.43) and ∑FLU (OR: 2.74, 95%CI: 1.77, 4.23) after adjusted for covariates. To address the contribution of PAH exposure as mixture towards COPD, weighted quantile sum (WQS) regression analyses revealed that 1-NAP, 9-Hydroxyfluorene (9-FLU), 3-Hydroxyfluorene (3-FLU) and 1-PHE were among the top contributors in the associations with COPD. Our results demonstrate the contemporary yet ongoing exposure burden of PAH exposure for over a decade, particularly towards NAPs and FLUs that contribute significantly to COPD risk, calling for more timely environmental regulation.

Association between asthma, chronic bronchitis, emphysema, chronic obstructive pulmonary disease, and lung cancer in the US population

Lung cancer is one of the primary causes of death with poor life expectancy after diagnosis. History of past respiratory diseases such as asthma, chronic obstructive lung disease (COPD), emphysema, and chronic bronchitis can increase the risk of lung cancer. Very few studies are available to simultaneously assess multiple respiratory diseases and lung cancer. The objective of this study was to investigate correlations between asthma, emphysema, chronic bronchitis, and chronic obstructive lung disease with lung cancer in the US adult population. This was a cross-sectional study using data from a total of 23,523 adult participants from the National Health Examination and Nutrition Survey (NHANES) datasets for seven cycles ranging from 2003-2004 to 2015-2016. To analyze the data, specialized weighted complex survey logit regressions were conducted. Linear logit regression models using only main-effects were constructed first to assess the correlation between the selected demographic and lifestyle variables and asthma, emphysema, chronic bronchitis, and COPD. A second set of linear, main-effects logit regression models were constructed to examine the correlation between lung cancer and asthma, emphysema, chronic bronchitis, COPD when corrected for the selected covariates. The study identified positive correlations between emphysema, chronic bronchitis, COPD, and lung cancer. No correlation between asthma and lung cancer was established. Of the covariates studied, race/ethnicity, marital status, highest educational level, age, family income to poverty ratio, and lifetime smoking were also found to be correlated with the presence of lung cancer. Correlations between the covariates gender, body mass index, alcohol consumption, and country of birth and lung cancer were not found. The study established statistically significant correlations between lung cancer and the lung diseases emphysema, chronic bronchitis, and COPD. The lack of association between asthma and lung cancer may arise from the timeline of diagnosis asthma or type of lung cancer. The study also established significant correlations between lung cancer and several of the covariates included in the analysis. It also established correlations between the covariates and the lung diseases asthma, emphysema, chronic bronchitis, and COPD.

Acute arsenic exposure exacerbates lipopolysaccharide-induced lung injury possibly by compromising the integrity of the lung epithelial barrier in rats

Inhalation of large amounts of arsenic can damage the respiratory tract and may exacerbate the development of bacterial pneumonia, but the exact mechanism remains unclear. In this study, male Wistar rats were randomly divided into control, arsenic trioxide (16.0 μg/kg ATO), lipopolysaccharide (0.5 mg/kg LPS), and ATO combined with LPS (16.0 μg/kg ATO + 0.5 mg/kg LPS) groups. Blood and lung tissue samples were collected from each group 12 h after exposure. The results showed that exposure to ATO or LPS alone produced different effects on leukocytes and inflammatory factors, while combined exposure significantly increased serum interleukin-6, interleukin-10, lung water content, lung lavage fluid protein, and p38 protein phosphorylation levels. Alveolar interstitial thickening, alveolar membrane edema, alveolar type I and II cell matrix vacuolization, and nuclear pyknosis were observed in rats exposed to either ATO or LPS. More severe ultrastructural changes were found in the combined exposure group, and chromatin splitting was observed in alveolar type I cells. Lanthanum nitrate particles leaked from the alveolar vascular lumen in the ATO-exposed group, whereas in the combined exposure group, Evans Blue levels were increased and lanthanum nitrate particles were present in the lung parenchyma. Claudin-3 protein expression increased and claudin-4 expression decreased after ATO or LPS exposure, while claudin-18 expression was unchanged. The changes in claudin-3 and claudin-4 protein expression were further exacerbated by combined exposure. In conclusion, these results suggest that inhalation of ATO may exacerbate the development of bacterial pneumonia and that common mechanisms may exist to synergistically disrupt epithelial barrier integrity.

Urinary polycyclic aromatic hydrocarbon, arsenic, and metal exposure and correlation with emphysema in smokers

PURPOSE

Environmental exposure to metals and chemicals can increase the risk of acute and chronic pulmonary diseases in the human population. This study aimed to analyze seven forms of polycyclic aromatic hydrocarbons (PAHs), seven types of arsenic species, fourteen types of urinary metals including antimony, barium, cadmium, cesium, cobalt, lead, manganese, mercury, molybdenum, strontium, thallium, tin, tungsten, uranium, and the link with emphysema in the US adult cigarette smoking population.

METHODS

A specialized weighted complex survey design analysis using 2011-2016 National Health and Nutrition Examination Survey (NHANES) datasets was conducted. Multivariate logistic regression models were used to assess the association between urinary metals, arsenic, PAHs, and emphysema in adult smokers. R software was used to conduct the statistical analysis.

RESULTS

All 4th quantile concentrations of PAHs, including 1-hydroxynaphthalene, 2-hydroxynaphthalene, 3-hydroxyfluorene, 2-hydroxyfluorene, 1-hydroxypyrene, 1-hydroxyphenanthrene, and 2 & 3-hydroxyphenanthrene, were significantly associated with emphysema in smokers. The 3rd quantile of 1-hydroxypyrene were also associated with increased odds of emphysema in smokers. Among arsenic and metals, the 4th quantile of cadmium was associated with an increased odds of emphysema in smokers. The 3rd quantile of dimethylarsinic acid (DMA) and 4th quantile of mercury were found to have inverse relationships with emphysema in smokers. Several demographic factors had significant associations with emphysema in smokers.

CONCLUSION

Urinary PAHs and cadmium were associated with increased odds of emphysema in smokers. DMA and mercury had an inverse association with emphysema in smokers.