PAH exposure-associated lung cancer: an updated meta-analysis

Use of micronucleus cytome assays with buccal cells for the detection of genotoxic effects: A systematic review and meta-analysis of occupational exposures to metals

Micronucleus (MN) assays with buccal cells are at present widely used to investigate occupational exposures to genotoxic carcinogens. This article describes their use for the monitoring of metal exposed workers. We found in total 73 relevant articles, in the majority (97 %) increased MN and/or other nuclear anomalies were reported. Most studies were realized in South East Asia and South America. A variety of different occupations was studied including welders, electroplaters, painters, workers in battery recycling and production, tannery workers, dental technicians, miners, workers in foundries and smelters, and also subjects working in waste recycling, glass, aluminum and steel production. In many investigations the effects increased with the duration of the working period. The quality of individual studies was evaluated with a quality score tool. The number of cells was in most studies sufficient and DNA-specific stains were used. However, many studies have shortcomings, e.g. they focused solely on MN formation and did not evaluate anomalies, which provide additional information about the stability of the genetic material and acute cytotoxic effects. Only 35 % of the investigations contain quantitative information about exposures to metals and other toxicants. In 6 of these studies, correlations were observed between the concentrations of specific metals (As, Pb, Cr, Cd) in body fluids and MN frequencies. Taken together, the available data indicate that the MN assay can be used to detect chromosomal damage in metal exposed groups; furthermore, it enables also comparisons between subgroups differing in regard to their exposure and allows an estimation of the efficiency of protective measures. The exposure of workers to metals is currently controlled with chemical analytical measurements only, MN assays with buccal cells could contribute to further improve the safety at workplaces as they reflect the biological consequences including synergistic and antagonistic interactions between toxicants.

A systematic review and dose-response meta-analysis of prospective cohort studies on coffee consumption and risk of lung cancer

Studies on the association between coffee consumption and risk of lung cancer have been conflicting. The aim of this study was to systematically review the current evidence on the association between coffee consumption and risk of lung cancer and to quantify this association by performing a meta-analysis. A comprehensive systematic search was performed on online databases up to July 2023 investigating the association between coffee consumption and risk of lung cancer. All prospective cohort studies reporting odds ratios (ORs), rate or risk ratios (RRs), or hazard ratios (HRs) and 95% confidence intervals (CIs) in this context were included. The overall effect size was calculated using the random-effects model and statistical between-studies heterogeneity was examined using Cochrane's Q test and I2. A total of 14 prospective cohort studies were included in this systematic review and meta-analysis. We found a significant positive association between coffee consumption and risk of lung cancer (RR: 1.28; 95% CI: 1.12, 1.47). This association remained significant when we included a pooled analysis paper and excluded 5 cohort studies (RR: 1.37; 95% CI: 1.12, 1.66). We observed no proof of significant publication bias using Egger's test (P = 0.58). Moreover, dose-response analysis showed that each one cup/day increase in coffee consumption was related with a 6% higher lung cancer risk (RR: 1.06; 95% CI: 1.03, 1.09). In conclusion, we found a significant positive association between coffee consumption and risk of lung cancer.

A unique circ_0067716/EIF4A3 double-negative feedback loop impacts malignant transformation of human bronchial epithelial cells induced by benzo(a)pyrene

Benzo(a)pyrene as a pervasive environmental contaminant is characterized by its substantial genotoxicity, and epidemiological investigations have established a correlation between benzo(a)pyrene exposure and the susceptibility to human lung cancer. Notably, much research has focused on the link between epigenetic alterations and lung cancer induced by chemicals, although circRNAs are also emerging as relevant contributors to the carcinogenic process of benzo(a)pyrene. In this study, we identified circ_0067716 as being significantly upregulated in response to stress injury and downregulated during malignant transformation induced by benzo(a)pyrene-7,8-diol-9,10-epoxide (BPDE) in human bronchial epithelial cells. The observed differential expression of circ_0067716 in cells treated with BPDE for varying durations suggests a strong correlation between this circRNA and BPDE exposure. The tissue samples of lung cancer patients also suggest that a lower circ_0067716 expression is associated with BPDE-DNA adduct levels. Remarkably, we demonstrate that EIF4A3, located in the nucleus, interacts with the flanking sequences of circ_0067716 and inhibits its biogenesis. Conversely, circ_0067716 is capable of sequestering EIF4A3 in the cytoplasm, thereby preventing its translocation into the nucleus. EIF4A3 and circ_0067716 can form a double-negative feedback loop that could be affected by BPDE. During the initial phase of BPDE exposure, the expression of circ_0067716 was increased in response to stress injury, resulting in cell apoptosis through the involvement of miR-324-5p/DRAM1/BAX axis. Subsequently, as cellular adaptation progressed, long-term induction due to BPDE exposure led to an elevated EIF4A3 and a reduced circ_0067716 expression, which facilitated the proliferation of cells by stabilizing the PI3K/AKT pathway. Thus, our current study describes the effects of circ_0067716 on the genotoxicity and carcinogenesis induced by benzo(a)pyrene and puts forwards to the possible regulatory mechanism on the occurrence of smoking-related lung cancer, providing a unique insight based on epigenetics.

Antioxidant diet/lifestyle could mitigate the adverse impacts of urinary polycyclic aromatic hydrocarbons on lung function

BACKGROUND

Extant research has demonstrated a correlation between exposure to polycyclic aromatic hydrocarbons (PAHs) and impaired lung function. The maintenance of an antioxidant-rich diet/lifestyle positively benefits pulmonary health. However, the potential ameliorative impact of an antioxidant-based diet/lifestyle on PAH-induced detrimental effects remains unclear.

METHODS

The study drew upon cross-sectional data encompassing 1615 participants derived from the National Health and Nutrition Examination Survey 2007 to 2012. To gauge the maintenance of an antioxidant-rich diet/lifestyle, we employed Oxidative Balance Score (OBS) that incorporates sixteen nutrients and four lifestyle factors. Lung function was evaluated using percent-predicted Forced Vital Capacity (FVC), Forced Expiratory Volume 1st Second (FEV1), FEV1/FVC, and fractional exhaled nitric oxide (FENO). Our analytical approach entailed the utilization of weighted linear models.

RESULTS

Our analysis unveiled interaction effects between urinary monohydroxy polycyclic aromatic hydrocarbons (OH-PAHs) and OBS concerning lung function. A one-unit increase in ∑OH-PAH (sum of eight OH-PAHs) was linked to a -0.75% reduction (95% CI: -1.28, -0.22) in FEV1/FVC. Individuals exhibiting low OBS displayed a marked decrease in FEV1/FVC (mean difference = -1.10%; 95% CI: -1.82, -0.39) for each unit increase in ∑OH-PAH, whereas no significant associations were discerned for those with medium or high OBS. Further stratification by gender yielded consistent results. The correlation between ∑OH-PAH and FENO proved statistically significant among participants with low OBS (P = 0.002) and medium OBS (P = 0.001), but non-significant for those with high OBS. Parallel findings emerged when examining percent-predicted FEV1 and FVC.

CONCLUSIONS

In conclusion, our study underscores the existence of statistically significant interactions between OH-PAHs and the maintenance of an antioxidant-rich diet and lifestyle concerning lung function. These findings underscore the pivotal role of maintaining an antioxidant-based diet and lifestyle in mitigating the adverse impacts of PAH exposure on lung function.

Surveillance and mitigation of soil pollution through metagenomic approaches

Soil pollution is one of the serious global threats causing risk to environment and humans. The major cause of accumulation of pollutants in soil are anthropogenic activities and some natural processes. There are several types of soil pollutants which deteriorate the quality of human life and animal health. They are recalcitrant hydrocarbon compounds, metals, antibiotics, persistent organic compounds, pesticides and different kinds of plastics. Due to the detrimental properties of pollutants present in soil on human life and ecosystem such as carcinogenic, genotoxic and mutagenic effects, alternate and effective methods to degrade the pollutants are recommended. Bioremediation is an effective and inexpensive method of biological degradation of pollutants using plants, microorganisms and fungi. With the advent of new detection methods, the identification and degradation of soil pollutants in different ecosystems were made easy. Metagenomic approaches are a boon for the identification of unculturable microorganisms and to explore the vast bioremediation potential for different pollutants. Metagenomics is a power tool to study the microbial load in polluted or contaminated land and its role in bioremediation. In addition, the negative ecosystem and health effect of pathogens, antibiotic and metal resistant genes found in the polluted area can be studied. Also, the identification of novel compounds/genes/proteins involved in the biotechnology and sustainable agriculture practices can be performed with the integration of metagenomics.

An umbrella review of the evidence associating occupational carcinogens and cancer risk at 19 anatomical sites

Occupational exposure to carcinogens of increasing cancer risk have been extensively suggested. A robust assessment of these evidence is needed to guide public policy and health care. We aimed to classify the strength of evidence for associations of 13 occupational carcinogens (OCs) and risk of cancers. We searched PubMed and Web of Science up to November 2022 to identify potentially relevant studies. We graded the evidence into convincing, highly suggestive, suggestive, weak, or not significant according to a standardized classification based on: random-effects p value, number of cancer cases, 95% confidence interval of largest study, heterogeneity between studies, 95% prediction interval, small study effect, excess significance bias and sensitivity analyses with credibility ceilings. The quality of meta-analysis was evaluated by AMSTAR 2. Forty-eight articles yielded 79 meta-analyses were included in current umbrella review. Evidence of associations were convincing (class I) or highly suggeastive (class II) for asbestos exposure and increasing risk of lung cancer among smokers (RR = 8.79, 95%CI: 5.81-13.25 for cohort studies and OR = 8.68, 95%CI: 5.68-13.24 for case-control studies), asbestos exposure and increasing risk of mesothelioma (RR = 4.61, 95%CI: 2.57-8.26), and formaldehyde exposure and increasing risk of sinonasal cancer (RR = 1.68, 95%CI: 1.38-2.05). Fifteen associations were supported by suggestive evidence (class III). In summary, the current umbrella review found strong associations between: asbestos exposure and increasing risk of lung cancer among smokers; asbestos exposure and increasing risk of mesothelioma; and formaldehyde exposure and higher risk of sinonasal cancer. Other associations might be genuine, but substantial uncertainty remains.

Chemical contaminant exposures assessed using silicone wristbands among fuel station attendants, taxi drivers and commercial motorcycle riders in Kampala, Uganda

There are concerns over traffic-related air pollution in Uganda's capital, Kampala. Individuals in the transportation sector are hypothesized to be at greater risk for exposure to volatile organic compounds, given their proximity to vehicle exhaust. Silicone wristbands are a wearable technology that passively sample individuals' chemical exposures. We conducted a pilot cross sectional study to measure personal exposures to volatile organic compounds among 14 transportation workers who wore a wristband for five days. We analyzed for 75 volatile organic compounds; 33 chemicals (35%) were detected and quantified in at least 50% of the samples and 15 (16%) chemicals were detected and quantified across all the samples. Specific chemicals were associated with participants' occupation. The findings can guide future large studies to inform policy and practice to reduce exposure to chemicals in the environment in Kampala.

Long-term exposure to ambient fine particulate matter-bound polycyclic aromatic hydrocarbons and cancer mortality: A difference-in-differences approach

The association of ambient fine particulate matter (PM2.5) exposure with cancer mortality was controversial, which may ascribe to the difference in PM2.5 constituents. Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic constituents in PM2.5, which are suspected to account for PM2.5-induced cancer mortality but are yet to be investigated. We aimed to assess the association between long-term exposure to PM2.5-bound PAHs and cancer mortality and estimate the attributable mortality. A difference-in-differences approach was used to investigate the causal effect of long-term exposure to PM2.5-bound PAHs on cancer mortality. We divided Jiangsu province, China into 53 spatial units and summarized the annual number of cancer deaths in each spatial unit during 2016-2020. Annual population-weighted exposure to PM2.5-bound PAHs of each spatial unit was assessed by an inverse distance weighting method. The association between PM2.5-bound PAHs exposures and cancer mortality was evaluated by controlling spatial differences, temporal trends, PM2.5 mass exposures, temperatures, and socioeconomic status. Records of 793,269 cancer deaths were identified among 84.7 million population. Each ln-unit increase of exposure to total benzo[a]pyrene equivalents (∑BaPeq), total carcinogenic PAHs (∑PAH7c), and total PAHs (∑PAHs) was significantly associated with a 3.21%, 3.48%, and 2.64% increased risk of cancer mortality, respectively; the risk increased monotonically at low-level exposures but attenuated or flattened afterward (all p for nonlinearity <0.05). Similar exposure-response associations were identified for specific PAHs except that the associations for both fluoranthene and benzo[a]anthracene were linear. We estimated that exposure to ∑BaPeq, ∑PAH7c, and ∑PAHs contributed to 5.73%, 8.73%, and 7.33% of cancer deaths, respectively. In conclusion, long-term exposure to PM2.5-bound PAHs was associated with an increased risk of cancer mortality and contributed to substantial cancer deaths. Our findings highlight the importance to prevent deaths from cancer by reducing PM2.5-bound PAHs exposures and the necessity to take into consideration specific constituents in particulate pollution management in future.

PIG-A gene mutation as a mutagenicity biomarker among coke oven workers

PIG-A gene mutations can be detected in humans, and PIG-A assays can potentially predict the risk of exposure to carcinogens. However, extensive, population-based studies to validate this are lacking. We studied a cohort of occupational coke oven workers with chronic high exposure to carcinogenic polycyclic aromatic hydrocarbons, which are well-studied genotoxins classified by the IARC as carcinogenic to humans. Peripheral blood erythrocytes of workers were assessed for gene mutations using a PIG-A assay, and chromosome damage using the cytokinesis-block micronucleus test with lymphocytes. Two sample populations from a non-industrialized city and new employees in industrial plants were selected as controls. We observed a significantly elevated PIG-A mutation frequency (MF) and increased frequencies of micronuclei (MN) and nuclear buds (NBUDs) in coke oven workers, compared with levels in the control groups. We found that the coke oven workers with different lengths of service had a relatively high mutation frequency. Overall, the study findings showed that occupational exposure of coke oven workers increases the genetic damage and the PIG-A MF could be a potential biomarker for risk assessment of carcinogen exposure.

Dose-response association of polycyclic aromatic hydrocarbon with self-reported trouble sleeping in adults: evidence from the National Health and Nutrition Examination Survey

Previous epidemiological evidence from large population-based studies on the association between polycyclic aromatic hydrocarbons (PAH) exposure and the risk of sleep disorders is inadequate. To comprehensively examine the relationship between independent and combined PAHs and trouble sleeping, we analyzed data from 8194 participants from the National Health and Nutrition Survey (NHANES) cycles. Multivariate adjusted logistic regression and restricted cubic spline models were applied to assess the relationship between PAH exposure and the risk of trouble sleeping. Bayesian kernel machine regression and weighted quantile sum regression models were used to estimate the combined association of urinary PAHs with trouble sleeping. In the single-exposure analyses, compared with the lowest level, the respective adjusted odds ratios (ORs) for trouble sleeping among subjects from the highest quartile were 1.34 (95% CI, 1.15, 1.56), 1.23 (95% CI, 1.05, 1.44), 1.31 (95% CI, 1.11, 1.54), 1.35 (95% CI, 1.15, 1.58), and 1.29 (95% CI, 1.08, 1.53) for 1-hydroxynaphthalene (1-NAP), 2-hydroxynaphthalene (2-NAP), 3-hydroxyfluorene (3-FLU), 2-hydroxyfluorene(2-FLU), and 1-hydroxypyrene(1-PYR). An overall positive correlation between the PAH mixture and trouble sleeping was observed when the mixture was at the 50th percentile or higher. The current study reveals that PAH metabolites (1-NAP, 2-NAP, 3-FLU, 2-FLU, and 1-PYR) may be detrimental to trouble sleeping. PAH mixture exposure was positively associated with trouble sleeping. The results suggested the potential impacts of PAHs and expressed concerns regarding the potential impact of PAHs on health. More intensive research and monitoring of environmental pollutants in the future will contribute to preventing environmental hazards.

Establishment of an artificial particulate matter-induced lung disease model through analyzing pathological changes and transcriptomic profiles in mice

Particulate matter (PM), an environmental risk factor, is linked with health risks such as respiratory diseases. This study aimed to establish an animal model of PM-induced lung injury with artificial PM (APM) and identify the potential of APM for toxicological research. APM was generated from graphite at 600 °C and combined with ethylene. We analyzed diesel exhaust particulate (DEP) and APM compositions and compared toxicity and transcriptomic profiling in lungs according to the exposure. For the animal study, C57BL/6 male mice were intratracheally administered vehicle, DEP, or APM. DEP or APM increased relative lung weight, inflammatory cell numbers, and inflammatory protein levels compared with the vehicle control. Histological assessments showed an increase in particle-pigment alveolar macrophages and slight inflammation in the lungs of DEP and APM mice. In the only APM group, granulomatous inflammation, pulmonary fibrosis, and mucous hyperplasia were observed in the lungs of some individuals. This is the first study to compare pulmonary toxicity between DEP and APM in an animal model. Our results suggest that the APM-treated animal model may contribute to understanding the harmful effects of PM in toxicological studies showing that APM can induce various lung diseases according to different doses of APM.

Contamination and Health Risk Assessment of Polycyclic Aromatic Hydrocarbons in Seasoning Flour Products in Hunan, China

Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants with carcinogenic, teratogenic, and mutagenic effects. Dietary intake is one of the significant exposure pathways of PAHs. In this study, gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) was used to detect 16 priority PAHs listed by the United States Environmental Protection Agency (USEPA) in seasoning flour products distributed in Hunan Province. The consumption of seasoning flour products by the Hunan population was investigated by questionnaire. The results showed that the detection rate of PAHs in seasoning flour products in Hunan Province was 92.41%. Among them, benzo[a]anthracene (BaA), phenanthrene (PHE), fluoranthene (FLA), and chrysene (CHR) were dominant. The total PAHs and benzo[a]pyrene (BaP) contents of soggy seasoning flour product samples were higher than those of crisp samples and chewy samples. The total amount of PAHs in rod-shaped and flaky samples were higher than that in filamentous and granular samples. The margin of exposure (MOE) values of various seasoning flour products and all age groups (children, adolescents, and adults) was much more significant than 10,000. Moreover, the incremental lifetime of cancer risk (ILCR) values of all age groups were below 1 × 10-5. The above results indicate that PAHs in seasoning flour products have a relatively low health risk for the Hunan population. Still, it is recommended that susceptible populations (children, adolescents, etc.) should control their intake of flour products.

Polycyclic aromatic hydrocarbons (PAHs): Updated aspects of their determination, kinetics in the human body, and toxicity

Polycyclic aromatic hydrocarbons (PAHs) are legacy pollutants of considerable public health concern. Polycyclic aromatic hydrocarbons arise from natural and anthropogenic sources and are ubiquitously present in the environment. Several PAHs are highly toxic to humans with associated carcinogenic and mutagenic properties. Further, more severe harmful effects on human- and environmental health have been attributed to the presence of high molecular weight (HMW) PAHs, that is PAHs with molecular mass greater than 300 Da. However, more research has been conducted using low molecular weight (LMW) PAHs). In addition, no HMW PAHs are on the priority pollutants list of the United States Environmental Protection Agency (US EPA), which is limited to only 16 PAHs. However, limited analytical methodologies for separating and determining HMW PAHs and their potential isomers and lack of readily available commercial standards make research with these compounds challenging. Since most of the PAH kinetic data originate from animal studies, our understanding of the effects of PAHs on humans is still minimal. In addition, current knowledge of toxic effects after exposure to PAHs may be underrepresented since most investigations focused on exposure to a single PAH. Currently, information on PAH mixtures is limited. Thus, this review aims to critically assess the current knowledge of PAH chemical properties, their kinetic disposition, and toxicity to humans. Further, future research needs to improve and provide the missing information and minimize PAH exposure to humans.

PM2.5: Epigenetic Alteration in Lung Physiology and Lung Cancer Pathogenesis

Particulate matter (PM) has a very negative impact on human health, specifically the respiratory system. PM comes in many forms, among these is PM2.5,which is a major risk factor for lung cancer and other cardiovascular diseases. PM is inherent in emissions from industrial production, manufacturing, vehicle exhaust, mining, and cigarette smoking. For this reason, the composition of PM differs from area to area although its primary constituents are heavy metals and petroleum elements. PM has a long and toxic impact on human health. After extended exposure to PM2.5 the mortality rate for lung cancer patients increases. Already, lung cancer is the leading cause of death globally with the highest mortality rate. PM2.5 creates epigenetic changes in miRNA, histone modification, and DNA methylation, causing tumorigenesis followed by lung cancer.

The Effect of Public Healthcare Expenditure on the Reduction in Mortality Rates Caused by Unhealthy Habits among the Population

The health systems of developed countries aim to reduce the mortality rates of their populations. To this end, they must fight against the unhealthy habits of citizens, such as smoking, excessive alcohol consumption, and sedentarism, since these result in a large number of deaths each year. Our research aims to analyze whether an increase in health resources influences the number of deaths caused by the unhealthy habits of the population. To achieve this objective, a sample containing key indicators of the Spanish health system was analyzed using the partial least squares structural equation modeling (PLS-SEM) method. The results show how increasing public health spending and, thus, the resources allocated to healthcare can curb the adverse effects of the population's unhealthy habits. These results have important implications for theory and practice, demonstrating the need for adequate investment in the healthcare system to reduce mortality among the population.

Long-term exposure to low concentrations of polycyclic aromatic hydrocarbons and alterations in platelet indices: A longitudinal study in China

Long-term exposure to low polycyclic aromatic hydrocarbon (PAH) concentration may ave detrimental effects, including changing platelet indices. Effects of chronic exposure to low PAH concentrations have been evaluated in cross-sectional, but not in longitudinal studies, to date. We aimed to assess the effects of long-term exposure to the low-concentration PAHs on alterations in platelet indices in the Chinese population. During 2014–2017, we enrolled 222 participants who had lived in a village in northern China, 1–2 km downwind from a coal plant, for more than 25 years, but who were not employed by the plant or related businesses. During three follow-ups, annually in June, demographic information and urine and blood samples were collected. Eight PAHs were tested: namely 2-hydroxynaphthalene, 1-hydroxynaphthalene, 2-hydroxyfluorene, 9-hydroxyfluorene (9-OHFlu), 2-hydroxyphenanthrene (2-OHPh), 1-hydroxyphenanthrene (1-OHPh), 1-hydroxypyrene (1-OHP), and 3-hydroxybenzo [a] pyrene. Five platelet indices were measured: platelet count (PLT), platelet distribution width (PDW), mean platelet volume (MPV), platelet crit, and the platelet-large cell ratio. Generalized mixed and generalized linear mixed models were used to estimate correlations between eight urinary PAH metabolites and platelet indices. Model 1 assessed whether these correlations varied over time. Models 2 and 3 adjusted for additional personal information and personal habits. We found the following significant correlations: 2-OHPh (Model1 β₁ = 18.06, Model2 β₂ = 18.54, Model β₃ = 18.54), 1-OHPh (β₁ = 16.43, β₂ = 17.42, β₃ = 17.42), 1-OHP(β₁ = 13.93, β₂ = 14.03, β₃ = 14.03) with PLT, as well as 9-OHFlu with PDW and MPV (odds ratio or Model3 OR_PDW[95%CI] = 1.64[1.3–2.06], OR_MPV[95%CI] = 1.33[1.19–1.48]). Long-term exposure to low concentrations of PAHs, indicated by2-OHPh, 1-OHPh, 1-OHP, and 9-OHFlu, as urinary biomarkers, affects PLT, PDW, and MPV. 9-OHFlu increased both PDW and MPV after elimination of the effects of other PAH exposure modes.

Respiratory Tract Cancer Incidences across Industry Groups: A Nationwide Cohort Study with More Than 70 Million Person-Years of Follow-Up

The number of cases and incidence rates of laryngeal and lung cancers have been increasing globally. Therefore, identifying the occupational causes of such cancers is an important concern for policymakers to prevent cancers and deaths. We used national health insurance service claims data in Korea. We included 10,786,000 workers aged between 25 and 64 years. In total, 74,366,928 total person-years of follow-up were included in this study with a mean follow-up of 6.89 years for each person. The standardized incidence ratio (SIR) and 95% confidence intervals (CIs) referenced with the total workers were estimated. For laryngeal cancer, increased SIRs were observed in the land transportation industry among male workers (SIR [95% CI]: 1.65 [1.02–2.53]). For lung cancer, elevated SIRs were observed in the industries including animal production (1.72 [1.03–2.68]), fishing (1.70 [1.05–2.60]), mining (1.69 [1.22–2.27]), travel (1.41 [1.00–1.93]), and transportation (1.22 [1.15–1.30]) among male workers. For female works, healthcare (2.08 [1.04–3.72]) and wholesale (1.88 [1.18–2.85]) industries were associated with a high risk of lung cancer. As an increased risk of respiratory tract cancers has been identified in employees associated with certain industries, appropriate policy intervention is needed to prevent occupational cancers.

Joint effects of polycyclic aromatic hydrocarbons, smoking, and XPC polymorphisms on damage in exon 2 of KRAS gene among young coke oven workers

Genetic polymorphisms may contribute to individual susceptibility to DNA damage induced by environmental exposure. In this study, we evaluate the effects of co-exposure to PAHs, smoking and XPC polymorphisms, alone or combined, on damage in exons. A total of 288 healthy male coke oven workers were enrolled into this study, and urinary 1-hydroxypyrene (1-OH-Pyr) was detected. Base modification in exons of KRAS and BRAF gene, and polymorphisms of XPC were determined in plasma by real-time PCR. We observed 1-OH-Pyr was positively related to damage in exon 2 of KRAS (KRAS-2) and in exon 15 of BRAF (BRAF-15), respectively, and KRAS-2 and BRAF-15 were significantly associated with increased 1-OH-Pyr. A stratified analysis found 1-OH-Pyr was significantly associated with KRAS-2 in both smokers and non-smokers, while 1-OH-Pyr was significantly associated with BRAF-15 only in smokers. Additionally, individuals carrying both rs2228001 G-allele (GG+GT) and rs3731055 GG homozygote (GG) genotype appeared to have more significant effect on KRAS-2. The high levels of 1-OH-Pyr were associated with KRAS-2 only in rs2228001 GG+GT genotype carriers and the high levels of 1-OH-Pyr were associated with KRAS-2 only in rs3731055 GG genotype carriers and the most severe KRAS-2 was observed among subjects carrying all four of the above risk factors. Our findings indicated the co-exposure effect of PAHs and smoking could increase the risk of KRAS-2 by a mechanism partly involving XPC polymorphisms.

Air pollution: A culprit of lung cancer

Air pollution is a global health problem, especially in the context of rapid economic development and the expansion of urbanization. Herein, we discuss the harmful effects of outdoor and indoor pollution on the lungs. Ambient particulate matters (PMs) from industrial and vehicle exhausts is associated with lung cancer. Workers exposed to asbestos, polycyclic aromatic hydrocarbons (PAHs), and toxic metals are also likely to develop lung cancer. Indoors, cooking fumes, second-hand smoke, and radioactive products from house decoration materials play roles in the development of lung cancer. Bacteria and viruses can also be detrimental to health and are important risk factors in lung inflammation and cancer. Specific effects of lung cancer caused by air pollution are discussed in detail, including inflammation, DNA damage, and epigenetic regulation. In addition, advanced materials for personal protection, as well as the current government policies to prevent air pollution, are summarized. This review provides a basis for future research on the relationship between lung cancer and air pollution.

Epidemiology beyond its limits

In 1995, journalist Gary Taubes published an article in Science titled "Epidemiology faces its limits," which questioned the utility of nonrandomized epidemiologic research and has since been cited more than 1000 times. He highlighted numerous examples of research topics he viewed as having questionable merit. Studies have since accumulated for these associations. We systematically evaluated current evidence of 53 example associations discussed in the article. Approximately one-quarter of those presented as doubtful are now widely viewed as causal based on current evaluations of the public health consensus. They include associations between alcohol consumption and breast cancer, residential radon exposure and lung cancer, and the use of tanning devices and melanoma. This history should inform current debates about the reproducibility of epidemiologic research results.

Trend Analysis of Occupational Lung Cancer from Coke Oven Emission Exposure - China, 2008-2019

What is already known about this topic?

Coke oven emissions are a complex mixture of particulate matter and gases, some with carcinogenicity, released during coke production. Lung cancer caused by coke oven emissions has been listed as a statutory occupational cancer in China and many countries.

What is added by this report?

In this study, coke oven emissions-induced lung cancer was mainly found in the manufacturing industries. Coke oven workers exposed to higher levels of polycyclic aromatic hydrocarbons in different workplaces had a high risk of occupational lung cancer.

What are the implications for public health practice?

It is necessary to take efforts to greatly reduce emissions from coke production and effectively monitor the health of workers.

DNA damage, serum metabolomic alteration and carcinogenic risk associated with low-level air pollution

Outdoor air pollution has been classified as carcinogenic to humans (Group 1) for lung cancer, but the underlying mechanism and key toxic components remain incompletely understood. Since DNA damage and metabolite alterations are associated with cancer progression, exploring potential mechanisms linking air pollution and cancer might be meaningful. In this study, a real-time ambient air exposure system was established to simulate the real-world environment of adult male SD rats in Beijing from June 13th, 2018, to October 8th, 2018. 8-OHdG in the urine, γ-H2AX in the lungs and mtDNA copy number in the peripheral blood were analyzed to explore DNA damage at different levels. Serum non-targeted metabolomics analysis was performed. Pair-wise spearman was used to explore the correlation between DNA damage biomarkers and serum differential metabolites. Carcinogenic risks of heavy metals and PAHs via inhalation were assessed according to US EPA guidelines. Results showed that PM_2.5 and O₃ were the major air pollutants in the exposure group and not detected in the control group. Compared with control group, higher levels of 8-OHdG, mtDNA copy number, γ-H2AX and PCNA-positive nuclei cells were observed in the exposure group. Histopathological evaluation suggested ambient air induced alveolar wall thickening and inflammatory cell infiltration in lungs. Perturbed metabolic pathways identified included glycolysis/gluconeogenesis metabolism, purine and pyrimidine metabolism, etc. γ-H2AX was positively correlated with serum ADP, 3-phospho-D-glyceroyl phosphate and N-acetyl-D-glucosamine. The BaPeq was 0.120 ng/m³. Risks of Cr(VI), As, V, BaP, BaA and BbF were above 1 × 10^-6. We concluded that low-level air pollution was associated with DNA damage and serum metabolomic alterations in rats. Cr(VI) and BaP were identified as key carcinogenic components in PM_2.5. Our results provided experimental evidence for hazard identification and risk assessment of low-level air pollution.

Epidemiologic evidence of exposure to polycyclic aromatic hydrocarbons and breast cancer: A systematic review and meta-analysis

Breast cancer (BC) is the most frequently diagnosed cancer in women. However, only 58% of cases have been associated with known risk factors (reproductive, hormonal, lifestyles, and genetic), and the rest to unknown causes. Nevertheless, growing evidence suggests that exposure to environmental contaminants is an important risk factor for BC. Polycyclic aromatic hydrocarbons (PAHs) are formed during organic matter combustion, including smoking, grilled meat, and fuels, and are important carcinogenic constituents of environmental pollution. We examined the information generated by epidemiological studies evaluating the association between BC and PAHs exposure from multiple sources. Our work was conducted according to Conducting Systematic Reviews and Meta-Analyses of Observational Studies of Etiology (COSMOS-E) guidelines. We searched PubMed, Web of Science, and Scopus from January 2000 to December 2019. A total of 124 records were identified, and only 23 articles met all inclusion criteria. Occupational and/or environmental exposure to PAHs was significantly associated with BC, irrespective of exposure being assessed by direct or indirect methods. CYP1A1 and CYP1B1 adverse polymorphisms, familial BC history and smoking status, significantly strengthened the association between PAHs exposure and BC, whereas high fruit and vegetable intake had antagonistic associations. The positive relationships obtained in the studies here reviewed indicated that PAHs exposure is a risk factor for BC. Research needs include the improvement of exposure assessment, particularly identification of specific PAHs, reconstruction of time-varying and distant past exposures and further studies on the interaction between known BC factors and modifiable diet and life-style factors allowing BC prevention and control.

Mechanistic insight into the synergism of IL-27 and IL-28B in regulation of benzo(a)pyrene-induced lung carcinogenesis associated ROS/NF-κB/NLRP3 crosstalk

AIM

Our previous work depicted that benzo(a)pyrene (BaP)-induced lung cancer associated pulmonary redox imbalance and inflammation were effectively regulated by the combinatorial treatment of IL-27 and IL-28B. So in continuation of that finding the present study was designed to reveal the inflammation regulating signaling network modulated by IL-27 and IL-28B treatment related to BaP-induced lung cancer.

METHODS

Male Swiss albino mice were treated with BaP to induce lung tumor. Then they received individual as well as combinatorial treatment of IL-27 and IL-28B. At the end of the experimental schedule, the expression of NF-κB signaling proteins, the formation of NLRP3 inflammasome complex and IL-18; IL-17A expression in the lung were observed using Western blot and RT-PCR. The tissue and serum levels of some proinflammatory cytokines were also studied using ELISA. Mast cell density was also studied using toluidine blue staining procedure.

RESULTS

Treatment with IL-27 or IL-28B alone was successful to regulate the expression of NF-κB signaling proteins and NLRP3 complex in some cases but best attenuation was observed in animals who received both IL-27 and IL-28B in combination. In combination, it was successful in down-regulating the expression of p-ERK1/2 and in reducing the accumulation of mast cells in the lung tissue associated with BaP-induced lung carcinogenesis. The impaired PPARγ expression was also reinstated upon combination treatment.

CONCLUSION

Altogether, the treatment in combination with IL-27 and IL-28B is an effective regimen to attenuate the ROS/NF-κB/NLRP3 axis associated with BaP-induced lung carcinogenesis.

Factors Associated with Urinary 1-Hydroxypyrene and Malondialdehyde among Adults near a Petrochemical Factory: Implications for Sex and Lifestyle Modification

Background: The association between the biomarkers of environmental exposure, oxidative stress, and health-related behaviors in community residents living in an endemic viral hepatitis area and near petrochemical industrial complexes remains unclear. From a health promotion perspective, healthcare providers must know what to do for residents concerned about their health and living environment, especially for individual-level and modifiable risk factors. Therefore, we aimed to explore the factors associated with urinary 1-hydroxypyrene (1-OHP) and malondialdehyde (MDA). Methods: A community-based, cross-sectional study was conducted between July 2018 and February 2019 in western coastal Yunlin County, Taiwan. All participants lived within a 10 km radius of a large petrochemical complex and did not work in the factory. This study was conducted with the local hospital through annual community health screening. Biological samples were collected and biomarkers determined and quantified in the central laboratory of the collaborating hospital. Results: A total of 6335 adult residents completed the study. The mean age was 47.7 (SD = 16) years. Out of the total population, 56.4% were female, 30.1% had metabolic syndrome (MetS), and 16.8% and 14.3% had hepatitis B virus antigen (HBsAg) and hepatitis C virus antibody (anti-HCV) positivity, respectively. The median 1-OHP and MDA level was 0.11 and 0.9 μg/g creatinine with an interquartile range of 0.07–0.18, and 0.4–1.5, respectively. The MDA levels correlated with specific diseases. The multivariable ordinal logistic regression model revealed that female sex, smoking, betel nut use, HBsAg, and anti-HCV positivity were associated with higher 1-OHP levels. In men, MetS was associated with higher 1-OHP levels and regular exercise with lower 1-OHP levels. High MDA levels were associated with smoking, betel nut users, HBsAg, and anti-HCV positivity. Conclusions: The findings highlight the importance of initiating individualized health promotion programs for residents near petrochemical factories, especially for adults with substance-use and cardiometabolic risk factors. Furthermore, it is crucial to provide further treatment to patients with viral hepatitis.

The relationship of smoking to cg05575921 methylation in blood and saliva DNA samples from several studies

Numerous studies have shown that cg05575921 methylation decreases in response to smoking. However, secondary to methodological issues, the magnitude and dose dependency of that response is as of yet unclear. This lack of certainty is a barrier to the use of DNA methylation clinically to assess and monitor smoking status. To better define this relationship, we conducted a joint analysis of methylation sensitive PCR digital (MSdPCR) assessments of cg05575921 methylation in whole blood and/or saliva DNA to smoking using samples from 421 smokers and 423 biochemically confirmed non-smokers from 4 previously published studies. We found that cg05575921 methylation manifested a curvilinear dose dependent decrease in response to increasing cigarette consumption. In whole blood DNA, the Receiver Operating Characteristic (ROC) Area Under the Curve (AUC) of cg05575921 methylation for predicting daily smoking status was 0.98. In saliva DNA, the gross AUC was 0.91 with correction for cellular heterogeneity improving the AUC to 0.94. Methylation status was significantly associated with the Fagerstrom Test for Nicotine Dependence score, but with significant sampling heterogeneity. We conclude that MSdPCR assessments of cg05575921 methylation are a potentially powerful, clinically implementable tool for the assessment and management of smoking.

Chemical contaminant exposures assessed using silicone wristbands among occupants in office buildings in the USA, UK, China, and India

Little is known about chemical contaminant exposures of office workers in buildings globally. Complex mixtures of harmful chemicals accumulate indoors from building materials, building maintenance, personal products, and outdoor pollution. We evaluated exposures to 99 chemicals in urban office buildings in the USA, UK, China, and India using silicone wristbands worn by 251 participants while they were at work. Here, we report concentrations of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and other brominated flame retardants (BFRs), organophosphate esters (OPEs), phthalates and phthalate alternatives, pesticides, and polycyclic aromatic hydrocarbons (PAHs). First, we found major differences in office worker chemical exposures by country, some of which can be explained by regulations and use patterns. For example, exposures to several pesticides were substantially higher in India where there were fewer restrictions and unique malaria challenges, and exposures to flame retardants tended to be higher in the USA and UK where there were historic, stringent furniture flammability standards. Higher exposures to PAHs in China and India could be due to high levels of outdoor air pollution that penetrates indoors. Second, some office workers were still exposed to legacy PCBs, PBDEs, and pesticides, even decades after bans or phase-outs. Third, we identified exposure to a contemporary PCB that is not covered under legacy PCB bans due to its presence as an unintentional byproduct in materials. Fourth, exposures to novel BFRs, OPEs, and other chemicals commonly used as substitutes to previously phased-out chemicals were ubiquitous. Fifth, some exposures were influenced by individual factors, not just countries and buildings. Phthalate exposures, for example, were related to personal care product use, country restrictions, and building materials. Overall, we found substantial country differences in chemical exposures and continued exposures to legacy phased-out chemicals and their substitutes in buildings. These findings warrant further research on the role of chemicals in office buildings on worker health.

Benzo(a)pyrene induces MUC5AC expression through the AhR/mitochondrial ROS/ERK pathway in airway epithelial cells

OBJECTIVES

Benzo(a)pyrene (BaP) is a ubiquitous air pollutants, and BaP exposure leads to a risk of respiratory diseases. The oversecretion of airway mucus and high expression of mucin 5AC (MUC5AC) are associated with common respiratory disorders caused by air pollution. We aimed to investigate the effect of BaP on MUC5AC expression, especially the mechanisms by which BaP induces MUC5AC gene expression.

METHODS

The human airway epithelial cell NCI-H292 was used to test the effects of BaP on the expression of MUC5AC in vitro. MUC5AC mRNA and protein expression were assessed with real-time quantitative PCR, immunochemistry, and western blotting. A luciferase assay was conducted to detect the activity of the promoter. The total cellular ROS and mitochondrial ROS were measured by corresponding probes. Small-interfering RNAs were used for gene silencing. AhR-overexpressing cell lines were constructed by transfection with AhR overexpression lentivirus.

RESULTS

We found that BaP stimulation upregulated the MUC5AC mRNA and protein levels and activated the ERK pathway. Suppressing ERK with U0126 (an ERK inhibitor) or knocking down ERK with siRNA decreased BaP-induced MUC5AC expression. The luciferase activity transfected with the MUC5AC promoter and cAMP-response element (CRE) was increased after BaP treatment, whereas CREB siRNA suppressed the BaP-induced overexpression of MUC5AC. In addition, BaP increased mitochondrial ROS production, and Mito-TEMP, a mitochondrial ROS inhibitor, inhibited BaP-induced MUC5AC expression and ERK activation. BaP increased the mRNA levels of CYP1A1 and CYP1B1, while Alizarin, a CYP1s inhibitor, suppressed the effects of BaP, including the MUC5AC overexpression, ERK activation and mitochondrial ROS generation. BaP induced the translocation of aryl hydrocarbon receptor (AhR) from the cytoplasm to the nucleus. SiRNA-mediated knockdown or chemical inhibition of AhR decreased the BaP-induced expression of MUC5AC, while the overexpression of AhR significantly enhanced the BaP-induced expression of MUC5AC. ITE, an endogenous AhR ligand, also upregulated the mRNA and protein expression of MUC5AC. Furthermore, resveratrol treatment inhibited the BaP-induced MUC5AC overexpression, AhR translocation, mitochondrial ROS production and ERK pathway activation.

CONCLUSION

Here, we highlighted the crucial role of AhR/mitochondrial ROS/ERK pathway activation in BaP-induced MUC5AC overexpression and identified resveratrol as a promising drug to reduce BaP-induced MUC5AC overexpression.

Cancer cluster among small village residents near the fertilizer plant in Korea

OBJECTIVES

In Jang-jeom, a small village in Hamra-myeon, Iksan-si, Jeollabuk-do, South Korea, residents raised concerns about a suspected cancer cluster that they attributed to a fertilizer plant near the village. We aimed to investigate whether the cancer incidence in the village was higher than that in the general Korean population when the factory was in operation (2001-2017) and whether living in the village was associated with a higher risk of cancer.

METHODS

Using national population data and cancer registration data of South Korea, we estimated the standardized incidence ratios (SIRs) in the village to investigate whether more cancer cases occurred in the village compared to other regions. The SIRs were standardized by age groups of 5 years and sex. In order to investigate whether residence in the village increased the risk of cancer, a retrospective cohort was constructed using National Health Insurance Service (NHIS) databases. We estimated the cancer hazard ratios (HRs) using the Cox proportional hazard model, and defined the exposed area as the village of Jang-jeom, and the unexposed or control area as the village neighborhood in Hamra-myeon. We considered potential confounding variables such as age, sex, and income index in the models. Additionally, we measured polycyclic aromatic hydrocarbons (PAHs) and tobacco-specific nitrosamines (TSNAs), suspected carcinogens that may have caused the cancer cluster, in samples collected from the plant and the village.

RESULTS

Twenty-three cancer cases occurred in Jang-jeom from 2001 to 2017. Between 2010 and 2016, the incidence rates of all cancers (SIR: 2.05, except thyroid cancer: 2.22), non-melanoma skin cancer (SIR: 21.14, female: 25.41), and gallbladder (GB) and biliary tract cancer in men (SIR: 16.01) in the village were higher than those in the national population in a way that was statistically significant. In our cohort analysis that included only Hamra-myeon residents who have lived there for more than 7 years, we found a statistically significant increase in the risk of all cancers (HR: 1.99, except thyroid cancer: 2.20), non-melanoma skin cancer (HR: 11.60), GB and biliary tract cancer (HR: 15.24), liver cancer (HR: 6.63), and gastric cancer (HR: 3.29) for Jang-jeom residents compared to other Hamra area residents. We identified PAHs and TSNAs in samples of deposited dust and residual fertilizer from the plant and TSNAs in dust samples from village houses.

CONCLUSIONS

The results of the SIR calculation and cancer risk analyses of Jang-jeom village residents from the retrospective cohort design showed consistency in the effect size and direction, suggesting that there was a cancer cluster in Jang-jeom. This study would be a good precedent for cancer cluster investigation.

Dietary exposure and cancer risk assessment of the Pakistani population exposed to polycyclic aromatic hydrocarbons

The sixteen-priority polycyclic aromatic hydrocarbons (PAHs) were determined in twenty-one groceries from six food groups consumed by the Pakistani population. The highest concentration of the total PAHs was found in fish (243 ng g^-1), while the lowest concentration was determined in rice (53 ng g^-1). The total B[a]P_eq dietary exposure for the male group followed an increasing order of children (865.5 ng day^-1) < adolescents (2301 ng day^-1) < seniors (2864 ng day^-1) < adults (3004 ng day^-1), whereas the similar order was also observed for the female group. The male group showed 1-8.5% (mean 5.5%) of higher exposure amount compared to the female group. Among all food categories, wheat (43%) and milk (34%) contributed the greatest while rice (1%) and egg (1%) contributed the smallest to the total dietary exposure of PAHs. The incremental lifetime cancer risk (ILCR) values for the adults and children revealed a potential cancer risk to the both male and female groups. Whereas at the 95th percentiles, the ILCR values for all age and gender groups exceeded the limit (>10^-5), demonstrating a high potential cancer risk in the Pakistani population. The sensitivity analysis found that the daily dietary intake, exposure duration and the cancer slope factor were the most influential variables contributed to the total variance of risk.

Association between Metabolites and the Risk of Lung Cancer: A Systematic Literature Review and Meta-Analysis of Observational Studies

Globally, lung cancer is the most prevalent cancer type. However, screening and early detection is challenging. Previous studies have identified metabolites as promising lung cancer biomarkers. This systematic literature review and meta-analysis aimed to identify metabolites associated with lung cancer risk in observational studies. The literature search was performed in PubMed and EMBASE databases, up to 31 December 2019, for observational studies on the association between metabolites and lung cancer risk. Heterogeneity was assessed using the I2 statistic and Cochran's Q test. Meta-analyses were performed using either a fixed-effects or random-effects model, depending on study heterogeneity. Fifty-three studies with 297 metabolites were included. Most identified metabolites (252 metabolites) were reported in individual studies. Meta-analyses were conducted on 45 metabolites. Five metabolites (cotinine, creatinine riboside, N-acetylneuraminic acid, proline and r-1,t-2,3,c-4-tetrahydroxy-1,2,3,4-tetrahydrophenanthrene) and five metabolite groups (total 3-hydroxycotinine, total cotinine, total nicotine, total 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (sum of concentrations of the metabolite and its glucuronides), and total nicotine equivalent (sum of total 3-hydroxycotinine, total cotinine and total nicotine)) were associated with higher lung cancer risk, while three others (folate, methionine and tryptophan) were associated with lower lung cancer risk. Significant heterogeneity was detected across most studies. These significant metabolites should be further evaluated as potential biomarkers for lung cancer.

Environmental Monitoring of PAHs Exposure, Biomarkers and Vital Status in Coke Oven Workers

A follow-up study of a cohort of workers from a coke plant compared with a control group from the same industrial area was conducted in 2019. The recruitment and environmental and biomarker measurements were performed during 1993/1994. The environmental concentrations of polycyclic aromatic hydrocarbons (PAH), B(a)P, pyrene and nitro-PAH were measured. Personal data were collected via an individual semi-structured questionnaire by a trained physician. All biomarkers were measured after a specific blood drawing for every test. Significant risks (ORs) were observed for nitro-PAH (≥0.12 µg/m³) [OR = 7.96 (1.01–62.82)], urinary 1-hydroxypyrene (1-OHpy) (≥0.99 µmoles/moles of creatinine) [OR = 11.71 (1.47–92.90)], PAH DNA adducts (P³²) (≥2.69 adducts/10⁸ nucleotides) [OR = 5.46 (1.17–25.58)], total nitro-PAH hemoglobin adducts (≥161.68 fg/µg of Hb) [OR = 5.92 (1.26–27.86)], sister chromatid exchange (SCE) with TCR (≥377.84 SCE/cell chromosomes) [OR = 13.06 (3.95–93.10)], sister chromatid exchange with T (≥394.72 total SCE) [OR = 13.06 (3.95–93.10)], and sister chromatid exchange with X (≥8.19 mean SCE) [OR = 13.06 (3.95–93.10)]. Significant risk of death for all causes and chromosomal aberrations (48 h) (OR = 7.19 [1.19–43.44]) or micronuclei in culture at 48 h (OR = 3.86 [1.04–14.38]) were also found.

Construction of polluted aerosol in accumulation that affects the incidence of lung cancer

Background

This model demonstrated the correlation between lung cancer incidences and the parts of ambient air pollution according to the National Aeronautics and Space Administration (NASA)'s high resolution technology satellites.

Methods

Chemical type of aerosols was investigated by the Aerosol Diagnostics Model such as black carbon, mineral dust, organic carbon, sea-salt and SO4. The model investigated associations between the six year accumulation of each aerosol and lung cancer incidence by Bayesian hierarchical spatio-temporal model. Which also represented integrated geophysical parameters.

Results

In analyses of accumulated chemical aerosol component from 2010 – 2016, the incidence rate ratio (IRR) of patients in 2017 were estimated. We observed a significant increasing risk for organic carbon exposure (IRR 1.021, 95%CI 1.020–1.022), SO₄, (IRR 1.026, 95% CI 1.025–1.028) and dust, (IRR 1.061, 95% CI 1.058–1.064). There was also suggestion of an increased risk with, every 1 ug/m³ increase in organic carbon compound is associated with 21% increased risk of lung cancer, whereas a 26% excess risk of cancer per 1 ug/m³ increase in mean SO₄ and 61% increased risk of lung cancer for dust levels. The other variables were the negative IRR which did not increase the risk of the exposed group.

Conclusion

With our results, this process can determine that organic carbon, SO₄ and dust was significantly associated with the elevated risk of lung cancer.

Association between polymorphism in CDKN2B-AS1 gene and its interaction with smoking on the risk of lung cancer in a Chinese population

Background

Long non-coding RNAs became the hot spots in the carcinogenesis of various tumors. This case-control study evaluated the association between the rs2151280 in lncRNA CDKN2B-AS1 and lung cancer risk.

Methods

This study included 507 lung cancer patients and 542 healthy individuals. Odds ratios and their 95% confidence intervals were calculated by unconditional logistic regression analysis to evaluate the association between the rs2151280 and lung cancer risk.

Results

Compared with individuals carrying TT genotype, individuals carrying CC genotype of rs2151280 had a decreased risk of lung cancer (OR = 0.640, 95%CI = 0.421–0.972, P = 0.036). In the recessive model, rs2151280 CC genotype was observed to reduce the risk of lung cancer (OR = 0.684). C allele was associated with non-small cell lung cancer risk (OR = 0.674). The rs2151280 was significantly associated with lung adenocarcinoma risk (CCvsTT: OR = 0.567, 95%CI = 0.333–0.965, P = 0.037; CCvsTC+TT: OR = 0.543, 95%CI 0.330–0.893, P = 0.016, respectively). However, there was no significant association between rs2151280 and lung squamous cell carcinoma risk in five models. The quantitative analysis suggested that there were no significant interactions of rs2151280 with smoking exposure to lung cancer susceptibility.

Conclusions

This hospital-based case-control study suggested that CDKN2B-AS1 rs2151280 T>C was associated with the risk of lung cancer.

Concentrations and distributions of polycyclic aromatic hydrocarbon in vegetables and animal-based foods before and after grilling: Implication for human exposure

The effects of grilling on health risks posed by polycyclic aromatic hydrocarbons (PAHs) in food remain poorly understood. The changes of concentrations, distributions, and risks of PAHs in vegetables and animal-based foods before and after grilling were investigated in this study. The sum of 16 (∑₁₆) PAH concentrations in grilled vegetables and grilled animal-based foods were 60.4-1936 and 69.1-4668 ng/g, respectively. Grilling markedly increased the ∑₁₆ PAH concentrations in most foods analyzed. Grilling clearly increased the low-molecular-weight PAH contributions to the ∑₁₆ PAH concentrations in vegetables but increased the heavier PAH contributions to the ∑₁₆ PAH concentrations in some animal-based foods. With the grilling, the total benzo[a]pyrene-equivalent concentrations of the 16 PAHs in Chinese chives and enoki mushrooms and most animal-based foods were improved significantly. Source assessments indicated that environmental sources contributed PAHs to the raw foods and high-temperature pyrolysis during grilling contributed large proportions of the PAHs in the grilled foods. The carcinogenic risks to humans from the exposure of PAHs in vegetables and animal-based foods were estimated. Grilling increased the total risks of PAHs in vegetables and animal-based foods by factors of 3.12 and 5.49, respectively. Total risks of PAHs in the 11 foods were 3.43 times higher when the foods were grilled than when raw. The results suggested that the negative effects of grilling on human health should be of great concern.

Environmental and occupational determinants of lung cancer

Lung cancer has become a global problem, from a rare disease to an emerging public health issue. The current data of GLOBOCAN 2018, indicates that this disease has recorded highest mortality among all types of cancer. The etiological factors of lung cancer have become more multiplex because of increasing industrialization and environmental pollution around the world, especially in India. There is a rise in incidence of lung cancer among non-smokers and this can be attributed to environmental and occupational exposure to various kinds of hazardous substances. Target mutations are high in Lung cancer among non-smokers when compared to smokers. Some developed countries have guidelines and policies for prevention and control of risk factors focusing on these issues. Intervention aiming for primary prevention can be an important and cost-effective tool in developing countries to deal with increasing incidence of lung cancer. There is a need to define high risk group among non-smokers after taking into account environmental and occupational determinants as important risk factors. Research on etiology of lung cancer and prevention provides evidence to work on global incidence and prevalence of lung cancer, and for designing cost effective lung cancer prevention strategies. Research in the area of lung cancer prevention should be considered to recognize the areas where action is required to prevent environment and occupation related lung cancer. The government and occupational health and safety organizations have taken many steps in the last few years that can help to protect workers from these exposures. But the dangers are still there, so there is a need to do more to limit these exposures around workplace. This whole situation guides us to advocate population-based intervention along with policy implementation.