The presence of erionite in North American geologies and the estimated mesothelioma potency by region

OBJECTIVE

Erionite is a naturally occurring fibrous mineral found in soils in some geographical regions. Known for its potency for causing mesothelioma in the Cappadocia region of Turkey, the erionite fiber has attracted interest in the United States due to its presence in a band of rock that extends from Mexico to Montana. There are few toxicology studies of erionite, but all show it to have unusually high chronic toxicity. Despite its high potency compared to asbestos fibers, erionite has no occupational or environmental exposure limits. This paper takes what has been learned about the chemical and physical characteristics of the various forms of asbestos (chrysotile, amosite, anthophyllite, and crocidolite) and predicts the potency of North American erionite fibers.

MATERIALS AND METHODS

Based on the fiber potency model in Korchevskiy et al. (2019) and the available published information on erionite, the estimated mesothelioma potency factors (the proportion of mesothelioma mortality per unit cumulative exposure (f/cc-year)) for erionites in the western United States were determined.

RESULTS AND DISCUSSION

The model predicted potency factors ranged from 0.19 to 11.25 (average ∼3.5), depending on the region. For reference, crocidolite (the most potent commercial form of asbestos) is assigned a potency factor ∼0.5.

CONCLUSION

The model predicted mesothelioma potency of Turkish erionite (4.53) falls in this same range of potencies as erionite found in North America. Although it can vary by region, a reasonable ratio of average mesothelioma potency based on this model is 3,000:500:100:1 comparing North American erionite, crocidolite, amosite, and chrysotile (from most potent to least potent).

Unlocking The Mysteries of DNA Adducts with Artificial Intelligence

Cellular genome is considered a dynamic blueprint of a cell since it encodes genetic information that gets temporally altered due to various endogenous and exogenous insults. Largely, the extent of genomic dynamicity is controlled by the trade-off between DNA repair processes and the genotoxic potential of the causative agent (genotoxins or potential carcinogens). A subset of genotoxins form DNA adducts by covalently binding to the cellular DNA, triggering structural or functional changes that lead to significant alterations in cellular processes via genetic (e. g., mutations) or non-genetic (e. g., epigenome) routes. Identification, quantification, and characterization of DNA adducts are indispensable for their comprehensive understanding and could expedite the ongoing efforts in predicting carcinogenicity and their mode of action. In this review, we elaborate on using Artificial Intelligence (AI)-based modeling in adducts biology and present multiple computational strategies to gain advancements in decoding DNA adducts. The proposed AI-based strategies encompass predictive modeling for adduct formation via metabolic activation, novel adducts' identification, prediction of biochemical routes for adduct formation, adducts' half-life predictions within biological ecosystems, and, establishing methods to predict the link between adducts chemistry and its location within the genomic DNA. In summary, we discuss some futuristic AI-based approaches in DNA adduct biology.

[Occupational carcinogens and mutagens in Poland - occurrence and workers' exposure in the years 2018-2021 based on the data from Central register of carcinogenic or mutagenic agents]

BACKGROUND

Central register of data on exposure to carcinogenic or mutagenic chemical substances, their mixtures, agents or technological processes (CRCR) conducted by Nofer Institute of Occupational Medicine (NIOM) enables monitoring of such agents occurrence in working environment in Poland. The NIOM conducts CRCR based on the provisions of the Regulation of the Minister of Health of 24 July 2012 on chemical substances, their mixtures, agents or technological processes with carcinogenic or mutagenic effects in the work environment. The work summarizes the information reported to CRCR in 2018-2021.

MATERIAL AND METHODS

The data were extracted from CRCR, to which it was transferred by sanitary inspections. The data were extracted from CRCR. Data in this register is gathered based on employers' notifications to sanitary inspection. The study includes the number of reported agents (chemical substances and technological processes), the number of enterprises and the number of persons exposed to particular groups of agents (chemical substances, technological processes, ionizing radiation).

RESULTS

The number of substances notified to the CRCR increases, from 382 reported substances in 2018 to 444 in 2021. Significant increase in the number of enterprises reporting technological processes (from 981 in 2018 to 5422 in 2021) and the number of exposed persons results from the law amendments extending the list of carcinogenic or mutagenic processes.

CONCLUSIONS

The CRCR is a unique database on the occurrence and exposure to occupational carcinogens and mutagens, in which data from over 20 years has been collected. The increase in the number of reports to the register was mainly influenced by legislative changes regarding carcinogenic or mutagenic agents. Due to amount and complexity of data, they can be used for analysis in projects and programs aimed at raising awareness and reducing risk of occupational exposure to carcinogens and also during legislative works in Poland and in the EU. Med Pr Work Health Saf. 2023;74(5):399-407.

The reignition of the Cancer Moonshot: An opportunity missed?

In relaunching the Cancer Moonshot in 2022, the Biden Administration is seeking to reduce the mortality rate from cancer by at least 50% over the next 25 years. In this Commentary, the authors discuss the history of the federal government’s efforts to reduce the morbidity and mortality of cancer, review the ontogeny of the President’s Cancer Moonshot initiative, and identify the challenges it faces in achieving its goals.

Asbestos exposure and small cell lung cancer: Systematic review and meta-analysis

Asbestos is a mineral that is carcinogenic to humans. Its use has been banned in many occidental countries yet it is still produced in the United States, and materials that contain asbestos remain in many occupational settings and indoor environments. Even though asbestos carcinogenicity is well known, there is scant literature on its specific effects regarding small cell lung cancer (SCLC). We therefore conducted a systematic review and meta-analysis to determine SCLC risk among workers exposed to asbestos. A systematic search of the literature was conducted to identify studies which reported occupational exposure to asbestos and SCLC-related deaths and/or incidence. We identified seven case-control studies that included 3,231 SCLC cases; four studies reported smoking-adjusted risks. A significantly increased risk of SCLC (pooled OR 1.89; 95% CI, 1.25-2.86) was observed on pooling studies on men (six studies) that displayed moderate heterogeneity (I2 = 46.0%). Overall, our synthesis suggests that occupational exposure to asbestos significantly increases the risk of SCLC on men.

Microplastics and leachate materials from pharmaceutical bottle: An in vivo study in Donax faba (Marine Clam)

Most pharmaceuticals are stored in synthetic polymer bottles, manufactured using polyethylene as the base material. The toxicological impact of pharmaceutical container leachate was studied on Donax faba. Several organics and inorganics were identified from the leachate. The concentrations of heavy metals in the leachate was higher than standard reference value for drinking water. In the leachate treatment the protein concentration increased to 8.5% more than the control. The reactive oxygen species (ROS) level elevated by 3 folds and malondialdehyde (MDA) increased by 4.3% in comparison to the control. Superoxide dismutase (SOD) and catalase (CAT) showed a decrease by 14 and 70.5% respectively. The leachate affected the antioxidant machinery of D. faba. Similarly, these PET (polyethylene terephthalate) pharmaceutical containers could potentially leach additives into the drugs and may cause oxidative and metabolic damages to higher organisms including human beings.

Association of multi-criteria derived air toxics hazard score with lung cancer incidence in a major metropolitan area

Background

Lung cancer remains a major health problem world-wide. Environmental exposure to lung cancer carcinogens can affect lung cancer incidence. We investigated the association between lung cancer incidence and an air toxics hazard score of environmental carcinogen exposures derived previously under the exposome concept.

Methods

Lung cancer cases diagnosed in Philadelphia and the surrounding counties between 2008 and 2017 were identified from the Pennsylvania Cancer Registry. Age-adjusted incidence rates at the ZIP code level were calculated based on the residential address at diagnosis. The air toxics hazard score, an aggregate measure for lung cancer carcinogen exposures, was derived using the criteria of toxicity, persistence, and occurrence. Areas with high incidence or hazard score were identified. Spatial autoregressive models were fitted to evaluate the association, with and without adjusting for confounders. Stratified analysis by smoking prevalence was performed to examine potential interactions.

Results

We observed significantly higher age-adjusted incidence rates in ZIP codes that had higher air toxics hazard score values after controlling for demographic variables, smoking prevalence, and proximity to major highways. Analyzes stratified by smoking prevalence suggested that exposure to environmental lung carcinogens had a larger effect on cancer incidence in locations with higher smoking prevalence.

Conclusion

The positive association between the multi-criteria derived air toxics hazard score and lung cancer incidence provides the initial evidence to validate the hazard score as an aggregate measure of carcinogenic exposures in the environment. The hazard score can be used to supplement the existing risk factors in identifying high risk individuals. Communities with higher incidence/hazard score may benefit from greater awareness of lung cancer risk factors and targeted screening programs.

Assessment of Occupational Carcinogenic Risk by Comparing Data from the Italian Register of Occupational Exposures to Carcinogens (SIREP) with the International Agency for Research on Cancer (IARC) Evidence

In Italy, the National Register on Occupational Exposure to Carcinogens (SIREP) is established pursuant to article 243 of Legislative Decree 81/2008 and is aimed to collect information on the exposure of workers to carcinogens transmitted by employers. The aim of this study is to assess its level of implementation comparing prevailing carcinogens reported in SIREP with the monitoring of risks in the workplace evidenced by the International Agency for Research on Cancer (IARC). The data reported in the SIREP have been integrated with IARC and the database on carcinogenic risk in the workplace named MATline in order to build a matrix containing the carcinogens classified according to the IARC (Group 1 and 2A agents) and to a semi-quantitative indicator of risk level (High or Low) calculated upon the number of exposures reported in SIREP. The matrix contains the following data: carcinogens, economic sector (NACE Rev2 coding) and cancer sites. The comparison between SIREP and IARC evidence allowed us to highlight situations with a high risk of carcinogenicity and to address appropriate actions of prevention to contain the risks of exposure to carcinogenic substances.

Assessment of Cadmium (Cd) and Lead (Pb) Blood Concentration on the Risk of Endometrial Cancer

BACKGROUND

Cadmium (Cd) and lead (Pb) are heavy metals with carcinogenic potential. Their increased concentration has been correlated with a risk of malignancies, including breast, lung, kidney, gastrointestinal, and gynecological cancers. Most of the studies have evaluated tissue heavy metal concentration. To the best of our knowledge, this is the first study to evaluate blood Cd and lead levels in different uterine pathologies and the risk of endometrial cancer.

METHODS

This study included 110 patients with a histopathological diagnosis of endometrial cancer, endometrial polyps, endometrial hyperplasia, uterine myoma, and normal endometrium. The patients included in the study were assessed in terms of their endometrial cancer risk factors and blood heavy metal levels. The analysis was conducted using inductively coupled plasma optical emission spectrometry.

RESULTS

There was a significant difference in the Cd and Cd/Pb ratio among the different groups of patients (p = 0.002), with higher a median Cd concentration among the endometrial cancer patients. The differences in Pb concentration were not significant (p = 0.717). There were also no differences in the Cd and Pb concentrations based on the patients' menopausal status nor BMI index. The univariate logistic regression showed a blood cadmium concentration above the median to be associated with an increased risk of endometrial cancer (OR = 5.25; 95% CI 1.56, 17.72). No significant associations were observed between the Pb concentration or Cd/Pb ratio and endometrial cancer risk.

CONCLUSION

The concentration of Cd varies in patients diagnosed with different uterine pathologies. Increased blood cadmium concentration seems to be a risk factor for endometrial studies. Further research on greater populations, accounting for environmental and lifestyle heavy metal exposure, is required to validate our findings.

Inequalities in Environmental Cancer Risk and Carcinogen Exposures: A Scoping Review

Background: Cancer is the leading cause of death in Canada and a major cause of death worldwide. Environmental exposure to carcinogens and environments that may relate to health behaviors are important to examine as they can be modified to lower cancer risks. Built environments include aspects such as transit infrastructure, greenspace, food and tobacco environments, or land use, which may impact how people move, exercise, eat, and live. While environments may play a role in overall cancer risk, exposure to carcinogens or healthier environments is not equitably spread across space. Exposures to carcinogens commonly concentrate among socially and/or economically disadvantaged populations. While many studies have examined inequalities in exposure or cancer risk, this has commonly been for one exposure. Methods: This scoping review collected and synthesized research that examines inequities in carcinogenic environments and exposures. Results: This scoping review found that neighborhoods with higher proportions of low-income residents, racialized people, or same-sex couples had higher exposures to carcinogens and environments that may influence cancer risk. There are currently four main themes in research studying inequitable exposures: air pollution and hazardous substances, tobacco access, food access, and other aspects of the built environment, with most research still focusing on air pollution. Conclusions: More work is needed to understand how exposures to these four areas intersect with other factors to reduce inequities in exposures to support longer-term goals toward cancer prevention.

Occupational Exposures and Risks of Non-Hodgkin Lymphoma: A Meta-Analysis

Non-Hodgkin lymphoma (NHL) is a heterogeneous group with different types of diseases. It remains unclear as to what has led to an increase in incidences of NHL, however, chemical substance exposure is known to be one of the risk factors for the disease. Therefore, we performed a systematic review and meta-analysis including case-control, cohort, and cross-sectional observational epidemiological studies to verify the association between occupational exposure to carcinogens and NHL risk. Articles between the years 2000 and 2020 were collected. Two different reviewers performed a blind selection of the studies using the Rayyan QCRI web app. Post-completion, the selected articles were extracted and analyzed via the RedCap platform. Our review resulted in 2719 articles, of which 51 were included in the meta-analysis, resulting in an overall OR of 1.27 (95% CI 1.04-1.55). Furthermore, it was observed that the main occupation associated with the increased risk of NHL was that in which workers are exposed to pesticides. We therefore conclude that the evidence synthesis of the epidemiological literature supports an increased risk for NHL, regardless of subtype, considering occupational exposure to certain chemical compounds, mainly pesticides, benzene, and trichlorethylene, and certain classes of work, primarily in the field of agriculture.

Identifying Toxic Consumer Products: A Novel Data Set Reveals Air Emissions of Potent Carcinogens, Reproductive Toxicants, and Developmental Toxicants

Consumer products are important sources of exposure to harmful chemicals. Product composition is often a mystery to users, however, due to gaps in the laws governing ingredient disclosure. A unique data set that the California Air Resources Board (CARB) uses to determine how volatile organic chemicals (VOCs) from consumer products affect smog formation holds a partial solution. By analyzing CARB data on VOCs in consumer products, we identified and quantified emissions of volatile chemicals regulated under the California Safe Drinking Water and Toxic Enforcement Act ("Prop 65"). We here highlight individual chemicals as well as consumer product categories that people are likely to be exposed to as individual consumers, in the workplace, and at the population level. Of the 33 Prop 65-listed chemicals that appear in the CARB emissions inventory, we classified 18 as "top tier priorities for elimination". Among these, methylene chloride and N-methyl-2-pyrrolidone were most prevalent in products across all three population groups. Of 172 consumer product categories, 105 contained Prop 65-listed chemicals. Although these chemicals are known carcinogens and reproductive/developmental toxicants, they remain in widespread use. Manufacturers and regulators should prioritize product categories containing Prop 65-listed chemicals for reformulation or redesign to reduce human exposures and associated health risks.

Data-Driven Quantitative Structure-Activity Relationship Modeling for Human Carcinogenicity by Chronic Oral Exposure

Traditional methodologies for assessing chemical toxicity are expensive and time-consuming. Computational modeling approaches have emerged as low-cost alternatives, especially those used to develop quantitative structure-activity relationship (QSAR) models. However, conventional QSAR models have limited training data, leading to low predictivity for new compounds. We developed a data-driven modeling approach for constructing carcinogenicity-related models and used these models to identify potential new human carcinogens. To this goal, we used a probe carcinogen dataset from the US Environmental Protection Agency's Integrated Risk Information System (IRIS) to identify relevant PubChem bioassays. Responses of 25 PubChem assays were significantly relevant to carcinogenicity. Eight assays inferred carcinogenicity predictivity and were selected for QSAR model training. Using 5 machine learning algorithms and 3 types of chemical fingerprints, 15 QSAR models were developed for each PubChem assay dataset. These models showed acceptable predictivity during 5-fold cross-validation (average CCR = 0.71). Using our QSAR models, we can correctly predict and rank 342 IRIS compounds' carcinogenic potentials (PPV = 0.72). The models predicted potential new carcinogens, which were validated by a literature search. This study portends an automated technique that can be applied to prioritize potential toxicants using validated QSAR models based on extensive training sets from public data resources.

Thermal Contaminants in Coffee Induced by Roasting: A Review

Roasting is responsible for imparting the main characteristics to coffee, but the high temperatures used in the process can lead to the formation of several potentially toxic substances. Among them, polycyclic aromatic hydrocarbons, acrylamide, furan and its derivative compounds, α-dicarbonyls and advanced glycation end products, 4-methylimidazole, and chloropropanols stand out. The objective of this review is to present a current and comprehensive overview of the chemical contaminants formed during coffee roasting, including a discussion of mitigation strategies reported in the literature to decrease the concentration of these toxicants. Although the formation of the contaminants occurs during the roasting step, knowledge of the coffee production chain as a whole is important to understand the main variables that will impact their concentrations in the different coffee products. The precursors and routes of formation are generally different for each contaminant, and the formed concentrations can be quite high for some substances. In addition, the study highlights several mitigation strategies related to decreasing the concentration of precursors, modifying process conditions and eliminating/degrading the formed contaminant. Many of these strategies show promising results, but there are still challenges to be overcome, since little information is available about advantages and disadvantages in relation to aspects such as costs, potential for application on an industrial scale and impacts on sensory properties.

Trihalomethane Cancer Risk Assessment for Private and Shared Residences: Addressing the Differences in Inhalation Exposure

The multi-pathway cancer risk (CR) assessment of trihalomethanes (THM) involves considering exposure via ingestion, dermal contact, and inhalation. Inhalation occurs during showering due to the volatilization of THMs from chlorinated water to the air. When assessing inhalation risks, exposure models commonly assume that the initial THM concentration in the shower room is zero. However, this assumption is only valid in private shower rooms where single or infrequent showering events take place. It fails to account for continuous or successive showering events in shared showering facilities. To address this issue, we incorporated the accumulation of THM in the shower room air. We studied a community (population ≈ 20,000) comprising two types of residences with the same water supply: population A with private shower rooms, and population B with communal shower stalls. The total THM concentration in the water was 30.22 ± 14.45 µg L^-1. For population A, the total CR was 58.5 × 10^-6, including an inhalation risk of 1.11 × 10^-6. However, for population B, the accumulation of THM in the shower stall air resulted in increased inhalation risk. By the tenth showering event, the inhalation risk was 2.2 × 10^-6, and the equivalent total CR was 59.64 × 10^-6. We found that the CR significantly increased with increasing shower duration. Nevertheless, introducing a ventilation rate of 5 L s^-1 in the shower stall reduced the inhalation CR from 1.2 × 10^-6 to 7.9 × 10^-7.

Potential Carcinogens in Makeup Cosmetics

Facial makeup cosmetics are commonly used products that are applied to the skin, and their ingredients come into contact with it for many years. Consequently, they should only contain substances that are considered safe or used within an allowable range of established concentrations. According to current European laws, all cosmetics approved for use should be entirely safe for their users, and the responsibility for this lies with manufacturers, distributors, and importers. However, the use of cosmetics can be associated with undesirable effects due to the presence of certain chemical substances. An analysis of 50 random facial makeup cosmetics commercially available on the European Union market and manufactured in six European countries was carried out, concerning the presence of substances with potential carcinogenic properties, as described in recent years in the literature. Nine types of facial makeup cosmetics were selected, and their compositions, as declared on the labels, were analyzed. The carcinogens were identified with information present in the European CosIng database and according to the Insecticide Resistance Action Committee's (IRAC) classification. As a result, the following potential carcinogens were identified: parabens (methylparaben, propylparaben, butylparaben, and ethylparaben), ethoxylated compounds (laureth-4, lautreth-7, or ethylene glycol polymers known as PEG), formaldehyde donors (imidazolidinyl urea, quaternium 15, and DMDM hydantoin), and ethanolamine and their derivatives (triethanolamine and diazolidinyl urea), as well as carbon and silica. In conclusion, all of the analyzed face makeup cosmetics contain potential carcinogenic substances. The literature review confirmed the suppositions regarding the potential carcinogenic effects of selected cosmetic ingredients. Therefore, it seems necessary to carry out studies on the long-term exposure of compounds present in cosmetics and perhaps introduce stricter standards and laws regulating the potential presence of carcinogens and their activity in cosmetics.

Concentrations of polycyclic aromatic hydrocarbons in Vietnamese takeaway coffee: effects of coffee variety, roasting temperature and time

The research goal was to estimate the level of risk to human health posed by polycyclic aromatic hydrocarbons (PAHs) in Vietnamese takeaway coffee. A variety of roasted coffee beans were collected and tested for the presence of PAHs in various takeaway locations throughout Vietnam. Furthermore, the effect of roasting conditions on PAH concentrations in Vietnamese Robusta coffee was also studied and demonstrated. Gas chromatography-mass spectrometry, a modern, accurate, and fast method, was used to determine the research results. Six PAHs, namely naphthalene, anthracene, pyrene, fluorene, phenanthrene, and benz[a]anthracene, were found in the 100 collected samples, with average concentrations (μg/kg dry weight) of 943.7 ± 40.3, 195.1 ± 4.9, 36.1 ± 1.1, 33.3 ± 2.2, 28.2 ± 1.7, and 2.0 ± 0.1, respectively. It was found that the tested samples were almost free of PAH4 contamination. The research showed that the total value of PAH quantifications in Robusta coffee increased with increasing roasting temperature and decreased with increasing roasting time. In addition, the calculated value of the total hazard quotient (THQ) was less than 1, and the obtained value of the incremental lifetime carcinogenic risk (ILCR) did not exceed 1·10^-5, meaning that coffee consumers in Vietnam are safe from exposure to PAHs present in the investigated coffee beans.

Use of the benchmark-dose (BMD) approach to derive occupational exposure limits (OELs) for genotoxic carcinogens: N-nitrosamines

N-Nitrosamines are potent carcinogens and considered non-threshold carcinogens in various regulatory domains. However, recent data indicate the existence of a threshold for genotoxicity, which can be adequately demonstrated. This aspect has a critical impact on selecting the methodology that is applied to derive occupational exposure limits (OELs). OELs are used to protect workers potentially exposed to various chemicals by supporting the selection of appropriate control measures and ultimately reducing the risk of occupational cancer. Occupational exposures to nitrosamines occur during manufacturing processes, mainly in the rubber and chemical industry. The present study derives OELs for inhaled N-nitrosamines, employing the benchmark dose (BMD) approach if data are adequate and read-across for nitrosamines without adequate data. Additionally, benchmark dose lower confidence limit (BMDL) is preferred and more suitable point-of-departure (PoD) to calculate human health guidance values, including OEL. The lowest OEL (0.2 μg/m³ ) was derived for nitrosodiethylamine (NDEA), and nitrosopiperidine (NPIP) (OEL = 0.2 μg/m³ ), followed by nitrosopyrrolidine (NPYR) (0.4 μg/m³ ), nitrosodimethylamine (NDMA), nitrosodimethylamine (NMEA), and nitrosodipropylamine (NDPA) (0.5 μg/m³ ), nitrosomorpholine (NMOR) (OEL = 1 μg/m³ ), and nitrosodibutylamine (NDBA) (OEL = 2.5 μg/m³ ). Limits based on "non-threshold" TD50 slope calculation were within a 10-fold range. These proposed OELs do not consider skin absorption of nitrosamines, which is also a possible route of entry into the body, nor oral or other environmental sources. Furthermore, we recommend setting a limit for total nitrosamines based on the occupational exposure scenario and potency of components.

Switching to cigarette brand variants with different filter ventilation levels: a descriptive analysis

BACKGROUND

Regulation of filter ventilation (FV) has been proposed to reduce misperceptions that ventilation reduces the health risks of smoking. We describe smoking behaviour and exposure after switching to a cigarette brand variant (CBV) with a different FV level.

METHODS

Wave 1 (2013-2014) of the Population Assessment of Tobacco Use and Health Study was merged with FV levels of participants' CBV and restricted to adults with a usual CBV, smoked daily and included in wave 4 (2016-2017; n=371). Generalised estimation equations method modelled changes in FV and cigarettes per day (CPD), quit interest, total nicotine equivalents (TNE) and total NNAL (biomarker of a tobacco-specific carcinogen). FV change was defined as a change in CBV resulting in a ≥20% increase or decrease in FV. Secondary analyses used FV change based on an increase from <5% to >10% or a decrease from >10% to <5%.

RESULTS

A non-significant pattern indicating an increase of 0.97 and 0.49 CPD was observed among those who switched to a CBV and increased FV by ≥20% and from <5% to >10%, respectively. A non-significant pattern indicating a decrease of 1.31 and 1.97 CPD was observed among those who decreased FV by ≥20% and from >10% to <5%, respectively. Changes in quit interest and biomarkers were also non-significant with one exception: greater reduction in TNE among those who decreased from >10% to <5% FV versus no change (-8.51 vs -0.25 nmol/mg creatinine; p=0.0447).

CONCLUSIONS

Switching to CBV with lower FV does not appear to increase exposure and may even reduce exposure for some. Additional investigations are recommended to confirm these descriptive findings.

Arsenic in drinking water, hair, and prevalence of arsenicosis in Perak, Malaysia

Arsenic is a carcinogen element that occurs naturally in our environment. Humans can be exposed to arsenic through ingestion, inhalation, and dermal absorption. However, the most significant exposure pathway is via oral ingestion. Therefore, a comparative cross-sectional study was conducted to determine the local arsenic concentration in drinking water and hair. Then, the prevalence of arsenicosis was evaluated to assess the presence of the disease in the community. The study was conducted in two villages, namely Village AG and Village P, in Perak, Malaysia. Socio-demographic data, water consumption patterns, medical history, and signs and symptoms of arsenic poisoning were obtained using questionnaires. In addition, physical examinations by medical doctors were performed to confirm the signs reported by the respondents. A total of 395 drinking water samples and 639 hair samples were collected from both villages. The samples were analyzed using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) to determine arsenic concentration. The results showed that 41% of water samples from Village AG contained arsenic concentrations of more than 0.01 mg/L. In contrast, none of the water samples from Village P exceeded this level. Whilst, for hair samples, 85 (13.5%) of total respondents had arsenic levels above 1 μg/g. A total of 18 respondents in Village AG had at least one sign of arsenicosis and hair arsenic levels of more than 1 μg/g. Factors significantly associated with increased arsenic levels in hair were female, increasing age, living in Village AG and smoking. The prevalence of arsenicosis in the exposed village indicates chronic arsenic exposure, and immediate mitigation action needs to be taken to ensure the wellbeing of the residents in the exposed village.

High Levels of the Carcinogenic Tobacco-Specific Nitrosamine NNAL and Associated Findings in Children of Smokers: A Case Series

High levels of NNAL, the tobacco smoke exposure (TSE) biomarker of the carcinogen 4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), indicate future cancer risk. A prior study of smokers’ children revealed NNAL levels as high as active smokers. Therefore, we conducted a case series to examine the sociodemographics, TSE and clinical patterns, and other TSE biomarker levels in 9 children with extreme NNAL levels of >200 pg/ml to generate hypotheses and explore potential causes and implications. We identified 0 to 4-year-olds who presented to an emergency setting and lived with ⩾1 smoker who were part of a parental tobacco cessation trial (n = 461). Of these children, 52 had urinary NNAL, cotinine, and N-oxides results (n = 52). Nine children (17.3%) had NNAL levels >200 pg/ml, ranging from 206.4 to 1399.0 pg/ml (Median (Mdn) = 489.2 pg/ml; Interquartile Range (IQR) = 222.7-1289.3 pg/ml). The cotinine Mdn (IQR) was 38.5 (10.3-102.2) ng/ml and the N-oxides Mdn (IQR) = 93.8 (24.7-109.6) pg/ml. While all biomarker levels were alarmingly high, these young children would not have been flagged for very high cancer risk based on urinary cotinine levels alone. This underscores the critical role of comprehensive TSE biomarker measurement in capturing different TSE exposure patterns and assessing children’s future risk for cancer and other TSE-related morbidities.

Relationship between low serum IgE levels and malignancies in 9/11 World Trade Center responders

BACKGROUND

Individuals with very low immunoglobulin E-(IgE)-levels have a high risk of developing malignancy. Previous studies have shown that World Trade Center (WTC)-responders exposed to carcinogens have an elevated risk of some cancers.

OBJECTIVE

To evaluate the association between low-serum IgE levels and cancer development in WTC-exposed-responders.

METHODS

IgE-levels were measured in 1,851 WTC-responders after 9/11/2001. This is the first pilot study in humans comparing the odds of developing cancer in this high-risk population, between the "low-IgE" (IgE in the lowest 3 rd percentile) versus "non-low IgE" participants.

RESULTS

A significantly higher proportion of hematologic malignancies was found in low-IgE (4/55, 7.3%) compared with non-low IgE (26/1,796, 1.5%, p<0.01) responders. The proportion of solid tumors were similar in both groups (5.5% vs 11.4%, p>0.05). After adjustment for relevant confounders (race, sex, age at blood draw, WTC-arrival time, smoking status), the low-IgE-participants had 7.81 times greater odds (95% CI=1.77-29.35) of developing hematologic cancer when compared with non-low-IgE-participants. The hematologic cancers found in this cohort were leukemia (n=1), multiple myeloma (n=1) and lymphoma (n=2). No statistical significance was found when estimating the odds-ratio for solid tumors in relation to IgE levels.

CONCLUSION

WTC-responders with low serum IgE levels had the highest odds of developing hematologic malignancies. This hypothesis-generating study suggests that low serum IgE levels might be associated with the development of specific malignancies in at-risk individuals exposed to carcinogens. Larger, multicenter studies with adequate follow up of individuals with different IgE levels are needed to better evaluate this relationship.

Concept for the Evaluation of Carcinogenic Substances in Population-Based Human Biomonitoring

The Human Biomonitoring (HBM) Commission at the German Environment Agency holds the opinion that for environmental carcinogens for which no exposure levels can be assumed and are harmless to health, health-based guidance values corresponding to the classical definition of the HBM-I or HBM-II value cannot be established. Therefore, only reference values have been derived so far for genotoxic carcinogens from exposure data of the general population or subpopulations. The concept presented here opens up the possibility of performing health risk assessments of carcinogenic substances in human biomonitoring, and thus goes decisively beyond the purely descriptive statistical reference value concept. Using the presented method, quantitative dose descriptors of internal exposure can be derived from those of external exposure, provided that sufficient toxicokinetic information is available. Dose descriptors of internal exposure then allow the simple estimate of additional lifetime cancer risks for measured biomarker concentrations or, conversely, of equivalent concentrations for selected risks, such as those considered as tolerable for the general population. HBM data of chronic exposures to genotoxic carcinogens can thus be used to assess the additional lifetime cancer risk referring to the general population and to justify and prioritize risk management measures.

Opium, street opium and cancer risk

Opium is defined as the air-dried latex obtained by incision from the unripe capsules of Papaver somniferum L. Opium is a complex mixture that contains approximately 10% morphine and 2% codeine. It is commonly used to prepare opium tinctures for people with chronic diarrhea. Morphine and related opioids are powerful but highly addictive analgesics; designing less addictive opioids is an active area of pharmaceutical research that may lead to significant improvements in chronic pain management. Recently, the International Agency for Research on Cancer (IARC) classified opium consumption as carcinogenic to humans (Group 1) based on sufficient evidence of carcinogenicity in human studies. However, all human studies analyzed by the IARC Working Group included participants who consumed opium that was mixed, adulterated, and/or contaminated with known and probable human carcinogens (e.g., tarry residues of combusted opium, arsenic, lead, and chromium). The Working Group considered that these carcinogens were part of the complex mixture that opium is, rather than co-exposure or confounders. No evidence of carcinogenicity was available for pure opium in human, animal, or mechanistic studies. To avoid confusion and concern in health professionals and patients using medicinal opium preparations, and in scientists involved in the design and development of new opium derivatives, opium should be classified in Group 3 (not classifiable as to its carcinogenicity to humans). The term 'street opium' could be used to refer to opium that probably contains human carcinogens not present in pure opium, and should remain in Group 1 (carcinogenic to humans).

Epidemiological Study of Risk Factors for Lung Cancer in KwaZulu-Natal, South Africa

The high incidence cancer rates are due to factors such as behavior, occupational exposures, genetics, environmental pollution and infections. The aim of this study was to identify risk factors associated with lung cancer among patients seen in the public health facilities in KwaZulu-Natal, South Africa. In this case-control study, 75 cases and 159 controls were interviewed using a structured close-ended questionnaire. Logistic regression showed a positive association between lung cancer and tobacco smoking (OR = 2.86, 95% CI: 1.21-6.77) and exposure to passive smoke (OR = 3.28, 95% CI: 1.48-7.30). When adjusted for other covariates, tobacco smoking and passive smoke were still positively associated with increased risk of lung cancer. Alcohol consumption (aORs ranging from 2.79 to 3.35) and history of lung disease (aORs ranging from 9.91 to 12.1) were statistically significantly associated with lung cancer. Our study suggests that tobacco smoke exposure is the major cause of lung cancer, and increased exposure to occupational and environmental carcinogenic substances, alcohol consumption and history of lung disease increase the risk of lung cancer. Based on our findings, policy development and planning of prevention strategies incorporating smoking legislations, occupational health and safety are essential in South Africa.

Screening-level assessment of cancer risk associated with ambient air exposure in Aamjiwnaang First Nation

The manuscript reports findings from a screening-level assessment of cancer risk from outdoor air in Aamjiwnaang First Nation. Ambient air pollution can contribute to cardiovascular/respiratory diseases, and certain types of cancer. Certain communities may be at higher risk to the negative health impacts due to their geographical proximity to pollution sources. Outdoor air concentrations were mapped and the Lifetime Excess Cancer Risks (LECR) associated with long-term exposure to known carcinogens were estimated. LECR results for both benzene and 1,3-butadiene were above one per million. The LECR for benzene was 6.4 per million when the Health Canada slope factor was applied and 12.0 when using the US EPA. For 1,3-butadiene the LECR estimate was 8.8 per million. This work provides a better understanding of environmental exposures and potential associated cancer risks for residents in the Aamjiwnaang community and highlights the need for further air monitoring and a more detailed risk assessment.

Role of the Synergistic Interactions of Environmental Pollutants in the Development of Cancer

There is a growing awareness that the large number of environmental pollutants we are exposed to on a daily basis are causing major health problems. Compared to traditional studies that focus on individual pollutants, there are relatively few studies on how pollutants mixtures interact. Several studies have reported a relationship between environmental pollutants and the development of cancer, even when pollutant levels are below toxicity reference values. The possibility of synergistic interactions between different pollutants could explain how even low concentrations can cause major health problems. These intricate that molecular interactions can occur through a wide variety of mechanisms, and our understanding of the physiological effects of mixtures is still limited. The purpose of this paper is to discuss recent reports that address possible synergistic interactions between different types of environmental pollutants that could promote cancer development. Our literature studies suggest that key biological pathways are frequently implicated in such processes. These include increased production of reactive oxygen species, activation by cytochrome P450, and aryl hydrocarbon receptor signaling, among others. We discuss the need to understand individual pathological vulnerability not only in relation to basic genetics and gene expression, but also in terms of measurable exposure to contaminants. We also mention the need for significant improvements in future studies using a multitude of disciplines, such as the development of high-throughput study models, better tools for quantifying pollutants in cancer patients, innovative pharmacological and toxicological studies, and high-efficiency computer analysis, which allow us to analyze the molecular mechanisms of mixtures.

Oral carcinogenesis triggers a nociceptive behavior and c-Fos expression in rats' trigeminal pathway

OBJECTIVE

To recognize changes that occur along the trigeminal pathway in oral cancer in order to establish an effective approach to pain control.

METHODS

Wistar rats were divided into control and 4-NQO-groups for 8, 12, 16, or 20 weeks. 4-NQO suspension was administered on the animals` tongues. Mechanical hyperalgesia, assessment of facial expressions and an open field test were performed. After euthanasia, the animals' tongues were removed for macro and microscopic analysis. c-Fos expression was analyzed in the trigeminal pathway structures.

RESULTS

4-NQO induced time-dependent macroscopic lesions that were compatible with neoplastic tumors. Histopathological analysis confirmed oral squamous cell carcinoma in 50% of the animals on the 20th week. There was a significant nociceptive threshold reduction during the first two weeks, followed by a threshold return to the baseline levels, decreasing again from the 12th week. Facial nociceptive expression scores were observed on the 20th week, while increased grooming and exploratory activity were observed on the 8th week. Trigeminal ganglion showed an increased c-Fos immunoexpression on the 20th week and in the trigeminal subnucleus caudalis, it occurred on the 16th and 20th. The long-term carcinogenic exposure caused changes in the nociceptive behavior and c-Fos expression in the rats' trigeminal pathway.

An Observational Cross-Sectional Study on Cancer Awareness and Beliefs about Carcinogens among Saudi Women

Public knowledge about the risk factors of cancer is essential to ensure an effective prevention program. This study aims to explore the knowledge of the general Saudi population about cancer and carcinogens and to determine the misconceptions about carcinogens to help create appropriate evidence-based prevention awareness programs. A questionnaire of 63 questions related to biographic data, source of knowledge, risk factors, and the burden of cancer was distributed online. The internet was the most sought source for cancer-related information (75.2%). The inclusion of cancer-related subjects in the educational curriculum was believed to be the best way to educate children about cancer (48.4%). Knowledge about cancer risk factors was good overall for 10 out of the 27 risk factors assessed in the study, with cigarette smoking being the most well-known risk factor (91.5%), followed by hookah smoking (85.6%), and nuclear waste exposure (80%). However, only 16.3% of participants were aware of the risk associated with Oral Contraceptive Pills (OCPs), and less than half of the participants knew the risk associated with poor physical activity. About 45% (44.9%) believed that envy and spiritual causes are associated with cancer. Most of the study participants (70%) considered cancer to be a significant health issue in Saudi, mainly due to the increasing incidence rate (44%). Conclusion: This study showed a good level of awareness regarding cancer risk factors and environmental carcinogens, which could serve as a roadmap for future awareness programs and studies targeted at the knowledge of other risk factors for cancer.

A tipping point in cancer epidemiology: embracing a life course exposomic framework

The pathogenesis of multifactorial malignant diseases, with variable onset, severity, and natural history, reflects development-specific exposures and individual responses to these exposures influenced by underlying genetic predisposition. Embedded in life course theory, exposomics provides a framework to more fully elucidate how environmental factors alter cancer risk, disease course, and response to treatment across the lifespan.

Using Collaborative Partnerships to Engage Firefighters in Rural Communities

The purpose of this study was to utilize community-based participatory research (CBPR) methods to identify behaviors that may increase the exposure rates of firefighters to carcinogens and other occupational hazards. Key informant interviews and focus groups were conducted as part of a larger study that included exposure assessments at fire stations, in fire engines, and in personal vehicles. A purposive sample of five fire chiefs and leaders of the firefighter association was chosen, and these individuals were selected to participate in interviews. Unstructured interviews explored issues related to firefighter exposures and occupational hazards. Three focus groups were conducted over a three-month period. Following the focus groups, survey questions emphasizing the following three aspects of firefighting were developed: exposure to airborne smoke contaminants during fire suppression, accumulated exposure on turnout gear after fire suppression, and exposure to airborne contaminants at the fire departments. The use of community-based participatory research can be very beneficial, especially when conducting research with a group that may be hard to reach or have misgivings regarding researchers. By utilizing this approach in the current study, researchers were able to partner with a community that may be hard to reach and gain buy-in from community leadership.

Rare Occurrence of Aristolochic Acid Mutational Signatures in Oro-Gastrointestinal Tract Cancers

BACKGROUND

Aristolochic acids (AAs) are potent mutagens commonly found in herbal plant-based remedies widely used throughout Asian countries.

PATIENTS AND METHODS

To understand whether AA is involved in the tumorigenesis of the oro-gastrointestinal tract, we used whole-exome sequencing to profile 54 cases of four distinct types of oro-gastrointestinal tract cancer (OGITC) from Taiwan.

RESULTS

A diverse landscape of mutational signatures including those from DNA mismatch repair and reactive oxygen species was observed. APOBEC mutational signatures were observed in 60% of oral squamous cell carcinomas. Only one sample harbored AA mutational signatures, contradictory to prior reports of cancers from Taiwan. The metabolism of AA in the liver and urinary tract, transient exposure time, and high cell turnover rates at OGITC sites may explain our findings.

CONCLUSION

AA signatures in OGITCs are rare and unlikely to be a major contributing factor in oro-gastrointestinal tract tumorigenesis.

Spatiotemporal Distribution and Analysis of Organophosphate Flame Retardants in the Environmental Systems: A Review

In recent times, there has been a cumulative apprehension regarding organophosphate flame retardants (OPFRs) owing to their high manufacturing and usage after brominated flame retardants were strictly regulated and banned from being distributed and used in many countries. OPFRs are known as the main organic pollutants in the terrestrial and aquatic environment. They are very dangerous to humans, plants and animals. They are also carcinogenic and some have been implicated in neurodevelopmental and fertility challenges. OPFRs are distributed into the environment through a number of processes, including the usage, improper disposal and production of materials. The solid phase extraction (SPE) method is suggested for the extraction of OPFRs from water samples since it provides high quality recoveries ranging from 67% to 105% and relative standard deviations (RSDs) below 20%. In the same vein, microwave-assisted extraction (MAE) is highly advocated for the extraction of OPFRs from sediment/soil. Recoveries in the range of 78% to 105% and RSDs ranging from 3% to 8% have been reported. Hence, it is a faster method of extraction for solid samples and only demands a reduced amount of solvent, unlike other methods. The extract of OPFRs from various matrices is then followed by a clean-up of the extract using a silica gel packed column followed by the quantification of compounds by gas chromatography coupled with a mass spectrometer (GC–MS) or a flame ionization detector (GC-FID). In this paper, different analytical methods for the evaluation of OPFRs in different environmental samples are reviewed. The effects and toxicities of these contaminants on humans and other organisms are also discussed.

Assessing Long Non-coding RNAs in Tobacco-associated Oral Cancer

Cancer is one of the compelling and pegged diseases battled by clinicians and researchers worldwide. Among different types of cancer, oral cancer holds the sixth position globally. With an escalating prevalence in Asian countries, India, China, and Pakistan constitute a large proportion of total incidents of oral cancer patients in terms of new cases or deaths. This mounting prevalence is ascribed to poor oral hygiene and rampant use of substances earmarked as potential risk factors for the disease. Risk factors (dietary/lifestyle habits/occupational/environmental) trigger the activation of oncogenes, dysregulation of lncRNA and miRNA, and silence the tumor suppressor genes, which robustly contributes to the onset and progression of tumorigenesis in oral squamous cell carcinoma. Evidence suggests that specific carcinogens identified in tobacco and related products alter many cellular pathways predisposing to advanced stages of oral cancer. Long non-coding RNAs represent a broad group of heterogenous transcripts longer than 200 nucleotides which do not translate to form functional proteins. They regulate various cellular pathways by specifically interacting with other RNAs, DNA, and proteins. Their role in the pathogenesis of OSCC and other cancer is still being debated. In this review, we discuss the molecular insights of significant lncRNAs involved in some crucial deregulated pathways of tobacco-associated OSCC. The implications and challenges to harnessing the potential of lncRNAs as biomarkers in early diagnosis and targeted treatment have also been analyzed.

Chemical characteristics and cancer risk assessment of smokeless tobacco used in Tunisia (neffa)

Introduction

neffa, a form of air-dried smokeless tobacco used in North Africa, is spuriously perceived as a lower risk alternative to smoking. The objective of this study was to provide information on some harmful constituents of neffa and to use them for cancer risk assessment.

Methods

a high-performance liquid chromatography method coupled with fluorescence detector was used to determine polycyclic aromatic hydrocarbons (PAHs) in one sample of neffa. An atomic absorption spectrometry was performed to determine the concentrations of lead and cadmium in three samples of neffa. The levels of toxicants found in neffa were used to assess for lifetime cancer risk as advocated by the US Environment Protection Agency.

Results

the determination of PAHs in neffa allowed the identification of phenanthrene and anthracene. However, the higher molecular weight PAHs such as Benzo(a)Pyrene B(a)P were not detected. The concentrations of cadmium and lead varied between 1.3 to 2.8µg/g and 1.7 to 4.6µg/g respectively. Cancer risk for cadmium and lead varied between 4.2E-03 to 9.3E-03 and 2.5E-06 to 6.4E-06 respectively. Cancer risk for Cd exceeded the range of 10E-04 to 10E-06 of an acceptable risk.

Conclusion

neffa is not a healthy alternative for overcoming smoking addiction. It contains mineral and organic pulmonary toxicants. This study could serve as a scientific basis to inform consumers about the products´ toxicity and help them to quit smokeless tobacco (SLT) use.

Integration of Epigenetic Mechanisms into Non-Genotoxic Carcinogenicity Hazard Assessment: Focus on DNA Methylation and Histone Modifications

Epigenetics involves a series of mechanisms that entail histone and DNA covalent modifications and non-coding RNAs, and that collectively contribute to programing cell functions and differentiation. Epigenetic anomalies and DNA mutations are co-drivers of cellular dysfunctions, including carcinogenesis. Alterations of the epigenetic system occur in cancers whether the initial carcinogenic events are from genotoxic (GTxC) or non-genotoxic (NGTxC) carcinogens. NGTxC are not inherently DNA reactive, they do not have a unifying mode of action and as yet there are no regulatory test guidelines addressing mechanisms of NGTxC. To fil this gap, the Test Guideline Programme of the Organisation for Economic Cooperation and Development is developing a framework for an integrated approach for the testing and assessment (IATA) of NGTxC and is considering assays that address key events of cancer hallmarks. Here, with the intent of better understanding the applicability of epigenetic assays in chemical carcinogenicity assessment, we focus on DNA methylation and histone modifications and review: (1) epigenetic mechanisms contributing to carcinogenesis, (2) epigenetic mechanisms altered following exposure to arsenic, nickel, or phenobarbital in order to identify common carcinogen-specific mechanisms, (3) characteristics of a series of epigenetic assay types, and (4) epigenetic assay validation needs in the context of chemical hazard assessment. As a key component of numerous NGTxC mechanisms of action, epigenetic assays included in IATA assay combinations can contribute to improved chemical carcinogen identification for the better protection of public health.

Post-9/11 excess risk of thyroid cancer: Surveillance or exposure?

An excess risk of thyroid cancer has been reported in different World Trade Center (WTC)-dust exposed cohorts. Increased surveillance of these cohorts has been suggested as a potential explanation of this reported excess thyroid cancer risk leading to an increased diagnosis of earlier-stage thyroid cancers. However, the uncertainty to what extent surveillance or physician bias may be contributing to the reported incidence of thyroid cancer in WTC-dust exposed populations remains, highlighting the need to investigate a potential causal link between WTC dust exposure and thyroid cancer. Future studies are therefore indicated to investigate potential consequences of WTC dust exposure on the thyroid gland. Studies of the heavily exposed populations offer the possibility to better understand the mechanisms behind the exposure to a variety of environmental contaminants, and may provide useful insights into exposures harmful to the thyroid. These can be used in risk stratification when implementing screening in high-risk populations and may inform shared decision-making regarding the extent of thyroid cancer treatment.

The Role of Microbiota in the Development of Cancer Tumour Cells and Lymphoma of B and T Cells

Human body harbours enormous numbers of microbial organisms, including bacteria, viruses, and fungi which have a momentous role in well-being and illness in humans. Immune system shelters us from pathogenic bacteria, microorganisms found in human tissues have many benefits related to the functional movement of the host by regulating important procedures such as immunity, signalling, and breakdown. Lymphocytes assume a significant part in the reaction to bacterial colonization, primarily by prompting a safe reaction to obstruction or initiation. Most immunologically occupant cells have a place with the mucosal invulnerable framework and are continually motioned by dendritic cells or other Antigen introducing cells that gather intestinal samples. Thus, Microbiome is a key contributor to developing lymphoma and specific alterations to microbiome composition could attenuate the risk. There is an indication that microbial morphology can affect and control humanoids. The difference in the composition of these microorganisms is associated with tumour development. With the increased knowledge of the connection among the human microbiome and carcinogenesis, the use of these findings to prevent, predict or diagnose of lymphomas has attracted a great attention. In this article, we explored current knowledge of various microbial ecosystems, their connection with carcinogens and the potential for useful microorganisms to control and prevent B and T cell lymphoma.

Human Hazard Assessment Using Drosophila Wing Spot Test as an Alternative In Vivo Model for Genotoxicity Testing-A Review

Genomic instability, one of cancer's hallmarks, is induced by genotoxins from endogenous and exogenous sources, including reactive oxygen species (ROS), diet, and environmental pollutants. A sensitive in vivo genotoxicity test is required for the identification of human hazards to reduce the potential health risk. The somatic mutation and recombination test (SMART) or wing spot test is a genotoxicity assay involving Drosophila melanogaster (fruit fly) as a classical, alternative human model. This review describes the principle of the SMART assay in conjunction with its advantages and disadvantages and discusses applications of the assay covering all segments of health-related industries, including food, dietary supplements, drug industries, pesticides, and herbicides, as well as nanoparticles. Chemopreventive strategies are outlined as a global health trend for the anti-genotoxicity of interesting herbal extract compounds determined by SMART assay. The successful application of Drosophila for high-throughput screening of mutagens is also discussed as a future perspective.

Electronic cigarette aerosol increases the risk of organ dysfunction by enhancing oxidative stress and inflammation

An electronic cigarette is a rechargeable device that produces an inhaled aerosol containing varying levels of nicotine, and inorganic and organic toxicants and carcinogenic compounds. The aerosol is generated by heating a solution of propylene glycol and glycerin with nicotine and flavoring ingredients at a high temperature. The e-cigarette was developed and marketed as a safer alternative to the regular cigarette which is known to be injurious to human health. However, published studies suggest that the aerosol of e-cigarette can also have adverse health effects. The main objective of this review is to briefly describe some consequences of e-cigarette smoking, and to present data showing that the resulting increased oxidative stress and inflammation are likely to be involved in effecting to lung damage. Other organs are also likely to be affected. The aerosol contains varying amounts of organic and inorganic toxicants as well as carcinogens, which might serve as the source of such deleterious events. In addition, the aerosol also contains nicotine, which is known to be addictive. E-cigarette smoking releases these toxicants into the air leading to inhalation by nonsmokers in residential or work place areas. Unlike regular tobacco smoke, the long-term consequences of direct and secondhand exposure to e-cigarette aerosol have not been extensively studied but based on available data, e-cigarette aerosol should be considered harmful to human health.

Applicability of Scrape Loading-Dye Transfer Assay for Non-Genotoxic Carcinogen Testing

Dysregulation of gap junction intercellular communication (GJIC) is recognized as one of the key hallmarks for identifying non-genotoxic carcinogens (NGTxC). Currently, there is a demand for in vitro assays addressing the gap junction hallmark, which would have the potential to eventually become an integral part of an integrated approach to the testing and assessment (IATA) of NGTxC. The scrape loading-dye transfer (SL-DT) technique is a simple assay for the functional evaluation of GJIC in various in vitro cultured mammalian cells and represents an interesting candidate assay. Out of the various techniques for evaluating GJIC, the SL-DT assay has been used frequently to assess the effects of various chemicals on GJIC in toxicological and tumor promotion research. In this review, we systematically searched the existing literature to gather papers assessing GJIC using the SL-DT assay in a rat liver epithelial cell line, WB-F344, after treating with chemicals, especially environmental and food toxicants, drugs, reproductive-, cardio- and neuro-toxicants and chemical tumor promoters. We discuss findings derived from the SL-DT assay with the known knowledge about the tumor-promoting activity and carcinogenicity of the assessed chemicals to evaluate the predictive capacity of the SL-DT assay in terms of its sensitivity, specificity and accuracy for identifying carcinogens. These data represent important information with respect to the applicability of the SL-DT assay for the testing of NGTxC within the IATA framework.

Hormesis: Transforming disciplines that rely on the dose response

This article tells the story of hormesis from its conceptual and experimental origins, its dismissal by the scientific and medical communities in the first half of the 20th century, and its rediscovery over the past several decades to be a fundamental evolutionary adaptive strategy. The upregulation of hormetic adaptive mechanisms has the capacity to decelerate the onset and reduce the severity of a broad spectrum of common age-related health, behavioral, and performance decrements and debilitating diseases, thereby significantly enhancing the human health span. Incorporation of hormetic-based lifestyle options within the human population would have profoundly positive impacts on the public health, significantly reducing health care costs.

Socio-Environmental Conditions Associated with Geospatial Clusters of Urothelial Carcinoma: A Multi-Institutional Analysis

PURPOSE

The interaction between sources of industrial byproducts and environmental pollutants (IBP/EP) and the prevalence of urothelial carcinoma (UC) in surrounding communities has been infrequently explored. The purpose of this research is to identify microregional UC hotspots and associated industrial and environmental risk factors.

MATERIALS AND METHODS

We retrospectively queried a multi-institutional database for UC patients diagnosed between 2008 and 2018. Addresses were geocoded and used to perform hotspot analysis on the census block level. Demographic and clinicopathological characteristics, census data and proximity to sources of IBP/EP were compared between patients who did vs did not reside in a hotspot. Associations were tested using multilevel logistic regression models using 95% confidence intervals.

RESULTS

A total of 5,080 patients met inclusion criteria and 148 (2.9%) were identified as living in 1 of 3 UC hotspots. In univariate analyses, race, tobacco and alcohol use, household income, IBP/EP exposure and proximity to traffic, industrial discharge and airports were significantly associated with UC hotspots. Multivariable analysis demonstrated that polycyclic aromatic hydrocarbon exposure (OR: 48.09, p ≤0.001) and proximity to high-density traffic (OR: >999, p ≤0.001) increased the odds of living in a hotspot. Patients living in a hotspot were significantly less likely to be white (OR: 0.06, p ≤0.001) or tobacco users (OR: 0.39, p=0.031) on multivariate analysis.

CONCLUSIONS

Spatially related clusters of UC may be associated with locoregional environmental exposures rather than tobacco exposure and may also be correlated with socioeconomic disparities. Geospatial analysis can help to identify at-risk populations, offering the opportunity to better focus preventive and diagnostic interventions.

Flavour chemicals, synthetic coolants and pulegone in popular mint-flavoured and menthol-flavoured e-cigarettes

Background

The Food and Drug Administration (FDA) has recently banned flavours from pod-style electronic cigarettes (e-cigarettes), except for menthol and tobacco. JUUL customers have quickly discovered that flavoured disposable e-cigarettes from other manufacturers, such as Puff, are readily available. Our goal was to compare flavour chemicals, synthetic coolants and pulegone in mint-flavoured/menthol-flavoured e-cigarettes from JUUL and Puff, evaluate the cytotoxicity of the coolants and perform a cancer risk assessment for pulegone, which is present in both JUUL pods and disposable Puff products.

Methods

Identification and quantification of chemicals were performed using gas chromatography/mass spectrometry. Cytotoxicity of the coolants was evaluated with BEAS-2B cells using the MTT 3-(4,5-dimethylthiazol-2-yl)−2,5-diphenyltetrazolium bromide assay. The cancer risk of pulegone was calculated using the margin of exposure (MOE).

Results

Menthol was the dominant flavour chemical (>1 mg/mL) in all products from both manufacturers. Minor flavour chemicals (<1 mg/mL) differed in the JUUL and Puff fluids and may produce flavour accents. The concentrations of WS-3 and WS-23 were higher in Puff than in JUUL. WS-23 was cytotoxic in the MTT assay at concentrations 90 times lower than concentrations in Puff fluids. The risk of cancer (MOE<10 000) was greater for mint than for menthol products and greater for Puff than for JUUL.

Conclusions

Switching from flavoured JUUL to Puff e-cigarettes may expose users to increased harm due to the higher levels of WS-23 and pulegone in Puff products. Cancer risk may be reduced in e-cigarettes by using pure menthol rather than mint oils to produce minty-flavoured e-cigarette products.

An Assessment on Ethanol-Blended Gasoline/Diesel Fuels on Cancer Risk and Mortality

Although cancer is traditionally considered a genetic disease, the epigenetic abnormalities, including DNA hypermethylation, histone deacetylation, and/or microRNA dysregulation, have been demonstrated as a hallmark of cancer. Compared with gene mutations, aberrant epigenetic changes occur more frequently, and cellular epigenome is more susceptible to change by environmental factors. Excess cancer risks are positively associated with exposure to occupational and environmental chemical carcinogens, including those from gasoline combustion exhausted in vehicles. Of note, previous studies proposed particulate matter index (PMI) as a measure for gasoline sooting tendency, and showed that, compared with the other molecules in gasoline, 1,2,4-Trimethylbenzene, 2-methylnaphthalene and toluene significantly contribute to PMI of the gasoline blends. Mechanistically, both epigenome and genome are important in carcinogenicity, and the genotoxicity of chemical agents has been thoroughly studied. However, less effort has been put into studying the epigenotoxicity. Moreover, as the blending of ethanol into gasoline substitutes for carcinogens, like benzene, toluene, xylene, butadiene, and polycyclic aromatic hydrocarbons, etc., a reduction of secondary aromatics has been achieved in the atmosphere. This may lead to diminished cancer initiation and progression through altered cellular epigenetic landscape. The present review summarizes the most important findings in the literature on the association between exposures to carcinogens from gasoline combustion, cancer epigenetics and the potential epigenetic impacts of biofuels.

Heterocyclic Aromatic Amines in Meat: Formation, Isolation, Risk Assessment, and Inhibitory Effect of Plant Extracts

Heterocyclic aromatic amines (HAAs) are potent carcinogenic compounds induced by the Maillard reaction in well-done cooked meats. Free amino acids, protein, creatinine, reducing sugars and nucleosides are major precursors involved in the production of polar and non-polar HAAs. The variety and yield of HAAs are linked with various factors such as meat type, heating time and temperature, cooking method and equipment, fresh meat storage time, raw material and additives, precursor’s presence, water activity, and pH level. For the isolation and identification of HAAs, advanced chromatography and spectroscopy techniques have been employed. These potent mutagens are the etiology of several types of human cancers at the ng/g level and are 100- to 2000-fold stronger than that of aflatoxins and benzopyrene, respectively. This review summarizes previous studies on the formation and types of potent mutagenic and/or carcinogenic HAAs in cooked meats. Furthermore, occurrence, risk assessment, and factors affecting HAA formation are discussed in detail. Additionally, sample extraction procedure and quantification techniques to determine these compounds are analyzed and described. Finally, an overview is presented on the promising strategy to mitigate the risk of HAAs by natural compounds and the effect of plant extracts containing antioxidants to reduce or inhibit the formation of these carcinogenic substances in cooked meats.

The Central Role of Cytochrome P450 in Xenobiotic Metabolism-A Brief Review on a Fascinating Enzyme Family

Human Cytochrome P450 (CYP) enzymes constitute a superfamily of membrane-bound hemoproteins that are responsible for the metabolism of a wide variety of clinically, physiologically, and toxicologically important compounds. These heme-thiolate monooxygenases play a pivotal role in the detoxification of xenobiotics, participating in the metabolism of many structurally diverge compounds. This short-review is intended to provide a summary on the major roles of CYPs in Phase I xenobiotic metabolism. The manuscript is focused on eight main topics that include the most relevant aspects of past and current CYP research. Initially, (I) a general overview of the main aspects of absorption, distribution, metabolism, and excretion (ADME) of xenobiotics are presented. This is followed by (II) a background overview on major achievements in the past of the CYP research field. (III) Classification and nomenclature of CYPs is briefly reviewed, followed by (IV) a summary description on CYP’s location and function in mammals. Subsequently, (V) the physiological relevance of CYP as the cornerstone of Phase I xenobiotic metabolism is highlighted, followed by (VI) reviewing both genetic determinants and (VI) nongenetic factors in CYP function and activity. The last topic of the review (VIII) is focused on the current challenges of the CYP research field.

Association between oral microflora and gastrointestinal tumors (Review)

The oral cavity contains the highest density and the most species of microorganisms compared with other parts of the body. Recent studies have determined that the species and abundance of oral microflora are closely associated with the development of upper gastrointestinal tumors, including oral, esophageal and gastric cancer. Additionally, differential abundant microbiota in patients with cancer and abnormal microorganisms inside the tumor tissue have been identified as critical markers of tumorigenesis. There is evidence to suggest that certain genera, including Firmicutes, along with various species, such as Porphyromonas, can increase the risk of oral cancer. Furthermore, Porphyromonas gingivalis is a risk factor for esophageal carcinoma, while Helicobacter pylori infections are a main cause of gastric cancer. Currently, as far as carcinogenic mechanisms of oral microorganisms are concerned, it has been hypothesized that the production of carcinogenic substances, chronic inflammation and altered cell metabolisms may be mechanisms by which oral microorganisms influence the development of upper gastrointestinal cancer. Certain phrases, including 'oral microbes', 'oral microorganism', 'oral microbiology', 'oral microflora', 'oral cancer', 'oral carcinoma', 'carcinoma of mouth', 'esophagus cancer', 'esophageal cancer', 'esophageal carcinoma', 'carcinoma of esophagus', 'gastric cancer', 'gastric carcinoma', 'stomach cancer', 'cancer of the stomach', 'carcinogenic mechanism' and 'carcinogenesis', were searched as key words in PubMed and Web of Science for articles published between 1975 to 2020. A total of 1,512 studies were obtained. After further searching the abstracts for key words, such as oral microorganisms, oral cancer, esophagus cancer, gastric cancer and carcinogenic mechanisms, 137 studies were selected. The current review systematically and comprehensively summarized the association between the oral microbiota and oral, esophageal and gastric cancer. Additionally, the current review described the carcinogenic mechanisms of oral microbes and attempted to identify common molecular mechanisms among different types of tumor. The association between upper gastrointestinal cancer therapy and oral microflora was also assessed. The present review may be used as a reference for future diagnosis and therapeutics for upper gastrointestinal tumors.

Review of aluminum, paraben, and sulfate product disclaimers on personal care products

BACKGROUND

Product disclaimers listed on personal care products face limited regulation. These disclaimers may be helpful or may mislead the public.

OBJECTIVE

Review the evidence supporting the potential harms of three compounds commonly addressed by product disclaimers: parabens, aluminum, and sulfates.

METHODS

Reported cases of adverse events to these compounds were identified. Trends in allergic contact dermatitis to chemicals used in place of these compounds were also identified.

RESULTS

There is limited evidence that parabens and aluminum pose a threat to human health; there is even less evidence that topical sulfate containing products pose a danger to consumers. In the setting of paraben avoidence, there has been a steady increase in cases of allergic contact dermatitis to preservatives which are more allergenic, specifically the isothiazolinones.

LIMITATIONS

Assessment of the toxicology of these compounds is ongoing and may change with new data.

CONCLUSION

There is limited evidence that parabens, aluminum, and sulfates used in personal care products pose a health risk. There is evidence that avoidance of parabens has resulted in an epidemic of allergic contact dermatitis to isothiazolonine preservatives.