Carcinogenicity of household solid fuel combustion and of high-temperature frying

Associations between atmospheric PM2.5 exposure and carcinogenic health risks: Surveillance data from the year of lowest recorded levels in Beijing, China

Scant research has pinpointed the year of minimum PM2.5 concentration through extensive, uninterrupted monitoring, nor has it thoroughly assessed carcinogenic risks associated with analyzing numerous components during this nadir in Beijing. This study endeavored to delineate the atmospheric PM2.5 pollution in Beijing from 2015 to 2022 and to undertake comprehensive evaluation of carcinogenic risks associated with the composition of atmospheric PM2.5 during the year exhibiting the lowest concentration. PM2.5 concentrations were monitored gradually in 9 districts of Beijing for 7 consecutive days per month from 2015 to 2022, and 32 kinds of PM2.5 components collected in the lowest PM2.5 concentration year were analyzed. This comprehensive dataset served as the basis for carcinogenic risk assessment using Monte Carlo simulation. And we applied the Positive Matrix Factorization (PMF) method to identity the sources of atmospheric PM2.5. Furthermore, we integrated this source appointment model with risk assessment model to discern the origins of these risks. The findings revealed that the annual average PM2.5 concentration in 2022 stood at 43.1 μg/m3, marking the lowest level recorded. The mean carcinogenic risks of atmospheric PM2.5 exposure calculated at 6.30E-6 (empirical 95% CI 1.09E-6 to 2.25E-5) in 2022. The PMF model suggested that secondary sources (35.4%), coal combustion (25.6%), resuspended dust (15.1%), biomass combustion (14.1%), vehicle emissions (7.1%), industrial emissions (2.0%) and others (0.7%) were the main sources of atmospheric PM2.5 in Beijing. The mixed model revealed that coal combustion (2.41E-6), vehicle emissions (1.90E-6) and industrial emissions (1.32E-6) were the main sources of carcinogenic risks with caution. Despite a continual decrease in atmospheric PM2.5 concentration in recent years, the lowest concentration levels still pose non-negligible carcinogenic risks. Notably, the carcinogenic risks associated with metals and metalloids exceeded that of PAHs. And the distribution of risk sources did not align proportionally with the distribution of PM2.5 mass concentration.

Global Burden of Lung Cancer Attributable to Household Fine Particulate Matter Pollution in 204 Countries and Territories, 1990 to 2019

INTRODUCTION

Household particulate matter (PM) air pollution is substantially associated with lung cancer. Nevertheless, the global burden of lung cancer attributable to household PM2.5 is still uncertain.

METHODS

In this study, data from the Global Burden and Disease Study 2019 are used to thoroughly assess the burden of lung cancer associated with household PM2.5.

RESULTS

The number of deaths and disability-adjusted life-years (DALYs) attributable to household PM2.5 was found to be 0.08 million and 1.94 million, respectively in 2019. Nevertheless, the burden of lung cancer attributable to household PM2.5 decreased from 1990 to 2019. At the sociodemographic index (SDI) district level, the middle SDI region had the most number of lung cancer deaths and DALYs attributable to household PM2.5. Moreover, the burden of lung cancer was mainly distributed in low-SDI regions, such as Sub-Saharan Africa. Conversely, in high-SDI regions, the age-standardized mortality rate and age-standardized DALY rate of lung cancer attributable to household PM2.5 exhibit the most rapid declines. The burden of lung cancer attributable to household PM2.5 is heavier for men than for women. The sex difference is more obvious in the elderly.

CONCLUSIONS

The prevalence of lung cancer attributable to household PM2.5 has exhibited a declining trend from 1990 to 2019 owing to a concurrent decline in household PM2.5 exposure.

Burn pit-related smoke causes developmental and behavioral toxicity in zebrafish: Influence of material type and emissions chemistry

Combustion of mixed materials during open air burning of refuse or structural fires in the wildland urban interface produces emissions that worsen air quality, contaminate rivers and streams, and cause poor health outcomes including developmental effects. The zebrafish, a freshwater fish, is a useful model for quickly screening the toxicological and developmental effects of agents in such species and elicits biological responses that are often analogous and predictive of responses in mammals. The purpose of this study was to compare the developmental toxicity of smoke derived from the burning of 5 different burn pit-related material types (plywood, cardboard, plastic, a mixture of the three, and the mixture plus diesel fuel as an accelerant) in zebrafish larvae. Larvae were exposed to organic extracts of increasing concentrations of each smoke 6-to-8-hr post fertilization and assessed for morphological and behavioral toxicity at 5 days post fertilization. To examine chemical and biological determinants of toxicity, responses were related to emissions concentrations of polycyclic hydrocarbons (PAH). Emissions from plastic and the mixture containing plastic caused the most pronounced developmental effects, including mortality, impaired swim bladder inflation, pericardial edema, spinal curvature, tail kinks, and/or craniofacial deformities, although all extracts caused concentration-dependent effects. Plywood, by contrast, altered locomotor responsiveness to light changes to the greatest extent. Some morphological and behavioral responses correlated strongly with smoke extract levels of PAHs including 9-fluorenone. Overall, the findings suggest that material type and emissions chemistry impact the severity of zebrafish developmental toxicity responses to burn pit-related smoke.

Correlation between the non-use of cooking oil fume extractors and bone mineral density in population aged 45 years and older in China: a cross-sectional study

Introduction

The correlation between the non-use of cooking oil fumes (COFs) extractors and bone mineral density (BMD) have not been clarified. Consequently, this study attempted to explore the impact of non-use COFs extractors on BMD in population aged 45 years and older based on a cross-sectional study.

Methods

This study was a cross-sectional study within the framework of an ongoing prospective population-based cohort study in China. The multivariate linear regression models were used to evaluate the correlation between the non-use of fume extractors in family cooking and total lumbar spine (LS), femoral neck (FN), total hip BMD and levels of bone metabolism markers.

Results

A total of 3433 participants were included in the final analyses, of which 2607 (75.93%) participants used fume extractors. The results of models indicated that there were significant correlations of the non-use of fume extractors on total LS BMD (β = -0.024, 95% CI, -0.036, -0.012, p < 0.001), PINP (β = 4.363, 95% CI, 2.371, 6.356, p < 0.001) and ALP (β = 4.555, 95% CI, 2.593, 6.517, p < 0.001) levels.

Conclusions

This study verified that the use of fume extractors is an efficacious measure to prevent LS bone loss. For the sake of public bone health, people should install a fume extractor in the kitchen and use it routinely when cooking.

Modeling polycyclic aromatic hydrocarbons in India: Seasonal variations, sources and associated health risks

Atmospheric polycyclic aromatic hydrocarbons (PAHs) are in high levels in developing countries like India. However, limited measurements are inadequate for better understanding of their ambient levels and health effects. This study predicted PAHs concentrations in atmosphere and estimated their sources and health risks in India in four representative months of winter, pre-monsoon, monsoon and post-monsoon in 2015 using an updated version of the Community Multiscale Air Quality model (CMAQ). Predicted PAHs were in agreement with observations from literature. Surface 16-PAHs were highest in winter, with a peak value of 2.5 μg/m³ and population-weighted average of 0.5 μg/m³ in northern and eastern India, where biomass burning and coal combustion were chief contributors. Pre-monsoon and monsoon had lower concentrations ∼0.2 μg/m³. The incremental lifetime cancer risk (ILCR) was greater than 4E-4 in many industrial and urban areas. Exposure to PAHs resulted in 7431 excess lifetime cancer cases. Coal combustion and biomass burning were major contributors to ILCR, followed by gas and oil activities. Much higher health risks were observed in urban than in rural areas. India showed much higher levels of total PAHs and cPAHs than the U.S but moderately less than China.

Assessing the cooking oil fume exposure impacts on Chinese women health: an influential mechanism analysis

Oil fume is always considered as a major source of indoor air pollution. This article aims to examine the effects of cooking oil fume as environmental pollution on the health of Chinese women by using the data obtained from China Labor force Dynamic Survey (CLDS). In order to estimate the effect of environmental pollution on the human health, we utilize probit model approach and baseline regression method. The results showed that oil fume has a significant negative impact on the health indicators of "physical pain, health impact on work and injury." By conducting endogeneity analysis, our results show the robustness and indicate that oil fume has a robust effect on the women health. Heterogeneity analysis show that heavier oil fume has a negative impact on the subjective health of middle-aged and young women, while it has  a significant negative impact on the objective health of middle-aged women. Analysis of the impact mechanism reveal that heavier oil fumes will reduce women's sleep quality and will lead to the poorer health. Based on our study findings, this study proposes policy recommendations from the perspectives of the use of smoke extraction equipment, cooking methods, and sleep quality to reduce the negative impact of cooking fumes on women's health.

The chemical composition and toxicological effects of fine particulate matter (PM2.5) emitted from different cooking styles

The mass, chemical composition and toxicological properties of fine particulates (PM_2.5) emitted from cooking activities in three Hong Kong based restaurants and two simulated cooking experiments were characterized. Extracts from the PM_2.5 samples elicited significant biological activities [cell viability, generation of reactive oxygen species (ROS), DNA damage and inflammation effect (TNF-α)] in a dose-dependent manner. The composition of PAHs, oxygenated PAHs (OPAHs) and azaarenes (AZAs) mixtures differed between samples. The concentration ranges of the Σ30PAHs, Σ17OPAHs and Σ4AZAs and Σ7Carbonyls in the samples were 9627-23,452 pg m^-3, 503-3700 pg m^-3, 33-263 pg m^-3 and 158 - 5328 ng m^-3, respectively. Cell viability caused by extracts from the samples was positively correlated to the concentration of benzo[a]anthracene, indeno[1,2,3-cd]pyrene and 1,4-naphthoquinone in the PM_2.5 extracts. Cellular ROS production (upon exposure to extracts) was positively correlated with the concentrations of PM_2.5, decaldehyde, acridine, Σ17OPAHs and 7 individual OPAHs. TNF-α showed significant positive correlations with the concentrations of most chemical species (elemental carbon, 16 individual PAHs including benzo[a]pyrene, Σ30PAHs, SO₄^2-, Ca²⁺, Ca, Na, K, Ti, Cr, Mn, Fe, Cu and Zn). The concentrations of Al, Ti, Mn, Σ30PAHs and 8 individual PAHs including benzo[a]pyrene in the samples were positively correlated with DNA damage caused by extracts from the samples. This study demonstrates that inhalation of PM_2.5 emitted from cooking could result in adverse human health effects.

Using a hybrid approach to apportion potential source locations contributing to excess cancer risk of PM2.5-bound PAHs during heating and non-heating periods in a megacity in the Middle East

Polycyclic aromatic hydrocarbons (PAHs) represent one of the major toxic pollutants associated with PM_2.5 with significant human health and climate effects. Because of local and long-range transport of atmospheric PAHs to receptor sites, higher global attentions have been focused to improve PAHs pollution emission management. In this study, PM_2.5 samples were collected at three urban sites located in the capital of Iran, Tehran, during the heating and non-heating periods (H-period and NH-period). The US EPA 16 priority PAHs were analyzed and the data were processed to the following detailed aims: (i) investigate the H-period and NH-period variations of PM_2.5 and PM_2.5-bound PAHs concentrations; (ii) identify the PAHs sources and the source locations during the two periods; (iii) carry out a source-specific excess cancer risk (ECR) assessment highlighting the potential source locations contributing to the ECR using a hybrid approach. Total PAHs (TPAHs) showed significantly higher concentrations (1.56-1.89 times) during the H-period. Among the identified PAHs compounds, statistically significant periodical differences (p-value < 0.05) were observed only between eight PAHs species (Nap, BaA, Chr, BbF, BkF, BaP, IcdP, and DahA) at all three sampling sites which can be due to the significant differences of PAHs emission sources during H and NH-periods. High molecular weight (HMW) PAHs accounted for 52.7% and 46.8% on average of TPAHs during the H-period and NH-period, respectively. Positive matrix factorization (PMF) led to identifying four main PAHs sources including industrial emissions, petrogenic emissions, biomass burning and natural gas emissions, and vehicle exhaust emissions. Industrial and petrogenic emissions exhibited the highest contribution (19.8%, 27.2%, respectively) during the NH-period, while vehicle exhaust and biomass burning-natural gas emissions showed the largest contribution (40.7%, 29.6%, respectively) during the H-period. Concentration weighted trajectory (CWT) on factor contributions was used for tracking the potential locations of the identified sources. In addition to local sources, long-range transport contributed to a significant fraction of TPHAs in Tehran both during the H- and NH-periods. Source-specific carcinogenic risks assessment apportioned vehicle exhaust (44.2%, 2.52 × 10^-4) and biomass burning-natural gas emissions (33.9%, 8.31 × 10^-5) as the main cancer risk contributors during the H-period and NH-period, respectively. CWT maps pointed out the different distribution patterns associated with the cancer risk from the identified sources. This will allow better risk management through the identification of priority PAHs sources.

Health impacts of indoor air pollution from household solid fuel on children and women

The inefficient and incomplete combustion of solid fuel (SF) is associated with high levels of indoor air pollutants leading to 3.55 million deaths annually. The risk is higher in women and children, due to their higher exposure duration and unique physical properties. The current article aims to provide a critical overview regarding the use of solid fuel, its associated pollutants, their toxicity mechanisms and, most importantly the associated health impacts, especially in women and children. Pollutants associated with SF mostly include polycyclic aromatic hydrocarbons, particulate matter, nitrous oxide, carbon monoxide and sulfur dioxide, and their concentrations are two- to threefold higher in indoor environments. These pollutants can lead to a variety of health risks by inducing different toxicity mechanisms, such as oxidative stress, DNA methylation, and gene activation. Exposed children have an increased prevalence of low birth weight, acute lower respiratory tract infections, anemia and premature mortality. On the other hand, lung cancer, chronic obstructive pulmonary disease and cardiovascular diseases are the major causes of disability and premature death in women. Indoor air pollution resulting from SF combustion is a major public health threat globally. To reduce the risks, it is important to identify future research gaps and implement effective interventions and policies.

Anti-Asian American Racism: A Wake-Up Call for Population-Based Cancer Research

Since the start of the COVID-19 pandemic, Asian Americans have been subjected to rising overt discrimination and violent hate crimes, highlighting the health implications of racism toward Asian Americans. As Asian Americans are the only group for whom cancer is the leading cause of death, these manifestations of anti-Asian racism provoke the question of the impact of racism across the cancer continuum for Asian Americans. In this Commentary, we describe how the myth of the "model minority" overlooks the diversity of Asian Americans. Ignoring such diversity in sociocultural trends, immigration patterns, socioeconomic status, health behaviors, and barriers to care masks disparities in cancer risk, access to care, and outcomes across Asian American populations. We recommend cancer epidemiologists, population science researchers, and oncology providers direct attention toward: (i) studying the impacts of structural and personally mediated racism on cancer risk and outcomes; (ii) ensuring studies reflect the uniqueness of individual ethnic groups, including intersectionality, and uncover underlying disparities; and (iii) applying a critical race theory approach that considers the unique lived experiences of each group. A more nuanced understanding of cancer health disparities, and how drivers of these disparities are associated with race and differ across Asian American ethnicities, may elucidate means through which these disparities can be alleviated.

Why cleaning the invisible in restaurants is important during COVID-19: A case study of indoor air quality of an open-kitchen restaurant

During the COVID-19 pandemic, restaurant sanitation and disinfection have become more important than ever although customers can hardly check visually. The most recent research argues that one invisible element leaving people vulnerable to the health effects of COVID-19 is particulate matter (PM), micron-sized particles known to cause acute or chronic respiratory illnesses, including lung cancer. While research shows PM is emitted from cooking, this study examines indoor PM pollution of an open-kitchen full-service chain restaurant, where commercial cooking occurs in the dining room, as a case study. The results of a week-long field test showed offensively harmful levels of PM10 and PM2.5, far beyond US EPA and WHO standards, while ambient outdoor PM associated with the sample restaurant was safe. The study reveals that working or frequently dining in an open-kitchen restaurant where grilling or frying takes place is likely to cause respiratory health problems and elevate susceptibility to COVID-19 unless surveillance and preventative measures are taken. Based on our findings, implications and recommendations for the industry are provided.

Sub-multiplicative interaction between polygenic risk score and household coal use in relation to lung adenocarcinoma among never-smoking women in Asia

We previously identified 10 lung adenocarcinoma susceptibility loci in a genome-wide association study (GWAS) conducted in the Female Lung Cancer Consortium in Asia (FLCCA), the largest genomic study of lung cancer among never-smoking women to date. Furthermore, household coal use for cooking and heating has been linked to lung cancer in Asia, especially in Xuanwei, China. We investigated the potential interaction between genetic susceptibility and coal use in FLCCA. We analyzed GWAS-data from Taiwan, Shanghai, and Shenyang (1472 cases; 1497 controls), as well as a separate study conducted in Xuanwei (152 cases; 522 controls) for additional analyses. We summarized genetic susceptibility using a polygenic risk score (PRS), which was the weighted sum of the risk-alleles from the 10 previously identified loci. We estimated associations between a PRS, coal use (ever/never), and lung adenocarcinoma with multivariable logistic regression models, and evaluated potential gene-environment interactions using likelihood ratio tests. There was a strong association between continuous PRS and lung adenocarcinoma among never coal users (Odds Ratio (OR) = 1.69 (95% Confidence Interval (CI) = 1.53, 1.87), p=1 × 10-26). This effect was attenuated among ever coal users (OR = 1.24 (95% CI: 1.03, 1.50), p = 0.02, p-interaction = 6 × 10-3). We observed similar attenuation among coal users from Xuanwei. Our study provides evidence that genetic susceptibility to lung adenocarcinoma among never-smoking Asian women is weaker among coal users. These results suggest that lung cancer pathogenesis may differ, at least partially, depending on exposure to coal combustion products. Notably, these novel findings are among the few instances of sub-multiplicative gene-environment interactions in the cancer literature.

Shortened telomere length in peripheral blood leukocytes of patients with lung cancer, chronic obstructive pulmonary disease in a high indoor air pollution region in China

Lung cancer and chronic obstructive pulmonary disease (COPD) are closely linked diseases. In Xuanwei, China, the extremely high incidence and mortality rates of lung cancer and COPD are associated with exposure to household smoky coal burning. Previous studies found that telomere length was related to lung disease. The objective of this study is to investigate the relationship of peripheral blood leukocyte telomere length to both lung cancer and COPD, as well as indoor coal smoke exposure in Xuanwei. We measured telomere length using quantitative polymerase chain reaction (qPCR) in peripheral blood leukocytes of 216 lung cancer patients, 296 COPD patients, and 426 healthy controls from Xuanwei. The telomere length ratios (mean ± SD) in patients with lung cancer (0.76 ± 0.35) and COPD (0.81 ± 0.35) were significantly shorter than in that of controls (0.95 ± 0.39). Individuals with the shortest tertile telomere length had 3.90- and 4.54-fold increased risks of lung cancer and COPD, respectively, compared with individuals with the longest tertile telomere length. No correlation was found between telomere length and pack-years of smoking. In healthy subjects, coal smoke exposure level affected telomere length. Lung function was positively and negatively associated with telomere length and environmental exposure, respectively, when combination the control and COPD groups. The result suggests that shortened telomere length in peripheral blood leukocytes was associated with lung cancer and COPD and might be affected by coal smoke exposure level in Xuanwei. Whether variation in telomere length caused by environmental exposure has a role in lung cancer and COPD development and exacerbation needs further research.

Feasibility of using bed filters packed with rice-straw-based activated carbon and selected biomass waste for the control of frying fume exhaust

Open-air burning of rice straw (RS) on sites after harvesting produces tremendous amounts of air pollutants in Southeast Asia. Additionally, cooking oil smoke (COS) from high-temperature frying is classified as "Probably carcinogenic to humans" (Group 2A) by the International Agency for Research on Cancer. To mitigate the air pollution from COS, RS was recycled to prepare activated carbon (AC), which was used as a bed filter (BF) packing material for COS removal, and to our best knowledge, this study is the first one. Besides, a negative air ionizer (NAI) was firstly utilized to enhance the removal efficiency (η) of COS particles. Other biomass waste, including tea leaves (TL), wood dust (WD), rice hulls (RH), and coffee grounds (CG), were also used as packing materials for comparison. Specific surface area and pore volume of the packing materials were determined by nitrogen adsorption/desorption isothermal. Laser airborne particle counters and volatile organic compound (VOC) monitors (photoionization detector) were utilized for real-time recording of the particle and VOC concentration of COS. Economic assessments for the control of COS was also conducted. For submicron particles, the removal efficiency of the BFs ranged from 0 to 98% and the AC filter had the highest quality factor. The NAI remarkably enhanced the η value and filter quality factor. For the removal of particles larger than 2.5 μm, all BFs had η > 96%. The removal efficiency of volatile organic compounds (VOCs) (ηVOC) of the test BFs ranged from 18.22 to 90.8%. The AC filter had the largest pore volume (0.432 cm3/g) and surface area (877 m2/g) among all packing materials, causing this filter to have the highest ηVOC and adsorption capacity (over 28.3 mg-VOCs/g-AC). The annual operating costs of the TL, WD, RH, CG, and AC filters were 319.4, 23.3, 29.1, 189.4, and 62.9 US$, respectively. Therefore, using RS to prepare an AC bed filter for the removal of COS is a practical and sustainable strategy for COS control.

Potential Adverse Public Health Effects Afforded by the Ingestion of Dietary Lipid Oxidation Product Toxins: Significance of Fried Food Sources

Exposure of polyunsaturated fatty acid (PUFA)-rich culinary oils (COs) to high temperature frying practices generates high concentrations of cytotoxic and genotoxic lipid oxidation products (LOPs) via oxygen-fueled, recycling peroxidative bursts. These toxins, including aldehydes and epoxy-fatty acids, readily penetrate into fried foods and hence are available for human consumption; therefore, they may pose substantial health hazards. Although previous reports have claimed health benefits offered by the use of PUFA-laden COs for frying purposes, these may be erroneous in view of their failure to consider the negating adverse public health threats presented by food-transferable LOPs therein. When absorbed from the gastrointestinal (GI) system into the systemic circulation, such LOPs may significantly contribute to enhanced risks of chronic non-communicable diseases (NCDs), e.g. cancer, along with cardiovascular and neurological diseases. Herein, we provide a comprehensive rationale relating to the public health threats posed by the dietary ingestion of LOPs in fried foods. We begin with an introduction to sequential lipid peroxidation processes, describing the noxious effects of LOP toxins generated therefrom. We continue to discuss GI system interactions, the metabolism and biotransformation of primary lipid hydroperoxide LOPs and their secondary products, and the toxicological properties of these agents, prior to providing a narrative on chemically-reactive, secondary aldehydic LOPs available for human ingestion. In view of a range of previous studies focused on their deleterious health effects in animal and cellular model systems, some emphasis is placed on the physiological fate of the more prevalent and toxic α,β-unsaturated aldehydes. We conclude with a description of targeted nutritional and interventional strategies, whilst highlighting the urgent and unmet clinical need for nutritional and epidemiological trials probing relationships between the incidence of NCDs, and the frequency and estimated quantities of dietary LOP intake.

Source Identification and Health Risk Assessment of Polycyclic Aromatic Hydrocarbon-Enriched PM2.5 in Tangshan, China

Tangshan city in Hebei Province is one of the most heavily polluted cities in China, with substantial industrial emissions. The development of effective air pollution emission reduction policies requires knowledge of the sources and health risks of polycyclic aromatic hydrocarbon (PAH)-enriched fine particulate matter (PM_2.5 ). We investigated the seasonal variation and source apportionment of 16 priority PAH-enriched PM_2.5 samples in Tangshan during 2014 and 2015, and we assessed the health risks associated with inhalation exposure to PAHs. The PM_2.5 samples were collected from April 2014 to February 2015. We analyzed the concentrations of PM_2.5 and PAH-enriched PM_2.5 , and used principal component analysis and molecular diagnostic ratios to identify potential sources. We explored the relationship between distribution and meteorological conditions, and used an incremental lifetime cancer risk (ILCR) model to quantitatively evaluate exposure from the inhalation risk of PAHs. The average mass concentration of PM_2.5 was 196 µg/m³ , with a range 34.0 to 586 µg/m³ . The median ∑₁₆ PAH values in PM_2.5 were 190 ng/m³ , with a range of 60.2 to 862 ng/m³ over the sampling period. The order of ∑₁₆ PAHs concentration was winter > autumn > summer > spring. The results show that the primary sources of PAH-enriched PM_2.5 are coal combustion, vehicle exhaust, and biomass burning. The annual mean of benzo[a]pyrene (BaP) was 8.37 ng/m³ , more than 8-fold greater than the BaP annual standard (1 ng/m³ ) set by the Chinese State Environmental Protection Agency. The ILCR values for 3 groups (children, teenagers, and adults) over the 4 seasons were between 10^-6 and 10^-4 , indicating a potential health risk from PAHs in Tangshan. Environ Toxicol Chem 2020;39:458-467. © 2019 SETAC.

Sources and health risks of ambient polycyclic aromatic hydrocarbons in China

Polycyclic aromatic hydrocarbons (PAHs) in the environment are of significant concerns due to their high toxicity to human health. PAHs measurements at limited air quality monitoring stations alone are insufficient to gain a complete understanding of ambient levels and public exposure of PAHs in China. This study simulated the concentrations of PAHs in China, identified the source contributions, and estimated the health risks. Anthropogenic emissions of 16 priority PAHs directly associated with health risks were generated from the global high-resolution PKU-FUEL-2007 inventory. Open biomass burning emissions were generated from the Fire Inventory from NCAR (FINN). PAHs concentrations in January, April, July, and October 2013 were simulated using the Community Multiscale Air Quality (CMAQ) model after incorporation of chemistry, partitioning, and deposition of PAHs. Predicted PAHs were in good agreement with seasonal and annual averaged observations from previous studies. The surface concentrations of 16-PAHs were higher in winter, with population weight average of 0.8 μg/m³ and peak value of 2.0 μg/m³ in urban areas in the North China Plain (NCP) and the Yangtze River Delta (YRD). Summer and spring exhibited lower concentrations of approximately 0.2 μg/m³ in most areas. The most important sources to PAHs were biomass burning and coal combustion in winter and industrial processes and oil and gas activities in summer. The cancer risk due to inhalation exposure of naphthalene (NAPH) and seven carcinogenic PAHs was significant, with the incremental lifetime cancer risk (ILCR) of >5 × 10^-4 in many urban and industrial areas. Exposure to PAHs was estimated to result in 15,198 excess lifetime cancer cases in China. Oil and gas burning associated with transport, residential and commercial activities were major contributors to ILCR in China. Coal combustion was predominant in Shanxi but less important in other regions.

A Distinct Epidemiologic Pattern of Precancerous Lesions of Esophageal Squamous Cell Carcinoma in a High-risk Area of Huai'an, Jiangsu Province, China

Better understanding of esophageal precancerous lesions (EPL) can inform prevention strategies for esophageal squamous cell carcinoma (ESCC). Here, a cross-sectional epidemiologic study based on the Early Diagnosis and Early Treatment Project of Esophageal Cancer database from 2011 to 2017 was performed to fully investigate and characterize the epidemiology of EPL in rural Huai'an District. Data of 11,518 participants ages 35-75 years were collected through face-to-face interviews by questionnaire. Participants underwent a routine endoscopy examination, tissues were biopsied, and diagnosed according to the histologic criteria of dysplasia. Unconditional univariate and multivariate logistic regression analyses were performed to obtain crude and adjusted odds ratios and corresponding 95% confidence intervals, respectively. A total of 667 subjects were diagnosed with EPL. Factors associated with an increased risk of EPL included: drinking shallow well water and surface water, irregular diet, excessive smoking, exposure to secondhand smoke, consumption of corn, corn flour, pickled food, fried food, and hot food, and having a history of digestive system diseases. In addition, liquor use, but not other alcohol types, contributed to risk of EPL. Consumption of deep well water and vegetables, fruits, and animal livers were associated with lower EPL risk. This study suggested a completely distinct pattern that alcohol use plays only a minor role in EPL and excessive tobacco use shows a significant association in rural Huai'an District, while eating habits and environmental exposure may be the dominant factors. This work may be promising to provide scientific evidence to support primary prevention of ESCC in this region.

The establishment of the Household Air Pollution Consortium (HAPCO)

Household air pollution (HAP) is of public health concern with ~3 billion people worldwide (including >15 million in the US) exposed. HAP from coal use is a human lung carcinogen, yet the epidemiological evidence on carcinogenicity of HAP from biomass use, primarily wood, is not conclusive. To robustly assess biomass's carcinogenic potential, prospective studies of individuals experiencing a variety of HAP exposures are needed. We have built a global consortium of 13 prospective cohorts (HAPCO: Household Air Pollution Consortium) that have site- and disease-specific mortality and solid fuel use data, for a combined sample size of 587,257 participants and 57,483 deaths. HAPCO provides a novel opportunity to assess the association of HAP with lung cancer death while controlling for important confounders such as tobacco and outdoor air pollution exposures. HAPCO is also uniquely positioned to determine the risks associated with cancers other than lung as well as non-malignant respiratory and cardiometabolic outcomes, for which prospective epidemiologic research is limited. HAPCO will facilitate research to address public health concerns associated with HAP-attributed exposures by enabling investigators to evaluate sex-specific and smoking status-specific effects under various exposure scenarios.

Determination of polycyclic aromatic hydrocarbons (PAHs) and other organic pollutants in freshwaters on the western shore of Admiralty Bay (King George Island, Maritime Antarctica)

Organic contamination in freshwater samples has never been investigated at the western shore of Admiralty Bay. Therefore, the presence of polycyclic aromatic hydrocarbons (PAHs) in five different sites distributed along a shore running from the Arctowski Station to the Baranowski Glacier was studied. Moreover, organic compounds such as n-alkanes, toluene and ethylbenzene were also noted. Increased ΣPAHs in late Austral summer 2016 are the result of long-range atmospheric transport of air masses from South America, confirmed by 10-day backward air mass trajectories analysis. The presence of n-alkanes and other hydrocarbons, as well as the evaluation of PAH indices (e.g. ΣLMW/ΣHMW* > 1), shows the use of fuel and indicate local human activity. As a final conclusion, our analysis indicates a mixed origin of PAHs (global and local). The presence of PAHs and other hydrocarbons in the water environment may constitute a potentially negative effect on the Antarctic ecosystem and it should be investigated in detail during further research (//*ΣLMW-sum of low molecular weight PAHs (two- and three-ring PAHs); ΣHMW-sum of high molecular weight PAHs (four- and five-ring PAHs)//). Graphical abstract.

Cancer and how the patients see it; prevalence and perception of risk factors: a cross-sectional survey from a tertiary care centre of Karachi, Pakistan

BACKGROUND

The incidence of cancer is rising but data available regarding prevalence of cancer and patient perception of the disease in Pakistan is limited. It is difficult to deal with Cancer if the main causes are negligence towards risk factors and bizarre myths. This study was aimed to investigate common cancer presentations at a government sector hospital and to gain insight into patient knowledge of the disease.

METHODS

This was a cross-sectional study conducted on cancer patients from Jinnah Postgraduate Medical Centre. A self-made questionnaire was used to assess the norms related to cancer prevalence in our society, associated myths, and the most common risk factors per them.

RESULTS

A total of 402 participants consented to participate in the study (mean age 42.3 ± 15.07 years), 204(50.7%) were females and 190(47.3%) were illiterate. Biomass exposure was found in 147(37%), drug abuse in 132(33%) and smoking in 63(16%). We found 103(25.6%) had positive family histories of cancer. The most common primary tumor site was breast for females 98(48%) and Head and neck 66(33.3%) for males. Patients considered fate 328(82%), gutka 284(71%) and injuries 282(70%) as the most common causes for cancer; while 222(55.5%) considered black magic and 236(58.75%) considered evil eye as a risk factor for cancer. Cancer treatment caused significant financial stress in 376(93.5%) patients.

CONCLUSION

Breast and head and neck cancers were found to be prevalent among patients. It was noted that patients are negligent in daily life regarding the consumption of substances that commonly cause cancer. Individuals had diminished knowledge and majority linked cancer to unrelated causes and myths like black magic and fate. Almost all the patients complained of severe financial stress imposed by the disease.

Individual and Combined Effects of Environmental Risk Factors for Esophageal Cancer Based on Results From the Golestan Cohort Study

BACKGROUND & AIMS

Northeast Iran has one of the highest reported rates of esophageal squamous cell carcinoma (ESCC) worldwide. Decades of investigations in this region have identified some local habits and environmental exposures that increase risk. We analyzed data from the Golestan Cohort Study to determine the individual and combined effects of the major environmental risk factors of ESCC.

METHODS

We performed a population-based cohort of 50,045 individuals, 40 to 75 years old, from urban and rural areas across Northeast Iran. Detailed data on demographics, diet, lifestyle, socioeconomic status, temperature of drinking beverages, and different exposures were collected using validated methods, questionnaires, and physical examinations, from 2004 through 2008. Participants were followed from the date of enrollment to the date of first diagnosis of esophageal cancer, date of death from other causes, or date of last follow-up, through December 31, 2017. Proportional hazards regression models were used to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) for the association between different exposures and ESCC.

RESULTS

During an average 10 years of follow-up, 317 participants developed ESCC. Opium smoking (HR 1.85; 95% CI 1.18-2.90), drinking hot tea (≥60°C) (HR 1.60; 95% CI 1.15-2.22), low intake of fruits (HR 1.48; 95% CI 1.07-2.05) and vegetables (HR 1.62; 95% CI 1.03-2.56), excessive tooth loss (HR 1.66; 95% CI 1.04-2.64), drinking unpiped water (HR 2.04; 95% CI 1.09-3.81), and exposure to indoor air pollution (HR 1.57; 95% CI 1.08-2.29) were significantly associated with increased risk of ESCC, in a dose-dependent manner. Combined exposure to these risk factors was associated with a stepwise increase in the risk of developing ESCC, reaching a more than 7-fold increase in risk in the highest category. Approximately 75% of the ESCC cases in this region can be attributed to a combination of the identified exposures.

CONCLUSIONS

Analysis of data from the Golestan Cohort Study in Iran identified multiple risk factors for ESCC in this population. Our findings support the hypothesis that the high rates of ESCC are due to a combination of factors, including thermal injury (from hot tea), exposure to polycyclic aromatic hydrocarbons (from opium and indoor air pollution), and nutrient-deficient diets. We also associated ESCC risk with exposure to unpiped water and tooth loss.

Bituminous coal combustion and Xuan Wei Lung cancer: a review of the epidemiology, intervention, carcinogens, and carcinogenesis

Indoor air pollution from bituminous coal combustion has been linked to the extremely high lung cancer rates of nonsmoking women in Xuan Wei County, Yunnan Province, China. Venting the smoke outdoors by installing chimneys was found to be effective at reducing the lung cancer risk in a cohort study of 21,232 farmers in central Xuan Wei. However, the lung cancer mortality rates in all 1.2 million residents of Xuan Wei have been increasing dramatically over the last four decades. It was higher than that in Yunnan Province and China overall, with significant heterogeneities in the geographic patterns of Xuan Wei. Intervention measures targeting certain types of coal or certain carcinogenic components in coal smoke need to be explored. To inform targeted intervention policies, it is essential to pinpoint the specific substance (particulate matter, organic extract, PAHs, free radicals, crystalline silica, and inorganic matter) that might account for the carcinogenicity of bituminous coal smoke. Exploring the underlying carcinogenesis mechanisms would also contribute to the intervention and control of the lung cancer epidemic in Xuan Wei, China. Here we review the suspected carcinogens and carcinogenesis mechanisms and discuss future research directions towards a better understanding of the etiology of lung cancer in Xuan Wei, China.

Street Dust-Bound Polycyclic Aromatic Hydrocarbons in a Saudi Coastal City: Status, Profile, Sources, and Human Health Risk Assessment

Polycyclic aromatic hydrocarbons (PAHs) in street dust pose a serious problem threatening both the environment and human health. Street dust samples were collected from five different land use patterns (traffic areas TRA, urban area URA, residential areas REA, mixed residential commercial areas MCRA and suburban areas SUA) in Jeddah, a Saudi coastal city, and one in in Hada Al Sham, a rural area (RUA). This study aimed to investigate the status, profile, sources of PAHs and estimate their human health risk. The results revealed an average concentration of total PAHs of 3320 ng/g in street dust of Jeddah and 223 ng/g in RUA dust. PAHs with high molecular weight represented 83.38% of total PAHs in street dust of Jeddah, while the carcinogenic PAH compounds accounted 57.84%. The highest average concentration of total PAHs in street dust of Jeddah was found in TRA (4980 ng/g) and the lowest in REA (1660 ng/g). PAHs ratios indicated that the principal source of PAHs in street dust of Jeddah is pyrogenic, mainly traffic emission. Benzo(a)anthracene/chrysene (BaA/CHR) ratio suggests that PAHs in street dusts of Jeddah come mainly from emission of local sources, while PAHs in RUA might be transported from the surrounding urban areas. The estimated Incremental Lifetime Cancer Risk (ILCR) associated with exposure to PAHs in street dusts indicated that both dermal contact and ingestion pathways are major contributed to cancer risk for both children and adults. Based on BaPequivalence concentrations of total PAHs, ILCRIngestion, ILCRdermal and cancer risk values for children and adults exposed to PAHs in street dust of different areas in Jeddah were found between 10-6 and 10-4, indicating potential risk. The sequence of cancer risk was TRA > URA > MCRA > SUA > REA. Only exposure to BaP and DBA compounds had potential risk for both children and adults.

Distribution of coal and coal combustion related organic pollutants in the environment of the Upper Silesian Industrial Region

In this study, a large sample set (276) was separated into up to 15 groups, including coal, fly ash, total particulate matter, coal wastes, river sediments, and different water types. Grouping the sample set into these categories helped to identify the typical features of combustion or water-washing and compare them using newly developed polycyclic aromatic hydrocarbon diagnostic ratios. A wide range of organic pollutants were identified in samples, including aromatic and polycyclic hydrocarbons, nitrogen-heterocycles, sulphur-heterocycles + trithiolane, and polycyclic aromatic hydrocarbons substituted with oxygen functional groups. The distribution of compounds was significantly influenced by water washing or combustion. During the self-heating of coal wastes, secondary compounds such as chlorinated aromatics (chlorobenzene, chloroanthracene, etc.) or light sulphur compounds (e.g. benzenethiol and benzo[b]thiophene) were formed (synthesised). Since these compounds are generally absent in sedimentary organic matter, their origin may be connected with high-temperature formation in burning coal dumps. These compounds should be identified as persistent organic pollutants (POPs) in the environment. The newly defined diagnostic ratios have worked well in separating samples (petrogenic and pyrogenic) and have pointed out the effect of incomplete combustion on self-heated coal waste, ash from domestic furnaces, or water washing and biodegradation of the studied compounds.

Polycyclic aromatic hydrocarbons (PAHs) associated with PM2.5 within boundary layer: Cloud/fog and regional transport

A study of PM_2.5-associated PAHs analysis at Mount Lushan (1165m) was conducted to investigate the distributions of PAHs in PM_2.5 and influences of cloud/fog. The main purpose was to quantify the main emission sources of PAHs and estimate regional transport effects within the boundary layer. Mount Lushan is located between the boundary layer and troposphere, which is an ideal site for atmosphere transport investigation. The concentrations of PAHs in PM_2.5 were analyzed with GC-MS. The results showed that the volume concentration was 6.98ng/m³ with a range from 1.47 to 25.17ng/m³ and PAHs mass were 160.24μg/g (from 63.86 to 427.97μg/g) during the sampling time at Mount Lushan. The dominant compounds are BbF, Pyr and BP. In terms of aromatic-ring PAHs distributions, 4-6-ring PAHs are predominant, indicating that the high-ring PAHs tend to contribute more than low-ring PAHs in particulates. Due to frequent cloud/fog days at Mount Lushan, PAHs concentrations in the PM_2.5 were determined before and after cloud/fog weather. The results demonstrated that the cloud/fog and rain conditions cause lower PAHs levels. Regression analysis was used for studying the relationship of PAHs distributions with meteorological conditions like temperature, humidity and wind. The results showed that the temperature and wind speed were inversely related with PAHs concentration but humidity had no significant relationship. Furthermore, backward trajectories and PCA combined with DR (diagnostic ratio analysis) were employed to identify the influences of regional transport and main emission sources. The results revealed that PAHs in PM_2.5 were mainly affected by regional transport with the main emissions by mobile vehicle and steel industry, which contributed about 56.0% to the total PAHs in the area of Mount Lushan. In addition, backward trajectories revealed that the dominant air masses were from the northwest accounting for about one third of total PAHs.

Environmental exposure to polycyclic aromatic hydrocarbons, kitchen ventilation, fractional exhaled nitric oxide, and risk of diabetes among Chinese females

Diabetes is related to exposure to polycyclic aromatic hydrocarbons (PAHs), inflammation in the body, and housing characters. However, associations of urinary monohydroxy-PAHs (OH-PAHs) or fractional exhaled nitric oxide (FeNO) with diabetes risk in relation to housing characters are unclear. In this study, 2645 individuals were drawn from the baseline survey of the Wuhan-Zhuhai Cohort Study. Associations of diabetes with urinary OH-PAHs or FeNO among cooking participants were estimated using logistic regression models. Among women with self-cooking meals, urinary OH-PAH levels were positively associated with diabetes risk (P < .05); the cooking women with high FeNO (≥25 ppb) had a 59% increase in the risk of diabetes (OR: 1.59, 95% CI: 1.06, 2.38), compared with those with low FeNO (<25 ppb). The cooking women with use of kitchen exhaust fans/hoods had a 52% decrease in the risk of diabetes (OR: 0.48, 95% CI: 0.27, 0.84), compared with those with nonuse of kitchen exhaust fans/hoods. The results indicated that the cooking women had an elevated risk of diabetes, which may be partly explained by an increase in the PAH body burden and higher inflammatory responses. Use of kitchen exhaust fan/hood can be associated with a lower risk of diabetes.

Mutagenicity and Lung Toxicity of Smoldering vs. Flaming Emissions from Various Biomass Fuels: Implications for Health Effects from Wildland Fires

BACKGROUND

The increasing size and frequency of wildland fires are leading to greater potential for cardiopulmonary disease and cancer in exposed populations; however, little is known about how the types of fuel and combustion phases affect these adverse outcomes.

OBJECTIVES

We evaluated the mutagenicity and lung toxicity of particulate matter (PM) from flaming vs. smoldering phases of five biomass fuels, and compared results by equal mass or emission factors (EFs) derived from amount of fuel consumed.

METHODS

A quartz-tube furnace coupled to a multistage cryotrap was employed to collect smoke condensate from flaming and smoldering combustion of red oak, peat, pine needles, pine, and eucalyptus. Samples were analyzed chemically and assessed for acute lung toxicity in mice and mutagenicity in Salmonella.

RESULTS

The average combustion efficiency was 73 and 98% for the smoldering and flaming phases, respectively. On an equal mass basis, PM from eucalyptus and peat burned under flaming conditions induced significant lung toxicity potencies (neutrophil/mass of PM) compared to smoldering PM, whereas high levels of mutagenicity potencies were observed for flaming pine and peat PM compared to smoldering PM. When effects were adjusted for EF, the smoldering eucalyptus PM had the highest lung toxicity EF (neutrophil/mass of fuel burned), whereas smoldering pine and pine needles had the highest mutagenicity EF. These latter values were approximately 5, 10, and 30 times greater than those reported for open burning of agricultural plastic, woodburning cookstoves, and some municipal waste combustors, respectively.

CONCLUSIONS

PM from different fuels and combustion phases have appreciable differences in lung toxic and mutagenic potency, and on a mass basis, flaming samples are more active, whereas smoldering samples have greater effect when EFs are taken into account. Knowledge of the differential toxicity of biomass emissions will contribute to more accurate hazard assessment of biomass smoke exposures. https://doi.org/10.1289/EHP2200.

Exposure to biomass smoke as a risk factor for oesophageal and gastric cancer in low-income populations: A systematic review

Background

Upper gastrointestinal cancers contribute significantly to cancer-related morbidity and mortality in sub-Saharan Africa, but they continue to receive limited attention. The high incidence in young adults remains unexplained, and the risk factors have not been fully described.

Methods

A literature search was conducted using the electronic database PubMed. Beginning from January 1980 to February 2016, all articles evaluating biomass smoke exposure with oesophageal and gastric cancer were reviewed.

Results

Over 70% of the African population relies on biomass fuel, meaning most Africans are exposed to biomass smoke throughout their lives. Cigarette smoke is an established risk factor for upper gastrointestinal cancers, and some of its carcinogenic constituents are also present in biomass smoke. We found eight case-control studies reporting associations between exposure to biomass smoke and oesophageal cancer, and two linking biomass smoke to gastric cancer. All of these papers reported significant positive associations between exposure and cancer risk. Further research is needed in order to fully define the constituents of biomass smoke, which could each have varying specific and synergistic or independent contributions to the development of upper gastrointestinal cancers

Conclusions

Exposure to biomass smoke is an environmental factor influencing the development of upper gastrointestinal cancers, especially in low-resource settings.

Assessment of DNA damage in blood lymphocytes of bakery workers by comet assay

The comet assay is widely used in screening and identification of genotoxic effects of different substances on people in either their working or living environment. Exposure to fuel smoke leads to DNA damage and ultimately different types of cancer. Using a comet assay, the present study aimed to assess peripheral blood lymphocyte DNA damage in people working in bakeries using natural gas, kerosene, diesel, or firewood for fuel compared to those in the control group. The subjects of this study were 55 people in total who were divided into four experimental groups, each of which comprised of 11 members (based on the type of fuel used), and one control group comprised of 11 members. Using CometScore, the subjects' peripheral blood lymphocytes were examined for DNA damage. All bakers, that is, experimental subjects, showed significantly greater peripheral blood lymphocyte DNA damage compared to the individuals in the control group. There was greater peripheral blood lymphocyte DNA damage in bakers who had been using firewood for fuel compared to those using other types of fuel to such an extent that tail moments (µm) for firewood-burning bakers was 4.40 ± 1.98 versus 1.35 ± 0.84 for natural gas, 1.85 ± 1.33 for diesel, and 2.19 ± 2.20 for kerosene. The results indicated that burning firewood is the greatest inducer of peripheral blood lymphocytes DNA damage in bakers. Nonetheless, there was no significant difference in peripheral blood lymphocyte DNA damage among diesel and kerosene burning bakers.

Association between Chinese cooking oil fumes and sleep quality among a middle-aged Chinese population

Poor sleep quality is an important symptom of many medical or psychiatric disorders. However, the impact of cooking oil fumes (COFs) on sleep quality has not been studied. This population-based cross-sectional study was conducted to examine the association between COFs of Chinese household cooking and sleep quality. Individual sleep quality assessment was completed in 2197 participants with an average age of 37.52 years, through Pittsburgh Sleep Quality Index (PSQI). Information about their cooking practice were also collected by self-reported questionnaire. As an internal biomarker of COFs, urinary 1-hydroxypyrene (1-HOP) (n = 562) was further measured using high-performance liquid chromatography. Binary logistic regression models were performed to evaluate the association between exposure to COFs and individual sleep quality. We found that, subjective poor kitchen ventilation, preheating oil to smoking, and cooking for over 30 minutes were positively associated with overall poor sleep quality (global PSQI score >5) [odds ratio (OR) = 1.75, 95% confidence interval (CI) = 1.43-2.16; 1.25, (1.03-1.52); 1.42, (1.15-1.76), respectively]. After adjusting for potential confounders, subjective poor kitchen ventilation still tend to increase the risk of long sleep latency, sleep disturbances, and daytime dysfunction [OR = 1.37, 95% CI = 1.09-1.73; 1.91, (1.39-2.61); 1.54, (1.23-1.93), respectively]. Similar results were observed in participants who preheated oil to smoking [OR = 1.36, 95% CI = 1.08-1.72; 1.55, (1.14-2.14); 1.25, (1.02-1.55), respectively] and cooked for over 30 minutes [OR = 1.34, 95% CI = 1.05-1.72; 1.46, (1.03-2.06); 1.36, (1.08-1.72), respectively]. Furthermore, high urinary 1-HOP level was also positively associated with overall poor sleep quality (OR = 2.30, 95% CI = 1.31-4.05). The results indicated that exposure to COFs from Chinese household cooking may be a risk factor for poor sleep quality among middle-aged Chinese population.

Risk factors associated with treatment refusal in lung cancer

Background

The incidence of lung cancer is increasing with longer life expectancy. Refusal of active treatment for cancer is prone to cause patients to experience more severe symptoms and shorten survival. The purpose of this study was to define the factors related to refusal or abandonment of active therapy in lung cancer.

Methods

We retrospectively reviewed the data of 617 patients from medical records from 2010 to 2014. Two groups were formed: 149 patients who refused anti‐cancer treatment and allowed only palliative care were classified into the non‐treatment group, while the remaining 468 who received anti‐cancer treatment were classified into the treatment group.

Results

The groups differed significantly in age, employment, relationship status, number of offspring, educational status, body mass index, presence of chest and systemic symptoms, Charlson Comorbidity Index, Eastern Cooperative Oncology Group score, and tumor node metastasis stage (P < 0.05). In logistic regression analysis, age (odds ratio [OR] 1.10, 95% confidence interval [CI] 1.07–1.13), educational status lower than high school (OR 1.95, 95% CI 1.2–3.2), no history of surgery (OR 2.29, 95% CI 1.4–3.7), body mass index < 18.5 (OR 2.49, 95% CI 1.3–4.7), and a high Eastern Cooperative Oncology Group score of 3 or 4 (OR 5.02, 95% CI 2.3–10.8) were significant factors for refusal of cancer treatment.

Conclusion

Individual factors, such as old age, low educational status, low weight, and poor performance status can influence refusal of cancer treatment in patients with lung cancer, and should be considered prior to consultation with patients.

Screening for lung cancer

This review will comprise a general overview of the epidemiology of lung cancer, as well as lung cancer risk factors, screening modalities, current guideline recommendations for screening, and our approach to lung cancer screening.

Comparative study of oxidative stress biomarkers in urine of cooks exposed to three types of cooking-related particles

OBJECTIVES

To evaluate how exposure to deep-frying oils, repeated frying oil (RFO) and restaurant waste oil (RWO) affects emission of polycyclic aromatic hydrocarbons (PAHs) and oxidative stress in male restaurant workers.

METHODS

The study participants included 236 male restaurant workers in 12 restaurants in Shenzhen. Airborne particulate PAHs were measured over 12h on each of two consecutive work days. Urinary 1-hydroxypyrene (1-OHP) measurements were used to indicate cooking oil fumes (COF) exposure, and urinary malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were adopted as oxidative stress markers.

RESULTS

The production and emission rates of ultrafine particles (UFPs) and PM2.5 were higher in the exposed groups than in the control group. The concentrations of summed PAHs were in the order of RFO-frying group>RWO-frying group>deep-frying group>unexposed control group. Urinary 1-OHP was found to be a significant predictor of elevated urinary MDA and 8-OHdG concentrations (all, P<0.05). UFPs were a significant predictor of elevated urinary 8-OHdG for restaurant workers (P<0.05). The RFO- and RWO-frying groups had higher mean urinary concentrations of 1-OHP, MDA and 8-OHdG than the control group (P<0.05). RFO exposure was found to be a significant risk factor for elevated urinary 8-OHdG and RWO exposure was found to be a significant risk factor for elevated urinary MDA (both, P<0.001).

CONCLUSIONS

Concentrations of urinary 1-OHP, MDA and 8-OHdG reflect occupational exposure to PAHs from COFs and oxidative stress in restaurants workers. Exposure to RFO may cause increased oxidative DNA damage, and exposure to RWO might cause increased lipid peroxidation.

Source identification, apportionment and toxicity of indoor and outdoor PM2.5 airborne particulates in a region characterised by wood burning

The occurrence of airborne particulate matter has been flagged as "of concern" in several megacities, especially in Asia. Selected Chilean regions have similar problems as wood burning is the major source of heating in homes. This concern has led to mitigation measures restricting the burning of wood at periods when the particulate matter smaller than 2.5 μm (PM2.5) concentrations are predicted to be high. This work investigates the linkage between indoor and outdoor particle concentrations, determines their source through the polyaromatic hydrocarbon (PAH) signature and investigates the efficacy of the current management practice of burning restrictions. The PM2.5 fraction was collected at 12 different properties with coincident indoor and outdoor sampling using a low-volume active sampler for 24 hours. Indoor concentrations of PM2.5 ranged from 6 to 194 μg m(-3) with a mean of 72 μg m(-3) and corresponding outdoor concentrations ranged from 5 to 367 μg m(-3) with a mean of 85 μg m(-3) over the winter periods of 2014 and 2015; the Chilean national permitted maximum in outdoor air is 50 μg m(-3) in 24 hours. Higher concentrations were measured when the outdoor air temperature was lower. The PAHs were analysed on the PM2.5 fraction; the indoor concentrations ranged from 2 to 291 ng m(-3) with a mean of 51 ng m(-3) compared to an outdoor concentration between 3 and 365 ng m(-3) with a mean of 71 ng m(-3). Multivariate statistical analysis of the PAH profiles using principal components analysis (PCA) and polytopic vector analysis (PVA) identified wood burning, static and mobile diesel emissions and kerosene combustion as the major contributors to the particulate matter. When converted to toxicity equivalents (BaP-TEQ), the highest toxicity arising from PAHs in the indoor air was associated with a property that used a "leaky" combined wood stove and heater and also used a wood-fired brazier for local heating. In outdoor air, there was a relationship between the housing density and the BaP-TEQ, such that denser housing had higher BaP-TEQ values. The restrictions in wood burning on selected days may have had a measureable effect on the PM2.5 concentrations in that region but the effects were small and only present for the day of the restriction.

Malignant tumors of the larynx: Clinicopathologic profile and implication for late disease presentation

Background:

Malignant laryngeal tumors are uncommon. Late presentation of the disease may worsen management outcomes. We described the epidemiologic, clinicopathologic profile, and management outcomes of laryngeal tumors in a tertiary health institution in Nigeria.

Materials and Methods:

An 11-year retrospective review of medical records of patients managed for malignant laryngeal tumor at the University College Hospital, Ibadan, Nigeria, was performed.

Results:

There were 97 patients comprising 74 (76.3%) males and 23 (23.7%) females with a mean age of 60.48 ± 12.15 years. The mean duration of illness was 7.3 ± 3.8 months. History of cigarette smoking and alcohol consumption was in 2.1% and 14.4% patients, respectively. The most common clinical presentations were hoarseness, cough, and dyspnea. Transglottis (91.8%) was the most common anatomic tumor location and 92.8% patients presented in advanced disease stage. Four histologic types were identified with squamous cell carcinoma accounting for 96.9%. About 92% patients had emergency tracheostomy and 56 (57.7%) patients had total laryngectomy. The postoperative complications were pharyngocutaneous fistula (5.2%) and peristomal recurrence (3.1%). The 5-year survival rate was 52.5%.

Conclusions:

Malignant laryngeal tumors are uncommon, but more females are getting the disease. Squamous cell carcinoma is the most common histologic variant. Late stage disease presentation and initial wrong diagnosis contributed to the poor management outcome.

Respiratory effects of air pollution on children

A substantial proportion of the global burden of disease is directly or indirectly attributable to exposure to air pollution. Exposures occurring during the periods of organogenesis and rapid lung growth during fetal development and early post-natal life are especially damaging. In this State of the Art review, we discuss air toxicants impacting on children's respiratory health, routes of exposure with an emphasis on unique pathways relevant to young children, methods of exposure assessment and their limitations and the adverse health consequences of exposures. Finally, we point out gaps in knowledge and research needs in this area. A greater understanding of the adverse health consequences of exposure to air pollution in early life is required to encourage policy makers to reduce such exposures and improve human health.

Characterization of particulate-bound PAHs in rural households using different types of domestic energy in Henan Province, China

The concentrations and composition of sixteen PAHs adsorbed to respirable particulate matter (PM10≤10 μm) and inhalable particulate matter (PM2.5≤2.5 μm) were determined during autumn and winter in rural households of Henan Province, China, which used four types of domestic energy [crop residues, coal, liquid petroleum gas (LPG) and electricity] for cooking and heating. The present results show that there were significantly (p<0.05) seasonal variations of particulate-bound PAHs in the rural households. The daily mean concentrations of particulate-bound PAHs in the kitchens, sitting rooms and outdoors were apparently higher in winter than those in autumn, except those in the kitchens using coal. The present study also shows that there were obvious variations of particulate-bound PAHs among the four types of domestic energy used in the rural households. The households using LPG for cooking can, at least in some circumstances, have higher concentrations of PAHs in the kitchens than using crop residues or electricity. In addition, using coal in the sitting rooms seemed to result in apparently higher concentrations of particulate-bound PAHs than using the other three types of domestic energy during winter. The most severe contamination occurred in the kitchens using LPG in winter, where the daily mean concentrations of PM2.5-bound PAHs were up to 762.5±931.2 ng m(-3), indicating that there was serious health risk of inhalation exposure to PAHs in the rural households of Henan Province. Rural residents' exposure to PM2.5-bound PAHs in kitchens would be roughly reduced by 69.8% and 85.5% via replacing coal or crop residues with electricity in autumn. The pilot research would provide important supplementary information to the indoor air pollution studies in rural area.

Secular trend analysis of lung cancer incidence in Sihui city, China between 1987 and 2011

Background

With industrial and econom ic development in recent decades in South China, cancer incidence may have changed due to the changing lifestyle and environment. However, the trends of lung cancer and the roles of smoking and other environmental risk factors in the development of lung cancer in rural areas of South China remain unclear. The purpose of this study was to explore the lung cancer incidence trends and the possible causes of these trends.

Methods

Joinpoint regression analysis and the age–period–cohort (APC) model were used to analyze the lung cancer incidence trends in Sihui, Guangdong province, China between 1987 and 2011, and explore the possible causes of these trends.

Results

A total of 2,397 lung cancer patients were involved in this study. A 3-fold increase in the incidence of lung cancer in both sexes was observed over the 25-year period. Joinpoint regression analysis showed that while the incidence continued to increase steadily in females during the entire period, a sharp acceleration was observed in males starting in 2005. The full APC model was selected to describe age, period, and birth cohort effects on lung cancer incidence trends in Sihui. The age cohorts in both sexes showed a continuously significant increase in the relative risk (RR) of lung cancer, with a peak in the eldest age group (80–84 years). The RR of lung cancer showed a fluctuating curve in both sexes. The birth cohorts identified an increased trend in both males and females; however, males had a plateau in the youngest cohorts who were born during 1955–1969.

Conclusions

Increasing trends of the incidence of lung cancer in Sihui were dominated by the effects of age and birth cohorts. Social aging, smoking, and environmental changes may play important roles in such trends.

Epidemiological review of laryngeal cancer: An Indian perspective

BACKGROUND

Laryngeal cancer is one of the 10 leading causes of cancer in Indian men. The association of laryngeal cancer and tobacco smoking is well-established, but the peculiarities such as wide variation of disease distribution and survival, role of tobacco chewing, indoor air pollution, and dietary factors in laryngeal cancer causation needs to be understood. In this study, we review the descriptive and observational epidemiology of laryngeal cancer in India.

MATERIALS AND METHODS

MEDLINE and Web of science electronic database was searched from January 1995 to December 2013, using the using keywords "laryngeal cancer, laryngeal cancer outcome, epidemiology, etiological factor and their corresponding Mesh terms were used in combination like OR, AND." Two authors independently selected studies published in English and conducted in India. A total of 15 studies were found to be relevant and eligible for this review.

RESULTS

In India, laryngeal cancer contributes to approximately 3-6% of all cancers in men. The age-adjusted incidence rate of cancer larynx in males varies widely among registries, highest is 8.18 per 100,000 in Kamprup Urban District and the lowest is 1.26 per 100,000 in Nagaland. The 5-year survival for laryngeal cancer in India is approximately 28%. Indian studies show tobacco, alcohol, long-term exposure to indoor air pollution, spicy food, and nonvegetarian diet as risk factors for laryngeal cancer.

CONCLUSION

There is wide regional variation in the incidence of laryngeal cancer in India. Survival rates of laryngeal carcinoma are much lower as compared to other Asian countries. Studies conducted in India to identify important risk factors of laryngeal cancer are very limited, especially on diet and indoor air pollution. Hence, more research is required for identifying the etiological factors and development of scientifically sound laryngeal cancer prevention programs.

Household air pollution and cancers other than lung: a meta-analysis

Household air pollution (HAP) from solid fuel combustion contributes to 2.6% of the global burden of disease. HAP emissions are an established lung carcinogen; however, associations with other cancer sites have not been fully explored. We conducted a meta-analysis of 18 case-control studies. Using fixed-effects models, utilizing the adjusted odds ratios (OR) and 95% confidence intervals (95% CI) from each study, we evaluated the association between HAP and cervical neoplasia (663 cases and 1747 controls) and upper aero-digestive tract cancers (6022 cases and 15 325 controls). We found that HAP was associated with cervical neoplasia (OR = 6.46; 95% CI = 3.12-13.36; 4 studies); oral (OR = 2.44; 95% CI = 1.87-3.19; 4 studies; 1000 cases/3450 controls); nasopharyngeal (OR = 1.80; 95% CI = 1.42-2.29; 6 studies; 2231 cases/2160 controls); pharyngeal (OR = 3.56; 95% CI = 2.22-5.70; 4 studies; 1036 cases/3746 controls); and laryngeal (OR = 2.35; 95% CI = 1.72- 3.21; 5 studies; 1416 cases/4514 controls) cancers. The elevated risk for esophageal cancer (OR = 1.92; 95% CI = 0.82-4.49; 2 studies; 339 cases/1455 controls) was non-significant. HAP was associated with cervical neoplasia among studies that accounted for HPV infection (OR = 9.60; 95% CI = 3.79-24.32) and smoking (OR = 4.72; 95% CI = 1.84-12.07). Similarly, our observed associations between HAP and upper aero-digestive tract cancers remained significantly elevated when analyses were restricted to studies that controlled for smoking. No significant publication bias was detected. Our results suggest that the carcinogenic effect of HAP observed for lung cancer may extend to other cancers, including those of the cervix and the upper aero-digestive tract. Further research is needed to confirm these associations in prospective studies.

An individual risk prediction model for lung cancer based on a study in a Chinese population

AIMS AND BACKGROUND

Early detection and diagnosis remains an effective yet challenging approach to improve the clinical outcome of patients with cancer. Low-dose computed tomography screening has been suggested to improve the diagnosis of lung cancer in high-risk individuals. To make screening more efficient, it is necessary to identify individuals who are at high risk.

METHODS AND STUDY DESIGN

We conducted a case-control study to develop a predictive model for identification of such high-risk individuals. Clinical data from 705 lung cancer patients and 988 population-based controls were used for the development and evaluation of the model. Associations between environmental variants and lung cancer risk were analyzed with a logistic regression model. The predictive accuracy of the model was determined by calculating the area under the receiver operating characteristic curve and the optimal operating point.

RESULTS

Our results indicate that lung cancer risk factors included older age, male gender, lower education level, family history of cancer, history of chronic obstructive pulmonary disease, lower body mass index, smoking cigarettes, a diet with less seafood, vegetables, fruits, dairy products, soybean products and nuts, a diet rich in meat, and exposure to pesticides and cooking emissions. The area under the curve was 0.8851 and the optimal operating point was obtained. With a cutoff of 0.35, the false positive rate, true positive rate, and Youden index were 0.21, 0.87, and 0.66, respectively.

CONCLUSIONS

The risk prediction model for lung cancer developed in this study could discriminate high-risk from low-risk individuals.

Vehicle refuelling, use of domestic wood heaters and the risk of childhood brain tumours: Results from an Australian case-control study

BACKGROUND

The aetiology of childhood brain tumours (CBT) is largely unknown. Damage to germ cells after parental exposure to airborne carcinogens, such as volatile organic compounds and polycyclic aromatic hydrocarbons is one plausible pathway. This analysis aimed to investigate whether parental refuelling of vehicles or the use of domestic wood heaters in key time periods relating to the child's birth was associated with an increased risk of CBT.

PROCEDURE

Cases <15 years of age were recruited through 10 paediatric oncology centres around Australia; controls were recruited through nationwide random-digit dialling, frequency matched to cases on age, sex and State of residence. Exposure to refuelling and wood heaters was ascertained through questionnaires from both parents. Odds ratios (ORs) and confidence intervals (CIs) were estimated using unconditional logistic regression, adjusting for relevant covariates.

RESULTS

Data were available for 306 case and 950 control families. Paternal refuelling ≥4 times/month was associated with an increased risk of CBT (OR 1.59, 95% CI: 1.11, 2.29), and a dose-dependent trend was observed (P = 0.004). No association was seen for maternal refuelling. Use of closed, but not open, wood heaters before (OR 1.51, 95% CI: 1.05, 2.15) and after (OR 1.44, 95% CI: 1.03, 2.01) the child's birth was associated with increased risk of CBT, but dose-response relationships were weak or absent.

CONCLUSIONS

Paternal refuelling of vehicles ≥4 times/month and the use of closed wood heaters before the child's birth may increase the risk of CBT. Replication in larger studies is needed. Pediatr Blood Cancer 2015;62:229-234. © 2014 Wiley Periodicals, Inc.

Role of household exposure, dietary habits and glutathione S-Transferases M1, T1 polymorphisms in susceptibility to lung cancer among women in Mizoram India

BACKGROUND

A case-control study was conducted to evaluate the effect of household exposure, dietary habits, smoking and Glutathione S-Transferases M1, T1 polymorphisms on lung cancer among women in Mizoram, India.

MATERIALS AND METHODS

We selected 230 newly diagnosed primary lung cases and 460 controls from women in Mizoram. Multivariate logistic regression analysis was performed to estimate adjusted odds ratio (OR).

RESULTS

Exposure of cooking oil fumes (p<0.003), wood as heating source for cooking (p=0.004), kitchen inside living room (p=0.001), improper ventilated house (p=0.003), roasting of soda in kitchen (p=0.001), current smokers of tobacco (p=0.043), intake of smoked fish (p=0.006), smoked meat (p=0.001), Soda (p<0.001) and GSTM1 null genotype (p=0.003) were significantly associated with increased risk of lung cancer among women in Mizoram. Significantly protective effect was observed for intake of bamboo shoots (p=<0.001) and egg (p<0.001). A clear increase in dose response gradient was observed for total cooking dish years. Risk for lung cancer tends to increase with collegial effect of indoor environmental sources (p=0.022). Significant correlation was also observed for interaction of GST polymorphisms with some of dietary habits.

CONCLUSIONS

We confirmed the important role of exposure of cooking oil emission and wood smoke, intake of smoked meat, smoked fish and soda (an alkali preparation used as food additives in Mizoram) and tobacco consumption for increase risk of lung cancer among Women in Mizoram.