A Historical Survey of Key Epidemiological Studies of Ionizing Radiation Exposure.

In this article we review the history of key epidemiological studies of populations exposed to ionizing radiation. We highlight historical and recent findings regarding radiation-associated risks for incidence and mortality of cancer and non-cancer outcomes with emphasis on study design and methods of exposure assessment and dose estimation along with brief consideration of sources of bias for a few of the more important studies. We examine the findings from the epidemiological studies of the Japanese atomic bomb survivors, persons exposed to radiation for diagnostic or therapeutic purposes, those exposed to environmental sources including Chornobyl and other reactor accidents, and occupationally exposed cohorts. We also summarize results of pooled studies. These summaries are necessarily brief, but we provide references to more detailed information. We discuss possible future directions of study, to include assessment of susceptible populations, and possible new populations, data sources, study designs and methods of analysis.

Tobacco Constituents, Flavorants, and Paper Permeability of Factory-Made and Roll-Your-Own Cigarettes on the Australian Market.

INTRODUCTION: Roll-your-own (RYO) tobacco is a popular choice in Australia, with some people who smoke finding these products more attractive than factory-made cigarettes (FMC). Differences in visual and tactile properties and in the feel and taste of the smoke may contribute to this attractiveness. These differences may be driven by variation in tobacco constituents and wrapping paper permeability. However, to date, there has been no comparison of RYO and FMC products on the Australian market. AIMS AND METHODS: Chemical constituents, pH, flavorants, and paper permeability were compared in unburned RYO tobacco and tobacco from FMC. RYO and FMC products from matched brands were compared, as were products from the most popular FMC and RYO brands on the Australian market in 2018. RESULTS: RYO tobacco had higher moisture and humectant content (glycerol and propylene glycol) than FMC tobacco. RYO tobacco also had higher amounts of total and reducing sugars and lower nicotine when comparing the most popular brands. RYO papers were less permeable than FMC papers. Both RYO and FMC tobacco contained many chemicals identified as flavorants, including fourteen with known potential health risks. For most measured constituents and flavorants, RYO tobaccos had more in common with other RYO than FMC, with the commonalities remaining even when matched brands were compared. CONCLUSIONS: Higher levels of moisture, humectants, and sugars in Australian RYO tobacco compared to FMC may be increasing attractiveness of RYO by reducing the harsh taste of the smoke and increasing the moist feel of the tobacco. IMPLICATIONS: While price is the main factor driving the use of RYO tobacco, some people who smoke find these products more attractive. This study has shown that Australian RYO tobacco contains higher amounts of glycerol, propylene glycol, and sugars than FMC. These chemicals may be improving the taste of the tobacco, as well as creating a moist feel that is falsely perceived as indicating that the tobacco is "fresh" and "less chemically." Ironically, it may be that higher amounts of some added chemicals in RYO contribute to false perceptions of a more natural and less harmful product.

Prospective study of e-cigarette use and respiratory symptoms in adolescents and young adults.

RATIONALE: Electronic cigarette (e-cigarette) aerosol contains volatile aldehydes, including flavourings and oxidant metals with known pulmonary toxicity. OBJECTIVES: To evaluate the associations of e-cigarette use with symptoms of wheeze, bronchitic symptoms and shortness of breath (SOB) across 4 years of prospective data. METHODS: Participants completed questionnaires on respiratory symptoms and past 30-day e-cigarette, cigarette and cannabis use in 2014 (wave 1; N=2094; mean age 17.3 years, SD=0.6 years). Follow-up information was collected in 2015 (wave 2; n=1609), 2017 (wave 3; n=1502) and 2018 (wave 4; n=1637) using online surveys. Mixed-effects logistic regression models evaluated associations of e-cigarette use with respiratory symptoms. MEASUREMENTS AND MAIN RESULTS: Participants were mostly Hispanic white (51.8%) and evenly representative by sex (49.6% female; 50.4% male). Compared with never e-cigarette users, past 30-day e-cigarette users reported increased odds of wheeze (OR 1.81; 95% CI 1.28, 2.56), bronchitic symptoms (OR 2.06; 95% CI 1.58, 2.69) and SOB (OR 1.78; 95% CI 1.23, 2.57), adjusting for study wave, age, sex, race, lifetime asthma diagnosis and parental education. Effect estimates were attenuated (wheeze (OR 1.41; 95% CI 0.99, 2.01), bronchitic symptoms (OR 1.55; 95% CI 1.18, 2.05), SOB (OR 1.48; 95% CI 1.01, 2.18)), after adjusting additionally for current cigarette use, cannabis use and secondhand exposure to e-cigarettes/cigarettes/cannabis. CONCLUSIONS: E-cigarette use in young adults was associated with respiratory symptoms, independent of combustible cannabis and cigarette exposures.

Commentary: Role and communications of cancer hazard determinations.

This commentary is written in response to a recent commentary in Carcinogenesis that provides several viewpoints on the International Agency for Research on Cancer's (IARC) Monographs program on cancer hazard identification. This commentary offers an alternative viewpoint of the role of cancer hazard identification derived from cancer epidemiology studies in risk characterization, as well as clarification on the previous commentary's interpretation of the purpose of the Monographs and other programs of cancer hazard identification and how IARC communicates the findings of the Monographs.

E-Cigarettes and Cardiopulmonary Health.

E-cigarettes have surged in popularity over the last few years, particularly among youth and young adults. These battery-powered devices aerosolize e-liquids, comprised of propylene glycol and vegetable glycerin, typically with nicotine, flavors, and stabilizers/humectants. Although the use of combustible cigarettes is associated with several adverse health effects including multiple pulmonary and cardiovascular diseases, the effects of e-cigarettes on both short- and long-term health have only begun to be investigated. Given the recent increase in the popularity of e-cigarettes, there is an urgent need for studies to address their potential adverse health effects, particularly as many researchers have suggested that e-cigarettes may pose less of a health risk than traditional combustible cigarettes and should be used as nicotine replacements. This report is prepared for clinicians, researchers, and other health care providers to provide the current state of knowledge on how e-cigarette use might affect cardiopulmonary health, along with research gaps to be addressed in future studies.

Retail Marketing of Menthol Cigarettes in Los Angeles, California: a Challenge to Health Equity.

INTRODUCTION: Sales of menthol cigarettes continue to increase, accounting for a third of the US cigarette market. Retail marketing of menthol cigarettes is a contributing factor to tobacco-related health disparities. To inform regulation to address associated disparities, we examined retail marketing strategies for menthol cigarettes and their features and characteristics in relation to neighborhood racial/ethnic composition. METHODS: We used multilevel regression models to examine associations of neighborhood racial/ethnic composition and store type with menthol cigarette sales outcomes, including availability, exterior advertising, price promotions, and price in a sample of tobacco retailers (N = 673) in Los Angeles County neighborhoods with a median or below-median household income. We also recorded the prices of Newport cigarettes (the highest selling menthol cigarette brand in the United States) and blu disposable menthol e-cigarettes. RESULTS: Overall, 94.5% of retailers sold menthol cigarettes, 31.2% displayed menthol cigarette price promotions, and 30.2% displayed at least one menthol cigarette advertisement on their exterior. Adjusting for racial/ethnic zip code cluster and store type, stores located in predominantly African American neighborhoods showed significantly higher odds in the availability of Newport cigarettes than stores in Hispanic neighborhoods (OR = 0.21; 95% CI, 0.09-0.53; P = .001) or non-Hispanic White (OR = 0.12; 95% CI, 0.05-0.31; P < .001) neighborhoods. Stores located in predominantly African American neighborhoods displayed significantly higher odds of having price promotions for menthol cigarettes and storefront advertisements than those in Hispanic neighborhoods (OR = 0.51; 95% CI, 0.30-0.88; P = .02 and OR = 0.25; 95% CI, 0.13-0.48; P < .001, respectively). CONCLUSION: In 2016 and 2017, menthol cigarettes were widely available in Los Angeles County across racial/ethnic neighborhoods. We found a disproportionate number of storefront advertisements and price promotions for menthol cigarettes in stores located in predominantly African American neighborhoods along with the lowest advertised pack price. This evidence supports tobacco control policies that restrict menthol cigarette sales in the retail environment.

Association of Exercise Behavior with Overall Survival in Stage I-IIIA Lung Cancer.

Rationale: Exercise assessments may help predict outcomes for patients with diagnosed lung cancer. Objectives: We examined the relationship between prediagnosis exercise behavior and clinical outcomes among patients with stage I-IIIA lung cancer. Methods: In a retrospective cohort study of patients with stage I-IIIA lung cancer at Kaiser Permanente Colorado who had at least one Exercise Vital Sign assessment-a questionnaire tool to help promote exercise in chronic disease management-within the year before diagnosis, we defined exercise behavior as active (any min/wk of moderate-to-vigorous-intensity physical activity) or inactive (no moderate-to-vigorous physical activity). The outcomes were 1) overall survival (OS) and 2) acute healthcare use (AHCU). We used the Kaplan-Meier method, Cox proportional hazard model, and negative binomial regression model to analyze the effects of exercise on outcomes, adjusting for demographic, socioeconomic, clinical, and lung-cancer characteristics. Results: Among 552 patients with lung cancer, 230 (42%) were identified as physically active before their diagnosis of cancer. There was no significant difference in the stage distribution between active and inactive patients. The median survival times were 2.4 years for the active group and 1.8 years for inactive patients (P < 0.001). The mean rates (standard deviations) of AHCU were 1.09 (1.55) and 2.31 (5.61) per person-year for active and inactive groups, respectively (P < 0.01). Active exercise, compared with inactivity, was associated with better OS (hazard ratio, 0.52 [0.39-0.69]) and lower AHCU (rate ratio, 0.63 [0.49-0.80]) in unadjusted analyses; in adjusted analyses, active exercise was associated with better OS (hazard ratio, 0.62 [0.45-0.86]), but AHCU was not lower by a statistically significant amount (rate ratio, 0.82 [0.65-1.04]). Conclusions: Prediagnosis active exercise was associated with better OS after diagnosis of stage I-IIIA lung cancer. Exercise assessments may help predict outcomes, risk-stratify patients for curative-intent therapy, and identify those who would benefit from increased physical activity and exercise.

Australian smokers' experiences and perceptions of recessed and firm filter cigarettes.

BACKGROUND: While cigarette filter modifications have long been used to increase product appeal and assuage health concerns, tighter marketing restrictions, including plain packaging, have further spurred the growth of filter variants. We explored and assessed experiences and perceptions of smokers who had tried and/or currently use recessed filter cigarettes (RFCs) and firm filter cigarettes (FFCs). METHOD: In November 2018, we undertook eight exploratory focus groups of Australian adult factory-made cigarette smokers (total n=56). In July 2019, we surveyed 999 smokers aged 18-69 years to quantify ever and current use of these products and associated beliefs and sensory experiences. RESULTS: Focus group and survey findings were consistent. Among 988 smokers who had at least tried factory-made cigarettes, 28.9% had tried FFCs and 11.1% currently smoked these, while 36.4% had tried RFCs and 7.5% currently smoked these. Smokers in both studies believed these filters may reduce harm and that FFCs increase appeal. In the survey, 58.9% of RFC triers agreed these hide the filter's brown stain and 48.9% agreed that RFCs keep harmful substances away from the mouth. Similarly, 58.4% of FFC triers agreed these trap more harmful substances than standard filters. Relative to standard filter cigarettes, more smokers experienced FFCs and RFCs as feeling clean (p=0.03) and more current FFC users experienced these as feeling smooth (p=0.01). CONCLUSION: RFCs and FFCs undermine plain packaging legislation, which aims to reduce appeal and minimise misperceptions about the relative harms of different tobacco products. Like other filter modifications, these filter variants should be disallowed.

Tobacco Products and the Risks of SARS-CoV-2 Infection and COVID-19.

IMPLICATIONS: This commentary addresses the state of the evidence on tobacco products, nicotine, and COVID-19. The evidence of the effects of smoking on respiratory infections and the immune system in general are examined and the current understanding of tobacco products and risk for SARS-CoV-2 infection and the course of COVID-19 is addressed.

Trends in the Age of Cigarette Smoking Initiation Among Young Adults in the US From 2002 to 2018.

Importance: Success in reducing the prevalence of adolescent smoking could reflect complete prevention of smoking initiation or a shift in the age of cigarette smoking initiation from adolescence into early adulthood. Objective: To assess trends in early adult (ages 18-23 years) vs adolescent (age <18 years) cigarette smoking initiation and transition to daily cigarette smoking from 2002 to 2018. Design, Setting, and Participants: Ages at initiation of smoking and the transition to daily smoking were ascertained from the National Survey on Drug Use and Health (2002-2018), an annual, population-based, repeated cross-sectional study representative of the US population. This cross-sectional analysis was restricted to young adults who completed the survey at ages 22 to 23 years during survey years 2002 to 2018 to limit potential age-related recall bias. Retrospectively collected age of cigarette smoking initiation was assessed among ever cigarette smokers; age of transition to daily smoking was assessed among ever daily cigarette smokers. Data analysis was performed from June 2019 to July 2020. Exposures: Calendar year of survey (2002 to 2018). Main Outcomes and Measures: The main outcomes were population-weighted cigarette smoking prevalence and cigarette smoking initiation and transition to daily smoking in adolescence (age <18 years) vs early adulthood (ages 18-23 years). Results: Among 71 756 young adults aged 22 to 23 years (38 226 women [50.5%]), ever cigarette smoking prevalence decreased from a population-weighted estimate of 74.6% (95% CI, 73.1%-75.9%) in 2002 to 51.4% (95% CI, 49.3%-53.5%) in 2018 (P < .001). Daily smoking prevalence rates similarly decreased from 41.1% (95% CI, 39.1%-43.1%) in 2002 to 20.2% (95% CI, 18.6%-21.8%) in 2018 (P < .001). However, among 48 015 ever smokers, the proportion initiating smoking in early adulthood (ages 18-23 years) increased over this time, from 20.6% (95% CI, 18.5%-22.8%) in 2002 to 42.6% (95% CI, 39.6%-45.7%) in 2018 (P < .001). Similarly, among 24 490 daily cigarette smokers, the proportion who transitioned to daily smoking in early adulthood increased from 38.7% (95% CI, 35.9%-41.6%) in 2002 to 55.9% (95% CI, 52.0%-59.8%) in 2018 (P < .001). Conclusions and Relevance: A substantial proportion of beginning smokers and most new daily smokers are now young adults, reflecting a shift from adolescence to early adulthood, a population segment once considered beyond the critical risk period for cigarette smoking onset. Expanding the long-standing emphasis on adolescent surveillance and prevention in adolescence to include the young adult population is warranted.

Carcinogenesis and lung cancer: 70 years of progress and more to come.

This commentary celebrates the 40th year of Carcinogenesis, spanning 1980-2020 with a focus on lung cancer. For lung cancer, these 40 years come toward the end of a century of scientific inquiry that began with descriptions of this highly fatal malignancy and that closes with emphasis on molecular processes and genomics. This commentary gives a historical perspective of lung cancer research as well as a look into the questions that remain to be addressed. Over the 20th century and into the first two decades of the 21st, a series of issues have more or less sequentially been the focus of epidemiological investigation of lung cancer, as questions have been answered and methodologies have evolved. These questions began with whether an epidemic was occurring and continue now with exploration of causal mechanisms and molecular risk predictors. With tobacco smoking firmly established decades ago as a cause of lung cancer, the evidence has long been sufficient to motivate tobacco prevention and control. There is unfinished business as tobacco smoking remains widespread and the industry continues to market new, addicting, products.

E-cigarette Product Characteristics and Subsequent Frequency of Cigarette Smoking.

BACKGROUND: There is a dearth of evidence regarding the association of use of electronic cigarettes (e-cigarettes) with certain product characteristics and adolescent and young adult risk of unhealthy tobacco use patterns (eg, frequency of combustible cigarette smoking), which is needed to inform the regulation of e-cigarettes. METHODS: Data were collected via an online survey of participants in the Southern California Children's Health Study from 2015 to 2016 (baseline) and 2016 to 2017 (follow-up) (N = 1312). We evaluated the association of binary categories of 3 nonmutually exclusive characteristics of the e-cigarette used most frequently with the number of cigarettes smoked in the past 30 days at 1-year follow-up. Product characteristics included device (vape pen and/or modifiable electronic cigarette [mod]), use of nicotine in electronic liquid (e-liquid; yes or no), and use for dripping (directly dripping e-liquid onto the device; yes or no). RESULTS: Relative to never e-cigarette users, past-30-day e-cigarette use was associated with greater frequency of past-30-day cigarette smoking at follow-up. Among baseline past-30-day e-cigarette users, participants who used mods (versus vape pens) smoked >6 times as many cigarettes at follow-up (mean: 20.8 vs 1.3 cigarettes; rate ratio = 6.33; 95% confidence interval: 1.64-24.5) after adjustment for sociodemographic characteristics, baseline frequency of cigarette smoking, and number of days of e-cigarette use. After adjustment for device, neither nicotine e-liquid nor dripping were associated with frequency of cigarette smoking. CONCLUSIONS: Baseline mod users (versus vape pen users) smoked more cigarettes in the past 30 days at follow-up. Regulation of e-cigarette device type warrants consideration as a strategy to reduce cigarette smoking among adolescents and young adults who vape.

The IARC Monographs: Updated Procedures for Modern and Transparent Evidence Synthesis in Cancer Hazard Identification.

The Monographs produced by the International Agency for Research on Cancer (IARC) apply rigorous procedures for the scientific review and evaluation of carcinogenic hazards by independent experts. The Preamble to the IARC Monographs, which outlines these procedures, was updated in 2019, following recommendations of a 2018 expert advisory group. This article presents the key features of the updated Preamble, a major milestone that will enable IARC to take advantage of recent scientific and procedural advances made during the 12 years since the last Preamble amendments. The updated Preamble formalizes important developments already being pioneered in the Monographs program. These developments were taken forward in a clarified and strengthened process for identifying, reviewing, evaluating, and integrating evidence to identify causes of human cancer. The advancements adopted include the strengthening of systematic review methodologies; greater emphasis on mechanistic evidence, based on key characteristics of carcinogens; greater consideration of quality and informativeness in the critical evaluation of epidemiological studies, including their exposure assessment methods; improved harmonization of evaluation criteria for the different evidence streams; and a single-step process of integrating evidence on cancer in humans, cancer in experimental animals, and mechanisms for reaching overall evaluations. In all, the updated Preamble underpins a stronger and more transparent method for the identification of carcinogenic hazards, the essential first step in cancer prevention.

Pollution in the Americas: a leading cause of disease burden and an opportunity for cancer prevention.

OBJECTIVE: Environmental and occupational agents are causes of cancer and disease worldwide while their control and the reduction of the associated disease burden remains complex. MATERIALS AND METHODS: This paper summarizes the current status of the burden of environmental and occupational causes of disease in the Americas based on presentations from a panel on environment, occupation and other environmental risk factors for cancer in the Americas, delivered in Panama, at the international conference Promoting Health Equity and Transnational Collaborations for the Prevention and Control of Cancer in the Americas. RESULTS: Three case studies are presented to illustrate the impact of specific environmental and occupational agents and the challenge of control. CONCLUSIONS: There are still fully avoidable exposures to carcinogens, as well documented in the case of asbestos in Brazil. Thus, there are abundant targets for intervention to reduce cancer in the Americas.

OBJETIVO: Los agentes ambientales y ocupacionales son causas de cáncer y enfermedades en todo el mundo, mientras que su control y reducción de la carga de enfermedad asociada siguen siendo puntos complejos. MATERIAL Y MÉTODOS: Este documento resume el estado actual de la carga de las causas ambientales y ocupacionales de las enfermedades en las Américas a partir de las presentaciones de un panel sobre medio ambiente, ocupación y otros factores de riesgo ambientales para el cáncer en las Américas, realizado en Panamá, en la conferencia internacional Promoviendo la Equidad en Salud y las Colaboraciones Transnacionales para la Prevención y el Control del Cáncer en las Américas. RESULTADOS: Se presentan tres estudios de caso para ilustrar el impacto de agentes ambientales y ocupacionales específicos y el desafío del control. CONCLUSIONES: Todavía hay exposiciones totalmente evitables a los carcinógenos, como está bien documentado en el caso del asbesto en Brasil. Hay abundantes puntos estratégicos de intervención para reducir el cáncer en las Américas.

Pollution in the Americas: a leading cause of disease burden and an opportunity for cancer prevention / Contaminación en las Américas: causa principal de carga de la enfermedad y una oportunidad para prevención del cáncer

Abstract: Objective: Environmental and occupational agents are causes of cancer and disease worldwide while their control and the reduction of the associated disease burden remains complex. Materials and methods: This paper summarizes the current status of the burden of environmental and occupational causes of disease in the Americas based on presentations from a panel on environment, occupation and other environmental risk factors for cancer in the Americas, delivered in Panama, at the international conference Promoting Health Equity and Transnational Collaborations for the Prevention and Control of Cancer in the Americas. Results: Three case studies are presented to illustrate the impact of specific environmental and occupational agents and the challenge of control. Conclusions: There are still fully avoidable exposures to carcinogens, as well documented in the case of asbestos in Brazil. Thus, there are abundant targets for intervention to reduce cancer in the Americas.

Resumen: Objetivo: Los agentes ambientales y ocupacionales son causas de cáncer y enfermedades en todo el mundo, mientras que su control y reducción de la carga de enfermedad asociada siguen siendo puntos complejos. Material y métodos: Este documento resume el estado actual de la carga de las causas ambientales y ocupacionales de las enfermedades en las Américas a partir de las presentaciones de un panel sobre medio ambiente, ocupación y otros factores de riesgo ambientales para el cáncer en las Américas, realizado en Panamá, en la conferencia internacional Promoviendo la Equidad en Salud y las Colaboraciones Transnacionales para la Prevención y el Control del Cáncer en las Américas. Resultados: Se presentan tres estudios de caso para ilustrar el impacto de agentes ambientales y ocupacionales específicos y el desafío del control. Conclusiones: Todavía hay exposiciones totalmente evitables a los carcinógenos, como está bien documentado en el caso del asbesto en Brasil. Hay abundantes puntos estratégicos de intervención para reducir el cáncer en las Américas.