Tobacco industry efforts at discrediting scientific knowledge of environmental tobacco smoke: a review of internal industry documents

STUDY OBJECTIVE: Using tobacco industry internal documents to investigate the use of tobacco industry consulting scientists to discredit scientific knowledge of environmental tobacco smoke (ETS). DESIGN: Basic and advanced searches were performed on the Philip Morris, Tobacco Institute, R J Reynolds, Brown and Williamson, Lorillard, and the Council for Tobacco Research document web sites, with a concentration on the years 1985-1995. Guildford depository files located on the Canadian Council on Tobacco Control website were also searched. The documents were found in searches undertaken between 1 March and 30 June 2000. MAIN RESULTS: The industry built up networks of scientists sympathetic to its position that ETS is an insignificant health risk. Industry lawyers had a large role in determining what science would be pursued. The industry funded independent organisations to produce research that appeared separate from the industry and would boost its credibility. Industry organised symposiums were used to publish non-peer reviewed research. Unfavourable research conducted or proposed by industry scientists was prevented from becoming public. CONCLUSIONS: Industry documents illustrate a deliberate strategy to use scientific consultants to discredit the science on ETS.     

Respiratory health consequences of environmental tobacco smoke

Over the last several decades there has been a growing interest in examining the health consequences of environmental tobacco smoke (ETS). As a result of a wide body of research, ETS is now considered an unacceptable and entirely preventable public health hazard, and public policy increasingly discourages the presence of tobacco smoke in the public domain. This article provides an overview of the composition of ETS and the major diseases and disorders strongly linked to ETS, emphasizing the effects of ETS on pulmonary function, asthma, and lung cancer.     

The tobacco industry's worldwide ETS consultants project: European and Asian components

BACKGROUND: The tobacco industry has formed regional environmental tobacco smoke (ETS) consultants programs in order to generate controversy on the issue of secondhand smoke (SHS) in Europe, Asia and Latin America. Only those countries in which the industry foresaw SHS restrictions were included. This paper describes the European and Asian components of the tobacco industry's worldwide ETS consultants program. METHODS: A systematic search was carried out of tobacco industry documents available on the Internet between October 2002 and February 2004. RESULTS: Beginning in 1987, Philip Morris assembled an international ETS consultants program in collaboration with other tobacco companies based on their market shares in different regions of the world. The law firm Covington & Burling contacted and hired consultants with a wide range of expertise, usually affiliated with an academic institution, in order to avoid direct contact with the industry. The objective of the program was to influence policy makers, media and the public by providing, through their consultants, 'accurate' (pro-industry) information concerning smoking regulations in public places and workplaces, indoor air quality and ventilation standards, and scientific claims regarding SHS. Consultants also conducted research related to SHS and organized and attended regional and international symposiums related to SHS without acknowledging industry funding. CONCLUSIONS: Despite evidence that the issue of smoke-free environments was close to emerging within the general public throughout the world in the late 1980s, the tobacco industry used its well-organized network of consultants to avoid SHS regulations in most of the world.     

Double exposure. Environmental tobacco smoke

One study after another is finding strong associations between a variety of human illness and exposure to environmental tobacco smoke (ETS). A 1986 report by the U.S. Surgeon General concluded that ETS is a cause of disease, including lung cancer, in healthy nonsmokers. Other reports have documented causal associations between ETS and lower respiratory tract infections, middle ear disease and exacerbation of asthma in children, heart disease, retardation of fetal growth, sudden infant death syndrome, and nasal sinus cancer. However, the findings from many of these studies remain controversial. A number of scientists remain skeptical about the association between ETS and serious illness in nonsmokers, charging that scientific journals either fail to publish pro-tobacco findings and meta-analyses or disregard those that are published. They also claim that many epidemiological studies declare causal associations based on marginal odds ratios.     

Environmental tobacco smoke and periodontal disease in the United States

OBJECTIVES: Cigarette smoking is a leading risk factor for periodontal disease. This cross-sectional study investigated the relation between environmental tobacco smoke (ETS) and periodontal disease in the United States. METHODS: Data were obtained from the Third National Health and Nutrition Examination Survey (1988-1994). The outcome was periodontal disease, defined as 1 or more periodontal sites with attachment loss of 3 mm or greater and a pocket depth of 4 mm or greater at the same site. Exposure to ETS at home and work was self-reported. The study analyzed 6611 persons 18 years and older who had never smoked cigarettes or used other forms of tobacco. RESULTS: Exposure to ETS at home only, work only, and both was reported by 18.0%, 10.7%, and 3.8% of the study population, respectively. The adjusted odds of having periodontal disease were 1.6 (95% confidence interval = 1.1, 2.2) times greater for persons exposed to ETS than for persons not exposed. CONCLUSIONS: Among persons in the United States who had never used tobacco, those exposed to ETS were more likely to have periodontal disease than were those not exposed to ETS.     

Restaurant smoking restrictions and environmental tobacco smoke exposure.

OBJECTIVES: This study evaluated the effectiveness of smoking restrictions. METHODS: We measured particulate concentrations in restaurants with different levels of allowable smoking. RESULTS: Mean particulate concentrations were 70% higher in establishments without smoking restrictions compared with those with partial smoking restrictions. Concentrations in nonsmoking restaurants were reduced by an additional 20% to 30%. Measurements of cadmium, an environmental tobacco smoke (ETS) marker, implicated ETS as the major source of particulate in restaurants that allowed smoking. CONCLUSIONS: Partial smoking restrictions substantially reduce, but do not eliminate, ETS exposure in restaurants. Occupants of nonsmoking restaurants avoid ETS exposure but may experience substantial particulate exposures from cooking emissions.     

Predictors of support for environmental tobacco smoke bans in state government

BACKGROUND: Environmental tobacco smoke (ETS) is a major threat to public health, associated with a number of serious diseases, and a leading cause of death. Previous research demonstrates that enactment of government policies mandating clean indoor air is effective in creating more smoke-free public places and decreasing the incidence of smoking. Both researchers and community activists have an interest in understanding the factors that predict support for the regulation of ETS. METHODS: This study examined predictors of support for regulating ETS by surveying 684 city and county public officials in Colorado who were interviewed by phone and mail (response rate 61%). RESULTS: Thirty-five percent of public officials reported that it is a "serious" or "very serious" problem that nonsmokers breathe in other people's cigarette smoke, 21% were "neutral," and 42% said that it was "not serious" or "not serious at all." Results indicated that support for policies to control ETS and promote clean indoor air is significantly more prevalent among public officials who: (1) believe that tobacco use is a serious problem in their community, (2) believe that breathing environmental tobacco smoke is a serious problem for nonsmokers, (3) believe that city and county government should get involved with people's decisions about smoking, (4) support smoking-cessation programs for public employees, and (5) have smoked less than 100 cigarettes during their lifetime. CONCLUSIONS: Both the harms of ETS and legislation to create smoke-free environments remain controversial among local officials. Smoke-free advocates should support officials who believe that ETS is a problem and persuade officials on the harms of ETS and the need for government intervention.     

Environmental tobacco smoke and risk of adult leukemia

BACKGROUND: The role of environmental tobacco smoke (ETS) in the causation of lung and breast cancer has been repeatedly evaluated over recent years. In contrast, its impact on the risk of adult leukemia has received little attention. METHODS: We used the lifetime residential and occupational ETS exposure histories from a population-based sample of 1068 incident and histologically confirmed adult leukemia cases and 5039 population controls age 20 to 74 years to evaluate the relationship between ETS exposure and adult leukemia risk among nonsmokers in Canada. The duration of exposure and smoker-years index were used as indices of ETS exposure. We restricted our analysis to the 266 case and 1326 control subjects who reported being lifetime nonsmokers and provided residential ETS exposure history for at least 75% of their lifetime. RESULTS: No association was found for most leukemia subtypes, and in particular for acute myeloid leukemia. In contrast, the risk for chronic lymphocytic leukemia was clearly associated with ETS exposure, with an adjusted odds ratio of 2.3 (95% confidence interval = 1.2-4.5) for more than 83 smoker-years of residential exposure and 2.4 (1.3-4.3) for more than 72 smoker-years of occupational exposure. There was a dose-response relationship for chronic lymphocytic leukemia with both indices of exposure. Risk was not higher with recent exposure, using time-window-exposure analyses. CONCLUSIONS: Regular long-term ETS exposure may be a risk factor for chronic lymphocytic leukemia.     

Environmental tobacco smoke and carotid arterial stiffness

BACKGROUND: Although active smoking acutely increases arterial stiffness, the association between arterial stiffness and chronic exposure to environmental tobacco smoke (ETS) has not been evaluated. We used baseline data from the Vitamin E Atherosclerosis Prevention Study to evaluate the association between ETS exposure and arterial stiffness among 227 healthy adult nonsmokers. METHODS: B-mode ultrasonograms of the common carotid artery were used to compute the carotid arterial wall stiffness index beta. Beta was compared by the number of sources and daily hours of ETS exposure. RESULTS: The carotid stiffness index beta was positively associated with age, body mass index (BMI), fasting glucose, and common carotid artery intima-media thickness (IMT). In the total sample, beta was not related to the number of ETS exposure sources. The carotid stiffness index beta increased with number of sources and daily hours of ETS in subjects with BMI > or =27.1 kg/m2 and IMT > or =0.707 mm. The association was not apparent in subjects with lower BMI or IMT (for number of ETS sources, interaction P values=0.006 and 0.01, respectively). For number of ETS sources, but not hours of exposure, positive associations were apparent among females (but not males) and among subjects > or =55 years old (but not younger subjects). CONCLUSIONS: These data indicate that arterial stiffness is adversely associated with ETS in a dose-dependent manner among individuals with higher BMI and greater carotid artery IMT.     

Intervention and policy issues related to children's exposure to environmental tobacco smoke

BACKGROUND: Children's exposure to environmental tobacco smoke (ETS) is unacceptably high; almost 40% of children in the United States are regularly exposed to ETS. METHODS: This paper presents a review of the literature that evaluates interventions designed to reduce ETS exposure among young children. In addition, it presents the study design for Project KISS (Keeping Infants Safe from Smoke), an intervention designed to utilize exposure-related feedback to increase parents' motivation for ETS reduction and to reduce household ETS levels. Baseline data are presented to illustrate factors that should be addressed in ETS interventions. RESULTS: The literature review demonstrates the dearth of studies in the literature targeting ETS reduction among children. Participants in Project KISS believed that smoking had affected their children's health and were in later stages of motivational readiness to quit smoking than is typically observed. However, they face a number of challenges to smoking, such as high prevalence of nicotine dependence, high prevalence of living with other smokers, and socioeconomic and stress-related barriers. CONCLUSIONS: The policy implications of this research are discussed, and recommendations are made for future research.     

Smoking and exposure to tobacco smoke at medium-sized and large-scale workplaces

BACKGROUND: The objective of the present study was to assess the smoking prevalence of workers, the attitudes toward smoking, and exposure to environmental tobacco smoke (ETS) in different work environments. METHODS: A questionnaire survey and indoor air quality (IAQ) measurements including the concentration of gaseous nicotine in indoor air were performed in 10 medium-sized and large-scale workplaces representing industrial, service, and office environments. The questionnaire was distributed to all workers (n=1471) in 10 workplaces. IAQ measurements were performed in 4-7 locations in each workplace. RESULTS: Altogether 1027 (70%) employees, of whom 31% were women, responded to the questionnaire. Prevalence of daily smokers was 28.3% (32.3% for men and 22.9% for women). The prevalence was highest among workers in the service sector (32.7%) and lowest in offices (21.6%). Among smokers, 86% of men and 75% of women smoked inside the building. Exposures greater than one hour to ETS were highest in industry (66.3%) and lowest in services (42.6%). Non-smokers complained more often than the regular smokers about the spreading of tobacco smoke to non-smoking areas, and they felt that workplace smoking was a significant discomfort. Mean concentration of nicotine was highest in service environments (3.0 microg/m(3)) and lowest in offices (0.6 microg/m(3)). CONCLUSIONS: According to the present questionnaire survey and IAQ measurements, smoking habits and exposure to tobacco smoke varied considerably depending on the position of the employees and the type of the workplace.     

A questionnaire for assessing environmental tobacco smoke exposure

Exposure to environmental tobacco smoke (ETS) has been associated with adverse health consequences. In this study, the association between self-reported ETS exposure and serum cotinine levels was examined. As part of the population-based Epidemiology of Hearing Loss Study in Beaver Dam, WI, self-reported data on ETS were obtained at the 5-year follow-up examination (1998-2000; n = 2800). Serum cotinine levels were obtained on 643 of these participants (53-75 years old). Serum cotinine levels increased with reported number of hours of recent ETS exposure. Most (95.3%) participants who reported being smokers had serum cotinine levels >15 ng/mL, compared with only 2.7% of nonsmokers. Usual ETS exposure among nonsmokers was assessed with a brief questionnaire quantifying exposure at work, at home, and in social settings, and then classified into three levels of exposure. Those reporting little or no exposure had a geometric mean cotinine level of 0.06 ng/mL (95% confidence interval (CI): 0.05, 0.07), compared with 0.14 (95% CI: 0.09, 0.22) and 0.63 (95% CI: 0.36, 1.10) for those reporting moderate and high ETS exposure, respectively (F-test for trend: P < 0.001). These results suggest that the questionnaire can be used to distinguish relative levels of exposure to ETS.     

Environmental tobacco smoke is just as damaging to DNA as mainstream smoke.

This study demonstrates the ability of tar isolated from environmental tobacco smoke (ETS) to nick DNA in mammalian cells. Solutions of ETS tar behave similarly to aqueous solutions of cigarette tar from mainstream smoke. Both solutions contain the tar semiquinone radical, and this radical associates with the DNA in viable rat alveolar macrophages. Solutions of tar from ETS cause single-strand DNA breaks in rat thymocytes in proportion to the amount of tar present, until a plateau is reached. ETS tar solutions, like mainstream tar solutions, produce hydrogen peroxide. Hydrogen peroxide appears to be an essential component of the mechanism by which both ETS tar and mainstream tar cause DNA damage in rat thymocytes, as catalase substantially protects against DNA damage. Glutathione also protects against DNA nicking by both ETS and mainstream tar solutions by scavenging radicals and/or oxidants. The chelator diethylenetriamine pentaacetic acid also provides partial (40%) protection. The studies demonstrate that the water-soluble components of ETS tar can enter cells, associate with, and then nick DNA.     

Respiratory irritation from environmental tobacco smoke.

Acute physiological and chronic pathological responses of the respiratory tract to environmental tobacco smoke (ETS) are reviewed briefly. This study excludes discussion of the possible risk of lung cancer and the known impact of carbon monoxide on the fetus and adult. In some environments, the dose of particulate matter and the concentrations of irritant vapors absorbed on the ETS particles reach a level for which a physiological response may be expected, not only in the nose but also the bronchi. However, direct measurements indicate only small increases of nasal and bronchial resistance if normal subjects are exposed to maximal, likely concentrations of ETS. ETS is readily detected by the nonsmoker, but there is no strong evidence that pulmonary reactions have a psychogenic basis. The condition of approximately 20% of asthmatic patients is exacerbated by ETS exposure. Further study is needed to clarify the likelihood that adults will progress from a minor physiological response to pathological reactions, e.g., chronic obstructive lung disease. In young children (who are less able to escape from ETS), the association between exposure and an increase in respiratory disease is stronger than in adults. Exacerbation of asthma and an increase of respiratory disease are further arguments for legislation to guarantee smoke-free air to the nonsmoking public.     

Exposure to environmental tobacco smoke and children health

This paper reviews the investigations of the effects of pre- and/or postnatal exposure to environmental tobacco smoke (ETS) on children health reported in the literature. The evidence from epidemiological studies demonstrate that children's exposure to ETS is a risk factor for a variety of diseases, including respiratory disorders and middle ear disease. However, the current research base on the ETS-associated risks is still inadequate to fully support strategies, programs and policy development in this area. For example, it is not definitively determined what methods should be used for assessing ETS exposure and predicting potential health risks of exposed children. Based on the available data, we tried to find out which methods seem to be most desirable for quantifying ETS exposure in children. It is our opinion that among all biomarkers, the measurements of blood, saliva or urinary cotinine and hair nicotine are, as for today, the most specific and sensitive methods for an objective assessment of ETS exposure in children. A combination of the measurement of body fluids cotinine and hair nicotine with the questionnaire and interview-derived information seems to be the optimal method for assessing ETS exposure in children.     

Exposure to environmental tobacco smoke in the nonsmoking population of Cambodia

OBJECTIVE: To estimate the extent of environmental tobacco smoke (ETS) exposure among nonsmokers in the adult population of Cambodia. METHODS: A cross-sectional survey was conducted on a nationally representative sample of 13,988 Cambodian adults in 2005. Information on smoking and exposure to ETS was obtained by trained interviewers using a standard questionnaire. RESULTS: Overall, 37.4% of the 10,263 nonsmoking responders, or an estimated 1,629,700 nonsmoking Cambodians, were exposed to ETS. One third of pregnant women (31.4%) were exposed to ETS at home. In both unadjusted and adjusted models, men were less likely to be exposed to ETS at home (OR=0.34; 95% CI=0.29-0.41) and more likely to be exposed to ETS at work and in public places (OR=3.08; 95% CI=2.14-4.43 and OR=2.17; 95% CI=1.82-2.59, respectively). Education was inversely related to ETS exposure at home (OR=0.51; 95% CI=0.27-0.96 for 10 years of education vs 5 years or less). Legislators, senior officials, and managers were less likely to be exposed to ETS at home than professionals (OR=0.13; 95% CI=0.04-0.46), but more likely to be exposed at work or in public places. Rural residence was associated with higher ETS exposure in the home (OR=2.52; 95% CI=1.71-3.71) and lower ETS exposure at work (OR=0.42; 95% CI=0.24-0.76) compared to urban residence. CONCLUSIONS: The high prevalence of ETS exposure among adult Cambodians indicates an urgent need for specific measures such as public awareness campaigns, policies, and regulations to protect nonsmokers in Cambodia.     

Environmental tobacco smoke and absenteeism related to respiratory illness in schoolchildren

Household environmental tobacco smoke (ETS) exposure accounts for substantial morbidity among young children, but the ETS-associated morbidity burden among school-age children is less well defined. Illness-related school absenteeism is a measure of a broad spectrum of adverse effects of ETS exposure in school-age children. The authors investigated the relations between ETS exposure, asthma status, and illness-related school absenteeism in a cohort of 1,932 fourth-grade schoolchildren from 12 southern California communities during January-June 1996. Incidence rates and adjusted relative risks of illness-related absences were determined by using an active surveillance system. The effects of ETS exposure on absenteeism were assessed by using stratified incidence rates and Poisson regression to adjust for sociodemographic factors. ETS exposure was associated with an increased risk of respiratory-illness-related school absences (relative risk (RR) = 1.27, 95% confidence interval (CI): 1.04, 1.56). Children living in a household with two or more smokers were at increased risk of such absences (RR = 1.75, 95% CI: 1.33, 2.30). Children's asthma status affected their response to ETS. Compared with unexposed children without asthma, children with asthma were at increased risk of respiratory-illness-related school absences when exposed to one (RR = 2.35, 95% CI: 1.49, 3.71) or two or more (RR = 4.45, 95% CI: 2.80, 7.07) household smokers. Children without asthma also had an increased risk if exposed to two or more smokers (RR = 1.44, 95% CI: 1.04, 2.00). Therefore, ETS exposure is associated with increased respiratory-related school absenteeism among children, especially those with asthma.     

Environmental tobacco smoke and the risk of pancreatic cancer: findings from a Canadian population-based case-control study

BACKGROUND: Despite the fact that tobacco is a well-recognized risk factor for pancreatic cancer, no study has yet reported on the association between environmental tobacco smoke (ETS) and this malignancy. We investigated the relationship between pancreatic cancer and childhood and adult exposure to ETS using a case-control study design. METHODS: Our study population consisted of 583 pancreatic cancer cases and 4,813 population-based controls that were identified within 8 Canadian provinces between 1994 and 1997. Mail-out questionnaires were used to collect risk factor information and a lifetime residential and occupational history of exposure to ETS. RESULTS: Among never smokers, those who were exposed to ETS both as a child and as an adult had an odds ratio of 1.21 (95% CI=0.60-2.44) relative to those with no exposure. For active smoking, when the referent group consisted of never smokers who had not been regularly exposed to ETS, the risk increases were more pronounced with an increased number of years of smoking, cigarette pack-years, years since quit smoking, and average number of cigarettes smoked daily. CONCLUSIONS: Overall, our results are suggestive of a weak association between pancreatic cancer and ETS. Perhaps more importantly, they suggest that ETS smoking exposures may confound the risk of pancreatic cancer associated with active smoking measures commonly used in epidemiologic studies.     

Environmental tobacco smoke and breast cancer incidence

To evaluate whether environmental tobacco smoke (ETS) influences breast cancer incidence, data from a population-based case-control study were analyzed. Respondents with available ETS information assessed by in-person questionnaires included 1356 newly diagnosed cases and 1383 controls. Relative to nonsmokers who reported no residential ETS exposure throughout the life course, the odds ratios (OR) for breast cancer were not substantially elevated in relation to ETS exposure, active smoking, or a joint measure of active and passive smoking (OR, 1.15, 95% CI, 0.90, 1.48). An increased OR, however, was noted among nonsmokers who lived with a smoking spouse for over 27 years (2.10, 95% CI, 1.47, 3.02), although no dose-response was evident. Also, among women with hormone-receptor-positive tumors only, the OR for both active and passive smoking was increased (1.42 for ER+ PR+, 95% CI, 1.00, 2.00). Our data suggest that if there is an effect for ETS on breast cancer, that effect is restricted to selected subgroups of women, such as those with long-term exposure from a smoking spouse.