Ethyl carbamate in Swedish and American smokeless tobacco products and some factors affecting its concentration.

BACKGROUND: We are interested in comparing the levels of harmful or potentially harmful constituents in Swedish and American smokeless tobacco products (STPs). We report here the concentrations of the IARC Group 2 A (probable human) carcinogen ethyl carbamate (EC) in seventy commercial STPs from the US and Sweden, representing 80-90% of the market share of the major STP categories in these countries. We also examine the effects of various additives, processing and storage conditions on EC concentrations in experimental snus samples. RESULTS: EC was determined from aqueous extracts of the STPs using ultra performance liquid chromatography tandem mass spectrometry (UPLC/MS/MS). EC was undetectable (< 20 ng/g wet weight basis WWB) in 60% of the commercial STPs, including all the chewing tobacco (CT), dry snuff (DS), hard pellet (HP), soft pellet (SP), and plug products. Measurable levels of EC were found in 11/16 (69%) of the moist snuff (MS) samples (average 154 ng/g in those samples containing EC) and 19/32 (59%) of the Swedish snus samples (average 35 ng/g). For the experimental snus samples, EC was only observed in ethanol treated samples. EC concentrations increased significantly with ethanol concentrations (0-4%) and with storage time (up to 24 weeks) and temperature (8 °C vs 20 °C). EC concentrations were lower at lower pHs but were unaffected by adding nitrogenous precursors identified from food studies (citrulline and urea), increasing water content or by pasteurisation. Added EC was stable in the STP matrix, but evaporative losses were significant when samples were stored for several weeks in open containers at 8 °C. CONCLUSIONS: EC was found in measurable amounts only in some moist STPs i.e. pasteurised Swedish snus and unpasteurised US MS; it is not a ubiquitous contaminant of STPs. The presence of ethanol contributed significantly to the presence of EC in experimental snus samples, more significantly at higher pH levels. Sample age also was a key determinant of EC content. In contrast, pasteurisation and fermentation do not appear to directly influence EC levels. Using published consumption rates and mouth level exposures, on average STP consumers are exposed to lower EC levels from STP use than from food consumption.

Comprehensive survey of radionuclides in contemporary smokeless tobacco products.

There is considerable interest in the chemical composition of smokeless tobacco products (STPs), owing to health concerns associated with their use. Previous studies have documented levels of 210Po, 210Pb and uranium in STP samples. Here, the levels of 13 α-particle and 15 ß-radiation emitting radionuclides have been measured in a broad and representative range of contemporary STPs commercially available in the United States and Sweden. For each radionuclide, the level of radioactivity and calculated mass per gram of STP are reported. The results indicate that, among 34 Swedish snus and 44 US STPs, a more complex radionuclide content exists than previously reported for these products. Of the 28 radionuclides examined, 13 were detected and quantified in one or more STPs. The most frequently identified radionuclides in these STPs were 40K, 14C, 210Po and 226Ra. Over half the STPs also contained 228Th, and an additional 8 radionuclides were identified in a small number of STPs. The presence of 14C, 3H and 230Th are reported in tobacco for the first time. The activity of ß-emitters was much greater than those of α-emitters, and the ß-emitter 40K was present in the STPs with both the greatest radioactivity and mass concentrations. Since the three radionuclides included in the FDA's HPHC list were either not detected (235U), identified in only three of 78 samples (238U), and/or had activity levels over fifty times lower than that of 40K (210Po, 238U), there may be a rationale for reconsidering the radionuclides currently included in the FDA HPHC list, particularly with respect to 40K. Using a model of the physical and biological compartments which must be considered to estimate the exposure of STP users to radionuclides, we conclude that exposure from α-emitters may be minimal to STP users, but 40K in particular may expose the oral cavities of STP users to ß-radiation. Although a more comprehensive picture of the radioisotope content of STPs has emerged from this study, epidemiological evidence suggests that the levels of radionuclides measured in this study appear unlikely to present significant risks to STP users.

Smoking prevalence: a comparison of two American surveys.

OBJECTIVES: To compare smoking prevalence estimates from two nationally representative surveys in the USA. STUDY DESIGN: Smoking prevalence estimates derived from the National Health Interview Survey (NHIS) and the National Survey on Drug Use and Health (NSDUH) for the period 1998-2005. METHODS: Comparisons according to age (18-34 or 35+ years) and according to smoking frequency (every day or some days). RESULTS: In 1998, the prevalence of smoking in both surveys was nearly identical at 24%. From 1999 to 2005, a divergence occurred in smoking prevalence found by the NSDUH and the NHIS. By 2005, NHIS prevalence had declined to 20.9% [95% confidence interval (CI) 20.3-21.5], but the NSDUH estimate was 25.4% (95%CI 24.6-26.2), amounting to 9.1 million more smokers. In 1999, prevalence among 18-34 year olds in the NSDUH was only 18% (95%CI 13-22) higher than that in the NHIS, but that difference had doubled by 2005, when smoking prevalence among 18-34 year olds was 36% (95%CI 30-41) higher in the NSDUH than in the NHIS. NSDUH and NHIS prevalence among 35+ year olds were similar in 1999 and 2001, but the difference was 13% (95%CI 9-18) in 2005. Higher smoking prevalence estimates in the NSDUH were largely due to much higher estimates for some-day smoking in that survey, although every-day smoking prevalence among 18-34 year-olds was also higher in the NSDUH than in the NHIS. CONCLUSIONS: These results raise doubt about the recent decline in smoking prevalence described by the NHIS. Further investigation of the NSDUH/NHIS discrepancy may lead to better surveys and to a clearer picture of smoking trends in the USA.

Tobacco use among Swedish schoolchildren.

OBJECTIVE: To study the prevalence of snus use and of smoking among Swedish schoolchildren from 1989 to 2003. DESIGN: Surveys conducted by the Swedish Council for Information on Alcohol and Other Drugs. SETTING: All of Sweden. SUBJECTS: 84,472 boys and girls age 15-16 years. MAIN OUTCOME MEASURES: Subjects are classified as non-smokers, occasional smokers, and regular smokers, and into three similar categories for snus use. Tobacco use is reported as sex specific prevalence. RESULTS: During the period 1989 to 2003, the prevalence of tobacco use declined both among boys and girls. For boys, regular smoking declined after 1992 from 10% to 4%. Their snus use was about 10% in the 1990s but increased to 13% by 2003. Regular smoking among girls was 20% in early years and declined to 15%. Smoking among girls was always double that among boys. Patterns of occasional tobacco use were similar to those of regular use. CONCLUSIONS: The high prevalence of snus use in Sweden not only reduces smoking rates among Swedish men, but suppresses smoking among boys as well.

Influence of smoking and snus on the prevalence and incidence of type 2 diabetes amongst men: the northern Sweden MONICA study.

OBJECTIVE: To explore the effect of smoking and smokeless tobacco, 'snus', on the risk of type 2 diabetes. DESIGN: Population-based cross-sectional and prospective follow-up study in northern Sweden. SUBJECTS: A total of 3384 men, aged 25-74 years, who participated in the MONICA study in 1986, 1990, 1994 or 1999, 1170 of whom had an oral glucose tolerance test. In 1999, 1757 men from previous cohorts returned for re-examination. Main outcome measures. We compared the prevalence of type 2 diabetes or pathological glucose tolerance (PGT) amongst tobacco users to that of nonusers at entry into the study and at follow-up, using odds ratios. RESULTS: Compared with never users, the age-adjusted risk of prevalent clinically diagnosed diabetes for ever smokers was 1.88 (CI 1.17-3.0) and for smokers 1.74 (0.94-3.2). Corresponding odds ratios for snus users were 1.34 (0.65-2.7) and 1.18 (0.48-2.9). We found no increased risk of prevalent PGT in snus users or smokers. Former smokers and snus users had an insignificantly increased risk for PGT. Compared with nonusers, the age-adjusted risk of developing clinically diagnosed diabetes during follow-up was 4.63 (1.37-16) in consistent exclusive smokers, 3.20 (1.16-8.8) in ex-smokers and no cases in consistent snus users. The risk of PGT during follow-up was not increased in consistent tobacco users but evident, although not statistically significant, in those who quit snus during the follow-up period, 1.85 (0.60-5.7). Adjustment for physical activity and alcohol consumption did not change the major findings. CONCLUSIONS: The risk of diabetes for snus users was not significantly increased. Smoking was associated with prevalent and incident cases of diabetes. Ex-tobacco users tended towards more PGT.

The influence of smoking and smokeless tobacco use on weight amongst men.

OBJECTIVE: To explore the effect of tobacco use (smoking and smokeless tobacco) and cessation on body weight. DESIGN: Cross-sectional and prospective follow-up study. SETTING: Northern Sweden. SUBJECTS: A total of 2993 men aged 25-64 years who participated in the northern Sweden MONICA study in 1986, 1990 or 1994, 1650 of whom were followed up in 1999. MAIN OUTCOME MEASURES: The prevalence of overweight [body mass index (BMI) >/= 27] amongst tobacco users was compared with nonusers at entry into the study. The average annual percentage weight gain amongst men was also determined according to tobacco use both at entry and at follow-up, and the development of overweight amongst tobacco-use groups was reported using standardized incidence ratios. RESULTS: Smokers who quit tobacco during the follow-up period gained significantly more weight than smokers who switched to snus (annual gain 0.96% vs. 0.51%, P < 0.05). At entry, ex-smokers had higher prevalence of overweight than nonusers of tobacco [prevalence ratio (PR) = 1.24, 95% confidence interval (CI) = 1.10-1.40]. Snus users had slightly higher prevalence of overweight at entry (PR = 1.20, CI = 1.01-1.42). Snus users who quit gained more weight than nonusers (0.70% vs. 0.44%, P < 0.05) or those who continued to use snus (0.42%). CONCLUSIONS: Cessation of tobacco, either cigarettes or snus, leads to significantly increased weight gain. However, snus use may play a role in lowering the weight gain following smoking cessation.

Evolving patterns of tobacco use in northern Sweden.

BACKGROUND AND OBJECTIVES: Cross-sectional data from northern Sweden suggest that the increased use of Swedish moist snuff (snus) may have contributed to a decline in the prevalence of smoking, especially amongst men. This study describes the evolving patterns of tobacco use in this population over the period 1986-1999. DESIGN: This is a prospective follow-up study of 1651 men and 1756 women, aged 25-64 years, who were enrolled in the northern Sweden MONICA project (entry in 1986, 1990, 1994) and who were followed-up in 1999. Information on tobacco use at entry and at follow-up was used to describe the stability of tobacco use over a period of 5-13 years ending in 1999. RESULTS: Snus was the most stable form of tobacco use amongst men (75%); only 2% of users switched to cigarettes and 20% quit tobacco altogether. Smoking was less stable (54%); 27% of smokers were tobacco-free and 12% used snus at follow-up. Combined use (smoking and snus) was the least stable (39%), as 43% switched to snus and 6% switched to cigarettes. Former users of both products were much less stable than former users of either cigarettes or snus. The stability of smoking amongst women was 69%, which was higher than that amongst men (P < 0.05). CONCLUSIONS: The use of snus played a major role in the decline of smoking rates amongst men in northern Sweden. The evolution from smoking to snus use occurred in the absence of a specific public health policy encouraging such a transition and probably resulted from historical and societal influences.

Impact of smokeless tobacco use on smoking in northern Sweden.

BACKGROUND AND OBJECTIVES: For many years Swedish men have had the world's lowest rates of smoking and smoking-related mortality. Despite these facts, a thorough analysis of tobacco use patterns in Sweden has not been performed. The purpose of this study was to examine the prevalence and interaction of cigarette smoking and use of Swedish moist snuff (snus) in the population of northern Sweden. DESIGN: The study cohort of 2998 men and 3092 women aged 25-64 was derived from the northern Sweden MONICA study, consisting of population-based surveys in 1986, 1990, 1994 and 1999. Detailed information on tobacco use was used to develop prevalence data, and the prevalence ratio was used to compare rates amongst various subgroups. RESULTS: Amongst men ever-tobacco use was stable in all survey years at about 65%, but the prevalence of smoking declined from 23% in 1986 to 14% in 1999, whilst snus use increased from 22% to 30%. In women the prevalence of smoking was more stable in the first three surveys (approximately 27%) but was 22% in 1999, when snus use was 6%. In all years men showed higher prevalence of ex-smoking than women. A dominant factor was a history of snus (PR = 6.18, CI = 4.96-7.70), which was more prevalent at younger ages. CONCLUSIONS: The recent transition from smoking to snus use amongst men, and incipiently amongst women, in northern Sweden is remarkable and relevant to the global discussion on strategies to reduce smoking.

Cancer and benign tumor incidence among employees in a polymers research complex.

The detection of several intracranial tumors among employees in one building complex (C500) at a petrochemical research facility prompted investigation of a possible workplace cause. This retrospective follow-up study included 1847 subjects, of whom 1735 had worked in C500. Medical records, death certificates, and Illinois State Cancer Registry data confirmed self-reported cancers and tumors. Analyses compared the subjects' cancer and benign intracranial tumor incidence rates with national general population rates. C500 employees had 15% fewer than expected total cancers (92 observed/108 expected; standardized incidence ratio [SIR], 85; 95% confidence interval [95% CI], 69 to 104). An excess of brain cancer (6/2.0; SIR, 302; 95% CI, 111 to 657) was concentrated among white men who had 10 or more years since hire and 5 or more years of C500 employment (4/0.7; SIR, 602; 95% CI, 165 to 1552) and who had worked in a particular building of C500 (5/0.7; SIR, 735; 95% CI, 239 to 1716). An excess of benign intracranial tumors (6/1.6; SIR, 385; 95% CI, 142 to 839) was not restricted to a single type of tumor and was not concentrated in any particular building. Occupational exposure may have caused the increased rate of brain cancer but is a less likely explanation for the elevated rate of benign intracranial tumors.

Aggressive osteoblastoma of the mandible closely simulating calcifying epithelial odontogenic tumor. Report of two cases with unusual histopathologic findings.

Aggressive osteoblastoma is a rare bone-forming neoplasm composed of prominent epithelioid cells that demonstrate locally invasive growth with a high rate of recurrence but no metastatic potential. Clinical, radiographic and pathologic features of mandibular aggressive osteoblastoma in a 21-year-old African-American male and a 12-year-old Caucasian female are presented. Both tumors were resected with wide surgical margins and neither patient had adjuvant radiation or chemotherapy. The patients showed no evidence of local recurrence or distant spread either clinically or radiographically after two years of follow-up. These tumors were composed of solid sheets of pleomorphic epithelioid cells, eosinophilic amorphous osteoid with foci of calcification, which closely simulated amyloid. Differentiation of this tumor from histologically similar calcifying epithelial odontogenic tumor and low-grade osteosarcoma proved difficult. Immunohistochemical study with osteocalcin confirmed the osteoblastic nature of these epithelioid cells.

Cancer incidence among employees at a petrochemical research facility.

This investigation evaluated cancer incidence among workers at a petrochemical research facility in Illinois. A cluster of brain cancer and other intracranial tumors had occurred at the facility before the study began. The subjects were 5641 people who had worked at the facility from 1970 through 1996 and who had lived in Illinois at any time between 1986 and 1997. Data on cancer cases came primarily from the Illinois State Cancer Registry. Analyses compared the 1986-to-1997 cancer incidence rates of employees with Illinois general population rates. Subjects had 18% fewer than expected total cancers (125 observed/153 expected cases; standardized incidence ratio [SIR], 82; 95% confidence interval [CI], 68 to 98), which was primarily attributed to a large deficit of lung cancer (10/26; SIR, 39; CI, 19 to 72). Brain cancer was increased in the overall study group (6/2.7; SIR, 222; CI, 81 to 484). This excess was restricted to white men who were scientists or technicians for one of the three companies at the facility (6/0.8; SIR, 750; CI, 275 to 1633); all cases in this group had worked in the "500 building complex" (6/0.6; SIR, 968; CI, 355 to 2106). Subjects also had an increased incidence of thyroid cancer (7/2.6; SIR, 265; CI, 106 to 546) that was not concentrated in particular occupational or building groups. The brain cancer incidence patterns indicated that an unidentified occupational exposure might have been responsible for the excess. Chance, socioeconomic factors leading to better case detection in facility employees than in the general population, and confounding by potential nonoccupational risk factors are plausible explanations of the observed increase in thyroid cancer.

The fifty-year decline of cancer in America.

PURPOSE: From 1950 to 1990, the overall cancer mortality rate increased steadily in the United States, a trend which ran counter to declining mortality from other major diseases. The purpose of this study was to assess the impact of lung cancer on all-cancer mortality over the past 50 years. METHODS: Data from the National Centers for Health Statistics were used to develop mortality rates for all forms of cancer combined, lung cancer, and other-cancer (all-cancer minus lung cancer) from 1950 to 1998. RESULTS: When lung cancer is excluded, mortality from all other forms of cancer combined declined continuously from 1950 to 1998, dropping 25% during this period. The decline in other-cancer mortality was approximately 0.4% annually from 1950 to 1990 but accelerated to 0.9% per year from 1990 to 1996 and to 2.2% per year from 1996 to 1998. CONCLUSION: The long-term decline is likely due primarily to improvements in medical care, including screening, diagnosis, and treatment.

Mortality among employees at a petrochemical research facility.

BACKGROUND: This retrospective follow-up study evaluated mortality during 1970-1996 among 6,956 employees at a petrochemical research facility in Illinois. METHODS: Standardized mortality ratios (SMRs) compared employees' mortality rates with those of the Illinois general population. Poisson regression procedures estimated rate ratios for various subject subgroups compared to other facility employees. RESULTS: Subjects had 267 observed/524 expected deaths (SMR = 51) from all causes combined and a large deficit of deaths from all cancers (76/136, SMR = 56) and from most other major diseases. Other results included fewer than expected brain cancers (1/4.0, SMR = 25) and a slight increase in colorectal cancer (20/14, SMR = 139) that was concentrated in white male scientists employed for one of the three main companies at the facility (SMR = 295, RR = 2.6). CONCLUSIONS: The deficit of brain cancer deaths contrasts with an excess incidence seen in a companion study. Subjects' generally favorable mortality experience probably reflects socioeconomic advantages of employees relative to the Illinois general population.

Case-control study of intracranial tumors among employees at a petrochemical research facility.

This case-control study evaluated the relation between potential exposure to chemical and physical agents and the occurrence of intracranial tumors among employees at a petrochemical research facility. Cases were employees with glioma (n = 6) or benign intracranial tumors (n = 6). Controls (n = 119) were individually matched to cases on gender and birth year, and they were alive and did not have an intracranial tumor at the case's diagnosis date. Exposure information came from interviews with subjects or surrogates and from corporate records on agents used in research projects. Analyses computed matched odds ratios (ORs) and corresponding 95% confidence intervals (CIs) for self-reported exposure to 15 agents and project-based estimates of exposure to 29 agents. For gliomas, the OR was elevated for self-reported exposure to ionizing radiation (OR, 15.7; CI, 1.4 to 179.4), n-hexane (OR, infinity; CI, 1.4 to infinity), organometallics (OR, 9.4; CI, 1.5 to 59.7), and amines other than nitrosamines (OR, 6.0; CI, 1.0 to 35.7). The OR also was elevated for project-based potential use of ionizing radiation (OR, 9.6; CI, 1.7 to 55.2) and for potential use of n-hexane lasting at least 4 years (OR, 16.2; CI, 1.1 to 227.6). For benign intracranial tumors, the OR was elevated only for self-reported exposure to ionizing radiation (OR, 5.4; CI, 1.7 to 43.1) and other amines (OR, 5.2; CI, 0.9 to 29.5). Occupational exposure may have contributed to the glioma excess, but the specific causal agents remain unknown. The study indicated that benign intracranial tumors were unlikely to be work-related.

Case-series investigation of intracranial neoplasms at a petrochemical research facility.

BACKGROUND: From 1970 through 1997, 17 intracranial neoplasms were identified among 6,800 employees of a petrochemical research facility. This investigation describes the case-series. METHODS: The intracranial neoplasms were identified by self reports and record linkages, and were confirmed by medical records and a pathology review. Standardized incidence ratios (SIRs) compare observed and expected numbers of cases according to certain work characteristics. RESULTS: Overall, there were 17 observed and 10.5 expected intracranial neoplasms, including 11/4.7 benign intracranial tumors and 6/5.9 brain cancers. All brain cancers occurred among male research scientists or technicians. Four had worked at some time on the same floor of one building (SIR=12.6, 95% CI=3.4-32.1), and several had worked on a research project with at least one other brain cancer case. The benign intracranial neoplasm cases did not have common building assignments or work activities. CONCLUSIONS: The occurrence pattern of brain cancers, but not that of benign tumors, suggests a possible occupational etiology.

Caliber-persistent labial artery. A common vascular anomaly.

Sixteen cases of caliber-persistent labial artery of the lips have been reported to date in the English literature. Six of these were clinically misdiagnosed as squamous cell carcinoma and treated with wedge resection. To date, we have seen 187 cases clinically and an additional 23 cases through our surgical oral pathology services. Careful clinical observation usually reveals a soft linear or papular bluish elevation above the labial mucosal surface. The unique feature is pulsation--not simply pulsation toward and away from the observer, which can be caused by an underlying artery, but lateral pulsation, which only an artery can exhibit. All but 2 of our 187 clinical cases were asymptomatic. To the best of our knowledge, this is the first report of caliber-persistent labial artery of the upper lip. The upper:lower lip ratio for the clinical cases was almost 2:1. Three times as many lower lip as upper lip lesions were biopsied. Males and females were almost equally affected (clinical cases, 76:86; histopathologic cases, 9:13). Although a vascular term (artery, hemangioma, phlebolith, varix, vascular malformation) was used on the biopsy form in one half of the clinical differential diagnoses, none of the clinical histories mentioned pulsation. In contrast to the cases of Miko et al. in 1980 and 1983, none of our cases manifested itself as an ulcer, nor was carcinoma ever mentioned in the clinical differential diagnosis. The purpose of this article is to familiarize clinicians and pathologists with the clinical and histopathologic features of this seldom reported but common vascular anomaly. Clinicians should carefully look for lateral pulsation in lip mucosal papules so as to avoid unnecessary surgery and intraoperative arterial bleeding. Pathologists should recognize that a relatively large-caliber superficial artery in a lip biopsy may not be an incidental finding but rather the clinical lesion that was biopsied.

A pilot study of smokeless tobacco in smoking cessation.

PURPOSE: The substitution of smokeless tobacco for cigarette smoking is a harm reduction alternative for inveterate smokers and reduces others' passive exposure to smoke. Two million smokers have used smokeless tobacco to quit on their own, but no formal program has employed this method of smoking cessation. We conducted a pilot study to determine if smokeless tobacco could be successfully employed in a smoking cessation program. PATIENTS AND METHODS: Subjects attended a lecture about the health effects of all forms of tobacco use and about the use of smokeless tobacco as an aid to quit smoking. The study population consisted of 63 evaluable subjects. Follow-up was accomplished by quarterly telephone interviews. Smoking abstinence was confirmed at 1 year by measurement of expired air carbon monoxide. RESULTS: At 1 year, 31% of men and 19% of women had attained smoking cessation, for an overall success rate of 25%. An additional 7% of subjects had reduced their cigarette consumption by at least 50%. CONCLUSION: This study suggests that the use of smokeless tobacco warrants evaluation as a potential smoking cessation strategy.

Ameloblastic fibrosarcoma in a bull.

This report describes a malignant odontogenic neoplasm in a 7-year-old bull. The mass, involving the right mandible, was locally invasive and destructive. Histologically, it consisted of islands and cords of benign odontogenic epithelium, entrapped in a population of malignant mesenchymal cells. These morphological features are characteristic of ameloblastic fibrosarcoma in man, an odontogenic tumour not previously described in animals.