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PubMed2000

Acute effects of smoking of cigarettes with different tar content on plasma oxidant/antioxidant status.

In this study, acute effects of two different types of cigarette smoking on plasma oxidant/antioxidant status were investigated. For this purpose, malondialdehyde (MDA) levels and antioxidant potential (AOP) values were measured in the plasma samples before and after cigarette smoking at fasting. After the first blood sample was obtained, second and third samples were withdrawn at 1.5 h and 3 h. In the first group, subjects smoked five cigarettes with full flavor (FF), and in the second group, five cigarettes with full-flavor low tar (FFLT). Quality classification is made mainly on the basis of tar content of the products. The cigarette with 23 mg tar is defined as FF and that with 12 mg tar as FFLT. MDA level was found to be significantly increased in the 1.5-h plasma samples of both groups, but the increase was greater in the FF group. AOP values, however, were found to be lower in the 3-h plasma samples of both groups, but the decrease was greater in the FF group compared with the FFLT group. It appears that acute smoking causes oxidant stress in blood plasma once exposed to smoke, and then this effect (MDA) begins to decrease. On the other hand, AOP is lowered due to oxidant stress created by smoke. With regard to the types of cigarettes, the FF product seems to be more oxidant than the FFLT product. Our results suggest that antioxidant supplementation might be beneficial for the smokers to cope with the oxidant load derived from cigarette smoke. It is also clearly seen from these results that cigarette manufacturers should reduce tar/nicotine ratio in their products in order to lessen the toxic effects of smoking without causing increased need to smoke.

Adult↗
PubMed1980

Estimating the hazards of "less hazardous" cigarettes. I. Tar, nicotine, carbon monoxide, acrolein, hydrogen cyanide, and total aldehyde deliveries of Canadian cigarettes.

The tar, nicotine, CO, HCN, total aldehyde, and acrolein deliveries of 102 brands of Canadian cigarettes have been determined. On the basis of these deliveries, 15 brands (9% of sales) were categorized as low hazard and 9 brands (10% of sales) as high hazards. All six constituents were used for the classification since for most brands tar was a poor indicator of gas-phase deliveries. As a result, smokers who indiscriminately switch to a brand with a lower tar delivery may inadvertently increase their exposure to gas-phase constituents such as CO and increase their risk of smoking-related pathology. With respect to Canadian cigarettes, the choice of a 30-mm standard butt length may result in omission of some of the available tobacco from the testing procedure, thus reducing the value of tar level as a guide to choosing a less harmful cigarette.

Acrolein↗
PubMed1981

How good are the numbers for cigarette tar at predicting deliveries of carbon monoxide, hydrogen cyanide, and acrolein?

Simple and multiple linear regression analyses were performed on the tar, nicotine, CO, HCN, and acrolein deliveries of 98 brands of commercially available Canadian cigarettes. Simple linear regressions of CO, HCN, and acrolein on tar and of acrolein on CO were not significant at the 5% level for plain cigarettes; all other regressions were very strongly significant (p less than 0.01). In addition there was strong statistical evidence that filter, vented filter, and plain cigarettes have different regression relations and different levels of precision associated with the regression parameters. With respect to CO, tar level could predict the corresponding CO value only within 3.9 mg (filter), 1.9 mg (vented filter), and 3.1 mg (plain). These results show that tar delivery alone is an inadequate predictor of gas-phase constituents such as CO. Information concerning these constituents is best conveyed by an analytically determined value for each component.

Acrolein↗
PubMed1987

Augmentation of elastase-induced emphysema by cigarette smoke: effects of reducing tar and nicotine content.

The effects of reducing the tar and nicotine concentration of cigarette smoke were examined in a rat model of smoke-augmented, porcine pancreatic elastase- (PPE-) induced, pulmonary emphysema. Sixty-eight female Long-Evans rats were divided approximately evenly into seven groups: control, PPE, PPE plus sham smoke, high-tar/nicotine cigarette smoke (2R1; 38.8 mg total particulate matter and 2.2 mg nicotine per cigarette), low-tar/nicotine cigarette smoke (1R4F; 10.8 mg total particulate matter and 0.8 mg nicotine per cigarette), PPE + 2R1, and PPE + 1R4F. Three days after intratracheal administration of PPE (400 IU/kg), animals in the smoke-treated groups were exposed to 8-10 puffs of cigarette smoke daily, 7 d/wk for 12 wk. Sham-treated animals received room air in place of cigarette smoke. At the conclusion of the exposures, pulmonary function tests were performed under general anesthesia. Cigarette-smoke exposure alone did not produce significant changes in pulmonary function. Elastase-treated groups demonstrated significant increases in total lung capacity, functional residual capacity, and dynamic and static compliance, as well as significant decreases in carbon monoxide (CO) diffusing capacity and CO diffusion coefficient. Morphometric measurements of mean linear intercept demonstrated a loss of alveolar fine structure with enlargement of distal airspaces in PPE-treated rats. Exposure to either 2R1 or 1R4F cigarette smoke significantly enhanced many of the emphysematous changes produced by PPE, but there were no significant differences between the effects of the two smokes. These data indicate that reducing the tar and nicotine concentration of cigarette smoke does not lessen its ability to augment PPE-induced pulmonary emphysema in the rat.

Animals↗
PubMed1989

Tobacco-specific nitrosamines in mainstream smoke of West German cigarettes--tar alone is not a sufficient index for the carcinogenic potential of cigarette smoke.

Fifty-five types of commercial cigarettes on the West German market were analyzed for tobacco-specific nitrosamines (TSNA) in mainstream smoke. The cigarettes included filter and nonfilter cigarettes with very high, high, medium, low and ultra-low tar and nicotine yields. The observed range for N'-nitrosonornicotine was from 5 to 625 ng/cigarette and for 4-(methylnitrosoamino)-1-(3-pyridyl)-1-butanone from not detected (less than 4 ng/cigarette) to 432 ng/cigarette. The highest TSNA values were obtained for nonfilter cigarettes made of dark tobaccos and the lowest values for nonfilter Oriental-type cigarettes. Relatively high TSNA yields were also observed in filter cigarettes with moderate and lower tar deliveries. The results demonstrated that there is no correlation between TSNA and tar deliveries in mainstrain smoke. The TSNA deliveries in mainstream smoke depended on the actual tobacco composition. According to these results the tar delivery, although crucial, is not a sufficient index for the biological activity and the carcinogenic potential of cigarette smoke.

Filtration↗
PubMed1995

Coal tar residues produce both DNA adducts and oxidative DNA damage in human mammary epithelial cells.

In the present study we compare the metabolic activation of coal tar, as measured by the production of both DNA adducts and oxidative DNA damage, with that of a single carcinogen that is a constituent of this complex mixture in human mammary epithelial cells (HMEC). We find that a significant level of DNA adducts, detected by 32P-postlabeling, are formed in HMEC following exposure to coal tar residues. This treatment also results in the generation of high levels of oxidative DNA damage, as measured by the production of one type of oxidative base modification, thymine glycols. The amounts of both DNA adducts and thymine varied considerably between the various coal tar residues and did not correlate with either the total amount of polycyclic aromatic hydrocarbons (PAH) or the amount of benzo[a]pyrene (B[a]P) present in the residue. Fractionating the residue from one of the sites by sequential extraction with organic solvents indicated that while the ability to produce both types of DNA damage was contained mostly in a hexane-soluble fraction, a benzene-soluble fraction produced high levels of reactive oxygens relative to the number of total DNA adducts. We find that the total amount of PAH or B[a]P present in the coal tars from the various sites was not a predictor of the level of total DNA damage formed.

Biotransformation↗
PubMed1995

Self-regulation of smoking intensity. Smoke yields of the low-nicotine, low-'tar' cigarettes.

It has been assumed for some time that the 'tar' and nicotine data for individual cigarette brands, as reported by the Federal Trade Commission (FTC), do not adequately reflect the levels of exposure to toxic and carcinogenic agents in the smoke. The trend of decreasing 'tar' and nicotine yields of the sales-weighted average US cigarettes was not followed by a proportionate decline of lung cancer incidence and mortality rates. Utilizing a 'tobacco smoke inhalation testing system', we determined smoking profiles for four men and four women who smoked low-nicotine cigarettes ( < or = 0.8 mg/cigarette according to FTC), and for two men and two women who smoked cigarettes with medium-nicotine (0.9-1.2 mg) yields. The recorded smoking profiles were programmed into a smoking machine to establish mainstream smoke yields for 'tar', nicotine, benzo[a]pyrene and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone. The analytical data obtained for each smoker's cigarette were compared with corresponding measurements in the smoke from the same cigarette brand that was generated by machine-smoking under the standardized FTC conditions (1 puff of 2 s duration and 35 ml volume drawn once/min). Significant increases in terms of total volume of smoke inhaled and exposures to 'tar', nicotine, and lung carcinogens were measured (2- to 4-fold) and, because of smokers' compensation for low nicotine delivery, much greater overall exposure resulted from smoking low-nicotine cigarettes. Although these measurements were obtained for a limited number of smokers, they strongly indicate that both low- and medium-nicotine cigarettes are being smoked much more intensely than would be implied from the FTC-data. Therefore, there is an urgent need to accurately quantify the exposure of consumers of the various types of cigarettes to toxic and carcinogenic agents.

Adult↗
PubMed1986

Mutagenic activity and polycyclic aromatic hydrocarbon levels in urine of humans exposed to therapeutical coal tar.

The urinary mutagenicity and the excretion of polycyclic aromatic hydrocarbons (PAH) in three non-smoking male patients, treated for psoriasis with cutaneous applications of crude coal tar, were analysed. Mutagenicity of the urinary extracts was measured by the plate incorporation assay using Salmonella typhimurium strains TA 98 and TA 100 in the presence of liver S9 fraction from Aroclor-induced rats with or without beta-glucuronidase. After concentration, hydrolysis and reduction of the urine sample, PAH levels were measured by high resolution gas chromatography/mass spectrometry. Following cutaneous treatment with coal tar, the urine of all three subjects showed noticeable levels of PAH and/or metabolites and marked mutagenicity both on strain TA 98 and TA 100 in the presence of S9 fraction. The addition of beta-glucuronidase increased the mutagenicity of the urinary extracts, the maximum values being attained on strain TA 100 in the presence of both microsomal fraction and deconjugating enzymes. The mutagenicity of urinary extracts from subjects treated therapeutically with crude coal tar was correlated (r = 0.788, P less than 0.01) with the total PAH levels in their urine. The PAH excreted in urine were mainly low molecular weight compounds, while benzo[a]anthracene was present in scarce amounts and the excretion of benzo[a]pyrene did not increase following the cutaneous exposure to the crude coal tar.

Coal Tar↗
PubMed1994

Differential effects of tar content, type of tobacco and use of a filter on lung cancer risk in male cigarette smokers.

BACKGROUND: To date, the effect of tar exposure, the use of a filter and the type of tobacco (light or dark) on the risk of lung cancer have not been studied together. METHODS: Data from a case-control study on lung cancer were used to evaluate the specific effects of these three parameters. Cases of lung cancer and controls were interviewed in hospitals in France from 1976 to 1980. The past tar content of cigarettes distributed by the French Tobacco Monopoly was obtained. The results presented concern an exclusively male population of lifelong smokers of French cigarettes and lifelong smokers of light imported cigarettes. The population comprised 1114 cases of histologically confirmed lung cancer and 1466 hospitalized controls. RESULTS: An increase in risk was found among smokers of both dark and light cigarettes (relative risk [RR] = 2.6, 95% confidence interval [CI]:1.1-6.5) and among lifelong smokers of dark cigarettes (RR = 1.7, 95% Cl: 0.9-3.2) compared to lifelong smokers of light cigarettes. Similarly, the risk of lung cancer was higher among smokers of both non-filter and filter cigarettes (RR = 1.6, 95% Cl: 0.9-2.7) and among lifelong smokers of non-filter cigarettes (RR = 1.6, 95% Cl: 0.9-2.8) than among lifelong smokers of filter cigarettes. A borderline significant increase in risk was observed for smokers of French cigarettes compared to smokers of light imported cigarettes (RR = 2.6, 95% Cl: 0.9-7.7). No significant difference in the risk of lung cancer was observed among smokers of French cigarettes according to the proportion of years of smoking high tar cigarettes. CONCLUSION: This study tends to demonstrate a separate effect of type of tobacco, use of a filter and tar content in addition to the usual characteristics of cigarette smoking on lung cancer risk.

Case-Control Studies↗
PubMed2006

Relationship between constituent labelling and reporting of tar yields among smokers in four countries.

Countries have adopted different approaches to disseminating cigarette tar, nicotine, and carbon monoxide (CO) levels to consumers, with some (e.g. EU member states, Canada, Australia, but not the United States) requiring disclosure of results from the International Organization for Standardization (ISO) test method on packs. Cross-country comparisons can provide insight into how smokers use yields when information is presented differently. We examined whether smokers in four different countries could recall the tar yield of their brand of cigarettes, using data from the third wave of the International Tobacco Control Four Country Survey (ITC-4). Of current smokers in the United States, Canada, Australia and the United Kingdom, 33.6% gave a numeric response when asked to report the tar yield of their brand, whereas 66.4% responded 'I don't know.' American participants (9.2%) were less likely than Canadian (28.0%), UK (36.5%) or Australian (68.2%) smokers to give an answer, even after controlling for sociodemographic and smoking behaviour factors. Constituent labelling policies can affect whether smokers report a tar yield for their cigarette brand. Pack labelling appears to be useful for conveying information about cigarettes to smokers; however, there is an urgent need to develop more meaningful information on toxic constituents of cigarette smoke.

Adolescent↗
PubMed1988

The importance of the coal tar bath in the Ingram treatment of psoriasis. Evaluation by evaporimetry and laser Doppler flowmetry.

The contribution of the tar component to the efficacy of the Ingram regimen in the treatment of psoriasis was assessed in 11 patients with symmetrical lesions on the upper extremities. One arm was immersed in an oil emulsion bath and the other in a coal tar bath. Whole body ultraviolet irradiation followed, and dithranol paste was applied to all lesions. Healing was assessed clinically at weekly intervals, and was found to parallel the normalization of transepidermal water loss (TEWL) as determined by evaporimetry, and the dermal blood flow as evaluated by laser Doppler flowmetry. Results obtained with coal tar baths were not significantly different from those obtained with oil emulsion. We conclude that coal tar bath additive has no advantage over oil emulsion in the Ingram regimen.

Adolescent↗
PubMed1992

Re-examining crude coal tar treatment for psoriasis.

Two separate, double-blind, randomized, half-and-half body comparisons, each involving 20 in-patients with psoriasis, were conducted to compare the effect of different concentrations of crude coal tar in yellow soft paraffin. The therapeutic effect of 1% crude coal tar used twice daily for 10 days was significantly less than that achieved with an incremental regimen starting at 5% and increasing by 5% every second day to a maximum of 25%. No such difference was seen when a steady concentration of 5% was compared with the same incremental regimen. We conclude that there appears to be no benefit from exceeding a concentration of 5% crude coal tar in yellow soft paraffin in the treatment of patients with psoriasis and that the plateau in the dose-response curve for the action of crude coal tar in psoriasis begins at a point between 1 and 5%.

Administration, Topical↗
PubMed1994

A comparative study of calcipotriol ointment and tar in chronic plaque psoriasis.

The antipsoriatic efficacy, tolerability and safety of calcipotriol ointment was compared with tar in a prospective, right/left randomized, investigator-blinded controlled study. Calcipotriol ointment 50 micrograms/g twice daily was applied to one-half of the body. On the opposite side, white soft paraffin was applied in the morning, and coal tar solution BP 15% v/w in aqueous cream in the evening. Thirty patients with stable chronic plaque-type psoriasis were recruited. Assessments were made at 2, 4 and 6 weeks. Three patients were withdrawn from the study. A decrease in PASI score was seen on both sides at 2, 4 and 6 weeks. The differences from baseline between the two treatments were statistically significant in favour of calcipotriol. Improvement with calcipotriol was rapid in the first 2 weeks of treatment. With tar, significant improvement occurred only after 4 weeks of treatment. The differences in the scores for erythema, induration and desquamation from baseline between the two treatments were also statistically significantly in favour of calcipotriol at all evaluation points. Seven patients developed irritation on the calcipotriol-treated side, but there were no adverse effects on the tar-treated side. In two patients, itching associated with psoriasis was reduced by the calcipotriol. Although the mean serum calcium and phosphate levels remained within the normal ranges after 6 weeks' treatment, there were significant changes in their values compared with baseline.

Administration, Cutaneous↗
PubMed1977

Pigmented cosmetic dermatitis and coal tar dyes.

Patch tests and photopatch tests with various cosmetics, coal tar dyes, perfumes, lanolin preparations and parabens-mix were performed in 53 patients with pigmented cosmetic dermatitis similar in clinical appearance to Riehl's melanosis. The results showed that coal tar dyes, particularly brilliant lake red R, were closely related to the cause of the disease. In patch testing and photopatch testing with coal tar dyes, the incidence of positive responses to the brilliant lake red R was found to be significantly higher than that to the other coal tar colors (22/38 = 57.9%). The relevance of ultraviolet light to the disease was found to be much less than the ratio expected (14/47 = 29.8%). A high incidence of positive responses to fragrances was also found, but it is considered to play a secondary role in the etiology of the disease.

Coal Tar↗
PubMed1981

Trends in tar, nicotine, and carbon monoxide yields of UK cigarettes manufactured since 1934.

The tar, nicotine, and carbon monoxide yields of cigarettes manufactured in the United Kingdom between 1934 and 1979 were studied. Over this period the average tar yield decreased by 49%, the nicotine yield by 31%, the carbon monoxide yield by 11%, all estimated on a sales-weighted basis. The average tar yield decreased progressively after the second world war, owing both to the introduction of filter cigarettes and to changes in the manufacture of plain cigarettes. The average nicotine yield increased initially, decreased by 43% from about 1950 to 1974, but increased again by 9% between 1974 and 1979. The average carbon monoxide yield started to decrease after about 1961; while it decreased substantially in plain cigarettes, the rapid increase in sales of filter cigarettes at this time, at the expense of plain cigarettes, largely offset the reduction in carbon monoxide yield that would otherwise have occurred. As with nicotine, carbon monoxide yield showed a small rise in later years (4% between 1976 and 1979). The trends in tar yield may well explain the reduction in lung cancer in the UK better than has been suspected hitherto. The trends in nicotine and carbon monoxide yields are probably not sufficiently different to distinguish which of them might be the more likely cause of cardiovascular disease.

Carbon Monoxide↗
PubMed1981

The importance of tar and nicotine in determining cigarette smoking habits.

Cigarette consumption and inhaling, assessed using carboxyhaemoglobin levels, were studied in 1786 men to investigate the importance of tar and nicotine as determinants of smoking habits. No prior warning was given that smoking habits would be studied. Neither nicotine nor tar yields materially influenced the number of cigarettes smoked a day. Both nicotine and tar yields were negatively associated with inhaling (p less than 0.001) but after allowing for either of the two yields the effect of the other on inhaling was no longer statistically significant. There was, therefore, no indication as to whether nicotine or tar was the more important determinant of smoking habit.

Carbon Monoxide↗
PubMed1996

Out-patient treatment of atopic dermatitis with crude coal tar.

BACKGROUND: Patients with atopic dermatitis benefit from treatment with crude coal tar. We started a program for the treatment of patients with atopic dermatitis in an out-patient facility using intermittent applications of crude coal tar. OBJECTIVE: To study the efficacy and feasibility of an out-patient regimen using crude coal tar in atopic dermatitis. METHODS: We treated 18 patients in the out-patient setting. A trained nurse and after thorough instruction the patients themselves at home applied crude coal tar in a zinc paste 2 or 3 times a week. We studied the improvement by visual scoring and compared the results with patients treated with daily applications at the in-patient department. RESULTS: The improvement was comparable at the end of the treatment period for both settings. The treatment period, however, was longer for the patients treated in the out-patient setting. CONCLUSION: The out-patient programme proved to be an efficacious and a well-appreciated approach.

Administration, Topical↗
PubMed1993

Cigarette yields of tar and nicotine and markers of exposure to tobacco smoke.

Although cigarette yields of tar and nicotine have been declining since the early 1970s, little information is available for the general population on the consequences of their use on exposure to tobacco combustion products. In a population-based sample of 298 smokers, the majority of whom were Hispanic, we examined the relationships between yields of cigarettes currently smoked and levels of salivary cotinine and end-expired carbon monoxide. Spearman correlation coefficients between the current number of cigarettes smoked and cotinine (r = 0.52) or carbon monoxide (r = 0.51) were higher than correlations between the Federal Trade Commission (FTC) nicotine data and these same markers, 0.12 and 0.05, respectively. Correlations between FTC tar and carbon monoxide yields and the biologic markers were similarly weak. In multiple linear regression models, the current number of cigarettes smoked was the most important predictor of cotinine and carbon monoxide levels (p < 0.0001). The addition of FTC tar, nicotine, or carbon monoxide to the models explained little of the variability in cotinine or carbon monoxide levels. Because FTC yields of tar and nicotine are poor predictors of exposure to tobacco combustion products, subjects' reports of cigarette brand should not be used as a primary marker of exposure in epidemiologic investigations. Furthermore, smokers need to be advised about the limitations of cigarette yield information for predicting the potential for adverse health effects of smoking.

Adult↗