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PubMedDate not supplied

The medical use of a nonmedical product: melted tar.

The use of hot tar in industry is widespread, and burns caused by this agent remain a problem. Instead of being classified as chemical injuries, these burns compose a unique class of thermal injury because of the difference of mechanisms of injury and the difficulties in removing the agent from the skin. Tar burns usually are occupational in nature and are observed mostly in male patients. This report presents a female burn case that had occurred after she applied hot tar to her skin for the treatment purposes of pain relief.

Aged↗

PubMed1985

Coal tar phototoxicity: characteristics of the smarting reaction.

We examined the properties and ultraviolet exposure parameters of tar smarts in an effort to elucidate the mechanisms involved. We showed that irradiation with 1 minimal smarting dose (MSD) of UVA immediately following tar removal lowered the MSD for 6 h, demonstrated by subsequent challenge with UVA. Following 3 MSDs this "memory" effect was demonstrable for 24 h. The smarting reaction was area dependent--smaller areas of exposure require higher doses of UVA to induce smarting. Smarting followed reciprocity over a 6-fold range of irradiances (2-12.5 mW/cm2) but higher irradiances required higher doses of UVA, perhaps due to a delay in the recognition and reporting of smarting. The smarting reaction and delayed erythema due to UVA and tar were equally blocked by sunscreen.

Adult↗

PubMed2001

Comparison of calcipotriol and coal tar in conjunction with sun exposure in chronic plaque psoriasis: a pilot study.

This study was a left-right comparison of the efficacy of 0.005% calcipotriol ointment and 5% coal tar ointment in conjunction with sun exposure in 10 patients with stable plaque psoriasis. After four weeks of therapy, the calcipotriol treated site showed a significantly faster fall in PASI compared to the coal tar treated site. At eight weeks, this difference was not significant with both sides showing comparable improvement in lesions, as shown by PASI values. There were no significant side effects from either therapy. We conclude that both calcipotriol and coal tar ointments have comparable efficacy in treating stable plaque psoriasis when used simultaneously with sun exposure, although the initial response to calcipotriol is faster.

Administration, Topical↗

PubMed1978

Suppression of epidermal proliferation by ultraviolet light, coal tar and anthralin.

360 nm ultraviolet light (UVA) plus coal tar depresses mitosis and DNA synthesis in epidermal cells. UVA has no effect by itself. In some models coal tar alone can partially depress DNA synthesis. 254 nm ultraviolet light (UVC) and 290--320 nm ultraviolet light (UVB) do not enhance depression of DNA synthesis by coal tar. Dithranol will suppress mitosis and DNA synthesis of epidermal cells but there appears to be no photo-activation by UVA. Dithranol suppression and suppression of DNA synthesis by UVB or UVC are additive when used together.

Animals↗

PubMed1981

The atrophogenic effect of crude coal tar on human epidermis.

The effects of crude coal tar on human epidermis were studied in fourteen healthy young adult males. A 20% reduction in viable epidermal thickness, as determined by computer assisted analytical microscopy, was observed after 40 days of topical treatment. Prior to this long term effect of crude coal tar, an initial transient hyperplasia was observed during the first 2 weeks of treatment. These findings indicate that crude coal tar by itself can act as a cytostatic agent on normal human skin, when applied intensively.

Adult↗

PubMed1984

Effect of coal tar on cutaneous aryl hydrocarbon hydroxylase induction and anthralin irritancy.

The inflammatory dose-response to topical anthralin and whole skin aryl hydrocarbon hydroxylase (AHH) activity were measured before and 24 h after application of a coal tar solution to the uninvolved skin of patients with psoriasis. The inflammatory response to anthralin decreased and total AHH activity increased after the tar treatment. A possible explanation is that anthralin or an irritant product is metabolized by AHH activity in the skin. Induction of AHH by coal tar increases its removal and reduces anthralin irritancy.

Adult↗

PubMed1985

Isoquinoline is a possible anti-psoriatic agent in coal tar.

Isoquinoline has been identified as a component of coal tar which causes interfollicular regions of parakeratotic stratum corneum in mouse tail epidermis to become orthokeratotic, with concomitant production of a granular layer. In this respect it behaves similarly to coal tar itself, and isoquinoline may contribute to the anti-psoriatic activity of coal tar.

Animals↗

PubMed1995

Acute severe bronchoconstriction precipitated by coal tar bandages.

We report the occurrence of severe symptomatic bronchoconstriction in an atopic asthmatic subject following the application of coal tar bandages. Investigations showed that this was likely to have been caused by inhalation of coal tar vapour. We suggest that coal tar preparations should be used with caution in asthmatic subjects.

Acute Disease↗

PubMedDate not supplied

In vitro comparison of antifungal effects of a coal tar gel and a ketoconazole gel on Malassezia furfur.

Malassezia furfur seems to be a major pathogenetic factor in seborrhoeic dermatitis, a frequent human skin disease. To estimate the antifungal properties of a coal tar gel (5 mg ml-1 coal tar) which is used in the treatment of seborrhoeic dermatitis of the scalp, we compared its effects on the in vitro growth of M. furfur with those of a ketoconazole gel (20 mg ml-1 ketoconazole). None of the gels was fungicidal within incubation times up to 20 min. During a single application, both gels remain on the skin for only 5 min. Fungicidal effects are consequently unlikely to play a substantial therapeutic role. Fungistatic effects were observed with both gels. In cultures inoculated with 1 x 10(3) cells ml-1, a 1:49 152 dilution of the ketoconazole gel and a 1:768 dilution of the coal tar gel still showed inhibitory effects. At inoculum densities of 1 x 10(5) ml-1, both gels were fungistatic only in dilutions of a maximum of 1:40. Our results suggest that under clinical treatment conditions the fungistatic activities of both preparations should be comparable.

Coal Tar↗

PubMed2004

Determination of tar, nicotine, and carbon monoxide yields in the mainstream smoke of selected international cigarettes.

OBJECTIVE: Survey of nicotine, tar, and carbon monoxide (CO) smoke deliveries from 77 cigarette brands purchased in 35 countries was conducted using a standardised machine smoking method. The goal of this study was to determine regional variations and differences in the tar, nicotine, and CO smoke yields of a cigarette brand manufactured by a leading transnational corporation and of non-US locally popular cigarette brands. DESIGN: The majority of the cigarettes were purchased in each of the participating countries by delegate members of the World Health Organization and forwarded to the Centers for Disease Control and Prevention for analysis. Smoke deliveries were determined using a standardised smoking machine method and subsequent gravimetric and gas chromatography analysis. RESULTS: The smoke deliveries varied widely. Mainstream smoke deliveries varied from 6.8 to 21.6 mg tar/cigarette, 0.5 to 1.6 mg nicotine/cigarette, and 5.9 to 17.4 mg CO/cigarette. In addition to the smoke deliveries, the cigarettes were examined to determine physical parameters such as filter composition, length, and ventilation levels. CONCLUSION: Analysis of the smoke deliveries suggested that cigarettes from the Eastern Mediterranean, Southeast Asia, and Western Pacific WHO regions tended to have higher tar, nicotine, and CO smoke deliveries than did brands from the European, American, or African WHO regions surveyed.

Air Pollutants↗

PubMedDate not supplied

The effects of topical corticosteroids and a coal tar preparation on dithranol-induced irritation in patients with psoriasis.

Dithranol has been a mainstay in the treatment of psoriasis for more than 80 years. Although a safe approach, the irritation of the clinically uninvolved perilesional skin remains a major limitation of this treatment. Corticosteroids and coal tar solution have an anti-inflammatory potential. The aim of the present study was to investigate the clinical and cell-biological effects of two topical corticosteroids and a coal tar preparation on dithranol-irritated skin. During 4 consecutive days, 2% dithranol cream was applied to six uninvolved skin sites (3 cm in diameter) on the lower back of 9 patients with psoriasis. Dithranol was left on the skin for 1 h, subsequently removed with water and soap and the skin was dried with a towel. Subsequently, SITE 1 was treated with 0.05% clobetasol-17-propionate ointment (CP), SITE 2 with unguentum cetomacrogolis (vehicle 1), SITE 3 with 0.005% fluticasonpropionate ointment (FP), SITE 4 with 10% coal tar solution in lanettewax cream (CTS), SITE 5 was left untreated (control) and SITE 6 was treated with lanettewax cream (vehicle 2). Erythema, oedema and vesicle formation was scored every day. On day 5, punch biopsies were taken from the six sites. The expression of epidermal proliferation, differentiation and inflammation markers and the clinical irritation scores indicate that the application of a high potency corticosteroid (CP) is the best approach to minimise dithranol irritation, whereas CTS had virtually no effect on dithranol irritation during this 4-day experimental model.

Administration, Topical↗

PubMed1980

Differing degrees of coal-tar shampoo-induced mutagenesis in the Salmonella/liver test system in vitro.

Hexane extracts of four commercial preparations of coal tar shampoos were studied for their mutagenic properties in the Salmonella/liver test system in vitro. Three of the four shampoos were highly mutagenic, whereas the fourth was not - under our experimental conditions. By high-performance liquid chromatographic, gas-liquid chromatographic, and gas-liquid chromatography-mass spectrometric analyses, more than 35 distinct fractions could be resolved; seven polycyclic aromatic chemicals believed to be present in coal tar were tentatively assigned as the major component of some of these fractions. The shampoo extract that was most mutagenic had a greater number of distinct fractions and contained approximately 50 times more benzo[a]pyrene, compared with the one shampoo extract that was not mutagenic under our experimental conditions. The possible clinical hazards of this observed mutagenicity of certain coal tar shampoos are presently not known.

Animals↗

PubMed1991

Relationship of respiratory symptoms and pulmonary function to tar, nicotine, and carbon monoxide yield of cigarettes.

The data from consecutive surveys of the Tucson Epidemiologic Study (1981-1988) were used to evaluate the relationship in cigarette smokers of respiratory symptoms and pulmonary function to tar, nicotine, and carbon monoxide (CO) yields of the cigarette. There were 690 subjects who reported smoking regularly in at least one survey, over age 15. After adjustment for intensity and duration of smoking and for depth of inhalation, the risk of chronic phlegm, cough, and dyspnea were not related to the tar and nicotine yields. In 414 subjects with pulmonary function tested in at least one of the three surveys the spirometric indices used were significantly related to the daily dose of tar, nicotine, and CO (product of the cigarette yield and daily number of cigarettes smoked). The effects were more pronounced for past than for current doses. However, the differentiation of pulmonary function due to various yields of cigarettes was small in comparison to the difference in pulmonary function between smokers and nonsmokers.

Age Factors↗

PubMed1983

Comparative carcinogenic potencies of particulates from diesel engine exhausts, coke oven emissions, roofing tar aerosols and cigarette smoke.

Mammalian cell mutagenesis, transformation and skin tumorigenesis assays show similar results in comparing the potencies of diesel, coke oven, roofing tar and cigarette smoke particulates. These assay results are reasonably consistent with the comparative carcinogenic potencies of coke oven and roofing tar emissions as determined by epidemiological studies. The bacterial mutagenesis assay tends to show disproportionately high potencies, particularly with diesel particulates. Results to date encourage the approach to the assessment for carcinogenic risks from diesel emissions based on the use of epidemiological data on cancer induced by coke oven emissions, roofing tar particulates and cigarette smoke with the comparative potencies of these materials determined by in vivo and in vitro bioassays.

Animals↗

PubMed1998

Tumors and DNA adducts in mice exposed to benzo[a]pyrene and coal tars: implications for risk assessment.

Current methods to estimate the quantitative cancer risk of complex mixtures of polycyclic aromatic hydrocarbons (PAH) such as coal tar assume that overall potency can be derived from knowledge of the concentration of a few carcinogenic components such as benzo[a]pyrene (B[a]P). Genotoxic damage, such as DNA adducts, is thought to be an essential aspect of PAH-induced tumorigenesis and could be a biomarker for exposure useful for estimating risk. However, the role of B[a]P and the relationship of adduct formation in tumorigenesis have not been tested rigorously in models appropriate for human health risk assessment. Therefore, we directly compared tumor induction and adduct formation by B[a]P and coal tars in several experimental protocols, including one broadly accepted and used by regulators. We found that B[a]P content did not account for tumor incidences after exposure to coal tars. DNA adducts were found in both tumors and tumor-free tissue and tumor outcomes were not predicted by either quantitation of total DNA adducts or by the DNA adduct formed by B[a]P. These data suggest that risk assessments based on B[a]P content may not predict accurately risk to human health posed by environmental PAH.

Administration, Oral↗

PubMed2006

[C-reactive protein value related to a smoking history and composition of nicotine and tobacco tar].

INTRODUCTION: The CRP is known to be an acute phase reactant, but with new high sensitivity assay methods it appears that CRP is also a marker of chronic inflammation. This study was to investigate whether smoking acts as a systemic disease and to see if there is a relation between CRP values and smoking. MATERIAL AND METHODS: 762 persons were studied, with a mean age of 41.74+/-10.03 years. 200 were smokers, 344 were non-smokers and 218 were ex-smokers. The following details were noted in the smoking history: cigarette brand, number of cigarettes/day, number of years smoking and milligrams of nicotine and tar. In the case of ex-smokers, the number of years since giving up smoking was noted. The CRP was determined using the high sensitive Tina-Quant assay. Windows SPSS version 11.0 software was used. RESULTS: The CRP values showed statistically significant differences between the smoking and non-smoking groups. A statistically significant increase in CRP was observed in relation to number of cigarettes/day (p=0.001), mg of nicotine (p=0.017), mg of tar (p=0.020) and number of years of smoking (p=0.0001). However, when analysing the relation between CRP and the number of years since giving up smoking, there was a negative curve of 0.02 in the equation, but this was not of statistical significance. CONCLUSIONS: CRP levels rise when there is an increase in number of cigarettes/day, mg of nicotine and tar and years smoking.

Adult↗

PubMed1986

Estimating the relationship between exposure to tar volatiles and the incidence of bladder cancer in aluminum smelter workers.

A previously reported case-referent study of 85 incident cases of bladder cancer among aluminum smelter workers and 255 matched referents revealed an excess risk among workers exposed to coal-tar pitch volatiles. For the study reported in the present investigation these data have been augmented by estimates of past workplace exposure to total tar (benzene-soluble matter) and to benzo-a-pyrene (BaP). From these new data, exposure-response relationships have been estimated by maximum likelihood. A linear relationship between cumulative exposure and relative risk and a minimum latency period of ten years were assumed on a priori grounds and found compatible with the data. Under these assumptions, relative risk increased for each year of exposure to benzene-soluble matter at a concentration of 1 mg/m3 by 13%, the 95% confidence interval being 5-31. The corresponding figure for BaP (as micrograms/m3 X year) was 2.3%. On the basis of these estimates, 40 years of exposure to benzene-soluble matter at the current exposure limit of 0.2 mg/m3 would lead to a relative risk of 2.4. There was suggestive but not conclusive evidence that relative risks due to exposure to tar volatiles and to cigarette smoke combined multiplicatively.

Air Pollutants, Occupational↗

PubMed2004

Should coal tar products carry cancer warnings?

This article addresses the controversy whether over-the-counter products that contain coal tar concentrations greater than 0.5% must carry cancer warnings. Evidence that topical coal tar is carcinogenic in laboratory animals and humans is reviewed. In addition, the potential risk of internal malignancies arising from the topical use of coal tar is discussed. The view is expressed that the California court decision that such products should carry cancer warnings is correct.

California↗