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PubMed1982

Peptic ulcer disease and the tar and nicotine yield of currently smoked cigarettes.

In order to examine the association of smoking cigarettes with a lower tar and nicotine yield to peptic ulcer disease, a common disease associated in past studies with cigarette smoking. We used questionnaire information provided by 9009 current regular cigarette smokers. The percentage who ever had peptic ulcer disease in smokers whose current cigarette yielded 0.00-0.81, 0.81-0.99, 1.00-1.27 and 1.28 + milligrams of nicotine per cigarette were 8.5, 9.2, 9.2 and 9.5, respectively . The percentages who ever has peptic ulcer in smokers whose current cigarette yielded 0.0-11.9, 12.0-15.9, 16.0-18.9 and 19.0+ milligrams of tar per cigarette were 8.6, 9.1, 8.9 and 10.8 per 100, respectively. In contrast, the percentages who ever had peptic ulcer disease increased with the smoking of a greater number of cigarettes, being 5.9, 8.8, 9.0, 11.8 and 10.5 in smokers of less than 10, 10-19, 20-29, 30-39 and 40+ cigarettes, respectively. In multiple logistic regression analyses, peptic ulcer disease was significantly (p = 0.002) associated with number of cigarettes (RR = 1.12 per 10 cigarettes; 95% CI 1.08, 1.16), age and sex. There was no significant association (both p's less than 0.10) either with the current cigarette's tar yield (RR = 1.09 per 10 milligrams; 95% CI 0.96, 1.25) or with its nicotine yield (RR = 1.15 per milligram; 95% CI 0.94, 1.42).

Adult↗

PubMed1991

Effects of varying marijuana smoking profile on deposition of tar and absorption of CO and delta-9-THC.

We investigated the effects of previously observed differences in smoking technique for marijuana (M) versus tobacco (T) on the amount of inhaled tar, the percentage retention of inhaled tar in the lung, the pre- to postcigarette boost in blood carboxyhemoglobin (COHb) and in serum delta-9-tetrahydrocannabinol (THC concentrations), and psychophysiologic responses to THC (increased heart rate and subjective "high"). Ten healthy, habitual smokers of M were studied on 6 separate days. On each day, subjects smoked a single M cigarette (approximately 900 mg, 1.24% delta-9-THC) using one of 6 different smoking profiles typical for marijuana [puff volume (PV) approximately 70 ml; breathholding time, (BHT) 14-16 s] or tobacco (PV approximately 45 ml; BHT 4-5 s) or a combination of the two techniques (PV approximately 70 ml and BHT 4-5 s; or PV approximately 45 ml and BHT 14-16 s). Inhaled volume (1.5 liters), interpuff interval (30 s) and number of puffs (6) were all fixed, except that for the approximately 45-ml PV condition, the number of puffs was increased to 10 in 2 additional sessions to standardize the total amount of cigarette consumed to that of the approximately 70-ml PV condition. The longer BHT significantly increased both percent retention of tar in the lung and the pre- to postsmoking rise in blood COHb, serum THC and heart rate, independent of puff volume and number. In contrast, the larger PV had no significant influence on these variables for the same amount of cigarette consumed.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption↗

PubMed1983

A comparison of the yields of tar, nicotine, and carbon monoxide of 36 brands of Canadian cigarettes tested under three conditions.

A number of countries, including Canada, sponsor routine monitoring of cigarette tar, nicotine, and carbon monoxide yields which are evaluated by cigarette-smoking machines according to a standard protocol. These standardized yields continue to decline as tobacco companies modify their brands to meet consumers' demand for "light" products. This trend toward cigarettes with low average deliveries of toxic substances may reduce health risks for some people. However, switching to low-yield cigarettes may not result in reduced risks for smokers who smoke these cigarettes intensively. Thirty-six brands of Canadian cigarettes, including 28 with ventilated filters, were tested under standard conditions and 2 others in order to determine how yields of tar, nicotine, and carbon monoxide change when cigarettes are manipulated by smokers in order to increase their smoke intake. While the rank order yields of tar, nicotine, and carbon monoxide was preserved, the average yields of all three substances more than doubled when cigarettes were intensively smoked in comparison with standard smoking.

Carbon Monoxide↗

PubMed1985

Characterization of tobacco products: a comparative study of the tar, nicotine, and carbon monoxide yields of cigars, manufactured cigarettes, and cigarettes made from fine-cut tobacco.

Yields of tar, nicotine, and carbon monoxide were compared in selected Canadian brands of manufactured and hand-rolled cigarettes, and small and large cigars. To control for varying volumes of smoke delivery per cigarette or cigar, standardized comparisons in milligrams of toxic substance per liter of smoke were made. The mean deliveries per liter of smoke and tar, nicotine, and carbon monoxide were highest for small cigars, followed by hand-rolled and manufactured cigarettes; large cigars had the lowest deliveries. Five out of six brands of cigarettes handmade from fine-cut tobacco delivered significantly more tar, nicotine, and carbon monoxide per cigarette or per liter than did the identically named manufactured brand.

Carbon Monoxide↗

PubMed1983

Toxic and teratogenic effects of chemical class fractions of a coal-gasification electrostatic precipitator tar.

Dimethyl sulfoxide slurries of a coal gasifier electrostatic precipitator tar and its chemical class fractions were assayed for their toxicity and teratogenicity using early embryos of the frog Xenopus laevis. Of the 5 tar fractions the ether-soluble base and polyaromatic were found to be the most teratogenic and the ether-soluble acid and ether-soluble base were the most toxic. The teratogenic effects of the raw tar suggest synergism. The toxic effects to newly metamorphosed froglets is 1-2 orders of magnitude less than those observed for embryos. Chemical analysis shows dihydroxybenzenes and organonitrogen compounds to be the major components of the acid and base fractions, respectively. The neutral fractions contain mainly alkyl-substituted two-ring hydrocarbons.

Abnormalities, Drug-Induced↗

PubMed1986

Effects of expanded tobacco on acceptability and reported consumption of low-tar cigarettes.

Experimental cigarettes designed for the low-tar band were made from one of two blends of tobacco and either 10% or 25% of expanded tobacco. They were smoked over a 7-day period by 24 habitual smokers of cigarettes in the middle-tar band. Sensory characteristics and acceptability of the cigarettes were assessed at first presentation, after 3 days and again at the end of the trial. The expanded-tobacco cigarettes were judged to be weaker than the smokers' own usual brands, and the 25% weaker than the 10% expanded. However, perceived strength increased over the 7-day trial. No effect of blend was detected. Smokers given cigarettes with 10% expanded tobacco smoked considerably more of them than was predicted from their reported normal consumption, but this sign of some compensation for reduced nicotine yield did not appear with 25% expanded tobacco. The implications are discussed for persisting smokers switching to the low-tar band, as officially advised to reduce health risks.

Adult↗

PubMed1982

Evidence that coal tar is a mixed inducer of microsomal drug-metabolizing enzymes.

Topical application of coal tar (U.S.P.) to neonatal rats resulted in the induction of hepatic cytosolic glutathione-S-transferase and microsomal epoxide hydrolase and aminopyrine N-demethylase activities. Analogous to the effect of the polychlorinated biphenyl Aroclor 1254, treatment of neonatal rats with coal tar resulted in a one nm shift to the blue region in the wavelength maximum of the hepatic microsomal hemoprotein cytochrome P-450. These results demonstrate that therapeutic coal tar contains both type I and type II inducers of hepatic drug-metabolizing enzymes.

Animals↗

PubMed1996

Hazards for the Rostock water supply from a tar-contaminated sediment in the river Warnow.

By the gas plant at Schwaan (a small city near Rostock), tar and other by-products were released into the river Warnow which supplies Rostock with drinking water 20 km downstream. The tar-contaminated river sediment contained phenols and polycyclic aromatic hydrocarbons (PAH), indicating a mutagenic potential. Investigations in the catchment area and on tributaries showed PAH contents up to about 10 ng/l in the water. The river sediment was found to be the sole PAH source. Although the PAH level is very low, sediment disturbances may produce an increase in concentrations. The consequences of such a worst case are difficult to estimate, even though the content of seston and humic substances in the river seems to reduce the PAH concentrations. Although this lowers the probability that increased PAH concentrations reach the Rostock water supply, the removal of the tar-contaminated sediment from the river is strongly recommended.

Environmental Monitoring↗

PubMed2005

Laboratory studies to characterize the efficacy of sand capping a coal tar-contaminated sediment.

Placement of a microbial active sand cap on a coal tar-contaminated river sediment has been suggested as a cost effective remediation strategy. This approach assumes that the flux of contaminants from the sediment is sufficiently balanced by oxygen and nutrient fluxes into the sand layer such that microbial activity will reduce contaminant concentrations within the new benthic zone and reduce the contaminant flux to the water column. The dynamics of such a system were evaluated using batch and column studies with microbial communities from tar-contaminated sediment under different aeration and nutrient inputs. In a 30-d batch degradation study on aqueous extracts of coal tar sediment, oxygen and nutrient concentrations were found to be key parameters controlling the degradation rates of polycyclic aromatic hydrocarbons (PAHs). For the five PAHs monitored (naphthalene, fluorene, phenanthrene, anthracene, and pyrene), degradation rates were inversely proportional to molecular size. For the column studies, where three columns were packed with a 20-cm sand layer on the top of a 5 cm of sediment layer, flow was established to sand layers with (1) aerated water, (2) N(2) sparged water, or (3) HgCl(2)-sterilized N(2) sparged water. After steady-state conditions, PAH concentrations in effluents were the lowest in the aerated column, except for pyrene, whose concentration was invariant with all effluents. These laboratory scale studies support that if sufficient aeration can be achieved in the field through either active and passive means, the resulting microbially active sand layer can improve the water quality of the benthic zone and reduce the flux of many, but not all, PAHs to the water column.

Biodegradation, Environmental↗

PubMed2005

Phototoxicity of bituminous tars-correspondence between results of 3T3 NRU PT, 3D skin model and experimental human data.

Bituminous tars (Ichthammol and Ichthyol Pale) are widely used in pharmaceutical, veterinary and cosmetic industries for their anti-microbial, anti-inflammatory and anti-pruritic effects. In contrast to coal tar, no phototoxicity of bituminous tars has been reported in man, although both Ichthammol and Ichthyol Pale exhibit UV absorption which is higher and broader for the former. The validated 3T3 NRU phototoxicity test indicated phototoxic potential of both substances. The phototoxicity test in a 3D human skin model (EpiDerm) only confirmed phototoxicity for Ichthammol. Human data on Ichthammol phototoxicity are missing. A photopatch test in human volunteers was performed in order to clarify the discrepancy between the phototoxicity found in the skin model and the absence of reported human phototoxicity. Following 4h exposure to 5% and 10% aqueous solutions of Ichthammol and Ichthyol Pale the test sites were irradiated with a UVA dose of 5 J/cm(2). Early phototoxic reaction (erythema) within 4-6h after irradiation was only elicited by Ichthammol and not by Ichthyol Pale. These data correspond well with those from the 3D skin model test and suggest the necessity to employ several test systems for final phototoxicity assessment. In addition to the results obtained in 3T3 NRU PT, further testing on 3D skin models may better reflect bioavailability of a given chemical in the skin, relevant to the situation in humans.

Adult↗

PubMed1980

Skin carcinoma in patients with psoriasis treated with topical tar and artificial ultraviolet radiation.

A case-control study, consisting of 59 skin cancer patients with severe psoriasis, was conducted to evaluate the effect of treatment with tar and/or artificial ultraviolet radiation on the risk of developing cutaneous carcinoma. Using 924 unmatched controls, we estimated that the crude rate of skin cancer was 2.4-fold for patients with high exposure to tar and ultraviolet radiation, compared with those lacking high exposure. Using a control series of 126 patients matched for age, skin type, region of residence, sex, history of exposure to ionising radiation, and number of 8-methoxypsoralen photochemotherapy treatments, we observed a stronger association (relative rate = 4.7, 95% confidence limits = 2.2 to 10.0). The magnitude of the relative rates argues for continued surveillance for tumours among patients with psoriasis who receive long-term tar or artificial ultraviolet radiation therapy.

Dose-Response Relationship, Drug↗

PubMed1986

Contribution of topical tar oil to ultraviolet B phototherapy for psoriasis.

A bilateral comparison study of twenty-two outpatients with psoriasis assessed clearing experience and remission time on halves of the body to which tar oil and oil vehicle (an emollient) were applied twice daily. In addition, both sides were treated three times a week with suberythemogenic doses of ultraviolet B radiation. Of the eighteen patients who complied with the protocol, fourteen (78%) had clearing. There was no significant difference between body halves with regard to the number of treatments to clearing, the dose of ultraviolet B to clearing, or the remission time (p greater than 0.2, all comparisons). Our data indicate with 95% confidence that using tar oil in conjunction with ultraviolet B phototherapy reduces the average total ultraviolet B dose required for clearing by a maximum of 9%, in comparison with using oil vehicle and ultraviolet B. These findings suggest that there is insufficient evidence for substantial clinical benefit to recommend tar oil use in conjunction with outpatient ultraviolet B phototherapy for psoriasis.

Adult↗

PubMed2006

Role of weathered coal tar pitch in the partitioning of polycyclic aromatic hydrocarbons in manufactured gas plant site sediments.

Polycyclic aromatic hydrocarbons (PAHs) in manufactured gas plant (MGP) site sediments are often associated with carbonaceous particles that reduce contaminant bioavailability. Although black carbon inclusive partitioning models have been proposed to describe elevated PAH partitioning behavior, questions remain on the true loading and association of PAHs in different particle types in industrially impacted sediments. In the studied MGP sediments, the light density organic particles (coal, coke, wood, and coal tar pitch) comprised 10-20% of the total mass and 70-95% of the PAHs. The remainder of the PAHs in sediment was associated with the heavy density particles (i.e., sand, silt, and clays). Among the different particle types, coal tar pitch (quantified by a quinoline extraction method) contributed the most to the bulk sediment PAH concentration. Aqueous partition coefficients for PAHs measured using a weathered pitch sample from the field were generally an order of magnitude higher than reported for natural organic matter partitioning, and match well with theoretical predictions based on a coal tar-water partitioning model. A pitch-partitioning inclusive model is proposed that gives better estimates of the measured site-specific PAH aqueous equilibrium values than standard estimation based on natural organic matter partitioning only. Thus, for MGP impacted sediments containing weathered pitch particles, the partitioning behavior may be dominated by the sorption characteristics of pitch and not by natural organic matter or black carbon.

Coal Tar↗

PubMed2000

Modulation of the atopy patch test reaction by topical corticosteroids and tar.

BACKGROUND: Pharmacologic studies in atopic eczema (AE) are difficult to standardize. Patients with AE differ in the stage of their skin disease (acute, subacute, chronic). OBJECTIVE: This study was designed to assess macroscopic and microscopic effects of pretreatment with topical glucocortico-steroids (GCSs) and tar on the atopy patch test (APT) reaction in patients with atopic eczema. METHODS: Nonlesional skin of the back of patients with AE (n = 6) was treated for 3 weeks at 3 different sites with triamcin-olonacetonide 0.1% in cetamacrogol ointment (GCSs), pix liquida 10% in cetamacrogol ointment (tar), and cetamacrogol ointment (vehicle), respectively. APTs were performed, and biopsy specimens were taken from all these sites (time = 0 and 24 hours) for immunohistochemical analysis. RESULTS: Treatment with both GCSs and tar was able to reduce the macroscopic outcome of the APT reaction. Furthermore, both treatment modalities had an almost equally inhibiting effect on the influx of T cells, eosinophils, and CD1(+), RFD1(+), IFN-gamma(+), and IL-4(+) cells, as well as on the percentage of vessels expressing the adhesion molecules vascular cell adhesion molecule 1 and E-selectin in response to epicutaneous aeroallergen challenge. CONCLUSION: Although both treatments significantly reduced the various cellular constituents of allergic inflammation, all cell types remained present. In addition, this study shows that the APT can be used to evaluate the effect of topical anti-inflammatory treatments on allergic inflammation in patients with AE.

Administration, Topical↗

PubMed2003

Coal tar pitch volatiles and polycyclic aromatic hydrocarbons exposures in expansion joint-making operations on a construction site: a case study.

This case study describes occupational exposures to coal tar pitch volatiles (CTPV) as benzene soluble fraction (BSF), polycyclic aromatic hydrocarbons (PAHs) and total particulates at a unique operation involving the use of coal tar in the making of expansion joints in construction of a multi-level airport parking garage. A task-based exposure assessment approach was used. A set of 32 samples was collected and analyzed for total particulate and CTPV-BSF. Twenty samples of this set were analyzed for PAHs. Current American Conference of Governmental Industrial Hygienists (ACGIH(R)) respective threshold limit value-time weighted average (TLV-TWA) for insoluble particulates not otherwise specified (PNOS) is 10 mg/m(3) as inhalable dust, which roughly corresponds to 4 mg/m(3) total particulate; for CTPV as BSF the TLV is 0.2 mg/m(3), and for specific PAHs such as benzo(a)-pyrene (B[a]P), ACGIH suggests keeping exposure as low as practicable. The recommended Swedish exposure limit for B(a)P is 2 microg/m(3). The highest exposure levels measured were 12.8 mg/m(3) for total particulate, 1.9 mg/m(3) for coal tar pitch volatiles as BSF, and 12.8 microg/m(3) for B(a)P. Several of the CTPV-BSF results were over the TLV of 0.2 mg/m(3). The data set is limited; therefore, caution should be used in its interpretation.

Coal Tar↗

PubMed2005

Studies on microbiological degradation of tobacco tar.

A bacterium, strain MR4, was isolated from tobacco tar-contaminated soil and identified as Klebsiella oxytoca based on morphology, physiological and biochemical characteristics and phylogenetic analysis of 16S rDNA sequence. The organism grew optimally at 34 degrees C and pH 7.0 to 7.5. During growth on tobacco tar the isolate produced acid materials, which caused the drop of pH in the cultures. GC/MS analysis indicated that the isolate had the ability to degrade phenolic compounds, heterocyclic compounds, especially nicotine in tobacco tar. The degradation rate of strain MR4 was 75.56% for nicotine, 35.84% to 58.16% for hydroxybenzenes and the other aromatic compounds, 29.15% to 65.56% for heterocyclics, and 35.17% to 82.59% for hydrocarbons.

Base Sequence↗

PubMed1992

Investigation on the carcinogenic effects of coal tar pitch in rat respiratory tract by intratracheal instillations.

The effects of coal tar pitch (CTP) on the tracheobronchial mucosa of Wistar rats were studied. Three groups of animals received 10 weekly intratracheal instillations of CTP at the cumulative doses of 6.48, 136.56 and 200 mg respectively. The control group of rats received 10 weekly intratracheal instillations of charcoal powder at a cumulative dose of 20 mg. The study in which the animals were killed serially revealed that CTP had conspicuous damage on the respiratory system of rats, especially on the bronchiolo-alveolar areas. The lesions induced by CTP ranged from hyperplastic, metaplastic and dysplastic changes to extensive cancers. These lesions were usually multifocal, and were more severe in the rats receiving higher dosages of CTP. The deposition of CTP particles within or adjacent to these lesions could be readily identified. Lung cancers occurred in 12.5% (4/32) and 25% (10/40) of the rats treated with 136.56 and 200 mg of CTP, whereas no tumors were found in control rats and the rats that received 6.48 mg of CTP. The overall cancer incidence significantly related to the cumulative dose of CTP. The histological types of lung cancers consisted of squamous cell carcinomas (10 out of the 14 lung cancers), adenocarcinoma (1/14), and combined squamous and adenocarcinomas (3/14). The development of CTP-induced rat lung cancers appears to derive from the hyperplasias of bronchiolo-alveolar epithelium, and processing stages of squamous metaplasias and/or dysplasias to carcinomas. The present results confirmed the carcinogenic effects of CTP on the respiratory system of rats, and provided experimental evidence for human lung carcinogenesis, particularly in those occupationally exposed to coal tars or tar products.

Adenocarcinoma↗

PubMed1980

Management of hot tar burns.

Burns due to hot tar present a difficult management problem because the tar is difficult to remove without inflicting further injury to the underlying burn. We have found the surface active agent polyoxyethylene sorbitan (Tween 80, Sigma, St. Louis, MO) or Polysorbate (Sigma), by itself or in combination with an antibiotic ointment (neomycin sulfate) to be a safe and effective means of tar removal.

Adult↗