People smoke for nicotine, but lose sexual and reproductive health for tar: a narrative review on the effect of cigarette smoking on male sexuality and reproduction

PURPOSE

To systematically review the impact of smoking habits on cardiovascular (CV) as well as on male sexual and reproductive function and to provide updated evidence on the role of electronic cigarettes (e-Cig) on the same topics.

METHODS

A comprehensive Medline, Embase, and Cochrane search was performed including the following words: smoking, CV system, CV risk, erectile dysfunction (ED), and male fertility. Publications from January 1, 1969 up to February 29, 2020 were included.

RESULTS

Smoking has a tremendous negative impact on CV mortality and morbidity. Current smoking behavior is also negatively associated with erectile dysfunction (ED) and impaired sperm parameters. E-Cig can release significantly lower concentrations of harmful substances when compared to regular combustible cigarettes. Whether or not the latter can result in positive CV, sexual, and fertility outcomes is still under study. Preliminary studies showed that exposure to e-Cig leads to lower vascular damage when compared to the traditional cigarette use. However, data on the long-term effects of e-Cig are lacking. Similarly, preliminary data, obtained in animal models, have suggested a milder effect of e-Cig on erectile function and sperm parameters.

CONCLUSION

Available evidence showed that e-Cig are much less dangerous when compared to the traditional tobacco use. However, it should be recognized that the risk related to e-Cig is still higher when compared to that observed in non-smoking patients. Hence, e-Cig should be considered as a potential tool, in the logic of harm reduction, to reduce the CV, sexual and fertility risk in patients refractory to the fundamental, healthy choice to definitively quit smoking.

Dr Michaels® (Soratinex®) product for the topical treatment of psoriasis: a Hungarian/Czech and Slovak study

Psoriasis is a chronic inflammatory T cell-mediated skin disease, affecting about 2% of Hungarian population. Genetic predisposition as well as environmental triggering factors, and innate immune processes play a role in its etiology. Treatment of psoriasis during the initial stages and first years of disease tend to be conservative and frequently based on topical agents. The aim of this study was to investigate and to describe the efficacy and safety of Dr Michaels® (Soratinex®) skin-care products for the topical treatment of stable chronic plaque psoriasis in a Hungarian population. Two-hundred-and-eight-six (120 female/166 male) patients, aged 10-80 years old (mean age 43 years) with mild to moderate plaque psoriasis had participated in the study. The products, including cleansing gel containing a coal tar solution, herbal oils and emulsifiers, were used twice daily and in the same manner for all the skin lesions. The study period was eight weeks. Assessment, using the Psoriasis Activity Severity Index (PASI) scores and photographic analysis, was done 2 weeks before treatment, at time 0, and after 2, 4, 6 and 8 weeks. Patient’s improvement was determined by the percentage reduction of the PASI scores. Side effects and tolerability were also evaluated. After 8 weeks treatment course, 46 patients had a moderate improvement, with the regression of 25-50% of skin lesions; 77 patients showed a good improvement, with the resolution of 51-75% of lesions. Another 115 patients had an outstanding improvement, with the regression of 76-98.9% of lesions. Only 13 patients did not achieve an improvement of psoriasis. Fifteen patients experienced folliculitis, which resolved after cessation of treatment. Seven patients worsened and discontinued treatment. Thirteen patients dropped out because of non-compliance. Our investigation demonstrates that Dr Michaels® (Soratinex®) products, an Australian treatment, can be used successfully in the treatment of stable chronic plaque psoriasis.

[DNA methylation and telomere damage in occupational people exposed to coal tar pitch]

OBJECTIVE

To investigate the promoter methylation of p16, FHIT and RASSF1A gene and telomere damage in the workers exposed to coal tar pitch, and to explore the effective biomarker of occupational exposure to coal tar pitch.

METHODS

180 cases of workers exposed to coal tar pitch in a certain carbon plant named as exposure group, and 145 healthy cases with a medical examination in the first affiliated hospital of Zhengzhou University were selected as control group. Relative telomere length in peripheral blood DNA was detected using real-time quantitative PCR, and the promoter methylation rate of p16, RASSF1A and FHIT gene in peripheral blood DNA were determined by real-time quantitative methylation specific PCR. The relative telomere length and gene promoter methylation in two groups were compared, and influencing factors were analyzed.

RESULTS

Relative telomere length in exposed group was lower than that in the control group, and the difference was statistically significant (Z = -5.395, P < 0.001). There was no significant difference in the promoter methylation rate of p16, FHIT and RASSF1A gene between the two groups (P > 0.05). Stratification analysis by gender, age, and smoking, we found that when the age was less than or equal to 40, the promoter methylation rate of p16 in exposed group was more than that in control group, and the difference was statistically significant (Z = -1.914, P = 0.011).

CONCLUSION

Occupational exposure to coal tar pitch may induce leukocyte DNA telomere length of human peripheral blood shortened, and may not change the promoter methylation rates of p16, FHIT and RASSF1A gene.

Comparative evaluation of topical calcipotriol versus coal tar and salicylic acid ointment in chronic plaque psoriasis

BACKGROUND

Calcipotriol is a newer topical treatment option available for plaque psoriasis and coal tar being one of the oldest treatment and still in use.

AIMS

To evaluate and compare the differences in terms of efficacy, safety and relapse with Calcipotriol 0.005% (50 mcg/gm) and 6% coal tar and 3% salicylic ointment in patients with Plaque psoriasis. SETTING and

DESIGNS

Study conducted on 60 patients of plaque psoriasis, who attended the skin OPD in our hospital.

METHODS

The patients with mild to moderate plaque psoriasis were selected. 60 patients were enrolled for the study after obtaining informed consent. Subjects were asked to apply Calcipotriol 0.005% (50 mcg/gm) (Heximar Win care) twice a day on the right side plaques and on left side plaques, Petroleum jelly (Vaseline) in the morning and 6% coal tar and 3% salicylic ointment (Protar® Percos) at nighttime. PASI score was used to assess the reponse to therapy at 2nd, 4th, 6th and 8th week. After treatment subjects were observed for 6 weeks for any relapse.

STATISTICAL ANALYSIS

It was done by paired t-test and independent sample t-test.

CONCLUSIONS

The results showed that statistically significant difference was seen in the mean percentage reduction of PASI score between both the groups, at all the assessment visits, 2, 4, 6, and 8 weeks, the mean percentage reduction at 2 weeks for calcipotriol being 21±12.06 and for coal tar being 13.44±11.19 (P=0.000), at 4 weeks for calcipotriol was 40±16.71 and for coal tar 25±99 (P=0.000), at 6 weeks for calcipotriol was 53.99+-22.43 and for coal tar 41±21.23 (P=0.002), at 8 weeks for calcipotriol was 62.73±24.04 and for coal tar was 51.53±23.27 (P=0.11). Relapse was seen in 5/60 (8.3%) of patients on calcipotriol treated side and 9/60 (15%) of patients with coal tar treated side. Thus it can be concluded that calcipotriol cream is more efficacious when compared with coal tar and does have a quick response. It is well tolerated and acceptable cosmetically.

Cancer risk from incidental ingestion exposures to PAHs associated with coal-tar-sealed pavement

Recent (2009-10) studies documented significantly higher concentrations of polycyclic aromatic hydrocarbons (PAHs) in settled house dust in living spaces and soil adjacent to parking lots sealed with coal-tar-based products. To date, no studies have examined the potential human health effects of PAHs from these products in dust and soil. Here we present the results of an analysis of potential cancer risk associated with incidental ingestion exposures to PAHs in settings near coal-tar-sealed pavement. Exposures to benzo[a]pyrene equivalents were characterized across five scenarios. The central tendency estimate of excess cancer risk resulting from lifetime exposures to soil and dust from nondietary ingestion in these settings exceeded 1 × 10(-4), as determined using deterministic and probabilistic methods. Soil was the primary driver of risk, but according to probabilistic calculations, reasonable maximum exposure to affected house dust in the first 6 years of life was sufficient to generate an estimated excess lifetime cancer risk of 6 × 10(-5). Our results indicate that the presence of coal-tar-based pavement sealants is associated with significant increases in estimated excess lifetime cancer risk for nearby residents. Much of this calculated excess risk arises from exposures to PAHs in early childhood (i.e., 0-6 years of age).

[Coal tar pitch smoke extract-induced pyroptosis in human bronchial epithelial cells]

OBJECTIVE

To explore whether coal tar pitch smoke extract (CTP) induced pyroptosis in human bronchial epithelial cells (BEAS-2B).

METHODS

BEAS-2B cells were treated with different concentrations of CTP (1, 3 µg/ml) for 8h and 24 h, respectively. Lactic dehydrogenase (LDH) activity and interleukin-1 beta (IL-1β) levels in the supernatants of cell culture media were measured with LDH activity or human IL-1β ELISA kit, respectively. The activity of Caspase-1 was measured with Caspase-1 colorimetric assay kit.

RESULTS

The activity of caspase-1 in 1 and 3 µg/ml CTP groups were (9.29 ± 0.30) and (8.67 ± 0.59) µmol/ml respectively which were both significantly increased compared to that (7.42 ± 0.59) µmol/ml in the control group (P < 0.05) after 8 h exposure, but there was no significant difference in the activity of LDH and levels of IL-1β in the cell culture media among the CTP and control groups. 24 h after exposure, the activity of LDH in the CTP (1, 3 µg/ml) groups were (1323.03 ± 28.53) and (1148.45 ± 16.42) U/dl respectively which were significantly higher than that (1091.93 ± 26.64) U/dl in the control group (P < 0.05), and the levels of IL-1β in the CTP (1 and 3 µg/ml) groups were (125.37 ± 25.00) pg/ml and (92.04 ± 19.09) pg/ml respectively which were significantly higher than that (46.20 ± 14.43) pg/ml in the control group (P < 0.05), but there was no significant difference in the activity of Caspase-1 among CTP and control groups (P < 0.05).

CONCLUSION

CTP treatment induced early increase in caspase-1 activity followed by the increase in LDH activity and IL-1 levels, indicative of pyroptosis in human bronchial epithelial cells.

Chronic and acute effects of coal tar pitch exposure and cardiopulmonary mortality among aluminum smelter workers

Air pollution causes several adverse cardiovascular and respiratory effects. In occupational studies, where levels of particulate matter and polycyclic aromatic hydrocarbons (PAHs) are higher, the evidence is inconsistent. The effects of acute and chronic PAH exposure on cardiopulmonary mortality were examined within a Kitimat, Canada, aluminum smelter cohort (n = 7,026) linked to a national mortality database (1957-1999). No standardized mortality ratio was significantly elevated compared with the province's population. Smoking-adjusted internal comparisons were conducted using Cox regression for male subjects (n = 6,423). Ischemic heart disease (IHD) mortality (n = 281) was associated with cumulative benzo[a]pyrene (B(a)P) exposure (hazard ratio = 1.62, 95% confidence interval: 1.06, 2.46) in the highest category. A monotonic but nonsignificant trend was observed with chronic B(a)P exposure and acute myocardial infarction (n = 184). When follow-up was restricted to active employment, the hazard ratio for IHD was 2.39 (95% confidence interval: 0.95, 6.05) in the highest cumulative B(a)P category. The stronger associations observed during employment suggest that risk may not persist after exposure cessation. No associations with recent or current exposure were observed. IHD was associated with chronic (but not current) PAH exposure in a high-exposure occupational setting. Given the widespread workplace exposure to PAHs and heart disease's high prevalence, even modest associations produce a high burden.

Efficacy and tolerability of a cosmetically acceptable coal tar solution in the treatment of moderate plaque psoriasis: a controlled comparison with calcipotriene (calcipotriol) cream

BACKGROUND

Topical coal tar is a well known and effective treatment for psoriasis, but the messiness, staining, odor, and inconvenience associated with its use make patient satisfaction and compliance a challenge.

OBJECTIVE

To determine the efficacy, patient tolerability, and cosmetic acceptability of a new topical liquor carbonis distillate (LCD) 15% solution compared with calcipotriene (calcipotriol) cream in patients with moderate, chronic plaque psoriasis.

STUDY DESIGN

A randomized, single-blind, active-controlled, parallel-group, clinical trial consisting of a 12-week treatment phase and a 6-week post-treatment follow-up phase.

SETTING

Outpatient dermatology research unit in an academic hospital.

PATIENTS

Sixty adults with moderate, chronic plaque psoriasis (3-15% body surface area affected) not receiving other psoriasis therapies.

INTERVENTION

Patients were randomized to apply either an LCD 15% solution (Psorent) or a commercially available calcipotriene 0.005% cream (Dovonex) to their psoriasis areas (excluding the head) twice daily at home for 12 weeks.

ASSESSMENTS

A blinded investigator evaluated the patients' psoriasis using a modified Psoriasis Area and Severity Index (PASI) that excluded the head, and a Physician's Global Assessment (PGA) scale at weeks 0 (baseline), 2, 4, 8, and 12 (end of treatment), and 18 (6 weeks after treatment was withdrawn). Patients assessed their psoriasis symptoms and quality of life and completed a cosmetic acceptability survey about their medication.

OUTCOME MEASURES

The changes in the baseline PASI scores after 12 weeks of treatment were compared between LCD and calcipotriene groups. Additional comparisons were performed for success rates during treatment (PASI 75 and PASI 50), changes in PGA scores, patient-reported psoriasis symptom scores, patients' quality-of-life scores, and recurrence rates during post-treatment follow-up.

RESULTS

Both treatment groups showed improvement in psoriasis severity and quality of life. However, the LCD group had greater mean reductions in PASI scores: 58% vs 37% in the calcipotriene group (p < 0.05) at week 12. Additionally, the LCD group had more patients (14/27) with absent or minimal psoriasis on the PGA scale than the calcipotriene group (6/28) by the end of treatment (p < 0.05). LCD-treated patients also maintained their improvement better than calcipotriene-treated patients through week 18 after treatment was withdrawn for 6 weeks. Both treatments were well tolerated and cosmetically acceptable to patients.

CONCLUSION

The newly formulated LCD solution, applied twice daily at home for 12 weeks, was more effective and as well tolerated and cosmetically acceptable as the calcipotriene cream over 12 weeks of treatment and 6 weeks of follow-up. The LCD solution is a patient-accepted and effective corticosteroid-sparing treatment alternative for psoriasis patients.

Tolerability and cosmetic acceptability of liquor carbonis distillate (coal tar) solution 15% as topical therapy for plaque psoriasis

Although generally recognized as an effective therapy for psoriasis, coal tar therapy lost appeal in modern clinical practice due to poor patient acceptability of its aesthetic properties. A new liquor carbonis distillate (LCD) solution 15% (equivalent to coal tar 2.3%) that uses an evaporative and transparent vehicle, fragrance, and a dab-on applicator was developed. Cosmetic acceptability of the LCD solution was compared to calcipotriene cream 0.005% during a randomized, active-controlled, investigator-blinded clinical trial. Participants with moderate plaque psoriasis applied LCD solution or calcipotriene cream twice daily to body lesions for 12 weeks and then were followed for 6 additional weeks without treatment. Participants completed a cosmetic acceptability survey about their medications after starting therapy. Mean ratings for aesthetic and product performance attributes were high in both groups; however, more participants treated with LCD solution versus calcipotriene cream rated their product as more convenient and beneficial compared to prior psoriasis therapies. Ratings of the scent, staining, drying time, and dab-on applicator for the LCD solution were favorable. Participant experience with LCD solution in this study suggests that it is a cosmetically acceptable psoriasis treatment that is comparable to calcipotriene cream.

Coal tar in dermatology

Coal tar is one of the oldest treatments for psoriasis and eczema. It has anti-inflammatory, antibacterial, antipruritic and antimitotic effects. The short-term side effects are folliculitis, irritation and contact allergy. Coal tar contains carcinogens. The carcinogenicity of coal tar has been shown in animal studies and studies in occupational settings. There is no clear evidence of an increased risk of skin tumors or internal tumors. Until now, most studies have been fairly small and they did not investigate the risk of coal tar alone, but the risk of coal tar combined with other therapies. New, well-designed, epidemiological studies are necessary to assess the risk of skin tumors and other malignancies after dermatological use of coal tar.

A comparative study of tar and betamethasone valerate in chronic plaque psoriasis: a study in Thailand

OBJECTIVE

Evaluate and compare the efficacy, safety, and tolerability of coal tar (10% LCD, liquor carbonis detergens), with betamethasone valerate in the therapy of large plaque-type psoriasis.

MATERIAL AND METHOD

Patients with stable, mild to moderate plaque psoriasis at the Department of Medicine, Lerdsin General Hospital, Bangkok, Thailand were randomized for treatment with either coal tar (10% LCD) cream or betamethasone valerate cream (0.1%). All patients entered a 2 week wash-out period followed by the creams being applied twice daily until completion at 6 weeks. The patient severity of psoriasis was assessed using the modified Psoriasis Area and Severity Index (PASI) score at baseline and after 2, 4, and 6 weeks of treatment.

RESULT

At the end of the trial, the mean reduction of the PASI score from baseline was 38.39% with the coal tar group and 69.36% with the betamethasone valerate group. The mean percentage of the PASI score reduction was statistically significant in both groups but the betamethasone valerate group was significantly superior to the coal tar group. Both drugs' adverse effects were limited to mild irritation localized to the skin without systemic side effects. The Betamethasone valerate cream was safe, effective, and well-tolerated while the coal tar cream was described as messy, malodorous, and with a tendency to staining clothes.

CONCLUSION

The investigator's overall assessment of the treatment response at completion of the trial demonstrated that the betamethasone valerate group achieved significantly greater clearance and marked improvement compared with the coal tar group.

Mortality and Cancer Experience of Quebec Aluminum Reduction Plant Workers. Part I: The Reduction Plants and Coal Tar Pitch Volatile (CTPV) Exposure Assessment

OBJECTIVES

This paper presents the exposure assessment and job-exposure matrix (JEM) used to estimate coal tar pitch volatile (CTPV) exposure for a study of mortality and cancer incidence in aluminum smelter workers in Quebec, Canada.

METHODS

Historical CTPV exposure was assessed by estimating benzene-soluble material (BSM) and benzo[a]pyrene (B[a]P) levels for combinations of job and time period. Estimates were derived by using several procedures including averaging measurement data, a deterministic mathematical model using process-related correction factors, and expert-based extrapolation.

RESULTS

The JEM comprised 28,910 jobs, covering 7 facilities from 1916 to 1999. Estimated exposures ranged from 0.01 microg/m(3) to 68.08 microg/m(3) (B[a]P) and 0.01 mg/m(3) to 3.64 mg/m(3) (BSM) and were lowest before 1940 and after 1980.

CONCLUSION

This methodology constitutes an improvement compared with methods used for previous studies of the Quebec cohort.

Treatment policy for psoriasis and eczema: a survey among dermatologists in the Netherlands and Belgian Flanders

Today, many therapies are available for the treatment of psoriasis and eczema. One of the oldest topical therapies is coal tar. Coal tar has been used for decades, but over the past years, the use of coal tar has decreased for several reasons, including the supposed carcinogenicity of coal tar. We investigated the current and past treatment policies for psoriasis and eczema with special emphasis on the use of tar products; a postal survey was conducted among all dermatologists in two European countries: the Netherlands (n = 360) and the Flemish speaking part of Belgium (Flanders) (n = 328). This study was conducted as part of the ongoing LATER-study ("Late effects of coal tar treatment in eczema and psoriasis; the Radboud study"). All practising dermatologists received a questionnaire. Dermatologists were asked to describe their treatment policies in mild/moderate psoriasis, severe psoriasis, mild/moderate eczema and severe eczema. The response rate to the questionnaire was 62.5% for the Dutch dermatologists and 45.7% for the Flemish dermatologists. Almost all dermatologists prescribe topical corticosteroids. In eczema, most of the dermatologists prescribe the recently introduced calcineurin inhibitors (95%). Coal tar is a second choice topical therapy. Dutch dermatologists mainly use tar in the treatment of eczema (72% vs. 48% in Flanders), whereas in Flanders, tar is mainly prescribed in psoriasis (60% vs. 41% in Holland). Flemish dermatologists very frequently prescribe PUVA in psoriasis (93% vs. 63%). Topical treatment, especially topical corticosteroids, is the mainstay in psoriasis and eczema. Coal tar still is an important (second choice) therapy for the topical treatment of psoriasis and eczema, but its use varies from country to country. Despite the carcinogenicity of PUVA, this photochemotherapy is frequently prescribed by dermatologists, mainly in Flanders.

Cancer risk in aluminum reduction plant workers (Canada)

A 14-year update to a previously published historical cohort study of aluminum reduction plant workers was conducted [1]. All men with three or more years at an aluminum reduction plant in British Columbia (BC), Canada between the years 1954 and 1997 were included; a total of 6,423 workers. A total of 662 men were diagnosed with cancer, representing a 400% increase from the original study. Standardized mortality and incidence ratios were used to compare the cancer mortality and incidence of the cohort to that of the BC population. Poisson regression was used to examine risk by cumulative exposure to coal tar pitch volatiles (CTPV) measured as benzene soluble materials (BSM) and benzo(a)pyrene (BaP). The risk for bladder cancer was related to cumulative exposure to CTPV measured as BSM and BaP (p trends <0.001), and the risk for stomach cancer was related to exposure measured by BaP (p trend BaP <0.05). The risks for lung cancer (p trend <0.001), non-Hodgkin lymphoma (p trend <0.001), and kidney cancer (p trend <0.01) also increased with increasing exposure, although the overall rates were similar to that of the general population. Analysis of the joint effect of smoking and CTPV exposure on cancer showed the observed dose-response relationships to be independent of smoking.

Occupational exposures to polycyclic aromatic hydrocarbons, and respiratory and urinary tract cancers: a quantitative review to 2005

BACKGROUND

Exposure to polycyclic aromatic hydrocarbons (PAHs) has been reported in several industries, including those of the aluminum production, coal gasification, coke production, iron and steel foundries, coal tar and related products, carbon black and carbon electrodes production.

PATIENTS AND METHODS

This paper reviews the results from cohort studies conducted on workers exposed to PAHs in these industries, with a focus on cancers of the respiratory and urinary tract.

RESULTS

An excess risk from lung/respiratory cancers was found in most industries, the pooled relative risk (RR) being 2.58 (95% CI 2.28-2.92) for coal gasification, 1.58 (95% CI 1.47-1.69) for coke production, 1.40 (95% CI 1.31-1.49) for iron and steel foundries, 1.51 (95% CI 1.28-1.78) for roofers and 1.30 (95% CI 1.06-1.59) for carbon black production. The evidence for cancers of the bladder and of the urinary system is less consistent, with a significant increased risk only for workers in aluminum production (pooled RR = 1.29, 95% CI 1.12-1.49), coal gasification (pooled RR = 2.39, 95% CI 1.36-4.21), and iron and steel foundries (pooled RR = 1.29, 95% CI 1.06-1.57).

CONCLUSIONS

Increased risks from lung and bladder cancers were found in PAH-related occupations. These were modest in most industries, apart from those for coal gasification, and whether they are due at least partially to some bias or confounding remains open to discussion.

Genotoxic effect of Goeckerman regimen of psoriasis

Goeckerman regimen (GR) of psoriasis includes daily dermal application of crude coal tar (CCT) and dermal exposure to UV-A and UV-B radiation. Observed group consisted of 23 patients with psoriasis treated by GR. Therapeutic ointment contained 5% of CCT. The level of psoriasis area and severity index was significantly decreased after GR (P < 0.001) and confirms high efficiency of GR. High levels of selected metabolites of pyrene and phenanthrene indicated high level of dermal penetration. We found significantly increased urinary mutagenicity in samples collected in the middle and in the end of GR (TA98+S9, P < 0.01; YG1041-S9, P < 0.001; YG1041+S9, P < 0.001). Significant increasing of chromosomal aberrations in peripheral lymphocytes (CA) in blood samples collected in the end of GR (P < 0.001) and consecutive decreasing of CA in 78th day after the end of GR has been observed. Almost all results indicated that the patients could be endangered by a peak genotoxic exposure. Nevertheless, the genotoxic effect does not seem to be long lasting. Despite conflicting results from cancer epidemiological studies, it is evident that single GR can contribute to the total load of environmental mutagens in a group of treated patients.

Association of cigarette smoking and tar and nicotine intake with development of type 2 diabetes mellitus in men and women from the general population: the MONICA/KORA Augsburg Cohort Study

AIMS/HYPOTHESIS

We examined sex-specific associations between cigarette smoking and incident type 2 diabetes mellitus in Germany.

SUBJECTS, MATERIALS AND METHODS

The study was based on 5,470 men and 5,422 women (aged 25-74 years) without diabetes who participated in one of the three population-based MONICA Augsburg surveys between 1984 and 1995. Incident cases of type 2 diabetes were assessed using follow-up questionnaires. Hazard ratios (HRs) were estimated from Cox proportional hazard models.

RESULTS

Up to 31 December 2002 a total of 409 cases of incident type 2 diabetes among men and 263 among women were registered. The number of cigarettes and the nicotine and tar consumption per day were associated with a significantly increased risk of type 2 diabetes among men, but not among women; this could be due to the low power of the study in women. After multivariable adjustment, the HRs for type 2 diabetes compared with never-smokers were 1.48, 2.03 and 2.10 for men smoking 1 to 14, 15 to 19 and > or =20 cigarettes/day (p for trend <0.0001) and 1.25, 1.34 and 1.37 for women smoking 1 to 9, 10 to 19 and > or =20 cigarettes/day (p for trend 0.0985). Compared with never-smokers, the HRs for increasing tar intake in men (1-167, 168-259 and > or =260 mg/day) were 1.45, 2.32 and 2.07 (p for trend <0.0001); the respective HRs in women (1-89, 90-194 and > or =195 mg/day) were 1.18, 1.57 and 1.24 (p for trend 0.1159).

CONCLUSIONS/INTERPRETATION

Cigarette smoking is an important modifiable risk factor of type 2 diabetes particularly in men from the general population.

Incidence of asthma among aluminum workers

Exposures to respiratory irritants encountered in aluminum smelters in Europe, Australia, and New Zealand have been suggested as the cause of "potroom asthma." However, there remains disagreement in North America regarding the existence of this entity. This study was designed to assess whether asthma occurs excessively among potroom workers and if so, delineate dose-response relationships for possible causal risk factors. The asthma incidence ratio between potroom and nonpotroom workers after adjusting for smoking was 1.40. Although bivariate analyses showed a relationship between asthma incidence and exposure to total fluoride, gaseous fluoride, particulate fluoride, sulfur dioxide, and smoking, only the effects of gaseous fluoride (relative risk [RR] = 5.1) and smoking (RR = 7.7) remained significant in a multivariate model. Potroom asthma appears to occur at the studied U.S. aluminum smelters at doses within regulatory guidelines.

Cytogenetic and immunological changes after dermal exposure to polycyclic aromatic hydrocarbons and UV radiation

Goeckerman's therapy (GT), which combines exposure to coal tar (polycyclic aromatic hydrocarbons - PAHs) and UV radiation (UV) is often used as the first option for treatment of psoriasis. However, PAHs and UV represent mutagenic, carcinogenic and immunotoxic agents. Therefore GT can represent a health risk for the patients. The group under observation consisted of thirty patients undergoing GT. Before and after the treatment, blood samples were collected and chromosomal aberrations and selected immunological markers were determined. The relationships between chromosomal aberrations and immunological markers and the extent (duration) of exposure to GT were evaluated. The Psoriasis Area and Severity Index (PASI) score confirmed the high efficacy of GT. However, significantly elevated levels of chromosomal aberrations of peripheral lymphocytes were also found after the therapy (p<0.001). The levels of chromosomal abnormalities correlated to the extent and the total duration of exposure to PAHs (r = 0.682, p<0.01 and r = 0.605, p<0.05). After the therapy, significantly decreased levels of IgE, IgM isotypes of immunoglobulin, alpha(2)-macroglobulin and transferrin together with beta(2)-microglobulin were found. From the immunological markers listed above only the decreased level of alpha(2)-macroglobulin correlated to the extent of exposure to PAHs (r = -0.568, p<0.05). No correlation was found between chromosomal aberrations, significantly changed immunological markers and the duration of UV exposure. Our study revealed that GT has a significant impact on both genetic and immunological parameters of psoriatic patients. The results indicate that GT could increase genotoxic risk and modulates immunity of treated patients.

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.

Possible genotoxic risk of combined exposure to pharmaceutical coal tar and UV-B radiation

Goeckerman's therapy of psoriasis combines exposure to pharmaceutical coal tar and UV-B radiation. In the pilot study (15 patients had been diagnosed with psoriasis, the average time period in hospital therapy was 24 days, the average age of the patients was 29 years, 47% of them were smokers) a level of genotoxic risk from therapy was evaluated by using chromosomal aberration of peripheral lymphocytes. The study suggested the presence of an increased genotoxic risk from the therapy. The PASI scores (Psoriasis Area and Severity Index) were monitored.

[Genotoxic risk of Goeckerman's therapy of psoriasis. Pilot study--children]

Goeckerman's therapy of psoriasis includes combined exposure to therapeutic tar and UV-B radiation. In a pilot study of (12 children) a level of genotoxic risk of the therapy was evaluated by chromosomal aberration of peripheral lymphocytes. Results of the pilot study suggest possible genotoxic risk of the therapy.

Multiple biomarkers study in painters in a shipyard in Korea

Shipbuilding workers are exposed to a variety of genotoxic compounds including polycyclic aromatic hydrocarbons (PAHs). A limited number of studies have been conducted to evaluate biomarkers related to PAH exposure in painters in the shipyard industry. We examined this in 208 workers recruited from a shipyard located in South Korea. Employees were grouped into three exposure groups: (1) 111 painters using coal tar paints, (2) 70 painters using general paints, and (3) 27 on-site controls using no paints. Levels of urinary 1-hydroxypyrene glucuronide (1-OHPG), as internal dose of PAH exposure, were measured by synchronous fluorescence spectroscopy. Glutathione S-transferase (GST) M1 and T1 genotypes were assessed by a multiplex polymerase chain reaction (PCR)-based method, aromatic-DNA adducts in peripheral white blood cells were measured by 32P-postlabeling, and glycophorin A (GPA) variant frequencies in red blood cells were assessed by flow cytometry. Information on demographic characteristics, smoking habits, diet, job title and use of personal protective equipment (e.g. respiratory and dermal) were collected by self-administered questionnaire. Average urinary 1-OHPG levels in coal tar paint (2.24 micromol/mol creatinine) and general paint (1.38 micromol/mol creatinine) users were significantly higher than in on-site controls (0.62 micromol/mol creatinine) (P<0.001). Paint use, irrespective of the type of paints, and smoking (yes/no) were positively associated with urinary 1-OHPG levels, whereas green tea consumption (yes/no) was negatively associated with the 1-OHPG levels. No significant effect in the 1-OHPG levels were observed for the GSTM1 and GSTT1 genotypes. Aromatic-DNA adduct levels tended to be higher in coal tar paint users (P = 0.06) and painters (P = 0.07) compared to on-site controls. No differences in adduct levels were observed, between the two groups of painters, and the combined group showed greater adduct levels than on-site controls (P = 0.05). GPA mutation frequencies measured in 55 individuals with MN heterozygote genotypes were not significantly different among the three exposure groups, and no correlation was observed between urinary 1-OHPG levels and aromatic-DNA adducts or GPA mutation frequency. These results suggest that painters in the shipyard were exposed to significant amounts of PAHs and possibly to other genotoxic aromatic compounds, and that urinary 1-OHPG may be a potential biomarker of PAH exposure in this population.

The topical treatment of psoriasis

According to the patients, improvement of efficacy, long-term safety and improvement of compliance are needed. The topical treatment has been innovated during the last decade. Most important are the introduction of two new classes of treatments: topical vitamin D(3) analogues and the retinoid tazarotene. To what extent, however, have we achieved developments which are in line with the needs as expressed by the patients? Improved efficacy has been realized by successful combinations of topical treatments. In particular, the combinations of dithranol, vitamin D(3) and tazarotene with a topical corticosteroid proved to be very effective with a reduced profile of side-effects. The efficacy of vitamin D(3) analogues and tazarotene is such that the efficacy of a potent corticosteroid (betamethasone-17-valerate) is approached; calcipotriol even showed an efficacy which is at least as good as this corticosteroid. The long-term safety of new compounds has been evaluated for at least 12 months in large studies. Remarkably for corticosteroids such information is available for only 12 weeks. However, intermittent applications of a topical corticosteroid in combination with another topical treatment provide an effective and safe long-term control of psoriasis. Compliance is a conditio sine qua non for an effective topical treatment. Important progress has been made to increase compliance. Short-contact dithranol has been popularized as an ambulatory treatment which is a highly effective approach as a care instruction programme. Formulations which are better from a cosmetical point of view have been developed for various topical treatments. Reduction of the frequency of applications proved to be possible for most treatments. Once daily applications for corticosteroids, vitamin D(3) analogues and retinoids have been developed, and intermittent applications, a few times per week, are possible for corticosteroids, which proved to be very effective with a reduced profile of side-effects, and are also developed for dithranol.

A systematic review of adverse effects associated with topical treatments for psoriasis

Mild to moderate psoriasis is a disease that can often be treated with topical medications. The diversity of topical therapies and their disparate side effects complicates treatment planning. Our purpose is to compare the rates of adverse events associated with different topical psoriasis treatments. A review of medical literature from 1996 to March, 2002 was conducted using guidelines set by QUORUM statement criteria. In monotherapy studies, corticosteriods caused fewer adverse reactions compared to vitamin D analogues and tazarotene. In combination studies adverse event rates were higher than in monotherapy studies, except for the combination of topical steroid and calcipotriene which decreased irritation. Irritant contact dermatitis was the main side effect with vitamin D analogues, tazarotene, dithranol or coal tar, while side effects of topical corticosteriods included headache, viral infection and skin atrophy. Topical agents for psoriasis are usually well-tolerated without severe side effects. Formulating a patient's medication regimen should take into account the needs for short-term management and long-term control of psoriasis. Since clearance is not a realistic expectation, reasonable goals should be set as excessive use of topical treatments may increase the risk of both cutaneous and systemic side effects.

Investigation of the presence of amino and nitro polycyclic aromatic hydrocarbons in a Söderberg primary aluminum smelter

An excessive risk of bladder cancer among Söderberg primary aluminum smelter potroom workers has been reported by several authors, and to date, a causal agent has not been identified. Certain nitro and amino polycyclic aromatic hydrocarbons (PAHs) are either known or suspected human bladder carcinogens, and their presence in this work environment would be cause for concern. In fact, one of these, 2-aminonaphthalene, has been found in both the air and the coal tar pitch used to fabricate process electrodes following an investigation in a Söderberg plant. During the present study, monitoring was conducted in a primary Söderberg aluminum smelter over a 3-week period using novel methods having very good specificity, reproducibility, and sensitivity. Results indicated that 1-aminonaphthalene and 2-aminonaphthalene and 1-nitronaphthalene and 2-nitronaphthalene were present at low parts-per-million levels in the coal tar pitch used to prepare the process electrodes. 1-aminonaphthalene and 2-aminonaphthalene were measured 40 cm above the electrolytic cells on days 1 and 2 of the investigation when the cells' ventilation systems had been shut down for repairs and maintenance. 2-aminonaphthalene was measured at concentrations ranging from 0.080 to 0.350 microg/m3. 1-nitronaphthalene and 2-nitronaphthalene, predominant in coal tar pitch, were not detected in any of the 43 air samples collected. A plausible explanation is their reduction to their respective amine during the electrolytic process. The routine screening of coal tar pitch used to prepare the process's electrode for both amino and nitro PAHs should be adopted by the aluminum industry as an effective means of controlling the presence of these carcinogenic pollutants in their workplace.

Cancer mortality among man-made graphite electrode manufacturing workers: results of a 38 year follow up

BACKGROUND AND AIMS

To examine the risk for cancer mortality among workers exposed to coal tar and coal tar pitch volatiles in a man-made graphite electrode factory. The risk for cancer mortality in this type of factory is still inconclusive, although coal tar and coal tar pitch are recognised as human carcinogens.

METHODS

The study cohort consisted of 332 male employees who served more than five years in the period 1951-74. The cohort was traced until 1988. Analyses used standardised mortality ratios (SMRs) to compare cause specific mortality with that in the general and local population. Effect of smoking was estimated based on the information collected from the subgroup of the cohort. SMRs for leading causes of death were compared among different job titles, duration of employment, time since first employment, and observation subperiods. Exposure level for tar and benzo[a]pyrene (BaP) in the factory was also discussed, based on measurements done by other researchers in the past.

RESULTS

During the study period, 52 deaths were identified (SMR 0.68), including 22 cancer deaths (SMR 1.01). The SMR for lung cancer was significantly increased in comparison with the general population (SMR 2.62). It was slightly decreased in comparison with the local population, but remained significant (SMR 2.35). Excess deaths were also observed for lymphatic and haematopoietic cancers (SMR 3.46). Smoking habits in the subgroup were similar to those in the general population; thus the increased SMR for lung cancer was unlikely to be explained by smoking.

CONCLUSION

Previous environmental measurements suggested that considerable exposure to tar and BaP had existed in the factory. The results suggest a possible risk for lung cancer among the cohort, but the limitations of the study, such as the small study population and insufficient information on exposure, indicate that further study is required.

Highly increased urinary 1-hydroxypyrene excretion rate in patients with atopic dermatitis treated with topical coal tar

Coal tar preparations, as used in dermatological practice, contain numerous polycyclic aromatic hydrocarbons of which many are proven animal carcinogens. Increased urinary 1-hydroxypyrene excretion in patients with atopic dermatitis treated with topical coal tar preparations has been demonstrated. Little is known about the relationship between the dermal uptake of polycyclic aromatic hydrocarbons on the one hand and the amount of tar applied to the skin, the total body area affected, the condition of the epidermal barrier and the severity of the dermatitis on the other. We compared urinary 1-hydroxypyrene excretion rate with these variables. The urinary 1-hydroxypyrene excretion rate was highly dependent on the total amount of tar applied to the skin and the total body area affected, and less on the severity of the atopic dermatitis or the condition of the epidermal barrier. Exposure to therapeutic doses of coal tar leads to much higher rates of urinary 1-hydroxypyrene excretion than occupational exposure. Because of the potential carcinogenicity of coal tar, as clearly demonstrated both in animal studies and from occupational exposure, careful consideration should be given to the use of coal tar preparations in dermatological practice. However, the risk of short-term high exposure is unknown. Restriction of the use of coal tar should be based on epidemiological studies and/or appropriate risk models taking into account its relative safety established over many years of clinical use.

Myeloperoxidase--463A variant reduces benzo[a]pyrene diol epoxide DNA adducts in skin of coal tar treated patients

The skin of atopic dermatitis patients provides an excellent model to study the role of inflammation in benzo[a]pyrene (BaP) activation, since these individuals are often topically treated with ointments containing high concentrations of BaP. In this study we have determined, by HPLC with fluorescence detection, the BaP diol epoxide (BPDE)-DNA adduct levels in human skin after topical treatment with coal tar and their modulation by the -463G-->A myeloperoxidase (MPO) polymorphism, which reduces MPO mRNA expression. BPDE-DNA adduct levels were 2.2 and 14.2 adducts/10(8) nt for MPO-463AA/AG and -463GG, respectively. The predominant BaP tetrol observed was tetrol I-1, which is derived after hydrolysis of the anti-BPDE-DNA adduct. The tetrol I-1/II-2 ratio, corresponding to the anti/syn ratio, was 6.7. The (32)P-post-labeling assay was also performed and thin layer chromatograms showed a major spot with a chromatographic location corresponding to BPDE-DNA. The mean values of the BPDE-DNA adduct spots were 3.8 +/- 2.4 per 10(8) nt for MPO-463AA/AG (n = 3) and 18.4 +/- 11.0 per 10(8) nt for MPO-463GG (n = 7), respectively (P = 0.03). One individual with the homozygous mutant genotype (-463AA) even had a 13-fold lower adduct level (1.4 per 10(8) nt) as compared to MPO-463GG subjects. In conclusion, these data show for the first time: (i) the in vivo formation of BPDE-DNA adducts in human skin treated with coal tar; (ii) that the MPO-463AA/AG genotype reduced BPDE-DNA adduct levels in human skin.

A double blind, randomized, controlled clinical trial to assess the efficacy of a new coal tar preparation (Exorex) in the treatment of chronic, plaque type psoriasis

Exorex is a new topical formulation for the treatment of psoriasis; it contains 1% coal tar and a synthetic analogue resembling components identified in banana skin (a complex of esterified essential fatty acids). To determine whether the esterified essential fatty acid complex confers any therapeutic advantage over coal tar alone, patients with chronic plaque psoriasis (n = 20) were entered into a double-blind, randomized, right/left comparison of Exorex, and Exorex without the essential fatty acid component (known hereafter as coal tar control) for 8 weeks. Target plaques were scored (0-4) for erythema, desquamation and infiltration at day 0 and at 2 week intervals throughout the study. No significant differences were detected between Exorex and coal tar control with respect to changes in the summed scores at baseline and following 8 weeks of treatment (mean difference in summed score changes from baseline between Exorex and coal tar control 0.2, 95% confidence interval - 0.44 to 0.84; P = 0.52) or in the area under the response-time curve (P = 0.16). Mean percentage improvement in summed scores of target plaques were 53.9% (SE = 4%) and 56.1% (SE = 4.9%) for Exorex and coal tar control, respectively. Results suggest that the complex of esterified essential fatty acids is not exerting any clinically important therapeutic effect in the treatment of chronic plaque psoriasis.

[A case of squamous cell carcinoma that developed on chronic tar dermatosis]

A 79-year-old Japanese man visited our clinic for evaluation of a large tumor on the left wrist and multiple keratotic tumors. He had handled creosote oil, which is a purified product of coal tar production, for 50 years. Physical examinations revealed poikiloderma with multiple hyperkeratotic tumors on the back of his hand and forearm bilaterally, and a cauliflower-like tumor, 80 x 60 x 15 mm in size, on the left wrist. Histopathologically, the large tumor showed a proliferation of atypical squamoid cells with many keratinization foci, indicating well-differentiated squamous cell carcinoma.

Proportionate mortality among unionized roofers and waterproofers

BACKGROUND

The United Union of Roofers, Waterproofers, and Allied Workers (UURWAW) is one of the 15 building and construction trades departments in the AFL-CIO. The U.S. roofing industry, including both roofing and waterproofing applications, both unionized and nonunionized, comprises about 25,000 firms, employing approximately 300,000 people, about 200,000 of whom are involved in the application of roofs. The specific toxins to which roofers may be exposed at the job site include, among others, bitumens (asphalt and/or coal tar pitch) as well as asbestos and fiberglass from roof removal operations. Excess deaths from occupational injuries are also of concern.

METHODS

This study evaluated causes of mortality among 11,144 members of the UURWAW. Age-adjusted proportionate mortality ratios (PMRs) were computed with 95% confidence intervals (CI) using U.S. age-, gender-, and race-specific proportional mortality rates for the years of the study, 1950-1996.

RESULTS

Statistically significant increased PMRs were found for all injuries (PMR = 142, CI = 134-150), especially falls (PMR = 464, CI = 419-513) and other injuries (PMR = 121, CI = 107-137), cancers of the lung (PMR = 139, CI = 131-148), bladder (PMR = 138, CI = 111-170), esophagus (PMR = 134, CI = 107-166), larynx (PMR = 145, CI = 106-193), and cancers of other and unspecified sites (PMR = 130, CI = 112-149), pneumoconioses and other nonmalignant respiratory diseases (PMR = 115, CI = 103-128), and homicides (PMR = 153, CI = 135-172). The occupational exposures which may have contributed to the excess risks of malignant and nonmalignant respiratory diseases include, among others, asphalt fumes, coal tar pitch volatiles and asbestos; however, cigarette smoking must also be considered a contributing factor.

CONCLUSIONS

The present study underscores the need to control airborne exposures to hazardous substances and especially to examine fall prevention efforts within the roofing industry. Am. J. Ind. Med. 37:478-492, 2000. Published 2000 Wiley-Liss, Inc.

Cancer risk estimation for mixtures of coal tars and benzo(a)pyrene

Two-year chronic bioassays were conducted by using B6C3F1 female mice fed several concentrations of two different mixtures of coal tars from manufactured gas waste sites or benzo(a)pyrene (BaP). The purpose of the study was to obtain estimates of cancer potency of coal tar mixtures, by using conventional regulatory methods, for use in manufactured gas waste site remediation. A secondary purpose was to investigate the validity of using the concentration of a single potent carcinogen, in this case benzo(a)pyrene, to estimate the relative risk for a coal tar mixture. The study has shown that BaP dominates the cancer risk when its concentration is greater than 6,300 ppm in the coal tar mixture. In this case the most sensitive tissue site is the forestomach. Using low-dose linear extrapolation, the lifetime cancer risk for humans is estimated to be: Risk < 1.03 x 10(-4) (ppm coal tar in total diet) + 240 x 10(-4) (ppm BaP in total diet), based on forestomach tumors. If the BaP concentration in the coal tar mixture is less than 6,300 ppm, the more likely case, then lung tumors provide the largest estimated upper limit of risk, Risk < 2.55 x 10(-4) (ppm coal tar in total diet), with no contribution of BaP to lung tumors. The upper limit of the cancer potency (slope factor) for lifetime oral exposure to benzo(a)pyrene is 1.2 x 10(-3) per microgram per kg body weight per day from this Good Laboratory Practice (GLP) study compared with the current value of 7.3 x 10(-3) per microgram per kg body weight per day listed in the U.S. EPA Integrated Risk Information System.

Lifestyle determinants of cancer among Danish mastic asphalt workers

Three reports suggest that asphalt workers, especially young mastic asphalt workers, in Denmark experience an increase in incidence and mortality from cancer and in mortality from other conditions. The methodology described in these reports raises questions about their validity and the data presented are limited and difficult to interpret. The cancers and the causes of death that are increased are highly correlated with those seen among men in the general population who use alcohol in excess, who smoke, and who engage in other risk-taking behaviors. The effects of these lifestyle causes of disease were largely not controlled in the reported studies. These behaviors, which cluster in young men, rather than exposure to asphalt fumes, probably caused the disease patterns that were reported. Policy makers who use epidemiologic results for risk assessment and regulation should do so with care. Working men and women sometimes die at high rates and their occupational exposures may or may not be responsible. The distinction is crucial if occupational health is to be improved. If asphalt workers die young from excessive drinking and smoking, we are not protecting their health by controlling asphalt fume exposures.

Influence of metabolic genotype GSTM1 on levels of urinary mutagens in patients treated topically with coal tar

Fifteen hospitalized, non-smoking, dermatological patients were treated with ointment containing 2% coal tar (CT) in order to assess the influence of metabolic genotype GSTM1 on urinary mutagen levels. Urinary 1-pyrenol, the main metabolite of pyrene, was used to check the high exposure to PAH of this population. The mean levels of urinary 1-pyrenol found in the 24-h urine of our patients were 467. 8+/-211.0 nmoles-24 h (range 94.6-890.1 nmoles-24 h). Mutagenicity was assessed on urine samples collected over a period of 24 h, after three consecutive days of topical application, using the bacterial mutagenesis test on Salmonella typhimurium strains TA98 and YG1024 in the presence of microsomal enzymes. The latter strain turned out to be more sensitive than the former in revealing urinary mutagens in these patients (42 693+/-30 867 vs. 6877+/-6040 net revertants-24 h). The mutagenicity on YG1024 strain and 1-pyrenol levels of urine samples were correlated (Spearman's rank correlation coefficient=0. 6678, P<0.01, z=2.795). The influence of genotype GSTM1 on urinary mutagen levels was assessed on strain YG1024. The values of urinary mutagenicity of subjects with genotype GSTM1-null (n=6) were on average higher than those of GSTM1-positive subjects (n=9) (55 498+/-45 957 vs. 34 156+/-11 933 net rev.-24 h), a non-significant statistical difference. The mean total excretion of mutagens corrected for PAH exposure (net rev./nmoles of urinary 1-pyrenol) in GSTM1-null patients was double that of GSTM1-positive ones (136. 8+/-34.7 vs. 70.8+/-23.3 net rev./nmoles of urinary 1-pyrenol; one-tailed Mann-Whitney U-test, U=11.5, P<0.05). These results indicate a greater body burden of promutagens, resulting from skin application of CT, in GSTM1-null subjects.

[Effects of coal tar on hematological parameters in experimental tuberculosis]

Guinea pigs were injected with coal tar (CT) (intratracheally, 25 mg per animal once a week or a month for 2 or 8 months, respectively), then they were infected with MBT (H37Rv, 0.1 mg, subcutaneously). There were changes in hematological responses to MBT changes (in the context of the cell composition of bone marrow and peripheral blood), their pattern was associated with the mode of exposure to CT preceding MBT inoculation. The greatest differences were found in the responses of bone marrow lymphopoiesis and peripheral lymphocytes upon both exposures to CT. On greater exposure to CT (once a week) the changes in the blood system indicated that CT had an adverse effect on the course of experimental tuberculosis, while on lesser exposure (once a month), the effect of CT was more favourable.

Aromatic DNA adducts in human white blood cells and skin after dermal application of coal tar

A group of eczema patients topically treated with coal tar (CT) ointments was used as a model population to examine the applicability of DNA adducts in WBC subpopulations as a measure of dermal exposure to polycyclic aromatic hydrocarbons (PAHs). Aromatic DNA adducts were examined by 32P-postlabeling in exposed skin and WBC subsets, and urinary excretion of PAH metabolites was determined to assess the whole-body burden. The median urinary excretion of 1-hydroxypyrene and 3-hydroxybenzo(a)pyrene was 0.39 (range, 0.12-1.57 micromol/mol creatinine) and 0.01 micromol/mol creatinine (range, <0.01-0.04 micromol/mol creatinine), respectively, before the dermal application of CT ointments. After treatment for 1 week, these levels increased to 139.7 (range, 26.0-510.5 micromol/mol creatinine) and 1.18 micromol/mol creatinine (range, <0.01-2.14 micromol/mol creatinine), respectively, indicating that considerable amounts of PAHs were absorbed. Median aromatic DNA adduct levels were significantly increased in skin from 2.9 adducts/10(8) nucleotides (nt; range, 0.7-10.0 adducts/10(8) nt) before treatment to 63.3 adducts/10(8) nt (range, 10.9-276.2 adducts/10(8) nt) after treatment with CT, in monocytes from 0.28 (range, 0.25-0.81 adducts/10(8) nt) to 0.86 adducts/10(8) nt (range, 0.56-1.90 adducts/10(8) nt), in lymphocytes from 0.33 (range, 0.25-0.89 adducts/10(8) nt) to 0.89 adducts/10(8) nt (range, 0.25-3.01 adducts/10(8) nt), and in granulocytes from 0.28 (range, 0.25-0.67 adducts/10(8) nt) to 0.54 adducts/10(8) nt (range, 0.25-1.58 adducts/10(8) nt). A week after stopping the CT treatment, the DNA adduct levels in monocytes and granulocytes were reduced to 0.38 (range, 0.25-0.71 adducts/10(8) nt) and 0.38 adducts/10(8) nt (range, 0.25-1.01 adducts/10(8) nt), respectively, whereas the adduct levels in lymphocytes remained enhanced [1.59 adducts/10(8) nt (range, 0.25-2.40 adducts/10(8) nt)]. Although the adduct profiles in skin and WBC subsets were not identical, and the adduct levels in WBCs were significantly lower as compared with those in skin, the total DNA adduct levels in skin correlated significantly with the adduct levels in monocytes and lymphocytes, but not with those in granulocytes. Excretion of urinary metabolites during the first week of treatment was correlated with the percentage of the skin surface treated with CT ointment and decreased to background levels within a week after the cessation of treatment. 3-Hydroxybenzo(a)pyrene excretion, but not that of 1-hydroxypyrene, correlated significantly with the levels of DNA adducts in skin that comigrated with benzo(a)pyrene-diol-epoxide-DNA. This study indicates that the DNA adduct levels in mononuclear WBCs can possibly be used as a surrogate for skin DNA after dermal exposure to PAHs.

[Detection of sister chromatic exchange in workers exposed to coal tar pitch and to coke oven volatiles]

In order to know the changes of genetic toxicological effects on workers occupationally exposed to polycyclic aromatic hydrocarbons (PAHs), sister chromatic exchange(SCE) was detected by the methods of peripheral lymphocyte culture in 23 workers exposed to coal tar pitch (CTP) and in 19 workers exposed to coke oven volatiles (COV) and 12 normal controls. The results suggested that the SCE in occupational workers was significantly higher than that in controls (11.31 vs 6.37, P < 0.001). The SCE in workers exposed to CTP and to COV was higher than that of control (10.27 and 12.58 vs 6.37) respectively. In workers exposed to CTP and COV, there were no differences of SCE for smokers and nonsmokers (P > 0.05). It is indicated that CTP and COV caused strong genetic toxicity and injury to chromosome.

A questionnaire study of road pavers' and roofers' work-related skin symptoms and bitumen exposure

BACKGROUND

Skin contact with the components in asphalt and bitumen can lead to irritant and allergic contact dermatitis, but few data are available in the dermatologic literature on the skin symptoms caused by work with bitumen. In addition, working methods have changed markedly during recent decades.

METHODS

A questionnaire was delivered to 50 roofers and 101 road pavers. The questionnaire dealt with skin symptoms, symptoms caused by solvent products, the use of personal protection, smoking, eating habits, work conditions, changing and cleaning of overalls, etc.

RESULTS

Forty-eight per cent of the road pavers and 58% of the roofers responded to the questionnaire. Relatively high percentages of work-induced skin irritation were reported by both the roofers (44%) and the road pavers (31%); 22% of the road pavers had dermatitis often or sometimes compared with 15% of the roofers. The hands, arms, face, and lower extremities were the most common sites affected. In addition to bitumen products, the road pavers considered amine adhesion-improving agents for paving and naphtha and solvents used in machine repairs, to be the main causes of their skin symptoms. The skin problems of the roofers were caused by man-made mineral fibers, cutback bitumen, and hot bitumen burns.

CONCLUSIONS

Roofers endure greater exposure to chemicals than road pavers. Certain components, e.g. polycyclic aromatic hydrocarbons in bitumen, can be absorbed through the skin. Skin exposure should be lowered by keeping the tools, working clothes, shoes, and gloves clean. Overalls and gloves are recommended to be changed at least once a week. Water laundering is not sufficient in dissolving bitumen from overalls and underwear. Cleaning the skin with solvents or naphtha is not recommended, as they are skin irritants.

Air pollution exposure-DNA adduct dosimetry in humans and rodents: evidence for non-linearity at high doses

The impact of air pollution exposure on the level of total DNA adducts in human white blood cells (WBCs) was evaluated in two populations in the Czech Republic and compared to the exposure-DNA adduct relationship in other populations in the US and China in human lung cells and rodent lung tissue. The human populations examined were exposed to respirable particles (< 2.5 microm) (PM2.5) in urban, rural, and occupational settings where the particles originated from coal and petroleum fuel combustion, coke production, and other coal-tar aerosols (e.g., used in aluminum production). These particles contain carcinogenic polycyclic aromatic hydrocarbons (PAHs) that are known to form DNA adducts through covalent binding. Personal exposure to PM2.5 and PAHs were measured prior to collection of blood samples for DNA adduct analysis by 32P-postlabeling. Coke oven workers (n = 76), in 10 job categories on the top and side of a coke oven in Ostrava, CZ, were studied and compared to a different population exposed to environmental levels of PAHs from air pollution in Teplice, CZ. Personal exposures to airborne particles ranged from < 1 to more than 15,000 microg/m3 and carcinogenic PAHs exposure ranged from < 5 to > 200,000 ng/m3. At low to moderate environmental exposures to carcinogenic PAHs, DNA adduct levels in the WBCs were significantly correlated with exposure. However, at the higher occupational levels found on the coke oven, the exposure-DNA adduct relationship became non-linear. Under these high exposure conditions, the relative DNA adduct level per unit of exposure (DNA-binding potency) was significantly lower than measured at environmental exposures. This finding is consistent with observations in lung cells from bronchoalveolar lavage of humans exposed to a wide range of PAH. This same high exposure-dose non-linearity was also observed in lung DNA from rats exposed by inhalation to a coal-tar pitch aerosol. DNA adduct levels in all these cases show evidence of a form of non-linearity at high doses that has been described by Lutz (W.K. Lutz, Dose-response relationship and low dose extrapolation in chemical carcinogenesis, Carcinogenesis, 11 (1990) 1243-1247) as a superlinear dose response. This superlinear response may be due to saturation of metabolic activation enzymes, induction of either DNA repair processes or detoxification enzymes, or other mechanisms. Regardless of the mechanism, this decrease in the DNA-binding potency at moderate to high doses of PAH has important implications for dose-response extrapolation in risk assessment.

[Longitudinal study of the excretion of 1-hydroxypyrene in urine after external treatment with coal tar]

In order to study the dermal uptake, time course, and urinary excretion of polycyclic aromatic hydrocarbons, the concentration of 1-hydroxypyrene in urine was determined by means of high performance liquid chromatography with fluorescence detection before, during, and after the topical treatment with coal tar in 19 patients suffering from prurigo simplex subacuta, microbial eczema, atopic dermatitis, eczematization after scabies, exanthematous lichen ruber, pityriasis lichenoides and cutaneous sarcoidosis. Beginning with a value of 6.04 +/- 2.06 micrograms 1-hydroxypyrene/g creatinine before treatment, the urinary excretion significantly increased during the therapy with coal tar (p < 0.0001 at 3rd, 5th, and 6th day of therapy). A maximum was reached at day 8 of topical treatment with a value of 584.35 +/- 191.96 micrograms 1-hydroxypyrene/g creatinine (p < 0.002). Already during treatment at day 10 there was a beginning decrease of 1-hydroxypyrene to 361.63 +/- 170.13 micrograms/g creatinine. After the end of treatment, the excretion further decreased reaching a value of 5.31 +/- 2.85 micrograms 1-hydroxypyrene/g creatinine at the 10th day after therapy. Skin carcinomas due to therapeutical use of coal tar occur extremely rarely and only after vergoten, non-controlled use. We suggest that the duration of exposure is the most important factor for the carcinogenic effect of coal tar.