Simulation of ¹³7Cs transport and deposition after the Chernobyl Nuclear Power Plant accident and radiological doses over the Anatolian peninsula.

The Chernobyl Nuclear Power Plant (CNPP) accident occurred on April 26 of 1986, it is still an episode of interest, due to the large amount of radionuclides dispersed in the atmosphere. Caesium-137 ((137)Cs) is one of the main radionuclides emitted during the Chernobyl accident, with a half-life of 30years, which can be accumulated in humans and animals, and for this reason the impacts on population are still monitored today. One of the main parameters in order to estimate the exposure of population to (137)Cs is the concentration in the air, during the days after the accident, and the deposition at surface. The transport and deposition of (137)Cs over Europe occurred after the CNPP accident has been simulated using the WRF-HYSPLIT modeling system. Four different vertical and temporal emission rate profiles have been simulated, as well as two different dry deposition velocities. The model simulations could reproduce fairly well the observations of (137)Cs concentrations and deposition, which were used to generate the 'Atlas of Caesium deposition on Europe after the Chernobyl accident' and published in 1998. An additional focus was given on (137)Cs deposition and air concentrations over Turkey, which was one of the main affected countries, but not included in the results of the Atlas. We estimated a total deposition of 2-3.5 PBq over Turkey, with 2 main regions affected, East Turkey and Central Black Sea coast until Central Anatolia, with values between 10 kBq m(-2) and 100 kBq m(-2). Mean radiological effective doses from simulated air concentrations and deposition has been estimated for Turkey reaching 0.15 mSv/year in the North Eastern part of Turkey, even if the contribution from ingestion of contaminated food and water is not considered, the estimated levels are largely below the 1 mSv limit indicated by the International Commission on Radiological Protection.

The contribution of Saharan dust in PM(10) concentration levels in Anatolian Peninsula of Turkey.

Sahara-originated dust is the most significant natural source of particulate matter; however, this contribution is still unclear in the Eastern Mediterranean especially in Western Turkey, where significant industrial sources and metropolitan areas are located. The Real-time Air Quality Modeling System (RAQMS) is utilized to explore the possible effects of Saharan dust on high levels of PM10 measured in Turkey. RAQMS model is compared with 118-air quality stations distributed throughout Turkey (81 cities) for April 2008. MODIS aerosol product (MOD04 for Terra and MYD04 for Aqua) is used to see columnar aerosol loading of the atmosphere at 550 nm (Aerosol optical depth (AOD) values found to be between 0.6 and 0.8 during the episode). High-resolution vertical profiles of clouds and aerosols are provided from CALIOP, on board of CALISPO satellite. The results suggest a significant contribution of Sahara dust to high levels of PM10 in Turkey with RAQMS and in situ time series showing similar patterns. The two data sets are found to be in agreement with a correlation of 0.87.

Simulated air quality and pollutant budgets over Europe in 2008.

Major gaseous and particulate pollutant levels over Europe in 2008 have been simulated using the offline-coupled WRFCMAQ chemistry and transport modeling system. The simulations are compared with surface observations from the EMEP stations, ozone (O3) soundings, ship-borne O3 and nitrogen dioxide (NO2) observations in the western Mediterranean, tropospheric NO2 vertical column densities from the SCIAMACHY instrument, and aerosol optical depths (AOD) from the AERONET. The results show that on average, surface O3 levels are underestimated by 4 to 7% over the northern European EMEP stations while they are overestimated by 7-10% over the southern European EMEP stations and underestimated in the tropospheric column (by 10-20%). Particulate matter (PM) mass concentrations are underestimated by up to 60%, particularly in southern and eastern Europe, suggesting underestimated PM sources. Larger differences are calculated for individual aerosol components, particularly for organic and elemental carbon than for the total PM mass, indicating uncertainty in the combustion sources. Better agreement has been obtained for aerosol species over urban areas of the eastern Mediterranean, particularly for nss-SO4(2), attributed to the implementation of higher quality emission inventories for that area. Simulated AOD levels are lower than the AERONET observations by 10% on average, with average underestimations of 3% north of 40°N, attributed to the low anthropogenic emissions in the model and 22% south of 40°N, suggesting underestimated natural and resuspended dust emissions. Overall, the results reveal differences in the model performance between northern and southern Europe, suggesting significant differences in the representation of both anthropogenic and natural emissions in these regions. Budget analyses indicate that O3 and peroxyacetyl nitrate (PAN) are transported from the free troposphere (FT) to the planetary boundary layer over Europe, while other species follow the reverse path and are then advected away from the source region.

Control de calidad en laboratorios de análisis clínicos a través de un programa de intervención educativa / Quality assessment in clinical laboratories throught on educative program

Estudios previos dirigidos a conocer el estado de calidad en química clínica de los laboratorios en Paraguay, revelaron inexactitud en los resultados y falta de conocimientos en control de calidad. Esto llevó a realizar este estudio de diseño experimental, con el objeto de investigar si cambia la calidad de los resultados emitidos por los laboratorios del Area Metropolitana de Asunción, con un programa educativo en control de calidad, con y sin seguimiento sistemático a los laboratorios participantes. De los 71 laboratorios participantes el 25 por ciento (18/17) fueron públicos y el 75 por ciento (53/71) fueron privados, de un total de 150 laboratorios registrados. Por selección al azar, 37 laboratorios conformaron el grupo de intervención con seguimiento y los 34 restantes del conjunto el grupo de intervención sin seguimiento. Las mediciones realizadas al inicio del estudio, a los 6 y 12 meses post-intervención fueron, el nivel de conocimiento del bioquímico responsable designado por el laboratorio y el nivel de exactitud de los resultados emitidos. Teniendo como instrumentos, un cuestionario de autorreporte y una encuesta serológica de exactitud. Las medidas de intervención proporcionadas a ambos grupos fueron, un manual y un curso básico de control de calidad interna en química clínica. El grupo de intervención con seguimiento recibió, además, jornadas teórico prácticas y material de control para implementar un control interno de precisión. En las mediciones realizadas al inicio del estudio no hubo diferencia en los grupos de intervención, detectándose 65 por ciento resultados insatisfactorios en exactitud y 53 por ciento de profesionales con resultados insatisfactorios en conocimientos de control de calidad. En las mediciones realizadas a los 6 y 12 meses en los 71 laboratorios, sin distinción de grupo, mejoró el nivel de conocimiento (p < 0,05). Lo que constata que el programa educativo empleado fue bueno. En las mediciones del nivel de exactitud no cambiaron los resultados en los grupos de estudio (p > 0,05). Sin embargo, el grupo con seguimiento sistemático, tuvo un incremento de los resultados satisfactorios de 32 por ciento a 41 por ciento y 38 por ciento respectivamente, sin ser estadísticamente significativo (p > 0,05). Los que mejoraron su exactitud fueron aquellos que ya trabajaban con precisión e implementaron medidas preventivas y correctivas en el trabajo diario. Mientras que en los laboratorios que no mejoraron, detectamos problemas de mala organización administrativa y falta de interés en adoptar medidas de control. Los resultados de este estudio sugieren que la duración del seguimiento sistemático educativo fue probablemente insuficiente para que el profesional de nuestro país adopte sistemas de control de calidad en el laboratorio y así poder mejorar la exactitud de los resultados emitidos. Siendo probablemente necesaria una educación continua que se inicie a nivel pregrado

Control de calidad en laboratorios de análisis clínicos a través de un programa de intervención educativa / Quality assessment in clinical laboratories throught on educative program

Estudios previos dirigidos a conocer el estado de calidad en química clínica de los laboratorios en Paraguay, revelaron inexactitud en los resultados y falta de conocimientos en control de calidad. Esto llevó a realizar este estudio de diseño experimental, con el objeto de investigar si cambia la calidad de los resultados emitidos por los laboratorios del Area Metropolitana de Asunción, con un programa educativo en control de calidad, con y sin seguimiento sistemático a los laboratorios participantes. De los 71 laboratorios participantes el 25 por ciento (18/17) fueron públicos y el 75 por ciento (53/71) fueron privados, de un total de 150 laboratorios registrados. Por selección al azar, 37 laboratorios conformaron el grupo de intervención con seguimiento y los 34 restantes del conjunto el grupo de intervención sin seguimiento. Las mediciones realizadas al inicio del estudio, a los 6 y 12 meses post-intervención fueron, el nivel de conocimiento del bioquímico responsable designado por el laboratorio y el nivel de exactitud de los resultados emitidos. Teniendo como instrumentos, un cuestionario de autorreporte y una encuesta serológica de exactitud. Las medidas de intervención proporcionadas a ambos grupos fueron, un manual y un curso básico de control de calidad interna en química clínica. El grupo de intervención con seguimiento recibió, además, jornadas teórico prácticas y material de control para implementar un control interno de precisión. En las mediciones realizadas al inicio del estudio no hubo diferencia en los grupos de intervención, detectándose 65 por ciento resultados insatisfactorios en exactitud y 53 por ciento de profesionales con resultados insatisfactorios en conocimientos de control de calidad. En las mediciones realizadas a los 6 y 12 meses en los 71 laboratorios, sin distinción de grupo, mejoró el nivel de conocimiento (p < 0,05). Lo que constata que el programa educativo empleado fue bueno. En las mediciones del nivel de exactitud no cambiaron los resultados en los grupos de estudio (p > 0,05). Sin embargo, el grupo con seguimiento sistemático, tuvo un incremento de los resultados satisfactorios de 32 por ciento a 41 por ciento y 38 por ciento respectivamente, sin ser estadísticamente significativo (p > 0,05). Los que mejoraron su exactitud fueron aquellos que ya trabajaban con precisión e implementaron medidas preventivas y correctivas en el trabajo diario. Mientras que en los laboratorios que no mejoraron, detectamos problemas de mala organización administrativa y falta de interés en adoptar medidas de control. Los resultados de este estudio sugieren que la duración del seguimiento sistemático educativo fue probablemente insuficiente para que el profesional de nuestro país adopte sistemas de control de calidad en el laboratorio y así poder mejorar la exactitud de los resultados emitidos. Siendo probablemente necesaria una educación continua que se inicie a nivel pregrado (AU)

Propranolol compared with propranolol plus isosorbide dinitrate in portal-hypertensive patients: long-term hemodynamic and renal effects.

The long-term hemodynamic and renal effects of propranolol were compared with those of propranolol plus isosorbide dinitrate in 44 portal-hypertensive alcoholic cirrhotic patients. Eight control patients, 8 patients receiving propranolol and 14 patients receiving propranolol plus isosorbide dinitrate were hemodynamically evaluated. Renal function was studied in a fourth group of 14 patients receiving propranolol plus isosorbide dinitrate. Portal pressure decreased more (p < 0.05) with combined therapy (-21.6%, from 19.5 +/- 4.8 to 15.4 +/- 4.3 mm Hg) than with propranolol alone (-12.5%, from 19.9 +/- 1.2 to 17.4 +/- 1.8 mm Hg). Serum urea and creatinine levels, plasma sodium concentration, urine volume and urinary sodium excretion showed nonsignificant changes in all groups studied. Combined therapy induced a significant (p < 0.05) decrease in plasma renin activity (from 4.42 +/- 4.7 to 1.59 +/- 1.9 ng/ml/hr) and nonsignificant reductions in plasma aldosterone concentration and creatinine clearance. None of the eight patients with ascites or history of ascites not receiving isosorbide dinitrate showed evidence of impairment in renal sodium metabolism during the study period. In contrast, 8 of the 14 patients (57%) with ascites or history of ascites receiving isosorbide dinitrate showed impairment in renal sodium metabolism (p < 0.01), as reflected by the development or worsening of ascites and the need of higher diuretic requirements. Long-term combined administration of propranolol plus isosorbide dinitrate is superior to propranolol alone in the pharmacological treatment of portal hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluación de precisión y exactitud de laboratorios en determinaciones de química clínica / Evaluation of precision and accuracy of results clinical chemistry

En el año 1990, el Instituto de Investigaciones en Ciencia de la Salud y la Asociación de Bioquímicos del Paraguay, realizaron un diagnóstico de la magnitud de la confiabilidad de los resultados emitidos por los laboratorios en Química Clínica, a través de una evaluación serológica, de precisión en el 37 por ciento (60/163) de los laboratorios registrados en la Asociación de Bioquímicos, el Ministerio de Salud Pública y firmas comerciales de ventas de reactivos; de exactitud en el 24 por ciento (39/163) de los laboratorios registrados, y un cuestionario sobre los factores que influyen en los resultados emitidos por los laboratorios. Los que remitieron sus resultados, en cuanto a su ubicación geográfica, 40//fueron de la capital del país (44/110) y del interior del país 30 por ciento (16/53). En cuanto a dependencia administrativa, 49 por ciento (17/35) fueron laboratorios públicos y 34 por ciento (43/128) privados. No se dispone de mayor información que permita caracterizar a los laboratorios que no remitieron sus resultados, debido al caracter anónimo de la encuesta. En cuanto a la evaluación de precisión, los coeficientes de variación se encontraban alejados de los publicados internacionalmente en un porcentaje que oscila entre el 38 y 84 por ciento, en todos los analitos estudiados. Y el 4l por ciento de los laboratorios tuvieron rendimiento insatisfactorio, utilizando el criterio del Colegio de Patólogos Americanos (CAP), en la evaluación serológica de exactitud. Este estudio revela la situación de la exactitud y precisión de los resultados emitidos en bioquímica clínica de los laboratorios que respondieron nuestra encuentra, que si bien no son representativos de la población total de los laboratorios existentes en el país, representa a aquellos que tuvieron mayor interés en participar. Por lo tanto, se ve la necesidad urgente de implementar Programas Educativos en Control de Calidad en los laboratorios de nuestro país

Evaluación de precisión y exactitud de laboratorios en determinaciones de química clínica / Evaluation of precision and accuracy of results clinical chemistry

En el año 1990, el Instituto de Investigaciones en Ciencia de la Salud y la Asociación de Bioquímicos del Paraguay, realizaron un diagnóstico de la magnitud de la confiabilidad de los resultados emitidos por los laboratorios en Química Clínica, a través de una evaluación serológica, de precisión en el 37 por ciento (60/163) de los laboratorios registrados en la Asociación de Bioquímicos, el Ministerio de Salud Pública y firmas comerciales de ventas de reactivos; de exactitud en el 24 por ciento (39/163) de los laboratorios registrados, y un cuestionario sobre los factores que influyen en los resultados emitidos por los laboratorios. Los que remitieron sus resultados, en cuanto a su ubicación geográfica, 40//fueron de la capital del país (44/110) y del interior del país 30 por ciento (16/53). En cuanto a dependencia administrativa, 49 por ciento (17/35) fueron laboratorios públicos y 34 por ciento (43/128) privados. No se dispone de mayor información que permita caracterizar a los laboratorios que no remitieron sus resultados, debido al caracter anónimo de la encuesta. En cuanto a la evaluación de precisión, los coeficientes de variación se encontraban alejados de los publicados internacionalmente en un porcentaje que oscila entre el 38 y 84 por ciento, en todos los analitos estudiados. Y el 4l por ciento de los laboratorios tuvieron rendimiento insatisfactorio, utilizando el criterio del Colegio de Patólogos Americanos (CAP), en la evaluación serológica de exactitud. Este estudio revela la situación de la exactitud y precisión de los resultados emitidos en bioquímica clínica de los laboratorios que respondieron nuestra encuentra, que si bien no son representativos de la población total de los laboratorios existentes en el país, representa a aquellos que tuvieron mayor interés en participar. Por lo tanto, se ve la necesidad urgente de implementar Programas Educativos en Control de Calidad en los laboratorios de nuestro país

Correlation between PAH airborne concentration and PAH-DNA adducts levels in coke-oven workers.

In order to evaluate the correlation between peripheral blood leukocyte DNA adducts as an indicator of exposure to polycyclic aromatic hydrocarbons (PAH) and the airborne contamination of PAH at the work places, a survey of a cohort of coke-oven workers has been carried out. In each workplace, total and specific PAH airborne concentrations were measured. Among the job title groups, the highest proportion of subjects with levels of adducts above the detection limit and the highest mean value were observed in the door-operators. The correlation between median values of environmental benzo(a)pyrene concentration and mean values of adducts concentration support the fact that the maintenance workers group has a higher relative risk (RR) to have detectable level of PAH-adducts, which is estimated to be 1.84 for an increase of 1 micrograms/m3 of benzo(a)pyrene.

Evaluation of a simple screening test for the quality of drinking water systems.

A simple and inexpensive assay for detection of H2S producing bacteria in drinking water was evaluated in Paraguay. Using an improved preparation procedure, results were basically temperature independent in the range of 22-37 degrees C and correlated well with the presence of total coliform bacteria (96%, 28 degrees C). The assay was not suitable for control of surface water and dug well water due to the frequent presence of non-faecal coliforms. However, it was very suitable for routine control of high quality water systems, like treated community water systems or deep-tube well water, where complete absence of coliforms is required. The H2S-test is very inexpensive and does not require a laboratory technician or special equipment. Its use permits a cost-effective routine control of high quality community water systems in developing countries. In addition, this test turned out to be an effective educational tool for heightening the awareness of people towards dangers of unclean drinking water.

Trace element reference values in tissues from inhabitants of the European community. I. A study of 46 elements in urine, blood and serum of Italian subjects.

Neutron activation analysis-electrothermal atomic absorption spectroscopy (ETA-AAS) and inductively coupled plasma atomic emission spectrometry (ICP-AES) have been used for the determination of 46 elements in urine, 35 in blood and 26 in serum of unexposed Italian subjects living in the same region (Lombardy). The results allowed the proposal of reference values for various elements determined in more than 350 healthy subjects, these being Ag, Al, As, Be, Bi, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Se, Tl, V, Zn, in urine; Ag, As, Bi, Cd, Cr, Co, Cu, Hg, Pb, Se, Tl, Zn in blood; and Ag, Al, Be, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Se, Tl, V, Zn in serum (or plasma). For all other elements indicative values are suggested. In addition to the mean value and the "reference range", a "range of uncertainty" and an upper limit above which metabolic abnormalities could be expected have also been defined on the basis of simple statistical considerations.

[Assessment of exposure to polycyclic aromatic hydrocarbons in 3 work activities using mineral oils]. / Valutazione dell'esposizione a idrocarburi aromatici policiclici in tre attività lavorative che utilizzano olii minerali.

The exposure to polycyclic aromatic hydrocarbons (PAH) in different industries using cutting, hardening and extruding oils, was investigated determining their concentration in oils and in environmental samples. The following compounds: phenanthrene, anthracene, fluoranthene, pyrene, benzo-a-anthracene, chrysene, triphenylene, benzo-a-pyrene, benzo-e-pyrene and perylene were evaluated by means of gas-chromatography-mass spectrometry. PAH concentrations in oils ranged from 652 to 4461 ng/gr and environmental concentrations from 63.86 to 120.54 ng/mc. In particular the BaP concentrations varied from 0.73 to 1.9 ng/mc. These results, compared with those measured in other environmental surveys and with the limit values proposed in various countries, point out the existence of a very low inhalatory risk of PAH.

[Qualitative and quantitative changes in the polycyclic aromatic hydrocarbons in cutting oils after their use]. / Modificazioni quali-quantitative degli idrocarburi aromatici policilici negli olii da taglio conseguenti al loro utilizzo.

The quantitative and qualitative variations in the mixture of polycyclic aromatic hydrocarbons (PAH) present in different samples of a cutting oil, unused and after 3,6 and 9 months of use, were evaluated by means of gas-chromatography mass spectrometry. Nine of the identified hydrocarbons (phenanthrene, anthracene, fluoranthene, pyrene, benzo-a-anthracene, chrysene, triphenylene, benzo-a-pyrene, benzo-e-pyrene and perylene) were studied. The total PAH concentration increased from 45 (first sample) to 915 ng/gr of oil, even if a different behaviour for various hydrocarbons was shown. In fact some of them, such as phenanthrene and anthracene increased with use, some, such as fluoranthene and pyrene decreased and the other did not exhibit a regular trend. In the light of results, the influence of variations of the PAH mixture in oil on the PAH air concentration and on the preventive measures to be adopted, is discussed.

Biological monitoring of human exposure to coal tar. Urinary excretion of total polycyclic aromatic hydrocarbons, 1-hydroxypyrene and mutagens in psoriatic patients.

Three methods for the biological monitoring of human exposure to coal tar were compared. Levels of 1-hydroxypyrene(1-OH PYR), polycyclic aromatic hydrocarbons (PAH) and mutagens (Ames plate incorporation assay using Salmonella typhimurium strain TA98 in the presence of S9 and beta-glucuronidase) were determined in urinary samples from psoriatic patients undergoing topical treatment with mineral coal tar. A single sample of urine with a high content of PAH was diluted with urine of nonexposed, non-smoking subjects in order to obtain nine samples with a decreasing content of PAh metabolites. Mutagenicity of the extracts was detectable down to the dilution corresponding to a content in 1-OH PYR of about 50 micrograms/g creatinine and total PAH of 7 micrograms/g creatinine. In a second phase the three indicators of exposure to PAH were compared in 16 urinary samples from four psoriatic patients. The total PAH levels determined by the acidic deconjugation/reduction method were confirmed to be nearly always lower than the corresponding levels of 1-OH PYR alone. Most of the extracts were mutagenic, however, some of the samples with a high content in PAh metabolites were not mutagenic. In all the urinary samples analyzed the excretion of 1-OH PYR was markedly greater than in control subjects. 1-OH PYR and urinary mutagenicity levels were well correlated. The present data suggest that both the determination of mutagenicity and 1-OH PYR in urine may be used to monitor occupational exposure to PAH, the latter method being cheaper and of greater specificity and sensitivity.

Urinary chromium levels in subjects living in two north Italy regions.

The concentration of total urinary chromium (Cr-U) in two different groups of healthy occupationally non-exposed subjects living in the Italian regions of Lombardia and Veneto has been determined using an ETA-AAS direct method. The age, sex, residence and smoking habits were correlated with CrU excretion. The mean CrU value found in subjects living in Lombardia (n = 310, males 170 and females 140) was 0.59 + 0.26 microgram/l (range 0.08 - 2.10); in Veneto subjects (n = 238, males 187 and females 51) the mean value was 0.52 +/- 0.31 microgram/l (range 0.05 - 1.90). A significative difference between male and female values and a decrease of CrU levels with age increasing have been evidenced in both groups. Smoking habits seem to influence metal urinary levels while, on the other hand, no influence of living sites was observed. Some analytical problems of ETA-AAS Cr determination systems are discussed and "normal" CrU values measured in this study are compared with data reported in the literature.

[Toxicological and analytical lists: chromium and its compounds]. / Schede tossicologiche e analitiche: cromo e composti.

The main aspects of occupational exposure to chromium and chromium compounds are surveyed. Special attention is paid to the toxic action of this metal at the different target organs. The nutritional aspect of CrIII is examined preliminarily, and data detailing the metal contents in water and food are provided. As far the different working processes that entail occupational exposure to chromium are concerned, hygienic and environmental problems are discussed while identifying the average environment exposure to the different chemical forms of chromium (CrIII, CrIV, soluble and not soluble), as a function of the worker's tasks, and the relevant human response (total human Cr). Different hygienic and environmental standards in force in various countries and applicable to chromium compounds are compared. Additional information is given on the main aspects of chromium metabolism (absorption, distribution, excretion), and on the prevailing toxic actions, with specific reference to cancerogenesis. As far as biologic monitoring of the exposed people is concerned, the significance of Cr-U as dose-exposure indicator is discussed, also in the light of a critical review of the reference values. The report describes a series of analytical methods for the identification of chromium in aqueous and biologic matrices. The problems connected with health monitoring and fitness for work are eventually covered.

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

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

Mutagenic activity and polycyclic aromatic hydrocarbon levels in urine of workers exposed to coal tar pitch volatiles in an anode plant.

The mutagenicity of urinary extracts and the excretion of PAH from workers occupationally exposed to coal tar pitch volatiles in an anode plant were analyzed. Mutagenicity of the urinary extracts was measured by means of the plate test using S. typhimurium strain TA 98. After concentration, hydrolysis and reduction of the urine samples, PAH levels were measured by high resolution gas chromatography/mass spectrometry. No significant difference was found in the mutagenicity of the urinary extracts of non-smokers occupationally exposed to PAH as compared with the controls. Low PAH concentrations were found in the urine of the exposed subjects, which lends further support to the negative results obtained with the Ames' test. The increase of urinary PAH excretion, in relation to occupational exposure, was mainly due to the less mutagenic, low molecular weight compounds.