Ambient and biological monitoring of exposure to polycyclic aromatic hydrocarbons at a coking plant.

The exposure to polycyclic aromatic hydrocarbons (PAH) was measured in a Finnish coking plant over a 7-year period (1988-1994), since the beginning of production. Hygienic measurements including dust and vapour sampling were performed and the correlations between the concentrations of airborne pyrene with the levels of pyrene metabolite 1-pyrenol in urine were calculated. The profile of measured 12 or 15 PAHs was very similar between mean concentrations of personal samples, which suggests that it is possible to calculate the concentrations of total PAH by using e.g. pyrene as a marker compound. Measurements suggest that the progress of working conditions has been very favourable because the mean exposure level of shift workers to benzo[a]pyrene has decreased from 2.5 micrograms/m3 to 0.3 micrograms/m3. This points to successful measures of technical prevention. The mean concentration of 1-pyrenol in urine has been 0.2-0.6 mumol/mol creatinine. The concentration increases slightly towards the end of the working day, but the correlation urinary pyrenol and air pyrene was weak. Therefore the usefulness of pyrenol level for predicting the pyrene concentration at low exposure level in the ambient air is very limited.

Assessment of PAH-exposure among coke oven workers.

Coke oven workers are exposed to high concentrations of polycyclic aromatic hydrocarbons. Only recently have methods been developed to try to assess the individual, biologically significant exposure. The only coke oven plant in Finland started to function in 1987, in Raahe, enabling the implementation of a cohort study among the workers to determine the usefulness of some currently available biomonitoring methods, e.g. methods of measuring PAH-DNA adducts. Urine and blood samples were taken several times from a sample of workers starting from before they worked at the plant. A questionnaire (smoking, diet, former and current occupations) was filled in by the workers at every sampling, and air samples (personal and stationary) were collected at the same time. The mean values of both benzo(a)pyrene diolepoxide (BPDE)-DNA adducts were measured by synchronous fluorescence spectrophotometry (SFS) and the antibodies to these adducts increased somewhat after the work at the plant started. However, all the adduct values were low, and no differences between the smokers and non-smokers at any time point were detected. Battery workers had slightly increased means of BPDE-DNA adducts compared to non-battery workers. Also, coke oven workers had slightly higher adduct values than age, sex and smoking matched controls.

World Health Organization international intercalibration study on dioxins and furans in human milk and blood.

Under the sponsorship of the World Health Organization (WHO), an interlaboratory calibration on the analysis of PCDD/PCDFs in human milk and blood was carried out which included 19 laboratories from 14 countries. The study design involved the analysis of three samples of each matrix in triplicate. Selected samples were spiked with native standards of certain 2,3,7,8-substituted congeners at concentrations known only to WHO staff. The study design resulted in approximately 4000 individual pieces of PCDD/PCDF data generated by a variety of analytical methods, at various concentrations, and by laboratories of widely different experience. This was, by considerable margin, the largest study which allowed for the direct comparison of laboratory and method performance. The results of statistical analysis of this data base addresses the effect on data quality of clean up methods, instrumental methods, analyte concentration, laboratory QA programs, and laboratory experience. The study has shown that the laboratory is the single most important determinant of data precision and accuracy. The method of analyte enrichment (sample clean up), analyte measurement [gas chromatography/mass spectrometry (GC/MS) protocol], and analyte concentration have weaker correlations with data quality.

Synchronous fluorescence spectrophotometry of benzo[a]pyrene diol epoxide-DNA adducts in workers exposed to polycyclic aromatic hydrocarbons.

Synchronous fluorescence spectrophotometry (SFS) for benzo[a]pyrene diol epoxide (BPDE)-DNA adducts detects adducts in lymphocyte DNA in some but not all individuals exposed occupationally to polycyclic aromatic hydrocarbons (PAHs). Individual differences in exposure, activation and/or DNA repair can be detected by SFS. Several in vitro and in vivo studies are currently being done to clarify the specificity and usability of SFS as a biomonitoring method for PAH exposure in the work environment.

Low serum selenium concentration and glutathione peroxidase activity in intrahepatic cholestasis of pregnancy.

Serum selenium concentrations were found to be significantly lower in women with intrahepatic cholestasis of pregnancy than in women with normal pregnancies during the last trimester of pregnancy and post partum. The activity of the selenoenzyme glutathione peroxidase had a significant positive correlation with selenium concentration and it was also significantly lower in women with the disease. These findings suggest that selenium deficiency and reduced glutathione peroxidase activity are associated with the aetiopathogenesis of intrahepatic cholestasis of pregnancy.

Lead and cadmium concentrations in maternal and umbilical cord blood, amniotic fluid, placenta, and amniotic membranes.

The lead and cadmium concentrations in maternal and umbilical cord blood and amniotic fluid were determined in 19 parturient women at delivery. Six placental and amniotic membrane tissue specimens were also investigated. The mean lead concentrations (mean +/- SD) in maternal (40.4 +/- 18.2 ng/ml) and umbilical cord (37.1 +/- 13.5 ng/ml) blood were similar and correlated significantly with each other (r = 0.77, p less than 0.001). The lead concentration in amniotic fluid (59.6 +/- 8.3 ng/ml) was significantly higher than in maternal or umbilical cord blood. Cadmium concentrations in maternal blood (1.1 +/- 0.9 ng/ml) and amniotic fluid (1.0 +/- 0.2 ng/ml) were significantly higher (p less than 0.001) than in umbilical cord blood (0.4 +/- 0.2 ng/ml) and there was no significant correlation among these values. The highest concentrations of cadmium (35.1 +/- 24.2 ng/gm of wet weight) and lead (87.3 +/- 154.2 ng/gm of wet weight) were found in the amniotic membranes. Our results show that lead and cadmium accumulate in amniotic fluid and amniotic membranes and that the distribution of lead and cadmium is different in the human maternal-fetoplacental unit. The fetal exposure to lead is similar and that to cadmium, lower, compared with maternal exposure. The inability of the placenta to totally prevent the fetus from exposure to lead and cadmium suggests that pregnant women should avoid occupations where exposure to these toxic elements is possible.

Serum selenium in patients with ovarian cancer during and after therapy.

Serum concentrations of selenium were determined by atomic absorption spectrophotometry in 40 patients with ovarian cancer in association with and after surgical and cytostatic therapy. Patients with ovarian cancer had significantly (p less than 0.001) lower serum concentrations (mean +/- SE) of selenium (0.93 +/- 0.04 mumol/l) than age-, weight- and place of residence-matched control subjects (1.22 +/- 0.03 mumol/l). In clinical stage IV disease there was a lower serum level of selenium (0.82 +/- 0.07 mumol/l) than in clinical stages I and II combined (1.00 +/- 0.04 mumol/l). Serum selenium concentrations also showed a tendency to follow the outcome of the disease; an increase in patients with remission and a decrease in patients with progressive disease, probably because of nutritional reasons.

Low serum selenium concentration in patients with cervical or endometrial cancer.

Serum concentrations of selenium were determined in 37 patients with cervical and 64 patients with endometrial cancer. The patients had lower (P less than 0.001) serum concentrations of selenium than the age-, weight- and place of residence-matched paired control women. There was no difference in the selenium concentration between various age groups or different clinical stages of cervical or endometrial cancer. A low serum concentration of selenium might be a contributing factor in uterine carcinogenesis.

Selenium concentration in maternal and umbilical cord blood, placenta and amniotic membranes.

The selenium concentration of maternal and umbilical cord whole blood was determined by atomic absorption spectrophotometry in 21 parturients at term. Six placental and amniotic membrane tissue specimens were also investigated. The mean selenium concentrations in the maternal (0.73 +/- 0.15 mumol/l) and umbilical cord blood (0.77 +/- 0.18 mumol/l) were similar and without significant correlation. Placental (2.24 +/- 0.20 mumol/kg wet weight) and amniotic membrane tissue specimens (2.32 +/- 0.54 mumol/kg wet weight) also contained similar concentrations of selenium which were about 3 times higher than those in the maternal and umbilical cord blood. Low whole blood selenium concentration in Finnish parturients may be a sign of deficient nutritional intake of selenium during pregnancy. The relatively high concentration of selenium in the placenta and amniotic membranes on the other hand suggest that metabolically active organs are being provided primarily with this essential trace element.

Effect of occupational mercury exposure on plasma lysosomal hydrolases.

The activities of three plasma lysosomal hydrolases, beta-galactosidase, beta-glucuronidase and beta-N-acetylglucosaminidase, were studied in 20 workers exposed to metallic mercury vapor in a chlorine alkali plant and in 10 nonexposed referents. The urinary excretion and blood levels of mercury were determined on the day of study, and the history of mercury exposure was reviewed from the records of mercury concentrations in urine and blood over periods of up to 133 months. The average levels of beta-N-acetylglucosaminidase and beta-glucuronidase were higher in the plasma of exposed workers, but the difference was not significant. No significant positive correlation was seen between lyosomal enzyme activities and cumulative long-term exposure to mercury. It is concluded that measurement of plasma lysosomal hydrolase-activities is not of great value in the biological monitoring of workers exposed to low concentrations of metallic mercury vapor. In line with published data, the concentration of mercury showed a clear-cut diurnal variation in nonexposed persons, persons currently exposed and persons with a history of past exposure. The excretion rate of mercury remained constant throughout the day.

Lack of effect of halothane on E, EA, and EAC rosette formation and cyclic AMP level of human lymphocytes.

The effect of halothane on rosette formation and cyclic adenosine monophosphate (cyclic AMP) level of human lymphocytes was investigated. A 4- or 24-hour incubation with 2% halothane had no significant effect on "early" or "late" E, EA and EAC rosette formation or intracellular cyclic AMP levels of human lymphocytes whereas cytochalasin B, which affects microfilament action, reversibly inhibited both E and EA but not EAC rosette formation. It is suggested that halothane in clinical concentrations neither disturbs the function of microfilaments, essential for E and EA rosette formation, nor affects the metabolism of cyclic AMP in unstimulated human lymphocytes.