Effect of occupational lead exposure on α- and γ-tocopherol concentration in plasma.

OBJECTIVES: Changes in enzymatic antioxidant activity are frequently observed in workers occupationally exposed to lead. Few studies have investigated the influence of lead on the non-enzymatic antioxidant system. The aim of our study was to assess the influence of occupational exposure to lead on the plasma concentration of two hydrophobic forms of vitamin E: α-tocopherol and γ-tocopherol. METHODS: A sample of 401 healthy men, aged 19-62, participated in the study. In total, 340 of these subjects were employed at the Mine and Metallurgical Plant in southern Poland. The workers who were occupationally exposed to lead were divided into quartiles (groups of 85 subjects). The lead concentrations in the blood of the subjects in the control group and in the lead exposure quartiles correspond to the following ranges: 10-72 µg/l (control group); 82-206 µg/l (Q1); 209-308 µg/l (Q2); 308-394 µg/l (Q3) and 395-644 µg/l (Q4), respectively. RESULTS: Significant differences were observed only for the plasma concentration of γ-tocopherol, which differed between the control group and Q1 (by 24.1%, p=0.0368), between Q1 and Q3 (by -18.8%, p=0.0115) and between Q1 and Q4 (by -25.7%, p=0.0002). Multiple linear regression analysis showed that the statistically significant, predictive properties of the γ-tocopherol plasma concentration were as follows: triglycerides (ß=0.440)> age (ß=0.131)> whole cholesterol (ß=0.117)> blood lead concentration (ß=-0.108). For α-tocopherol, significant prognostic properties were triglycerides and total cholesterol (ß=0.485 and ß=0.399, respectively). CONCLUSIONS: Occupational exposure to lead is strongly correlated with the concentration of γ-tocopherol but not α-tocopherol.

Environmental exposure to airborne asbestos fibres in a highly urbanized city.

Asbestos fibres, when released into the air, can pose serious health hazards to exposed people. The aim of this study was to determine the concentration of respirable asbestos fibres in a highly urbanized and densely populated town, where asbestos-containing materials have been widely used in building constructions. Their presence and degree of corrosion were the main criterion for location of sampling stations. All air samples were collected applying the recently elaborated sampling strategy. The origin of sampled fibres was additionally proved by SEM analysis. Concentrations of respirable fibres, derived from 2 groups of asbestos minerals (crocidolite and chrysotile) varied from 0.0010-0.0090 f/cm(3). The highest concentrations were observed in the immediate vicinity of the buildings where a large accumulation of damaged asbestos-containing materials was found, compared to sites located from 100-500 m from such buildings, or treated as a "free" from asbestos sources. It was revealed that even a relatively gentle air movement (1 m/s) plays an important role in the spreading of fibres near the asbestos source. The data of spatial distribution of respirable asbestos fibres in the form of a map can be a useful tool for the official bodies to plan necessary asbestos remediation actions.

[Estimation of optimal levels of tobacco biomarkers to distinguish active and passive smokers using ROC analysis]. / Wykorzystanie krzywych ROC do optymalizowania wartosci granicznych biomarkerów w celu klasyfikacji badanych osób do grupy czynnych lub biernych palaczy.

Many epidemiological studies on health consequences of tobacco smoke exposure require classification of examined subjects either as active or passive smokers. Receiver operating characteristics (ROC) curves are useful for organizing cut-off values of tobacco biomarkers and visualizing their performance. The cut-off values might be applied to distinguish cigarette smokers and persons involuntary exposed to second-hand tobacco smoke (SHS). Aim of the study was estimation of optimal levels of three biomarkers (cotinine, 1-hydroxypyren, and carboxyhemoglobin) to distinguish active and passive smokers using ROC curves. 98 subjects (62% females) were qualified to the study. Mean age was 40 +/- 12 years. Active smokers (n = 38) had an average smoking history of 9 +/- 8 years and declared smoking at least 5 cigarettes per day (mean 17 +/- 7). Passive smokers (n = 60) declared being exposed to environmental tobacco smoke either at home or work (n = 18) or other indoor microenvironments, where they spent some time during their daily activity (n = 42). Cut-off values were determined for each biomarker using ROC curves. Optimal cut-off values were: 327 microg/g creatinine for cotinine, 47 ng/g creatinine for hydroxypyren, and 1.27% HbCO for carboxyhemoglobin. Among three studied biomarkers, cotinine showed the best sensitivity of 97.4% and specificity of 90.0%. Carboxyhemoglobin showed sensitivity of 89.5% and specificity of 93.3%, whereas 1-hydroxypyren 76.3% and 78.3%, respectively. Analysis of ROC curves appears to be a way to distinguish active and passive smokers using various tobacco biomarkers.

[Workers' exposure to selected biological agents in libraries of Upper Silesia]. / Narazenie pracowników na wybrane szkodliwe czynniki biologiczne w bibliotekach województwa slaskiego.

The aim of this study was to assess the exposure of library workers to biological agents based on quantitative and qualitative characteristics of airborne and settled dust microflora supplemented with the analysis of dust mite allergens. The bioaerosol sampling was carried out using a 6-stage Andersen impactor. The settled dust samples were collected from book covers using cotton swabs and vacuum cleaner. Isolated microbial colonies were identified to the genus and/or species level. Moreover, the concentration of guanine as a predictor of dust mite allergen content was determined with the semi-quantitative Acarex test. The bioaerosol concentrations were low and they did not exceed the proposed Polish reference limits. The presence of air-conditioning or ventilating system resulted in the decreased biological contamination in libraries. The identification ofmicroorganisms in bioaerosol and settled dust samples revealed the presence of strains classified into group 2 according to their risk of infection. The level of dust mite allergens was elevated. Inhalation exposure to molds and dust mite allergens may result in the occurrence of allergic reactions and SBS symptoms.