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Monitoring of personal exposure of population from environmental pollution is a very complicated process. There are many different pollutants in environment in very low concentrations and their distribution is non-homogenous. To measure these pollutants is not often feasible or possible due to technical problems. On the other side these can influence the health status of inhabitants by the way of a long time exposition by low doses. In our work we studied an incidence of the cancer of colon and rectum in rural area of Trnava district during the years 1986-1995. These are the most frequent types of cancer in our district-13.4 %, incidence rate is 27.5 per 100,000 inhabitants. The standardised incidence ratio (observed/expected cases) were calculated for all villages, including statistical parameters. The population in this small area (1390 km²) is relatively stabile from point of view of migration and nutritional habits. The urban area consisting from five towns was excluded from analysis because the life style and nutritional habits of people living in towns and villages are different. These suppositions enabled to concentrate our attention to the study of environmental factors which can influence development of the colorectal cancer. The SIR's were correlated with time of public drinking water supply, surface water quality, location of waste dumps, and time of gas heating using as kind of house heating. Positive and statistically significant correlation's were found between SIR of the colorectal cancer and waste dump location for females and weaker for surface water and SIR for males. Statistically significant elevation of SIR both for males and females were found in one village. Ecological design of study did not allow to study confounders, yet served enough information for preparation of analytical studies and public health decision-making process on local level.

The results indicate that even with careful operation, in the environment of waste incinerators one has to count with pollution. The authorities and the representatives of the populations check the operation of the incinerator regularly. The existing landfill basins are practically full, a new landfill site is planned. Inhabitants have a definite dislike of the incinerator manifested by protests against the settling of the new landfill site (though this would influence favourably the process of groundwater contamination). It is not out of the question that the landfill of solid wastes should be removed to a far away site, which will raise further the prices of incineration that are quite high now as it is. The frequency of respiratory complaints of children makes a more detailed examination of air concerning its polluting components, especially that of organic components, necessary.

Urban and rural regions are affected by different microorganism loads depending on their structure and utilization. At 7 sampling sites in the metropolitan area of Graz, counts of airborne bacteria as well as yeasts and molds were conducted over a one-year period at two-week intervals. Bacteria and yeasts/molds counts in a village area to the South of Graz dominated by agriculture exceeded the corresponding counts in a suburban residential area fourfold (327 CFU/m³ air-bacteria) and twofold (185 CFU/m³ air-yeasts/molds) respectively. In the vicinity of a composting facility located in the same residential area, microorganism counts exceeded those of the neighboring "unaffected" area by 29 % in the case of bacteria and by 54 % in the case of yeasts/molds. At an industrial and business site with heavy traffic, the counts are twice that of the area affected by the composting facility (146 CFU/m³ for bacteria and 168 CFU/m³ for yeasts/molds). The proportion of Aspergillus fumigatus is highest in the village area with 23 %, compared to 10 % in the open land. 49 % of the bacteria and 54 % of the yeasts and molds can be shown on stages 4-6 of the Andersen-Volumetric-Sampler registering the respirable particle sizes.

Background: Consumption levels for saturated fats do not explain why mortality attributed to ischaemic heart disease (IHD) has generally fallen in established market economies but not in eastern Europe. We hypothesised that low intakes of fresh fruit and vegetables would be strongly associated with ischaemic heart disease in Bulgaria. Methods: Patients (n = 155) were admitted to the cardiology unit, Central Clinical Hospital, Sofia, aged 45 to 69, with confirmed diagnoses of ischaemic heart disease. Controls (n = 154) were patients admitted for minor elective Surgery. Measurements were made of blood pressure, height and weight and a blood sample taken around three days after admission. Subjects were interviewed before discharge and asked about the frequency with which they consumed fresh foods. Results: Reported frequency of fruit and vegetable intake was associated with the risk of IHD: odds ratio = 0.33 (95 % Cl 0.17 - 0.63) for fruit and 0.44 (95 % Cl 0.24 - 0.82) for vegetables for reported daily consumption versus reported consumption ≤ 3 days per week. The association was independent of socio-demographic characteristics, cholesterol concentration, blood pressure, body mass index and reported physical activity. Conclusions: The potential of constituents of fresh fruit and vegetables to protect against ischaemic heart disease merits further investigation - especially in populations where intakes have been low for much of the year.

Male rats and female mice were exposed to vapours of toluene, o-xylene and acetone in basic or double concentrations or to binary combinations of basic concentrations, for 4 and 2 hours, respectively. Basic air concentrations were for rats and mice (in ppm): toluene 270 and 380, o-xylene 230 and 320, acetone 1700 and 1530, respectively. The CNS effect-inhibition of electrically evoked seizure discharge-was measured immediately after exposure and blood levels of solvents were monitored during the desaturation phase. The effect of all binary mixtures was lower than that of double concentrations of each single component, the difference being significant only in mice, and lower than the additive effects predicted on the basis of regressions of the effect on air or on blood concentrations of individual components. On the target site in the neuronal membrane, the effects of mixtures were substantially less than additive. Blood concentrations of solvents immediately after the exposure to a mixture were generally higher in aromatics and lower in acetone than after exposure to individual solvents. The decline of blood toluene and even more so that of xylene after exposure was slowed down by acetone. Presumption of additivity seems to protect safely from acute neurotropic effects of solvents at realistic exposure levels. On the other hand, substantially protracted late phases of desaturation of aromatic solvents in the presence of slowly eliminated polar solvent points to a possible underestimation of exposure by biological exposure tests.

Groundwater contamination by non-aqueous phase liquids (NAPLs) and denser than water non-aqueous phase liquids (DNAPLs) poses one of the greatest remedial challenges in the field of environmental engineering. Due to low water solubilities and aqueous diffusivities, conventional pump-and-treat technologies have a poor record of success in remediation of DNAPL contaminated aquifers. Better success has been found with the removal of volatile LNAPLs due to higher gaseous diffusivities, propensity for aerobic biodegradation, and ease of pumping and handling large quantities of gas. An evaluation of in situ cleanup technologies on the basis of their applicability to in situ treatment of NAPL contaminated aquifers is presented. Emphasis is placed on treatment of the separate phase occurring in the saturated zone. Soil washing, air sparging, biodegradation, electro-osmosis, enhanced steam extraction, stabilization/solidification, treatment walls, radio frequency heating, and containment systems and barriers are among the in situ technologies reviewed. In the context of the governing contaminant fate and transport processes, the relative merits of each technology are assessed on the basis of its theoretical background, field implementability, level of demonstration and performance, waste, technical and site applicability/limitations, commercial availability, and cost and residuals management.

Iodine supplementation programmes began in designated high risk mountainous districts in Bulgaria in 1958. The prevalence of goitre fell. But the programmes became less effective and by the mid 1980s there were strong indications that goitre was resurgent. Ten villages that had been surveyed in 1956 and 1974 were re-surveyed between 1986 and 1989. All persons available were examined (not just residents) - at home, workplace or school - by a trainee or specialist endocrinologist. Goitres were graded according to the WHO/ICCIDD system. 2,901 females and 1,885 males were examined. Diffuse, stage 1 enlargements were common in males and females under 35, with prevalences exceeding 20 % in several age/sex groups. Nodular stage 1 and 2 enlargements became commoner at ages above 45, with prevalences exceeding 15 % in females over 55. Overall prevalences were 28 % in females and 14 % in males. 6 cretins were identified. In recognised endemic areas of Bulgaria, epidemiological surveillance of IDD should be maintained. Detailed studies are required to determine why iodine supplementation became less effective after the mid 1970s and to develop and test new, cost-effective public health strategies appropriate to the changed socio-political circumstances.