Water is a unique and irreplaceable natural resource of limited quantities and uneven spatial and temporal distribution. All life forms and all human activities are more or less related to water, clearly showing the importance of the relationship with water. It is a necessary resource in households as drinking water, washing and food preparation, in agriculture for irrigation, and in industry it plays an important role in almost all industrial processes. Economic development and urbanization lead, on the one hand, to a large increase in water demand, and on the other hand to the threat to water resources and the aquatic environment. Water can thus become a limiting factor in development, a threat to human health and the sustainability of natural ecosystems. Until recently, there was a centuriesold illusion of water inexhaustibility, and the concept of minimum investments for the purification of used water and water protection in general appeared. Much of the water used is not purified before it is discharged into watercourses and thus pollutes the water mass and reduces the resources of drinking water. Providing enough drinking water is one of the world's most important issues today. Therefore, it is especially important for every society to balance these relations and devise policies and strategies for the regulation, exploitation and protection of water resources.

The problem of air pollution has been a challenge for modern humanity in recent times. The environment, including the air, is burdened by a large amount of pollutants that are released into the environment. The atmosphere contains primary and secondary pollutants, emitted as basic or specific pollutants. Air pollution is present in industrial areas and larger cities, with the fact that there are no areas without any impact of air pollution. Air pollution is also present in the Republic of Srpska, as is the case in other areas. Areas of increased pollution in Republic of Srpska, with high concentrations of pollution, can further worsen the impact on the population and lead to unwanted health effects.

Waste is a by-product of human activities and living. With the increase in the number of inhabitants, the standard of living and urbanization, the quantities of municipal waste are increasing day by day. Every segment of waste management starting from generation, through collection, storage, transport, treatment and disposal can pose a potential hazard to human health and the environment. Waste management in Republic of Srpska is organized at the regional level. Since only waste disposal is still present in the Republic of Srpska, the regional approach implies that there is a landfill on the territory of one of the local self-government units, where all local self-government units in the region dispose of waste. In addition, waste disposal in illegal and unregulated landfills is still evident. LGUs or utility companies often face a lack of money to organize waste collection, with the result that not all households are covered by waste collection. In recent years, a lot has been invested in infrastructure, such as the filling of containers and containers and the purchase of new or newer used waste collection vehicles. Future directions of improving the waste management system in Republic of Srpska must go in the direction of sustainable waste management, ie waste management in a way to reduce the negative impact on human health and the environment, as well as avoiding leaving this problem to future generations.

The municipal solid waste (MSW) landfill is recognized as an anthropogenic source of air pollutants that can have a negative impact on human health and the environment. Workers who work at the MSW landfill may be exposed to risk due to the inhalation of substances such as volatile organic compounds (VOCs). Although VOCs account for 1% in landfill gas, they are important because of the high level of toxicity associated with them. Regular monitoring of air quality and risk assessment provides important information in protecting the health of workers at the landfill. This study focuses on a health risk assessment related to VOCs (benzene, toluene and xylene) exposure via inhalation for workers at a landfill Banja Luka, Republic of Srpska, Bosnia and Herzegovina. Additionally, cancer risk and non-cancer risk of benzene, toluene and xylene of workers indicated that occupational exposures were above recommended standard. This implies that landfill workers are exposed to a significant health risk associated with inhalation exposure to VOCs

. Water samples were collected near the thermal power plant and coal mine (Gacko, Republic of Srpska, Bosnia and Herzegovina) and analyzed to measure the concentration of 33 parameters (pH, temperature, electrical conductivity, alkalinity as CaCO 3 , total hardness as CaCO 3 , total solids, total suspended matter, dissolved oxygen, oxygen saturation, biological oxygen demand, chemical oxygen demand with permanganate, ammonia, nitrite, nitrate, P, PAH, PCBs, phenolic index, mineral oils, detergents, content of As, Cd, Cr, Fe, Mn and Pb, sulfates, chlorides, fluorides, aerobic organotrophs, total coliforms, fecal coliforms and fecal streptococci). Determined average mean pH values and EC are within the reference values for class I surface water quality. The surface water in the study area is alkaline, with a mean pH value of 8.01. Depending on the location, other analyzed parameters correspond from I to V water quality classes. The ERI for As, Cd, Cr and Pb is low and for Mn is appreciable. The RI of the surface water in location 1 and 2 were moderate. In other locations, risk coefficients are low.

Soil samples were collected in an industrial area (Banja Luka, Bosnia and Herzegovina) and analyzed the concentration of 16 polycyclic aromatic hydrocarbons (PAHs). The total concentration of 16 PAHs in surface soil varied within the range of 0.599-2.848 mg/kg and in deeper layer soil samples 0.041-0.320 mg/kg. Two basic sources of PAHs at this location are: pyrogenic and petrogenic sources. Benzo(a)pyrene toxic equivalency factors (TEFs) were used to calculate BaPeq in order to evaluate carcinogenic risk of soil contamination with PAHs. The total BaPeq of seven carcinogenic PAHs in surface soil and deeper soil layer were in the range 23.270-368.63 µg/kg (mean of 151.223 µg/kg), and 15.71-80.24 µg/kg, (mean of 48.08 µg/kg), respectively. These indicated that PAHs in this industrial soil presented relatively high toxicity potential. This study identifies the concentration and estimation of the potential cancer risk caused by contact with soils for adults, adolescents and children. In accordance with the estimated values of incremental life cancer risks (ILCRs), the cancer risk resulting from contact with the contaminated surface soil should be considered high (total ILCR>10 -3 ). The results suggest that current PAHs concentration highly carcinogenic and may hold a serious health risk for local residents and employees.

This study examined the concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) in soil and groundwater at a former cellulose factory in the city of Banja Luka, Republic of Srpska, Bosnia and Herzegovina. The objective of the study was to determine the concentrations of 16 PAHs in soil and groundwater at the site. The research area consisted of four representative locations in the industrial complex where the soil was sampled at depths of 0.3, 1, 2, 3, and 4 m and groundwater was sampled at 3.10, 2.50 and 3 m for two samples. In addition to the 16 PAHs, soil organic matter content and pH were also measured. The sum of the 16 PAHs (Σ16PAHs) in soil ranged from 0.99 to 2.24, 0.34 to 0.46, 0.24 to 0.32, 0.13 to 0.27 and 0.13 to 0.47 mg/kg for the 0.3, 1, 2, 3, and 4 m depths, respectively. Mean values were 1.70, 0.40, 0.28, 0.20 and 0.26 mg/kg, respectively. The Σ16PAHs in groundwater ranged from 0.23 to 4.50 mg/m3, with a mean value of 1.42 mg/m3. The concentrations of all 16 PAHs in the soil decreased with depth and there was no significant correlation between the concentrations of PAHs in the soil and groundwater. The concentrations of PAHs in the soil surface (0.3 m) and groundwater indicate that this industrial site is heavily contaminated and might need remedial action. Factor analysis indicates three sources of contamination, i.e. principal component (PC) PC1 (pyrogenic), PC2 (petrogenic) and PC3 (biomass), with 52.39%, 26.14% and 8.46% of the total variance, respectively. The results of this study reflect the effects of coal combustion (pyrogenic origin), petrogenic and biomass origin and may provide basic data for the remediation of PAHs in the location.

ABSTRACT The digital printing process contributes to the quality of indoor air through the emission of chemical stressors such as total volatile organic compounds (TVOCs) and suspended particulate matter (SPM). The concentration levels of SPM and TVOCs were determined using the gravimetric and gas chromatography method, respectively. The results show that the digital printing machines and the cutting machine do not produce PM2.5 particles. The significant cumulative mass concentrations of PM10 suspended particles of 9.91 μg/m3 for a single-colour digital printing machine, 4.45 μg/m3 for a four-colour digital printing machine, and 2.02 μg/m3 for a cutting machine, were detected. By comparing the cumulative values of TVOC concentration levels measured, it can be concluded that the values have been 4 to 12 times higher for the four-colour digital printing machine than for the single-colour digital printing machine. Namely, the TVOC concentration levels measured for the four-colour digital printing machine ranged from 28.69 to 57.30 mg/m3, while the values for the single-colour digital printing machine ranged from 2.31 to 13.51 mg/m3. Considering the fact that there are no standards of quality of indoor air in printing offices defined in the Republic of Serbia, the results obtained could represent a valid basis and a worthy guideline for the definition of values necessary for the indoor air quality assessment.

Concentrations of dangerous and harmful substances (PCB, TPH and heavy metals) were determined in soils in an industrial zone near the center of Banja Luka and the Vrbas River. PCB, TPH and heavy metals were found in the analysis location as a result of general anthropogenic factors. Contaminated soils have a negative impact on human health and the environment. The mean concentrations of Pb, TPH, Cu, PCB, Ni, Cd and Hg were 4874, 4105, 545.7, 282.1, 225.7, 12.15 and 5.896 mg/kg, respectively. Results show that concentrations were very high for all analyzed parameters, and these values indicated that the soil was highly polluted. Principal component analysis has shown that industrial factors and human activities are the cause of pollution. At the location it is necessary to determine the origin of pollution and recultivation and remediation activity of planned activity.