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.

Uncontrolled acetylene release during production processes, transportation, or storage can lead to explosions and detonations endangering safety of people and material assets. This paper investigates the impact of accidental release of acetylene gas in surrounding areas. The ALOHA software has been used in this paper to modelling of acetylene release. The modelling was performed for an accidental release of 2,000 kg acetylene from direct source for one minute. F or a typical average atmospheric condition in location, this accidental acetylene release would cause a red zone of 197 m (15,000 ppm) and yellow zone of 483 m (2,500 ppm) to downwind from the source. Inadequate storage can lead to accidental situations and negative impact on people and the environment.

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.

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.