Abstract Polycyclic aromatic hydrocarbons (PAHs) are formed from anthropogenic activities, i.e. industrial emissions, incomplete combustion of petroleum, coal and other fossil fuels and other industrial and domestic activities. Research areas of this study are four representative locations in the industrial complex, in the city of Banja Luka, Republic of Srpska, Bosnia and Herzegovina. The main objective of the paper is to determine the ecological risk and to assess probable sources of PAHs contamination in soil and groundwater. 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. The ecological risk in soil (at depths of 30, 100, 200, 300 and 400 cm) and groundwater is determined. The mean values of ecological risk in soil and groundwater decreased with soil depth. Values of RQ(NCs) for groundwater were found at high ecological risk, for Ant, Chr, DahA, Acy, Pyr, BaA, Phe, Flo, Nap, Ace and Fluo, with values 28.57, 20.59, 300.00, 242.86, 185.71, 1700.0, 76.67, 53.33, 15.83, 100.00 and 57.14, respectively. ∑16PAH indicated high ecological risk for most PAHs, which decreased with soil depth. The value of RQ(NCs) for ΣPAHs in groundwater indicates high ecological risk (ΣPAHs ≥ 800 and RQ(MPCs) ≥ 1). This is the first study on the ecological risk of PAHs in soil and groundwater in industrial soils in Banja Luka and provides baseline information for further studies and additional investigations of this industrial complex.

Popularity and use of dietary supplements are constantly growing. Dietary supplements are food products intended to supplement the usual diet and are concentrated source of nutrients or other substances with nutritional or physiological effecst. The purpose of the Paper is to determine frequency of presence of cadmium, lead and mercury metals in dietary supplements based on protein and amino acids that were analyzed during 2018 and 2019 at the Public Health Institute of Republic of Srpska in Banja Luka. Content of metal was determined by the Atomic Absorption Spectrophotometry method. No health defective samples were identified by public health control, but due to modern frequent use of dietary supplements in various population groups (children, adolescents, pregnant women, athletes, etc.), the aim of the Paper is to raise people’s awareness of the risks, such as heavy metals and artificial sweeteners, colors, prohormones and other chemical risks from dietary supplements since they may be associated with chronic health risks.

Microorganisms in the air of occupational indoor environments are associated with a wide range of adverse health effects with major public health impact. The aim of this study was testing the presence of microbiological parameters (bacteria and fungi) and microclimatic parameters (temperature and relative humidity) in the clinical hospital “St. Luke the Apostle” in Doboj, which is located in the Republic of Srpska (Bosnia and Herzegovina). Concentrations of bacteria ranged from 35 CFU/m3 to 6,295 CFU/m3. Maximum fungal concentration was 1,135 CFU/m3, while the minimum was 10 CFU/m3. The average levels of bacteria (1,113 CFU/m3) and fungi (186 CFU/m3) indicated that all hospital rooms were generally contaminated. Statistical analysis confirmed direct connection between the number of bacteria, fungi and microclimatic parameters, especially relative humidity.

Rapid science and technology development, as well as population growth and solving global problems require a different approach to considering and solving these problems by including many scientific disciplines or technologies. The growing amount of waste and unsystematic depletion of natural resources impose new concepts and tools in creating new environmental products. The existing linear economy, based on the ‘take, make and dispose’ principle, is being replaced by a new approach, the ‘circular economy’. A circular economy seeks to sustainably manage natural resources, extend product lifecycle and reduce waste. Some of the directions or tools in a circular economy are biomimicry and cradle to cradle. Biomimicry seeks to solve problems by imitating natural processes, while cradle to cradle tends to reduce waste using knowledge obtained from nature. Understanding of nature, its systems and cycles will provide analogies and models for creation of innovative solutions to global problems.

Research subjects of this study are four representative locations in the industrial complex, in the city of Banja Luka, Republic of Srpska, Bosnia and Herzegovina. 16 polycyclic aromatic hydrocarbons (PAHs) (∑16PAHs), humus and pH were determined. The main objective of the paper is to determine the concentration levels, to assess the probable sources of PAHs contamination in soil and groundwater and to determine the ecological risk. The ∑16PAHs in soil (at depths of 30 cm, 100 cm, 200 cm, 300 cm and 400 cm) ranged from 0.99 to 2.24 mg/kg, from 0.34 to 0.46, from 0.24 to 0.32, from 0.13 to 0.27 and from 0.13 to 0.47, with mean values of 1.70 mg/kg, 0.40 mg/kg, 0.28 mg/kg, 0.20 mg/kg and 0.26 mg/kg, respectively. The ∑16PAHs in groundwater ranged from 0.23 to 4.50 mg/m3, with a mean value of 1.42 mg/m3. Surface soil and groundwater are heavily contaminated. All values of ∑PAHs in soil layers were lower in the depths of the soil. 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. ∑PAH and PAHs indicate high ecological risk for most PAHs, which decreases with soil depth.

This paper investigates the impact of accidental release of propane gas in surrounding areas consequences of propane gas leak studying the negative effects on both the environment and individuals. Subject of the research is impact of accidental release of propane gas in in business zone “Ramići-Banja Luka”, Banja Luka. The ALOHA software has been used in this paper to modelling of propane release. The modelling was performed for an accidental release of 4,000 kg propane from unsheltered single storied for one hour. For a typical average atmospheric condition in location, this accidental propane release would cause a red zone of 101 metres (AEGL-3=33,000 ppm), orange zone of 159 metres (AEGL-2=17,000 ppm) and yellow zone of 324 metres (AEGL-1=5,500 ppm) to downwind from the source.