Experiences with the accreditation of the Institute for Medical Research and Occupational Health, Zagreb, Croatia.

Accreditation in accordance with the international General Requirements for the Competence of Testing and Calibration Laboratories (HRN EN ISO/IEC 17025 standard) has become a widely accepted method of quality management and objective evidence of technical competence, knowledge, and skills of testing and calibration laboratories. In 2010, the Institute for Medical Research and Occupational Health (IMROH) had its management system accredited against the HRN EN ISO/IEC 17025 standard for the following scopes: determination of radioactivity, testing of ambient air quality, and testing in the scope of ionising radiation protection. This accreditation encompassed three laboratories: Radiation Protection Unit, Environmental Hygiene Unit, and the Radiation Dosimetry and Radiobiology Unit. In accordance with the rules of the Croatian Accreditation Agency, the second re-accreditation is due in 2020. This paper describes and discusses the quality management system at IMROH over the ten years of its implementation. We share our experiences about non-conformities discovered during regular work, internal audits, and external audits performed by the Croatian Accreditation Agency. The accredited management system significantly improved the performance of the accredited units, and the Institute increased its visibility and marketing advantage, consequently improving its market position.

Carbon species in PM10 particle fraction at different monitoring sites.

The aim of this study was to determine and compare the levels of elemental carbon (EC), organic carbon (OC) and polycyclic aromatic hydrocarbons (PAHs) mass concentrations in PM10 particles (particles with aerodynamic diameter less than 10 µm) between seasons (winter and summer) and at different monitoring sites (urban background and rural industrial). Daily samples of airborne particles were collected on pre-fired quartz fibre filters. PM10 mass concentrations were determined gravimetrically. Samples were analysed for OC and EC with the thermal/optical transmittance method (TOT) and for PAHs by high-performance liquid chromatography (HPLC) with a fluorescence detector. Measurements showed seasonal and spatial variations of mass concentrations for carbon species and for all of the measured PAHs (Flu, Pyr, Chry, BaA, BbF, BaP, BkF, BghiP and IP) in PM10 at the urban site and rural monitoring site described here. Diagnostic PAH ratios (Flu/(Flu + Pyr), BaA/(BaA + Cry), IP/(IP + BghiP), BaP/BghiP, IP/BghiP and BaP/(BaP + Chry)) make it possible to assess the sources of pollution, and these showed that diesel vehicles accounted for most pollution at the rural-industrial (RI) site in the summer, whereas coal and wood combustion were the causes of winter pollution. This difference between winter and summer PAH ratios were more expressed at the RI site than at the UB site because at the UB site the predominant heating fuel was gas. The OC/EC ratio yielded the same conclusion. Factor analysis showed that EC and OC originated from traffic at both sites, PAHs with 5 or more benzene rings originated from wood pellets industry or biomass burning, while Pyr and Flu originated from diesel combustion or as a consequence of different atmospheric behaviour - evaporation and participation in oxidation and photo oxidation processes.

Sulphur cycling between terrestrial agroecosystem and atmosphere.

Central gas station of the natural gas borehole system Podravina is located near the village Molve. It delivers more than a quarter of total energy used in Croatia to its consumers. Over the years, adapting technology to increasingly demanding and rigorous standards in environmental protection has become paramount. Yet, despite all the industry has undertaken to address the risk of harmful substances entering the food chain, a multidisciplinary research team of independent scientists monitors the content of specific substances in all components of the ecosystem. This paper presents measurements of total sulphur contents in soil surface [(0 to 3) cm] and subsurface [(3 to 8) cm] layers (study period: autumn 2006 - spring 2010) and in plants (study period: spring 2000 - spring 2010), and the concentration of gaseous sulphur compounds in the air. Concentrations of hydrogen sulphide (H2S) and mercaptans (RSH) were measured from the summer of 2002 until the autumn of 2010, while concentrations of sulphur dioxide (SO2) were measured from the spring of 2008 until the autumn of 2010. The paper also shows total annual atmospheric sulphur (S-SO4) deposition at Bilogora measuring station (study period: 2001 - 2010). Average monthly concentrations of H2S in air varied between 0.2 µg m-3 and 2.0 µg m-3, RSH between 0.1 µg m-3 and 24.5 µg m-3, and SO2 between 0.4 µg m-3 and 2.8 µg m-3 depending on the location and the season of sampling. Mean values of total sulphur in soil and in Plantago lanceolata plant ranged between 610 mg kg-1 and 1,599 mg kg-1 and between 3,614 mg kg-1 and 4,342 mg kg-1, respectively, depending on the soil type, location, and sampling depth. Average values of total sulphur mass ratio for all examined single soil samples (n=80) were 1,080 mg kg-1 for both studied layers, and 4,108 mg kg-1 for all analysed plant samples (n=85). Average total annual atmospheric sulphur deposition at Bilogora measuring station was 6.3 kg of S-SO4 per hectare.

Winter mass concentrations of carbon species in PM10, PM 2.5 and PM1 in Zagreb air, Croatia.

The purpose of our investigation was to examine the mass concentrations of EC, OC and TC (EC + OC) in PM(10), PM(2.5) and PM(1) particle fractions. Daily PM(10), PM(2.5) and PM(1) samples were collected at an urban background monitoring site in Zagreb during winter 2009. Average OC and EC mass concentrations were 11.9 and 1.8 µg m(-3) in PM(10), 9.0 and 1.4 µg m(-3) in PM(2.5), and 5.5 and 1.1 µg m(-3) in PM(1). Average OC/EC ratios in PM(10), PM(2.5), and PM(1) were 7.4, 6.9 and 5.4, respectively.

Acidic anions in PM10 particle fraction in Zagreb air, Croatia.

This paper presents the results of 7 years continuous measurement of acidic anions chlorides, nitrates, and sulphates in PM(10) particle fraction in the city of Zagreb, Croatia. The mean annual mass concentrations of the investigated anions in PM(10) particle fraction varied from 0.28 to 0.95 microg/m(3) for chlorides, from 3.21 to 7.87 microg/m(3) for nitrates and from 3.98 to 9.71 microg/m(3) for sulphates. The concentration levels of all measured anions showed significant seasonal differences. The most contributing to the PM(10) mass were sulphates, then nitrates, and then chlorides. The mobile source emission was an important contributor to particle mass.

Heavy metals and acidic components in total deposited matter in Sibenik and National Park Kornati, Croatia.

This article presents the results of 6 years (1999-2004) of monitoring acidic components (fluoride, chloride, nitrate, sulfate) and heavy metals (lead, cadmium, thallium) in total deposited matter (TDM) in the town of Sibenik and the National Park Kornati, Croatia, in order to determine their levels, spatial and temporal variations, and possible emission source. Bulk deposition samples were collected using the Bergerhoff samplers. TDM matter was determined gravimetrically. Acidic anions were analyzed using ion chromatography. Metallic components were determined by atomic absorption spectrometry. Results show that the levels of measured pollutants were relatively low compared to those reported in other investigations. Statistical analysis indicates that the measured pollutants originate from several sources such as resuspended soil, industry, road dust, traffic, and secondary aerosols as the most important. The levels of TDM show a slightly increasing trend at all sampling sites. A significant increasing trend in the levels of nitrate and sulfate in TDM could be the consequence of increasing traffic activity and urbanization. The significant increasing trend in the ratio between nitrate and sulfate in TDM indicates that the nitrate and sulfate relative contribution to acidification is increasing. The level of heavy metals in TDM was in order of lead > thallium > cadmium at all sampling sites with slightly decreasing trend.

Characterisation of major acidic anions in TSP and PM10 in Zagreb air.

This article presents the results of mass concentration of major acidic anions (chlorides, nitrates and sulphates) in TSP and PM(10) particle fraction in Zagreb air measured continuously at one measuring site in 2004. The annual average mass concentrations of the investigated anions followed the order chloride < nitrate < sulphate. Significant correlations were obtained between TSP and investigated anions and between PM(10) and investigated anions, the latter showing a higher correlation coefficient. The annual average mass ratio of (NO(3)(-))/(SO(4)(2-)) obtained in TSP and PM(10) was >0.8, which suggests that mobile source emission was an important contributor to particle mass.