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The paper reviews the state of water quality in Ialomita River Basin (IRB), Romania, between 2007 and 2018 using the land use/land cover and basin-specific conditions effects on sediments and nutrients load. On-site monitoring was performed in two control sections of the Ialomita River, one in the upper part of the basin (near Targoviste city) and the second near the discharge into the Danube (downstream of Tandarei town). The statistical averages of water parameters for 10 years&rsquo, monitoring in the control section that is close to the Ialomita River discharge in Danube were pH = 7.60 (range: 6.41&ndash, 8.40), NH4-N = 1.20 mg/L (0.02&ndash, 14.87), alkalinity = 4.12 mmol/L (1.34&ndash, 6.27), NO3-N = 2.60 mg/L (0.08&ndash, 17.30), PO4-P = 0.09 mg/L (0&ndash, 0,31), dissolved oxygen (DO) = 8.87 mg/L (2.72&ndash, 15.96), BOD5 = 5.50 mg/L (0.01&ndash, 74.71), suspended solids (TSS) = 508.32 mg/L (15.2&ndash, 4457), total dissolved salts (TDS) = 733.69 mg/L (455.2&ndash, 1053), and river discharge = 38.60 m3/s (8.22&ndash, 165). Expected mean concentration and soil and water assessment tool (SWAT) modeling have been employed in the GIS environment to extend the approach to large spatial patterns within the basin. The estimated average specific emission on the total area for nitrogen was 3.2 kg N/ha, and 0.3 kg P/ha for phosphorus highly influenced by the agricultural activities. The results are useful to raise awareness regarding water-quality degradation and the need to stop and even reverse such trends for local and national sustainable development.

ᅟWe study the transmission channels for rises in the minimum wage using a unique firm-level dataset from eight Central and Eastern European countries. Representative samples of firms in each country were asked to evaluate the relevance of a wide range of adjustment channels following specific instances of rises in the minimum wage during the recent post-crisis period. The paper adds to the rest of literature by presenting the reactions of firms as a combination of strategies and evaluates the relative importance of those strategies. Our findings suggest that the most popular adjustment channels are cuts in non-labour costs, rises in product prices, and improvements in productivity. Cuts in employment are less popular and occur mostly through reduced hiring rather than direct layoffs. Our study also provides evidence of potential spillover effects that rises in the minimum wage can have on firms without minimum wage workers.JEL ClassificationsD22, E23, J31

The paper describes the application of real-time environmental monitoring, local and long-range transport dispersion modeling and Volunteered Geographic Information (VGI) systems that can improve the fast knowledge regarding the air pollution status to determine the actual outdoor conditions for living in a specific urban area. A case study using such techniques is presented for a pollution event with fine particulate matter (PM2.5) in Targoviste, Romania. PM2.5 time series were recorded during the pollution event by two optical monitoring systems providing an average of 184.1, maximum of 323, and minimum of 107 �g m-3 (DustTrackTM 8533 EP system), and 177.4, 321 and 93 �g m-3 (Rokidair microstation), respectively. PM2.5 concentrations and forward trajectories were computed using two programs: BREEZE� AERMOD 7.9 and HYSPLIT dispersion model. The obtained results emphasize the usefulness of embedding dispersion modeling advanced tools to supplement monitoring results and to characterize the source apportionment.

This paper presents the approach used to develop the information chain required to reach the objectives of the EEA Grants� RokidAIR project in two Romanian cities i.e., Targoviste and Ploiesti. It describes the PM2.5 monitoring infrastructure and architecture to the web-based GIS platform, the early warning system and the decision support system, and finally, the linking of air pollution to health effects in children. In addition, it shows the analysis performance of the designed system to process the collected time series from various data sources using the benzene concentrations monitored in Ploiesti. Moreover, this paper suggests that biomarkers, mobile technologies, and Citizens� Observatories are potential perspectives to improve data coverage by the provision of near-real-time air quality maps, and provide personal exposure and health assessment results, enabling the citizens� engagement and behavioural change. This paper also addresses new fields in nature-based solutions to improve air quality, and studies on air pollution and its mental health effects in the urban areas of Romania.

Airborne particulate matter (PM) is a major environmental problem in urban areas mainly because of its demonstrated impact on human health. The present work aimed to assess the outdoor pollution to fine (PM2.5), and submicrometric (PM1) particulate matter that includes the ultrafine fraction - UFP), in Ploiesti city, which is a major urban-industrial area in the Southeast of Romania. This is the first study in an urban area of Romania that analyzes the spatiotemporal variation of PM2.5 and PM1. Particulate matter samples collected in sequential monitoring campaigns performed in 2015 were investigated using 12 relevant sampling points. A precision optical portable monitoring system with a laser beam (DusttrakTM DRX 8533EP) was used for PM assessments.. It was observed that Ploiesti inner city presented �moderate� and �unhealthy for sensitive groups� conditions for particulate pollution with PM2.5 depending on the area of the city. The difference between the PM10 and PM1 medians of all sampling points was only 2.2 �g�m-3, PM4 and PM1 of 1.5 �g�m-3, and PM2.5 and PM1 of 0.8 �g�m-3 respectively (p ] 0.05 � DL5% = �5.8 �g m-3). The correlation between the PM fractions was very significant (p [ 0.01; r = 0.996). The results pointed out that PM1, which has an increased impact on human health, because it includes the UFP, was the most frequent fraction in Ploiesti inner city.

The study examines the association between exposure to sub-micrometric Particulate Matter (PM1) and allergic response in a group of sensitive young children (age: 2–10 years) from Ploiesti city, Romania. The city is the only urban agglomeration in Europe surrounded by four oil refineries. A panel study was conducted by collecting medical information from children with respiratory illnesses and atopy (n = 135). Hot Spot Analysis revealed the areas of the city that are susceptible to high levels of PM1. We found a close interaction between exposure to PM1 outdoor concentrations and various physiological changes and clinical symptoms in children including triggering of allergic reactions, rhinitis, alteration of lung function, upper and lower respiratory tract symptoms, and bronchial asthma. During the 2-year study period, the incidence of hospitalizations was 40.7%. Strong correlations (p Capsule Exposure to sub-micrometric particles (PM1) influences the frequency of wheezing episodes, hospitalizations, and the levels of allergic blood indicators in children, especially in infants and pre-schoolers.

Exposure to airborne fine particulate matter (PM2.5) carries substantial health risks, particularly for younger children (0–10 years). Epidemiological evidence indicates that children are more susceptible to PM health effects than adults. We conducted a literature review to obtain an overview of existing knowledge regarding the correlation of exposure to short- and long-term PM concentrations with respiratory symptoms and disease in children. A collection of scientific papers and topical reviews were selected in cooperation with two experienced paediatricians. The literature review was performed using the keywords “air pollution”, “particulate matter”, “children’s health” and “respiratory” from 1950 to 2016, searching the databases of Scopus, Google Scholar, Web of Science, and PubMed. The search provided 45,191 studies for consideration. Following the application of eligibility criteria and experts’ best judgment to titles and abstracts, 28 independent studies were deemed relevant for further detailed review and knowledge extraction. The results showed that most studies focused mainly on the effect of short-term exposure in children, and the reported associations were relatively homogeneous amongst the studies. Most of the respiratory diseases observed in outdoor studies were related to changes in lung function and exacerbation of asthma symptoms. Allergic reactions were frequently reported in indoor studies. Asthma exacerbation, severe respiratory symptoms and moderate airway obstruction on spirometry were also observed in children due to various sources of indoor pollution in households and schools. Mixed indoor and outdoor studies indicate frequent occurrence of wheezing and deterioration of lung function. There is good evidence of the adverse effect of short-term exposure to PM on children’s respiratory health. In terms of long-term exposure, fine particles (PM0.1–PM2.5) represent a higher risk factor than coarse particles (PM2.5–PM10). Additional research is required to better understand the heterogeneous sources and the association of PM and adverse children’s health outcomes. We recommend long-term cooperation between air quality specialists, paediatricians, epidemiologists, and parents in order to improve the knowledge of PM effects on young children’s respiratory health. A Review of Airborne Particulate Matter Effects on Young Children’s Respiratory Symptoms and Diseases

The present study analyzes the background pollution in Romania using official data reported for recorded air pollutants from the automated regional stations located at three mountain sites. A series of key figures regarding the trend of background pollution at Romanian mountain sites was extracted based on annual average concentrations recorded between 2010 and 2013 i.e. 8.8 5.2 g NO2/m3, 5.3 1.6 g SO2/m3, 0.075 0.035 g CO/m3, 3.2 0.9 g C6H6/m3 and 11.4 6.9 g PM10/m3. A case study is presented for EM-3 EMEP Station (RO0008R, Poiana Stampei) located in the north of Romania. Multivariate techniques provided the trends and patterns of collected data structure. Meteorological input data were long time series (1961-2012) of air pressure, air temperature, precipitations, sunshine hours, cloud cover, and relative humidity in the area. Strong correlations were observed between air pollutants, and between air pollutants and meteorological factors. The latent factors resulted from the Principal Component Analysis have explained the total variance in the data structure of Poiana Stampei as follows: factor 1 meteorology; factor 2 aerosols; and factor 3 heavy metals. NOAA HYSPLIT backward trajectory model was applied to overview the most probable source region of two pollution episodes (NO2 and SO2) at EM-3 location. The results confirmed that meteorological processes, local topography and air mass trajectory controlled significantly the amount of air pollution in the studied area.

The paper presents the application of cross-spectrum analysis (CSA) to air pollution and meteorological time series collected from seven air quality monitoring stations located in three urban agglomerations of Romania, affected by industrial and traffic pollution: Brasov, Ploiesti and Târgoviste. Data have been collected from November 2011 till March 2012, at one hour sampling rate. The purpose of the analysis was to reveal the correlations between two series at different frequencies. The in-sync interaction assessments started from the cross-periodogram, which was realized by smoothing using Parzen window. All computed crossamplitude values were interpreted as a measure of covariance between the respective frequency components in the two series, selecting five highest peaks with the associated corresponding periods, which were filtered out and decreasingly ranked. The results show an important contribution of short-term fluctuations (12 hours and 24 hours periods) to the total variance for the analyzed pollutants (nitrogen dioxide, sulfur dioxide and suspended particles), with significant dependence on the meteorological factor (incident radiation, air temperature or relative humidity) and less on the site conditions. Many significant bivariate correlations were also observed in the total of 48 possible pollutant – meteorological factor pairs: 33 (p < 0.01) and 3 (p < 0.05). This type of data analysis might help the identification of constants or patterns characterizing the interactions between variables, which is a useful tool for the parameterization and calibration of air pollution models.

The overall objective of this research was to study children’s respiratory illness levels in Targoviste (Romania) in relationship to the outdoor concentrations of airborne particulate matter with an aerodynamic diameter below 2.5 µm (PM2.5). We monitored and analysed the PM2.5 concentrations according to a complex experimental protocol. The health trial was conducted over three months (October–December 2015) and required the active cooperation of the children’s parents to monitor carefully the respiratory symptoms of the child, i.e., coughing, rhinorrhoea, wheezing, and fever, as well as their outdoor program. We selected the most sensitive children (n = 25; age: 2–10 years) with perturbed respiratory health, i.e., wheezing, asthma, and associated symptoms. The estimated average PM2.5 doses were 0.8–14.5 µg·day−1 for weekdays, and 0.4–6.6 µg·day−1 for the weekend. The frequency and duration of the symptoms decreased with increasing age. The 4- to 5-year old children recorded the longest duration of symptoms, except for rhinorrhoea, which suggested that this age interval is the most vulnerable to exogenous trigger agents (p < 0.01) compared to the other age groups. PM2.5 air pollution was found to have a direct positive correlation with the number of wheezing episodes (r = 0.87; p < 0.01) in November 2015. Monitoring of wheezing occurrences in the absence of fever can provide a reliable assessment of the air pollution effect on the exacerbation of asthma and respiratory disorders in sensitive children.

Introduction: It is well documented that air pollution has negative health effects, but children's exposure to air pollution is of special concern. There are many studies on children’s exposure to ...

Many previous studies revealed a high ability of mushrooms to accumulate heavy metals from environment. This paper concerns the capacity of some wild macromycetes belonging to Russula genus to accumulate heavy metals in natural condition of pH (between 6.5 and 6.8) and the pattern of metal translocation in the fruiting body.The studied Russula species are Russula virescens, Russula cyanoxantha, Russula foetens, and Russula nigrescens, which were harvested from forestry ecosystem from South Romania. The metal concentration in mushrooms and their substrate was established by EDXRF method.The concentrations of iron (Fe), zinc (Zn), and copper (Cu) in the fruiting body depends on species and vary between 58.83-340.34, 19.70-99.62, and 5.03-9.37 mg/kg for Fe, Zn, and Cu, respectively. The bioaccumulation factor has subunit values for the three studied trace metals, which show the low capacity of these species of mushrooms to accumulate metals if the concentrations in soil increase over the normal threshold for these elements. The high values of translocation factor demonstrate the mobility of Fe, Zn, and Cu in the studied mushrooms.

The paper presents the screening of various feedforward neural networks (FANN) and wavelet–feedforward neural networks (WFANN) applied to time series of ground-level ozone (O3), nitrogen dioxide (NO2), and particulate matter (PM10 and PM2.5 fractions) recorded at four monitoring stations located in various urban areas of Romania, to identify common configurations with optimal generalization performance. Two distinct model runs were performed as follows: data processing using hourly-recorded time series of airborne pollutants during cold months (O3, NO2, and PM10), when residential heating increases the local emissions, and data processing using 24-h daily averaged concentrations (PM2.5) recorded between 2009 and 2012. Dataset variability was assessed using statistical analysis. Time series were passed through various FANNs. Each time series was decomposed in four time-scale components using three-level wavelets, which have been passed also through FANN, and recomposed into a single time series. The agreement between observed and modelled output was evaluated based on the statistical significance (r coefficient and correlation between errors and data). Daubechies db3 wavelet–Rprop FANN (6-4-1) utilization gave positive results for O3 time series optimizing the exclusive use of the FANN for hourly-recorded time series. NO2 was difficult to model due to time series specificity, but wavelet integration improved FANN performances. Daubechies db3 wavelet did not improve the FANN outputs for PM10 time series. Both models (FANN/WFANN) overestimated PM2.5 forecasted values in the last quarter of time series. A potential improvement of the forecasted values could be the integration of a smoothing algorithm to adjust the PM2.5 model outputs.

Emissions of air pollutants derive from almost all economic and societal activities. Due to the concentration of crude oil processing activities around Ploiesti city, which is an urban agglomeration of Romania, this area was carefully monitored regarding air pollutants concentrations. The aim of this work was the characterization of air quality in the city of Ploiesti, affected by industrial and traffic pollution, the analysis of nitrogen dioxide (NO 2 ) and sulfur dioxide (SO 2 ) concentrations collected from a continuous monitoring system and the identification of some relationships between air pollution and meteorological parameters in the studied area. Descriptive statistics was applied to analyze the time series of air pollutants monitored by an automated monitoring network composed by six stations, in order to establish the relationship between air pollutants and important weather factors. Data were measured in Ploiesti urban area between November 2011 and March 2012. The statistical models indicated that weather variables such as temperature and relative humidity had significant impact on the most air pollutants.

Pollutants' data, meteorological data and medical data feeds the relational database with information from vulnerable urban areas (i.e., Targoviste and Ploiesti), which will help the running of algorithms between air quality, meteorology and health effects and later use of forecasted outputs to forecast health effects. Several computer-based tools were developed to facilitate the population of the database with specific data from various sources. One of these tools allows the automatic capturing of pollutants’ concentrations from web-based official sources. The relational database structure integrates the fields for the required variables in the attributed data tables (PM 2.5 and carried compounds/metals sub-database, meteorological sub-database and medical sub-database). The main criteria in selecting the respiratory illnesses that are linked to atmospheric pollution for children are the wheezing. The medical database contains as main fields: the number of wheezing episodes, number of asthma attacks (with hospitalization), the response to inhalation medication, medication controller, eosinophil count, serum level of E immunoglobins (lgE), and residential address and school/kindergarten address of the children. The presented database structure and adjacent tools are expected to improve the current monitoring methodology of air pollutants, mainly respirable dusts, and their content in various compounds in correlation with children’s health.

We have developed a decision support system that prompts the user for site and contaminant characteristics from petroleum extraction and transportation processes and filters out those technologies that are most adequate for site remediation from the categories of remedial methods in its database. The computerized rule-based structure facilitates the evaluation and selection of the most applicable and feasible treatment technology for petroleum-contaminated soil on a site polluted from pipeline deterioration, which this paper presents as a case study. The technology-screening feature is a useful tool in the early evaluation phase of the soil remediation process and can assist specialists in the simulation of various scenarios. The system has accurately estimated pollutant migration and extent for preliminary soil investigations and provided recommendations in accordance with the current remedial actions taken at these petroleum-contaminated sites. The decision elaboration is close to the situations often encountered in real life.

Among human activities, those in which fuel combustion processes intervene are those who contaminate the atmosphere greatly. The combustion process is a process of rapid oxidation, followed by light phenomena and the release of large amounts of energy, able to maintain it at high temperatures. Compared with slow oxidation processes, it is characteristic to the combustion process sudden acceleration of the reaction rate to achieve theoretically infinite values. This applies, for example, to the stoichiometric mixture of methane oxygen heated to a temperature of 560°C in a sealed container. Heating the same mixture to a temperature of only 200°C, result in a slow oxidation process, which produces methanol, formic acid, formaldehyde, carbon monoxide and carbon dioxide gas, with an overall response rate with an evolution with measured values up to a maximum, after which rate value decreases with the depletion of reagents. In everyday life we encounter slow oxidation processes at every step. Thus, minerals are subject to slow oxidation process which occurs at ambient temperature by consumption of oxygen from atmospheric air, with production of oxides in a state of maximum stability. Such a process is carbon steel corrosion under the action of atmospheric oxygen at ambient temperatures, which is transformed first into ferrous oxide (FeO) and then in a more stable substance, ferric oxide (Fe2O3). Also, living organisms consume oxygen in the atmosphere, at room temperature to oxidize nutrients over a slow but very complex process. In both examples above, as in any oxidation process, there are necessary two substances: the oxidant, which has the ability to quickly combine with the substance subject to oxidation, respectively, the substance that is oxidized, called fuel. The transformation of chemical energy of fossil fuels in forms of energy directly useable, primarily mechanical energy, electrical energy and heat energy, is practically done only by means of combustion. In the production of electrical and heat energy, are consumed by burning, at present, 87% fossil fuels, the remainder being nuclear energy and regenerative energy (hydraulic, wind energy, solar, geothermal and marine) 6%, respectively 7%. At this consumption of the fossil fuels the consumption to produce mechanical energy in transports and the technological consumption, e.g. consumption of coal to produce metallurgical coke and for injection in blast furnaces, is added. In 2008, according to the World Energy Outlook (2010), world consumption of fuels was 12 300 million toe (tons oil equivalent), of which 30 660 million barrels of oil and 3100 billion cubic meters of natural gas. For the year 2035, according to the script "new scenario" of the

The main objective of the study is to optimize the agronomical variables for prediction of water quality at river basin scale for various time intervals using the numerical modeling of the cumulative impact of agricultural operations due to the use of chemical inputs and specific tillage. SWAT (Soil & Water Assessment Tool) model was developed to determine with reasonable accuracy the effect of potential management decisions regarding the water use, sediment transport, and chemical transformations of substances discharged into surface waters in rural ungauged basins. The information flow must start with the adaptation of the inputs required by the SWAT model for the accurate definition of Hydrological Response Units that include unique combinations between slope, soil type, and land use/land cover. All thematic layers must be related to the same coordinate system using the 1970 stereographic projection and Dealul Piscului 1970 geographic coordinate system that are in force in Romania. The meteorological inputs used in SWAT include rainfall, maximum and minimum temperature, solar radiation, relative humidity and wind speed. The prediction of SWAT model considering the diffuse sources of pollution (land areas with intensive agriculture) were analyzed considering the cropping technologies used in various Romanian hydrographical basins, i.e. Ialomita River, Calmatui River, Teleajen River, and Mostistea River. The main constraints observed in the use of SWAT model for efficient predictions in various control sections can be adjusted by the careful selection/adaptation of inputs, the optimal calibration/sensitivity analysis of the model, and the updating of information regarding the land use/land cover in a specific river basin.

The aim of this study was to link the concentrations of particulate matter with an aerodynamic diameter below 2.5 μm (PM2.5) and associated heavy metals with occurrence of wheezing and hospitalizations due to wheezing in 111 children who live near metallurgical plants in Targoviste City, Romania. A group of 72 children with high levels of immunoglobulin E (IgE) and eosinophils, as well as frequent wheezing episodes, was geolocated on digital thematic maps. Monitoring campaigns and medical assessments were performed over two consecutive years (2013-2014). The multiannual average concentrations of PM2.5 ranged from 4.6 to 22.5 μg m(-3), up to a maximum value of 102 μg m(-3). Significant correlations (p 0.01) were observed between the locations of the children with respiratory issues and the PM2.5 multiannual average (r = 0.985) and PM2.5 maximum (r = 0.813). Fe, Ni, Cd, and Cr were the main marker elements of the emissions from steel production and metal-working facilities in the Targoviste area. The results support the hypothesis that increased PM2.5 levels directly influence wheezing symptom and asthma attacks in the analyzed group. IgE, eosinophils, and wheezing episodes may be considered key indicators with which to evaluate the adverse effects of PM2.5 air pollution on children's health.

Some of the major stressors of air quality in the urban areas are nitrogen oxides, ozone and suspended particles. The effect of air pollution on respiratory diseases can increase considerably at high levels of pollution and might trigger asthma symptoms. Longterm exposure can increase the rate of respiratory infections and symptoms at population level, but particularly in children. The goal was to analyze with statistical techniques the pollutant concentrations (NO, NO2, and SO2) recorded by 15 automated monitoring stations, to establish weekdays-weekend trends in various towns of the South Muntenia Region during cold months when residential heating contributes to the overall emissions. Raw data of the monitored parameters were acquired from 7 stations for NO and NO2, and 14 stations for SO2. Data acquisition and processing were performed between November 15, 2013 and February 28, 2014 and hourly-recorded time series were characterized for central tendency, dispersion and distribution. The statistical analysis determined the degree of differentiation between different sites and time intervals of the monitored pollutants using the screening of air quality trends based on hourly concentrations of each weekday using a specific grouping of data. The results support the characterization of weekday/weekend patterns in air pollutant concentrations in several urban areas of Southern Romania, where air pollution data were available: 4 cities (NO, NO2) i.e., Ploiesti, Slobozia, Turnu Magurele, and Giurgiu, respectively 6 cities (SO2), i.e., Ploiesti, Pitesti, Cimpulung, Giurgiu, Alexandria and Turnu Magurele.

This study aims to evaluate the concentrations of heavy metals in airborne particulate matter (PM) collected in Ploiesti city (Romania) during the monitoring campaigns performed in 2015. Various health effects of airborne PM, from less serious to very serious ones, are often associated with its chemical speciation. The heavy metals bounded on PM may accumulate in human body by inhalation and can produce both short-term and long-term negative health effects especially in children and sensitive people. We investigated several heavy metals associated with PM2.5 collected in 12 relevant sampling points to estimate their potential impact on urban population health. PM samples were collected on 37 mm quartz fiberglass filters using a precision optical instrument i.e., DustTrak DRX8533EP. The deposition of elements on the surface of samples was determined using a scanning electron microscope (SEM). The analysis and quantification of trace elements were performed using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The experiments indicated that samples of PM contained heavy metals in the following order Zn ] Ni ] Cr ] Pb ] As ] Cd. Monitoring of elemental composition in atmospheric particles can contribute to a better air quality management.

The study aims to investigate the chemical composition of airborne particulate matter with size below 2.5 �m (PM2.5) collected from Targoviste City area, in the summer of 2015. For this consideration eleven representative points have been chosen for sampling. This research provides interesting data which can clarify the relationship between PM2.5 exposure and the negative effects on human health at urban area level. Three analytical techniques have been developed for the qualitative, quantitative and morphological characterization of PM2.5. The inorganic and organic functional groups of the PM2.5 samples were investigated by Attenuated Total Reflectance - Fourier Transform Infrared Spectrometry (ATR-FTIR). The content of several elements (i.e. Pb, Cd, Cr, Ni, Cu, Mn, Al, Zn and Fe) in samples was determined by Inductively Coupled Plasma - Mass Spectrometry (ICP-MS). The measured concentration of these metals was compared with values reported by the International Agency on urban area in order to establish the minimal element level which cannot be considered as a potential health risk for the urban population. The morphological characterization of PM2.5 was performed by Scanning Electron Microscopy - Energy Dispersive Spectrometry (SEM-EDS). The elemental analysis of samples were performed by EDS and showed that airborne particle was mainly composed of elements, such as C, O, Si, Ca, N and S.