Air quality assessment regarding metals and metalloids using experimental measurements is expensive and time consuming due to the cost and time required for the analytical determination of the levels of these pollutants. According to the European Union (EU) Air Quality Framework Directive (Directive 2008/50/EC), other alternatives, such as objective estimation techniques, can be considered for ambient air quality assessment in zones and agglomerations where the level of pollutants is below a certain concentration value known as the lower assessment threshold. These conditions occur in urban areas in Cantabria (northern Spain). This work aims to estimate the levels of As, Cd, Ni and Pb in airborne PM10 at two urban sites in the Cantabria region (Castro Urdiales and Reinosa) using statistical models as objective estimation techniques. These models were developed based on three different approaches: partial least squares regression (PLSR), artificial neural networks (ANNs) and an alternative approach consisting of principal component analysis (PCA) coupled with ANNs (PCA-ANN). Additionally, these models were externally validated using previously unseen data. The results show that the models developed in this work based on PLSR and ANNs fulfil the EU uncertainty requirements for objective estimation techniques and provide an acceptable estimation of the mean values. As a consequence, they could be considered as an alternative to experimental measurements for air quality assessment regarding the aforementioned pollutants in the study areas while saving time and resources. | The authors gratefully acknowledge the financial support from the Spanish Ministry of Economy and Competitiveness through the Project CMT2010-16068. The authors also thank the Regional Environment Ministry of the Cantabria Government for providing the PM10 samples at the Castro Urdiales and Reinosa sites.

Due to increasing amounts of pharmaceutically active compounds (PhACs) in the aquatic environment, their largely unknown effects to non-target organisms need to be assessed. This study examined physiological changes in the freshwater mussel Dreissena polymorpha exposed to increasing concentrations (0.534, 5.34, 53.4 and 534 mg L1) of the b-blocker metoprolol in a flow-through system for seven days.The two lower concentrations represent the environmentally relevant range. Surprisingly, metallothionein mRNA was immediately up-regulated in all treatments. For the two higher concentrations mRNA up-regulation in gills was found for P-glycoprotein after one day, and after four days for pi class glutathione S-transferase, demonstrating elimination and biotransformation processes, respectively. Additionally, catalase and superoxide dismutase were up-regulated in the digestive gland indicating oxidative stress. In all treated mussels a significant up-regulation of heat shock protein mRNA was observed in gills after four days, which suggests protein damage and the requirement for repair processes. Metoprolol was 20-fold bioaccumulated for environmentally relevant concentrations. | International audience

peer reviewed | The effects of chronically enhanced (NH(4))(2)SO(4) deposition on ion concentrations in soil solution and ionic fluxes were investigated in a Picea abies plot at Grizedale forest, NW England. Soil cores closed at the base and containing a ceramic suction cup sampler were 'roofed' and watered every 2 weeks with bulk throughfall collected in the field. Treatments consisted of the inclusion of living roots from mature trees in the lysimeters and increasing (NH(4))(2)SO(4) deposition (NS treatment) to ambient + 75 kg N ha(-1) a(-1). Rainfall, throughfall and soil solutions were collected every 2 weeks during 18 months, and analysed for major cations and anions. NO(3)(-) fluxes significantly increased following NS treatment, and were balanced by increased Al(3+) losses. Increased SO(4)(2-) concentrations played a minor role in controlling soil solution cation concentrations. The soil exchange complex was dominated by Al and, during the experimental period, cores of all treatments 'switched' from Ca(2+) to Al(3+) leaching, leading to mean [Formula: see text] molar ratios in soil solution of NS treated cores of 0.24. The experiment confirmed that the most sensitive soils to acidification (through deposition or changing environmental conditions) are those with low base saturation, and with a pH in the lower Ca, or Al buffer ranges.

Due to the dynamic development of industry, related to the processing of plant materials and a subsequent significant increase in the number of employees working in this kind of industry, the indoor air quality is of great importance for the human health. The premises of plants processing plant materials are a specific environment, related to exposure to biological agents. The major sources of microbial contamination of premises are employees’ activities and the operation of devices used in the production process, quality of plant materials, technological processes, construction materials, ventilation (air-conditioning) systems, and outdoor air. Biological agents (primarily bacteria and fungi) transported in the air can cause numerous adverse health outcomes in exposed workers | Bioaerosols, Bacteria, Fungi, Processing plants, Materials of plant origin | 100 | 27507-27514

The study determined the impact of restrictions introduced by the Ministry of Health in connection with the COVID-19 pandemic on traffic and sound pressure levels in the university building and its immediate vicinity. Mickiewicza Street was selected for the study. It is one of the city’s busiest streets, located relatively close to the old historic center, and is the main artery connecting the north and south of the city. There are residential buildings on this street, but primarily offices and institutions, as well as schools and universities. Noise near the street and in buildings located relatively close to the road can be a serious problem in places where peace is required (e.g., libraries, reading rooms, university halls). Therefore, the acoustic comfort needed in these places may be disturbed, and the perception of knowledge acquisition may be limited. The aim of the work was achieved through measurements and analysis of street traffic intensity and sound pressure levels, taking into account pandemic restrictions. Then, statistical analyses were performed, which showed significant variability in traffic intensity and sound pressure values in individual periods of the pandemic. The pandemic’s beginning was mainly characterized by a significant decrease in the above data, deviating from the norm. In the pre-pandemic period, an average of 47,733 vehicles passed through the street daily, and the median sound pressure was Leq.OUT = 62.0 dBA outside the building and Leq.INS = 44.0 dBA inside. During the greatest restrictions, a period called “lockdown,” the number of cars driving decreased a little to an average of 44,153 per day, but there were days with 10,000-20,000 cars passing. In turn, noise decreased to 59.9 dBA for Leq.OUT and 43.2 dBA for Leq.INS. Between the first and second waves of infections, traffic was comparable to the post-pandemic period (an average of 69,027 cars per day), and noise also increased to Leq.OUT = 64-65 dBA and close to Leq.INS = 47.5 dBA. Studies have shown that noise on Mickiewicza Street is mainly caused by traffic (correlation coefficient: r = 0.92 for Leq.OUT and r = 0.86 for Leq.INS). The sound pressure level is high outside (Leq.OUT = 63.9 dBA) but relatively low inside the building (Leq.INS = 47.0 dBA) and should not negatively affect university staff and students (Leq.WH < LWH.acc). Based on the analyses, three stages show society’s approach to the COVID-19 pandemic: (1) fear of the COVID-19 pandemic; (2) relaxation after restrictions; (3) getting used to the COVID-19 pandemic. These periods did not correlate with the development of the pandemic or the number of people infected and dead. | 100 | 62772–62789 | 31

Heterorhabditis bacteriophora, entemopathogenic nematodes,metal ion toxicity, nematode infectivity | 0 | 157-166

The experiment was aimed at estimating the effect of mineral fertilization with ternary mineral fertilizers (NPK) on the development of Larix deeidua Mill. seedlings remaining under the influence of simulated acid rain. The soils with a mechanicai composition of poor loamy sands were treated with water solutions of H2SO4 of pH: 2.5, 3.0, 3.5, 4.0, 4.5, 7.8. and selected biometric features were measured. The experiment was carried over a period of 2 yr. The analysis of changes in the biometric features demonstrated that the poor alkaline reaction of water solutions (7.8), and strong acid (2.5) has a negative effect on the development of the Larix deeidua Mill. seedlings, resulting in the limitation of the length increment, decrease in the mass of seedlings, mass of needles etc. Optimal development of the seedlings was at pH 4.0. A decrease in the biometric features analyzed together with an increase in the acidity of water solution was observed. | 0 | 175-184