Organochlorine contaminants (OCs) – organochlorine pesticides (OCPs) and industrial products and byproducts – are included in different monitoring programmes and surveys, involving various animal species. Fish-eating birds are suitable indicator species for OCs. Adult birds may be difficult to capture, but chicks can be sampled more easily. Blood of birds is a potentially suitable non-destructive matrix for analysis, as OC levels in blood reflect their concentrations in the body. The study was aimed at investigating how age of fast-growing Grey heron (Ardea cinerea) chicks affects contaminant levels in their blood and thus how important is sampling at exact age for biomonitoring purposes. In 1999 on Lake Engure in Latvia whole blood samples of heron chicks were collected at three different time points, with seven and nine days in between the first and second and second and third sampling points, respectively. Twenty-two chicks were sampled at all three times. In total, 102 samples were analysed for 19 polychlorinated biphenyl (PCB) congeners, DDT metabolites – DDE and DDD, hexachlorobenzene (HCB), α-, β-, γ-hexachlorocyclohexane (HCH), and trans-nonachlor. Total PCB concentrations averaged around 2000 ng/g dry extracted matter (EM). DDE was the dominant individual contaminant (ca. 800 ng/g EM), followed by CB-153, -138, and −118. Most of the other analysed OCs were below 100 ng/g EM. No significant (p > 0.05) differences in OC concentrations were found between the three sampling occasions, except for trans-nonachlor. This means that blood can safely be sampled for biomonitoring purposes during the 17 days’ time window. The analysed legacy contaminants may serve as model substances for other persistent organic pollutants.

The Gulf of Riga, river Daugava and several interconnected lakes around the City of Riga, Latvia, form a dynamic brackish-freshwater system favouring occurrence of toxic cyanobacteria. We examined bioaccumulation of microcystins and nodularin-R in aquatic organisms in Latvian lakes, the Gulf of Riga and west coast of open Baltic Sea in 2002–2007. The freshwater unionids accumulated toxins efficiently, followed by snails. In contrast, Dreissena polymorpha and most lake fishes (except roach) accumulated much less hepatotoxins. Significant nodularin-R concentrations were detected also in marine clams and flounders. No transfer of nodularin-R and microcystins between lake and brackish water systems took place. Lake mussels can transfer hepatotoxins to higher organisms, and also effectively remove toxins from the water column. Obvious health risks to aquatic organisms and humans are discussed.

The intensification of the human activity in urban areas as a result of the increasing population has contributed to the air pollution worsening in cities. To reverse this trend, the European Commission established a legal framework to improve the air quality. Thereby the Member States need to develop air quality plans (AQP) for zones and agglomerations where air quality limit values are exceeded, in order to implement pollution control strategies and meet the legal requirements. Understanding the reasons for the levels of air quality non–compliance as well as evaluating available and commonly used tools to predict the air quality and their effects, is crucial for the decision–making process on air quality management policies. Based on a compilation of regional and local AQP, a review of assessment capabilities and used modeling tools to evaluate the effects of emission abatement measures on the air quality and health was performed. In most cases, models are applied to estimate emissions and to assess the resulting air quality from both reference and emission abatement scenarios. Air quality’s impacts on the health and environment are rarely quantified. Regarding the air quality assessment, beyond the modeling, monitored data for validation of simulations are also used. Some studies, however, do not include the use of air quality models, considering the monitoring network as spatially representative of the study domain (e.g. Lisbon Region, Riga, Malta). In order to overcome methodological limitations for quantifying the impacts of emission abatement measures, economic evaluation techniques or even Integrated Assessment Methodologies (IAM) have been developed. IAM, already applied in some AQP or case studies, namely for Antwerp and London, are used for assessing how reductions in emissions contribute to improve air quality, reduce exposure and protect human health.

Recognizing the factors responsible for the gradual increase in greenhouse gas [e.g. carbon dioxide (CO₂)] emissions is crucial to reduce the detrimental consequences on environmental sustainability and human life. Accordingly, spotting the sectors which contribute the most to CO₂ emissions and dampen economic growth have become one of the major concerns for policymakers around the globe. Against this background, this paper examines the nexus between economic growth and CO₂ emissions in three Baltic countries namely Estonia, Latvia and Lithuania. Thus, the study basically checks the validity of the environmental Kuznets curve (EKC) hypothesis by taking into account the role of energy consumption and financial development over the period of 1990–2018. This type of study is highly important for the region in order to comply with the commitments of the Paris Agreement and Sustainable Development Goals of the United Nations. The study first employs appropriate testing procedures and second-generation panel data methods to account for cross-sectional dependency and slope heterogeneity among countries. Applying unit roots and cointegration tests, the study then employed different mean group estimation models and heterogeneous panel causality methods suitable for cross-sectionally dependent and heterogeneous panels. The results of the econometric analyses reveal that the inverted U-shaped EKC hypothesis does not hold in the Baltic countries. But the pollution haven hypothesis is evidenced to hold for these nations. By boosting the CO₂ emissions figures, again, the study also revealed that higher levels of energy consumption exhibit adverse environmental consequences. Financial development is found to be effective in explaining the variations in the CO₂ emission figures of the selected countries as well. Causality test results confirm bi-directional causality between economic growth and CO₂ emissions, energy use and CO₂ emissions, CO₂ emissions and financial development, energy use and economic growth as well as between energy use and financial development. Furthermore, country-specific impacts are found to be similar to the corresponding panel estimates. Consistent with the findings, the study finally puts forward some policy-level suggestions. Accordingly, it is recommended that the Baltic countries need to move away from fossil-fuel dependent energy consumption growth policies to mitigate environmental degradation.

Agricultural production has a major impact on the environment. Indeed, the emissions from agricultural machinery have a significantly negative impact on ambient air, thereby contributing to Climate Change. This study analyses combine harvesters and justifies their optimization in order to increase resource efficiency as well as reduce any negative impact on the environment. Data from 90 combine harvesters in Lithuania and Latvia from 2016 to 2018 is collected using telematics, and the parameters that directly influence engine exhaust emissions are analyzed, such as operation time, grain unloading method, fuel consumption, and auto-steering, according to the engine-operating modes of harvesting, transportation, and idling. Statistically reliable strong correlations can be found between harvesting time and idling time, as well as between fuel consumption during harvesting and idling modes. On average, roughly 20% of the operating time consists of idling and roughly 15% of transportation; moreover, roughly 14% of the diesel fuel is used per year in the aforementioned engine modes. In addition, the auto-steering function enables the efficient use of diesel fuel (average cost per combine harvester is reduced by 0.2 t year⁻¹), thereby reducing air pollution (pollution per combine harvester is reduced on average by 0.6 t year⁻¹). The results suggest telematics system data can be effectively used for data analysis, problem identification, and decision-making with respect to pollution prevention and optimizing combine harvester operation. Graphical Abstract

One of the main aims of European Common Agricultural Policy (CAP) has been established on a considerable reduction of greenhouse gas (GHG) emissions without any decline in productivity by 2030. This introduces some challenges in the assessment of agricultural technical efficiency. In particular, we can formulate at least two problems that are worth to be addressed: (i) possibility of treating undesirable outputs and (ii) panel data analysis of agricultural technical efficiency enriched by eco-efficiency assessment. In this study, we applied a Window Slack-Based Measurement Data Envelopment Analysis (W-SBM-DEA) model in the presence of undesirable outputs to evaluate the performance of agriculture sector of EU-27 countries during the period from 2008 to 2017. The country-level cultivated agricultural area, labor, specific costs, overheads, and depreciation were considered as the model inputs, and the gross value of country-level crop and livestock products represented the desirable outputs. The agricultural total GHG emissions at the country-level were accounted for as the undesirable output in the model. Having compared the results of different models, the substantial difference in the performance of the EU countries was registered mainly due to incorporating undesirable outputs and window analysis when using SBM-DEA model. The results of eco-efficiency assessment indicated that the Netherlands, Belgium, Italy, and Malta are the most eco-efficient countries with a score higher than 0.90, while the lowest eco-efficiency scores were reported for Slovakia, Latvia, and Estonia. The highest average eco-efficiency scores of all EU members were registered in 2011 (0.82), 2012 (0.83), and 2017 (0.84). A comparison of eco-efficiency performance between the old and new EU members indicated that the greater scores were obtained by old EU members. The variability assessment results showed a low variability and subsequently a high stability in the European agricultural sector, particularly in the Netherlands, Italy, and Malta. Based on our findings, it was concluded that for assessing agricultural technical efficiency in European agriculture in the context of eco-efficiency, application of a W-DEA model with undesirable output for a specified period of time reduces the impacts of temporary changes and provides more realistic results when comparing to models without undesirable output. These more realistic assessments of technical efficiency could help policy-makers to make more precise decisions.

Flame retardants (FRs) are additives used in consumer products to reduce flammability, even though they can easily contaminate the indoor environment. Since it is common for people in modern cities to spend up to 85% of time indoors, the quality of the indoor environment is critical for human health. In this study, polybrominated diphenyl ethers (PBDEs), organophosphorus flame retardants (OPFRs), emerging brominated flame retardants (EBFRs), and dechlorane-related compounds (DRCs) were measured in household dust samples (n = 34) from Latvia, followed by human exposure assessment. Among all studied compounds, OPFRs showed the highest concentrations (1380–133,000 ng g⁻¹). Despite the phase-out of PBDEs, they were the second most significant flame retardants in the studied dust samples (468–25,500 ng g⁻¹) and the predominant compound was BDE-209. The concentrations of EBFRs were in the range of 120–7295 ng g⁻¹, with the most abundant contaminant being DBDPE, which is widely used as a substitute for the deca-BDE formulation. DRCs were the least common flame retardants in the Latvian indoor environments, with concentrations ranging 22.4–192 ng g⁻¹. Although the concentrations of specific FRs are known to vary between different countries, the levels and patterns observed in dust samples from Latvia were similar to those reported from Central Europe. Human exposure was evaluated as the estimated daily intake (EDI). The calculated exposure to most of the FRs was several orders of magnitude lower than the available reference dose (RfD) values.

Spores of the genus Alternaria belong to one of the most prevailing constituents of the air in all regions of the world. They form infectious inoculum of numerous plant species as well as severe inhaled allergies. The aim of this study was to compare the biological pollution with Alternaria spores of the air of 12 cities located in central and eastern Europe. The experiment was done in 2010 and it covered the territory of Latvia (LV), Lithuania (LT), Poland (PL) and Ukraine (UA). The spores were counted using an identical method and standard equipment (7-day Lanzoni volumetric sampler) followed by extensive statistical calculations. The timing of the day of maximum concentration changed mainly along the N-S direction and had a positive correlation with latitude. The most important factor determining the increase in Alternaria spore concentration was the temperature, whereas other weather parameters were not related or of low significance. Regardless of geographical location, the first phase of the season (0–0.9 % of Alternaria spores in the air) was the longest (up to 60 days) and the last (97.5 to 99 %) was the shortest (22 days or less). The means of daily concentrations of Alternaria spores ranged from 11 spores m⁻³ in Klaipeda (LT, Baltic Sea coast) to 187 in Poznan (west PL, agricultural plain). The threshold value of 80 spores m⁻³ that triggers the first allergy symptoms was exceeded in 8 to 86 days (Vinnitsa, UA, temperate continental, forest-steppes region). There were considerable differences between the highest number of spores per cubic metre of air, varying from 139 in the north (Klaipeda, LT) to 2,295 in central west (Poznan, PL). The biological pollution by Alternaria spores in several places of central and eastern Europe was high; the number of days exceeding the threshold value of 300 spores m⁻³ connected with serious health problems of atopic people ranged from 0 to 1 on the north (LV, LT) to 29 in central west (Poznan, PL).