Concentrations In July Research Articles

A Simulation Study to Reveal the Epidemiology and Aerosol Transmission Characteristics of Botrytis cinerea in Grape Greenhouses.

Most previously studies had considered that plant fungal disease spread widely and quickly by airborne fungi spore. However, little is known about the release dynamics, aerodynamic diameter, and pathogenicity threshold of fungi spore in air of the greenhouse environment. Grape gray mold is caused by Botrytis cinerea; the disease spreads in greenhouses by spores in the air and the spore attaches to the leaf and infects plant through the orifice. In this study, 120 μmol/L propidium monoazide (PMA) were suitable for treatment and quantitation viable spore by quantitative real-time PCR, with a limit detection of 8 spores/mL in spore suspension. In total, 93 strains of B. cinerea with high pathogenicity were isolated and identified from the air samples of grapevines greenhouses by a portable sampler. The particle size of B. cinerea aerosol ranged predominately from 0.65-3.3 μm, accounting for 71.77% of the total amount. The B. cinerea spore aerosols were infective to healthy grape plants, with the lowest concentration that could cause disease being 42 spores/m3. Botrytis cinerea spores collected form six greenhouse in Shandong Province were quantified by PMA-qPCR, with a higher concentration (1182.89 spores/m3) in May and June and a lower concentration in July and August (6.30 spores/m3). This study suggested that spore dispersal in aerosol is an important route for the epidemiology of plant fungal disease, and these data will contribute to the development of new strategies for the effective alleviation and control of plant diseases.

Implementation of an On-Line Reactive Source Apportionment (ORSA) Algorithm in the FARM Chemical-Transport Model and Application over Multiple Domains in Italy

A source apportionment scheme based on gas and aerosol phase reactive tracers has been implemented in the chemical-transport model FARM, to efficiently estimate contributions of different sources to ambient concentrations. The on-line scheme deals with all the main processes that the chemical species undergo in the model, to enhance consistency with the calculation of bulk concentrations. The fate of precursors through gas-phase chemical reactions is followed by an efficient solver that determines their incremental reactivity, while the contributions to the secondary particulate species from their gaseous precursors is determined by assuming the thermodynamic equilibrium between the two phases. The paper details the new employed methodologies and illustrates the application of the apportionment scheme (based on 6 source sectors) to PM10 and O3, simulated on three domains of different dimensions in Italy, all sharing the same horizontal resolution and a common region (Lombardy). Spatial patterns of results show, on average, a relevant contribution of heating on PM10 concentration in January, with local hotspots dominated by road traffic. Contributions appear consistent in the three simulated domains, apart from the boundary conditions, influenced by the dimension of the domain. Hourly series of contributions to O3 concentrations in July at three selected sites show the dominance of boundary conditions, underlining the large scale of O3 formation. Finally, for PM10 components, the resulting sectorial contributions are compared with the impacts computed via the brute force method, showing that results are similar for elemental carbon and sulfate, while they are different for nitrate and ammonium, due to a different allocation of contributions and impacts between the methods. Each approach responds in principle to a different purpose, and their combined use provides possibly a wide set of information useful for addressing the different air quality management needs.

Meteorological impacts on the unexpected ozone pollution in coastal cities of China during the unprecedented hot summer of 2022

Surface ozone pollution under climate warming has become a serious environmental issue. In the summer of 2022, abnormal warming spread over most of the Northern Hemisphere and resulted in the abnormal increase in O3 concentrations. In this study, we focused on the coastal cities in China and investigated the O3 trends in July during 2015 to 2022. Four regions with different locations and emission levels were selected for comparison. A significant increase of O3 concentration in July 2022 were observed in the southern coastal cities (16.7–22.8 μg m−3) while the opposite characteristics were found in the northern coastal cities (decrease of 0.26–2.18 μg m−3). The results indicated various distribution patterns of the O3 concentrations responded to heat wave across China. The weakening of East Asian summer monsoon, extension of the western Pacific subtropical high, significant warming, stronger solar radiation, lower relative humidity, less rainfall and sinking motion of atmosphere in 2022 were beneficial for O3 generation and accumulation in the southern coastal areas. Meteorological changes in July 2022 could lead to an increase of 15.6 % in O3 concentrations in southern coastal cities compared to that in 2015–2021, based on the analysis of machine learning. Air temperature was the main contributor to high O3 concentrations in the coast of Fujian province, while other coastal cities depended on relative humidity. This study indicated the challenge of O3 pollution control in coastal areas under global warming, especially in extreme heat wave events.

Spatiotemporal Evolution of Precipitation Heterogeneity Characteristics in the Heilongjiang Province from 1961 to 2020

Precipitation unevenness significantly influences the rational allocation of water resources and the management of agricultural irrigation. Based on precipitation data from 29 meteorological stations in Heilongjiang Province, China, from 1961 to 2020, this study calculated the precipitation concentration index (PCI), precipitation concentration degree (PCD), and precipitation concentration period (PCP) to analyze the spatial distribution characteristics of precipitation heterogeneity at three distinct timescales: year, maize growth period, and the four stages of the maize growth period. The findings reveal that the rainy season in Heilongjiang Province commences earlier in the southwest compared with the northeast and northwest, with a primary concentration in July. At the annual scale, PCI in southwestern Heilongjiang Province surpasses that in the southeastern region, displaying an approximate east–west gradient in PCD and PCP values ranging from 0.544 to 0.746 and 196 to 203, respectively. During the growth period scale, precipitation concentrates in the southwest and central regions, occurring earlier than in the northeast and northwest. In contrast to the annual scale, the PCI value is smaller, and precipitation predominantly concentrates in mid and late July. Examining the four stages of the maize growth period, PCD generally exhibits a decreasing gradient from west to east. The highest values of PCI and PCD manifest in the southwestern part of Heilongjiang Province, with precipitation concentrated in the middle of each growth stage. The research results serve as a valuable reference for policymakers and stakeholders involved in water resource allocation and agricultural water management in Heilongjiang Province.

Measurement and Modeling of Ship-Related Ultrafine Particles and Secondary Organic Aerosols in a Mediterranean Port City.

Maritime transport emerges as a major source of ultrafine particle (UFP) pollution in coastal regions with consequences for the health of people living in port cities. Inhalation of UFPs can cause inflammation and oxidative stress, which are starting points for further diseases. In addition to primary particles, secondary organic aerosol (SOA) may form through the photo-oxidation of volatile organic compounds emitted in ship exhaust. The characterization of size-segregated and chemical properties of particles is essential for assessing the health implications related to shipping. We applied a coupled regional-local chemistry transport modeling system to study the effects of ship emissions on atmospheric concentrations of UFP and SOA in the Mediterranean port city Marseille (France), which is characterized by the combination of high port activity, industrialized emissions, and active photochemistry in summer. Our results show that the average potential impact from local shipping in the port area was 6-9% for SOA and 27-51% for total particle number concentration in July 2020. The estimated oxidative potential of daily mean particulate organic matter related to shipping was lower than the oxidative potential reported for heavy fuel oil (HFO). The lower oxidative potential in this study is very likely due to the low share of ships using HFO during stopover.

Prediction and Analysis of Chlorophyll-a Concentration in the Western Waters of Hong Kong Based on BP Neural Network

The Chlorophyll-a (Chl-a) concentration is an important indicator of water environmental conditions; thus, the simultaneous monitoring of large-area water bodies can be realized through the remote sensing-based retrieval of Chl-a concentrations. Together with hyperspectral remote sensing data, a BP neural network model was used to invert chlorophyll-a concentration, with remote sensing reflectance as the input factor. Given the presence of many bands in the hyperspectral data, selecting an appropriate band reflectance as the input factor is crucial to improving inversion accuracy. In this study, a Pearson correlation analysis method was proposed to select bands. A normality test was performed on the reflectance of each band of the Zhuhai-1 hyperspectral remote sensing data, and the significance index was p < 0.05. The absolute kurtosis value was less than 10, and the absolute skewness value was less than 3, indicating that the Pearson method was applicable. Pearson correlation analysis was utilised to calculate the correlation coefficient between the reflectance data and chlorophyll-a concentration. Five reflectance data with high correlation were selected as the input factors, and chlorophyll-a concentration was adopted as the output factor. An error backpropagation network model was constructed to predict chlorophyll-a concentration, and a Garson function was added to clarify the connection weights of the input factors in the model construction process. Model 12 was determined as the optimal model on the basis of the criteria of the coefficient of determination, the average relative variance, and the minimum mean square error. The chlorophyll-a concentration was predicted for July and November 2020 in the study area, and the results showed that the predicted values had a small error compared with the measured values. The root-mean-square error and mean relative error of the chlorophyll-a concentration predicted and measured values were 2.12 μg/L and 9.66%, respectively. Significant spatial differences in the Chl-a concentration were observed in the study area due to the influence of islands and land; the Chl-a concentration in July was generally higher than that in November. The results of these studies provide a reference for monitoring the water environment in the study area.

Occurrence, fate, seasonal variability, and risk assessment of twelve triazine herbicides and eight related derivatives in source, treated, and tap water of Wuhan, Central China

Triazine herbicides have been widely used, are frequently detected in aqueous environments and soils, and can cause acute or chronic toxicity to living organisms. We collected source water samples (n = 20) originating from the Hanshui River and the Yangtze River of Wuhan section, treated water samples (n = 20), and tap water samples (n = 169) in Wuhan, Central China during 2019 for determination of twelve triazine herbicides and their eight derivatives (collectively defined as TZs) and characterizing their fate during water treatment. Eighteen of the twenty TZs were detected in the source water. Atrazine (ATZ) had the highest concentrations (median: 22.4 ng/L) in the source water samples while DACT had the highest concentrations (median: 31.4 ng/L) in the treated water. “Tryns” (ametryn, prometryn, simetryn, terbutryn) were efficiently removed by conventional water treatment, while other target analytes were not; interestingly, hydroxypropazine and prometon increased significantly accompanied by prometryn disappearance, which implicated potential transformation pathways. In addition, “tryns” might be transformed into “tons” (atraton, prometon, secbumeton, terbumeton) by ozonation. In the tap water samples, diaminochlorotriazine had the highest concentrations (median: 34.9 ng/L) among the target analytes, followed by ATZ (18.3 ng/L), hydroxyatrazine (5.17 ng/L), deethylatrazine (5.00 ng/L), hydroxypropazine (3.20 ng/L), deisopropylatrazine (2.05 ng/L), hydroxydesethylatrazine (1.68 ng/L), and others. The TZs had the highest cumulative concentration in July in the tap water samples (median: 89.7 ng/L). This study found that ozonation in combination with activated carbon was more efficient in removing triazine herbicides, although “tryns” could also be transformed during conventional treatment. Ecological risk assessment showed moderate risks posed by hydroxyterbuthylazine, prometryn, and simetryn; the Hanshui River had higher risks than the Yangtze River, and July had higher risks than February. Human exposure to the TZs via water ingestion was low compared to the reference doses. This study characterized the occurrence of some new emerging TZs in the source water, their fate during drinking water treatment, and their seasonal variability in the tap water.

Spatiotemporal characteristics of arsenic and lead with seasonal freeze-thaw cycles in the source area of the Yellow River Tibet Plateau, China

Study regionThe source region of the Yellow River, China (SAYR) Study focusThis study focuses on demonstrating the impact of seasonal freeze-thaw process on the seasonally arsenic (As) and lead (Pb) concentration in the water bodies, such as river, lake, and spring. 113 surface water samples in April (freeze permafrost), 164 in July (active layer in permafrost thawed), and 86 soil samples at various depths in July were collected. Statistical correlation and principle analysis were applied to find the connection between tracer metals in water bodies and the various environmental factors. The percentage of soil particle size (5–50 µm), which can reflect the intensity of the freeze-thaw process in the permafrost soil, influenced the soil and water As and Pb trace metal concentrations differently in the permafrost area. New hydrological insights for the regionIn April, the average As concentrations were 23.4 ± 16.7, 39.4 ± 32.6, 26.5 ± 24.4 μg/L, respectively in river, lake and spring water samples, and Pb concentrations were 34.9 ± 27.1, 47.4 ± 38 and 48.9 ± 33.4 μg/L. While the As concentrations in waters in July all decreased by 2 or 3 times compared with those in April, Pb concentrations slightly increased. Permafrost thawing enhanced the weathering of As and Pb, but the high As adsorption on fine soil particles, resulting from the seasonal freeze-thaw cycles, leaded to the significant decrease in the water As concentration in July, in addition to the rainfall dilution. The slight increase in Pb water concentration in July suggesting the effects of enhanced weathering and dilution were equally important. The higher As and Pb concentrations around the large Gyaring and Ngoring lakes than other SAYR area, shaping the spatial distribution of As and Pb, might be due to evaporative enrichment and the high phosphate content in the lakes. Results are helpful in assessing the ecological impact of trace metals in the permafrost area with climate change.

Spatiotemporal variability of formaldehyde content in atmospheric air according to satellite measurements

Formaldehyde (HCHO) is a key ingredient in atmospheric chemistry, a precursor to ozone (O3) and an important indicator of atmospheric photochemical activity. It is also known to be a human and animal carcinogen. To assess the spatial and temporal variability of the formaldehyde content, the article analyzes long-term data (2003–2016) of measurements of the OMI spectrometer located on the Aura satellite. The results of the analysis showed that the tropospheric content of formaldehyde over most of the territory of Belarus for 2003–2016 had an uneven spatial distribution: there is a decrease in concentrations in the direction from the southwest to the northeast. Large cities and industrial centers form zones of increased troposphere pollution. The content of formaldehyde in the cells over the territory of Belarus during the study period was in the range of up to 30.8×1015 mol/cm2 and averaged 6.5×1015 molec./cm2. In most of the obtained values (84.1 %), the formaldehyde concentrations were fixed within the range of 2.0–10.0×1015 molec./cm2, and only 0.6 % exceeded 15.0×1015 molec./cm2. The obtained data are compared with the data of the ground-based atmospheric air monitoring system. The content of formaldehyde in the troposphere over the territory of Belarus, as well as in the surface layer of the atmosphere, has a pronounced seasonal dynamics with a maximum in the warm season with the highest concentrations in July and August. An analysis of the intra-annual dynamics of formaldehyde content in the surface layer and in the troposphere column indicates the presence of general trends, both for Belarus as a whole and for individual cities.1

Modeling Biogenic Volatile Organic Compounds Emissions and Subsequent Impacts on Ozone Air Quality in the Sichuan Basin, Southwestern China

Biogenic volatile organic compounds (BVOCs) impact atmospheric oxidation capacity and regional air quality through various biogeochemistry processes. Accurate estimation of BVOC emissions is crucial for modeling the fate and transport of air pollutants in chemical transport models. Previous modeling characterizes the spatial variability of BVOCs while estimated BVOC emissions show large uncertainties, and the impacts of BVOC emissions on ozone (O3) air quality are not well understood. In this study, we estimate the BVOC emissions by model of emissions of gases and aerosols from nature (MEGAN) v2.1 and MEGAN v3.1 over the Sichuan Basin (SCB) situated in southwestern China for 2017. Further, the critical role of BVOC emissions on regional O3 pollution is illustrated with a CMAQ modeled O3 episode in summer 2017. Annual BVOC emissions over the SCB in 2017 are estimated to be 1.8 × 106 tons with isoprene emissions as high as 7.3 × 105 tons. Abundant BVOC emissions are depicted over the southern and southeastern SCB, in contrast to the relatively low emissions of BVOC over the Chengdu Plain and northeastern SCB. CMAQ simulations depict a strong influence of BVOC on ambient O3 formation over densely forested regions including southern SCB and Chongqing city, accounting for 10% of daily maximum hourly O3 concentration (DM1h O3) and 6% of daily maximum 8-h average O3 (MDA8h O3) concentrations in July 2017. Over the severe O3 episode in summer 2017, sensitivity experiments indicate that enhanced BVOC emissions contribute substantially to basin-wide O3 concentrations and elevate peak O3 levels by 36.5 and 31.2 μg/m3 for the southern SCB and Chengdu Plain, respectively. This work identifies robustly important effects of BVOC emissions on O3 exceedance events over the SCB and contributes insight into pursuing an O3 abatement strategy with full consideration of potential contributions from BVOC emissions.

Measurements of aerosol particle concentrations in the atmosphere of the south-eastern coast of Lake Baikal (at Boyarsky station) in the summer of 2020

Atmospheric measurements of aerosol particle concentrations were made at a station named Boyarsky, the south-eastern coast of Lake Baikal (Russia) in the summer of 2020. The measurement period was conventionally divided into two ranges: 1) the smoke emission period of July 17-25; 2) the period of weakening of the influence of smoke emissions from forest fires in the neighbouring regions (from 14 August to 10 September). The diurnal behaviour of the total number concentrations of ultrafine particles in the size range from 5 to 200 nm (UFA) and submicron aerosols (SMA) from 0.2 to 1 μm was studied. The mean concentrations of UFA and SMA are 2705 (±1791) cm−3 and 40 (±19) cm−3 in July; 1247 (±780) cm−3 and 57 (±58) cm−3 in August; 1205 (±764) cm−3 and 37 (±19) cm−3 in September, respectively (the values in parentheses represent the respective standard deviations). The temporal evolution of the UFA particle number concentrations has shown a pronounced variation with lower concentrations in August-September and higher concentrations in July, whereas the diurnal patterns have been mostly found to be strongly influenced by the wildfire emissions. A strong relationship between the total particle number concentration has been established with the concentration of nitrogen dioxide NO2 (R =0.81), O3 (R = 0.66) and a weaker one with the concentration of sulphur dioxide (R =0.46). The thus obtained data on aerosol particle concentrations have been used to identify the events of bursts of nanoparticle formation in the atmosphere.

Non-Invasive Measurement of Progesterone and Cortisol Metabolites in the Faeces of Captive Female Rusa unicolor at Zoo Negara, Malaysia and Its Reproductive and Stress Behaviour

Sambar deer are listed as vulnerable and are bred in captivity under governmental management. The success of captive breeding programs varies, and the underlying causes are unclear. The advantage of using non-invasive faecal samples to obtain hormonal profiles without the animal being sedated or restrained has not been tested in sambar deer. This experiment was aimed to study the reproductive and stress behaviours of sambar deer and to measure the levels of reproductive and stress hormones in captive female sambar deer via a non-invasive procedure using faeces samples. Data on reproductive and stress behaviour were collected from six sambar deer for six months. Behaviours were recorded by instantaneous sampling method using direct observation. The reproductive and stress hormones in faecal samples were analysed using ELISA procedures. There are differences in frequency of certain reproductive behaviours recorded within different sessions of data collections while stress behaviour was in the low count and no huge difference in frequency between different sessions. Progesterone metabolites showed some trend of high concentrations in July and started to drop at the end of July till the end of December with constantly negative concentrations. Sambar deer in Zoo Negara can be considered not in stress due to low reading of cortisol concentration even though there was a presence of visitors. In future, it is important to make sure the faecal samples for hormonal analysis are collected daily to look for the pattern of the oestrus cycle in sambar deer.

Predicting the Nonlinear Response of PM2.5 and Ozone to Precursor Emission Changes with a Response Surface Model.

Reducing PM2.5 and ozone concentrations is important to protect human health and the environment. Chemical transport models, such as the Community Multiscale Air Quality (CMAQ) model, are valuable tools for exploring policy options for improving air quality but are computationally expensive. Here, we statistically fit an efficient polynomial function in a response surface model (pf-RSM) to CMAQ simulations over the eastern U.S. for January and July 2016. The pf-RSM predictions were evaluated using out-of-sample CMAQ simulations and used to examine the nonlinear response of air quality to emission changes. Predictions of the pf-RSM are in good agreement with the out-of-sample CMAQ simulations, with some exceptions for cases with anthropogenic emission reductions approaching 100%. NOX emission reductions were more effective for reducing PM2.5 and ozone concentrations than SO2, NH3, or traditional VOC emission reductions. NH3 emission reductions effectively reduced nitrate concentrations in January but increased secondary organic aerosol (SOA) concentrations in July. More work is needed on SOA formation under conditions of low NH3 emissions to verify the responses of SOA to NH3 emission changes predicted here. Overall, the pf-RSM performs well in the eastern U.S., but next-generation RSMs based on deep learning may be needed to meet the computational requirements of typical regulatory applications.

Juvenile growth deficit as an early alert of cockle Cerastoderma edule mortality

In the population dynamics of bi-phasic marine invertebrates, the fitness of one stage in the life of a cohort affects that of the following stage. This effect makes the prediction of the fate of a cohort challenging. We conducted a 22 yr monthly survey of a population of cockles Cerastoderma edule focussed on the juvenile stage. Two types of years were distinguished in terms of cohort longevity: a low-mortality group (‘L’) and a high-mortality group (‘H’). The cockle shell lengths of the 0+ cohorts was higher in the L group, in August and September. A cohort could hereby confidently be assigned to the L or H group as soon as August. Maximum cockle abundance in the cohorts, parasite load, or date of recruitment did not discriminate the groups, while an early date for the peak of the 0+ cohort abundance could be related to the L group. The maximum air temperature and the chl a concentration in July were higher in the H group, whereas the minimum salinity during the month of September was slightly lower in the H group of years. Therefore, a juvenile shell length under a given threshold was identified as an early alert for a short lifespan of the cockle cohort. This long-term analysis contributes to the deeper understanding of the population dynamics of bi-phasic invertebrates. The success of juveniles is not solely related to the intensity of recruitment or mortality by predation, but could also be linked to their fitness, their growth rates appearing as a proxy.

Temporal variation of airborne fungi in university library rooms and its relation to environmental parameters and potential confounders.

Indoor airborne fungi have been associated with adverse human health effects. Therefore, it is important to understand the causes of underlying variation in airborne fungi in indoor environments. This study consequently aimed to investigate the association between indoor fungi with temporal variation, environmental parameters, and potential confounders over 10months in four library rooms using Andersen samplers. Indoor fungal concentrations peaked in October and were lowest in March in both stack rooms, whereas the highest concentrations in both reading rooms were observed in September with lowest concentrations in July. Nonparametric analyses revealed higher fungal concentrations in the rooms that were significantly associated with relative humidity ≥ 60%, PM2.5 ≥ 35μg/m3, number of people ≥ 16, open windows, working air conditioners, and room area < 400m2. Multiple linear regression modeling for the library building considering only continuous variables revealed that relative humidity, PM2.5, and the number of people were significant predictors of fungal concentrations. Additionally, the model with continuous and categorical variables suggested that relative humidity, PM2.5, the number of people, ceiling fan condition, window state, and air conditioner operating status were significant predictor variables of concentrations. Outdoor fungal concentrations were a significant predictor for the two models of indoor fungal concentrations for each room. Ceiling fan or air conditioner operation was associated with altered fungal particle concentrations. These results provide a deeper understanding of indoor air fungal quality.

Seasonal and spatial variation in abundance of the copepod Calanus sinicus: Effects of decreasing dissolved oxygen and small jellyfish bloom in northern Yellow Sea, China, nearshore waters

A hypoxia event occurred in the nearshore of the northern Yellow Sea in summer 2016, and a bloom of small jellyfish occurred in June of this year. As a key copepod species in the Yellow Sea, Calanus sinicus exhibits early recruitment mainly in this nearshore area. Therefore, this study assessed the effects of these two phenomena on C. sinicus especially on their early recruitment. Sampling in nearshore waters was performed every month from May to December, except for October 2016. The numerical abundance of eggs and nauplii (E + N), copepodites and adults (C + A) of C. sinicus was determined in relation to environmental factors. Results showed that dissolved oxygen (DO) concentrations decreased from June on, attaining a minimum in August, and showed a significant positive relationship with C. sinicus E + N abundance. This suggested that decreasing DO had potential negative effects on early recruitment of C. sinicus. The abundance of small jellyfish, dominated by Sugiura chengshanense (Hydromedusa), also showed a significant positive relationship with C. sinicus E + N abundance, indicating a potential predator-prey relationship between them. Spatial relationships were also examined between E + N abundance and DO concentration in July and with small jellyfish abundance in June. Both bottom DO (B-DO) and E + N abundance in inshore waters were significantly lower than those in offshore water in July, indicating a potential negative effect of low B-DO (<6 mg L−1) in nearshore water. Spatial variation of small jellyfish abundance showed no correlation with C. sinicus abundance in June, but the non-overlapping patchy distribution also suggested their potential predator-prey relationship. Together, both the seasonal and spatial results indicated that low DO and a small jellyfish bloom in nearshore waters had detrimental effects on early recruitment of C. sinicus. These negative effects thus have the potential to indirectly impact the trophodynamics of fishery resources in the northern Yellow Sea.

Исследования формирования радонового поля в помещении (на примере Дальневосточного государственного университета путей сообщения)

Full-scale investigations have demonstrated that radon contained in soil air provides dominant influence on the university’s radon field formation. The change of radon volume activity in the university’s civil defense hideout and premises have strongly pronounced seasonal pattern with maximum values of radon concentration in July and August, and minimum values in March, April and November. Radon escaping from the soil surface in the summertime does not affect the radon field change in the university’s premises. The most precise estimation of radon annual average volume activity can be obtained when performing observations during a year. The substitution of this approach by the method of measurements with various duration leads to errors in the estimation of the normative parameter because of difficulties in registration of radon variations in various conditions.

Urban trees assimilation efficiency and assessment of environment quality

The conception of functional adaptation of woody plants in the changing conditions of natural ecotopes and the urban ecosystem is substantiated. The new integrated methods for estimation of the natural environment transformation under the pressure of urbanization are suggested. The objects of our research are 49 species and forms of woody plants inhabiting the urban ecosystem of Lviv, natural and artificial tree stands of Ukrainian regions. Also, we focused our attention on the anthropotransformation of microclimate, soil changing in tree plantations and problems of edaphotopes contamination. The main subject of the original plant studies were the general phenotypic functional changes in the assimilation apparatus of tree species, which can be estimated by the complex of conventional and new indicators of chemical and biochemical composition of leaf dry matter from ecotopes with different living conditions and origin. We investigated the morphological, physiological and biochemical reactions of assimilating organs of woody plants affecting their growth and development in the conditions of the Lviv city and in the natural conditions of forests and parks. As a result of long-term studies of such reactions, we have suggested an original methodological approach to elucidating the levels of phenotypic functional adaptation. Also, the ability of autochthonous and allochthonous (exotic) tree species to adapt their growth and development to new or modified anthropogenic environment has been studied out. The average level of sugars in the leaves during vegetation was considered as a normal level with the maximum at the beginning, and subsequent decrease in the middle while the minimum of content was determined at the end of the growing season. The appropriate character of starch metabolism are displayed by average levels in different species, with the maximum concentration in July and subsequent minimization of their content at the end of the growing season. The naturally determined dynamics of fiber (cellulose) concentrations implies gradual decline in the period from spring to autumn of its proportion in the leaves dry matter at the high level of concentration, similarly as in the native species. The gradual increase in the proportion of all water-soluble carbohydrates about insoluble in adapted native plants was considered as a natural. A small amount of sugars in a ratio with the general concentration of ash in the leaves at the end of the growing season, we consider as auspicious. Suggested by us clusterization of native and exotic tree species concerning of the efficiency of their introduction in different urban plantations, and depending on the degree of anthropogenic ecotope transformation, allows diversely and effectively recommend different tree species and their forms in varied scopes of application. We used indicators of phenotypic functional adaptation while inventorization of Lviv botanical gardens collections has taken place. The informative criteria for assessing the status of plants, selection of resistant local and introduced individuals with high adaptive potential were elicited by mentioned above indices. A comprehensive approach to the study of ecotope qualities is effective for assessing the acclimatization conditions for tree exotics in the botanical gardens of Western Ukraine and for developing agrotechnical measures for their cultivation.

Air quality and health impacts from the updated industrial emission standards in China

To improve air quality, China has been increasing the stringency of national emission standards for industrial sectors. However, from the projected air quality and associated health impacts it is not known if the updated emission limits have been completely followed. Here, we develop emission inventories based on the emission limits at different stages and use the Weather Research and Forecasting with Chemistry (WRF-Chem) model and health impact function to determine the potential air quality and health impacts for different scenarios. We found that full implementation of the special emission standards would decrease PM2.5 concentrations by over 25% in April, July and October, and decrease O3 concentrations in July by 10%–20%. Overall, the number of PM2.5-related premature deaths could be reduced by 0.15 million (95% confidence level 0.13–0.17 million) if special emission limits were met and that O3-related premature deaths would decrease by 18oo (95% confidence level 500–3000). However, even with these special emission limits, a greater than 25% increase in O3 levels occurred in northern China during October, January and April, leading to an increase in O3-related premature deaths in northern provinces which would offset the decrease in provincial PM2.5-related mortality by 10%–20%. These findings indicate that emissions of volatile organic compounds (VOCs) should be reduced to avoid increases in O3 in VOC-limited provinces. Despite the increase in O3 in certain provinces, improvement of industrial emission standards could greatly limit PM2.5 pollution and reduce the associated health burden. Therefore, we suggest that government should accelerate full implementation of strict emission standards in order to improve air quality.

Temporal–spatial variations and source identification of dissolved nitrate in the upper Han River basin, China

Human activities have greatly increased the nitrogen (N) loading in rivers over the past century, and consequently, N pollution has become a severe problem in aquatic systems. Nitrate (NO3−) is the predominant form of dissolved N in aquatic environments. In the present study, we evaluated N pollution characteristics and identified N sources using an isotope tracing technique in the upper Han River, a tributary of the Yangtze River with a length of 925 km in China. The objectives of this study were to evaluate the variations of N concentrations and explore the N sources in different time periods and areas. The results revealed that NO3− had significantly higher concentrations in July (22.75 ± 17.75 mg L−1) than that in other sampling months (14.00 ± 10.85 mg L−1 in November, 13.70 ± 11.55 mg L−1 in January, 4.99 ± 6.10 mg L−1 in April), and it also presented significant spatial variations (p < 0.05) along the riverine network. Isotope analysis indicated a rather large range of isotope values, implying that the NO3− in the upper Han River originated from different sources, primarily from sewage. There was a large overlap of δ15NO3− values between different sources during the growing season (April/July), demonstrating the various inputs of N sources. Our results revealed the degraded water quality and poor control of N run off into the river. With the assessment of temporal–spatial variation and sources of N, improved management practices can be implemented to protect water resource and avoid further water quality deterioration in the upper Han River.