The existence of biological (pollen and spore) and non-biological (PM2.5, PM10, O3, CO, NO2, SO2, etc.) particles in the atmosphere is connected to the frequency of adverse allergenic reactions ...affecting human health. Considering all probable effects of atmospheric pollutants and airborne pollen on allergic reactions, the present study mainly examines the influence of non-biological pollutants and weather parameters on the concentration of airborne pollen in the Guangzhou city area by using Pearson's correlation, Spearman's rho test, and multiple linear regressions. Accordingly, we analyze the seasonal variation of non-biological pollutants, meteorological parameters, and airborne pollen during 2017 from two districts (Haizhu and Panyu) of Guangzhou, China. The airborne pollen data were collected using the volumetric method. Spring and autumn were the primary seasons for most of the pollen identification in this area. Pearson's correlation and Spearman's rho test revealed that pollen dispersion was significantly correlated with non-biological pollutants and meteorological parameters. Among them, PM2.5 and O3 were positively correlated with pollen concentration and NO2 was negatively correlated. A significant positive correlation was observed between temperature and wind speed with pollen concentration. Precipitation and relative humidity were negatively correlated with pollen concentration during the study period. In contrast, multiple linear regressions revealed a minor effect among these parameters on pollen concentration. However, the meteorological parameter shows more valid regression than the air pollutants. Some inconsistent results were discovered, which might be due to differences in climate, vegetation type, and rapid urbanization. Therefore, considering the long periods needed to collect data on pollen, further research is necessary to investigate the allergenic effects and health burden due to atmospheric pollutants.
•Spring and autumn were the major airborne pollen-dominated seasons in Guangzhou.•PM2.5 and O3 were positively and NO2 was negatively correlated with pollen concentration.•Temperature and wind speed were positively correlated with pollen concentration.•Humidity and precipitation were negatively correlated with pollen concentration.
The increase in winter haze over eastern China in recent decades due to variations in meteorological parameters and anthropogenic emissions was quantified using observed atmospheric visibility from ...the National Climatic Data Center Global Summary of Day database for 1980–2014 and simulated PM2.5 concentrations for 1985–2005 from the Goddard Earth‐Observing System (GEOS) chemical transport model (GEOS‐Chem). Observed winter haze days averaged over eastern China (105–122.5°E, 20–45°N) increased from 21 days in 1980 to 42 days in 2014 and from 22 to 30 days between 1985 and 2005. The GEOS‐Chem model captured the increasing trend of winter PM2.5 concentrations for 1985–2005, with concentrations averaged over eastern China increasing from 16.1 µg m−3 in 1985 to 38.4 µg m−3 in 2005. Considering variations in both anthropogenic emissions and meteorological parameters, the model simulated an increase in winter surface‐layer PM2.5 concentrations of 10.5 (±6.2) µg m−3 decade−1 over eastern China. The increasing trend was only 1.8 (±1.5) µg m−3 decade−1 when variations in meteorological parameters alone were considered. Among the meteorological parameters, the weakening of winds by −0.09 m s−1 decade−1 over 1985–2005 was found to be the dominant factor leading to the decadal increase in winter aerosol concentrations and haze days over eastern China during recent decades.
Key Points
Anthropogenic emissions dominated the increase in winter haze days
Meteorological parameters explained 17% of the increase
Winds contributed the most to the decadal increase among the meteorological parameters
In order to establish a regional database on natural radioactivity, a series of measurements of 713 atmospheric aerosol samples collected on filters over a two-year period (2018–2019) in center of ...Beijing, northeastern China have been performed to analyze 7Be and 210Pb activity concentrations. The mean activity concentrations of 7Be and 210Pb were found to be 7.10 ± 2.44 mBq m−3 and 2.93 ± 1.52 mBq m−3, respectively. Both the radionuclides exhibited strong seasonal variations, with maximum concentration of 7Be occurring in the spring and that of 210Pb in the winter. The concentration of both the radionuclides was minimum in the rainy summer. Higher 7Be concentration in the spring was mainly caused by the stratosphere to troposphere exchange. Higher 210Pb concentration during winter was maybe attributed to the combustion processes in heating systems and the ingression of continental air masses resulted from winds originating from northwest. The dependence of the activity concentrations of 7Be and 210Pb with meteorological parameters such as rainfall, temperature, and humidity was studied through linear correlation analysis. Statistically significant negative correlations were observed between 7Be and 210Pb activity concentrations with rainfall, respectively, which suggested that the removal mechanisms of these two radionuclides were similar. Lead-210 showed statistically significant correlations with temperature, humidity and PM10. A comparison of the data obtained in the present study for Beijing with the northern hemisphere literature values of 7Be and 210Pb in the atmospheric aerosols showed that the values were smaller than the ones observed in the present study. Overall, the study provides an improved understanding of the temporal variability and correlation of 7Be and 210Pb concentrations in the atmosphere in center of Beijing, northeastern China.
•Regional database on7Be and 210Pb activity concentrations in the atmospheric aerosols in center of Beijing was established.•Rainfall is suggested as the major removal means for 7Be and 210Pb from the atmosphere.•Causal factors for the temporal variability of7Be and 210Pb activity concentrations were identified.•Correlations of temperature, relative humidity and PM10 with 7Be and 210Pb were explored.•Correlation between 7Be and 210Pb activity concentrations was studied.
To construct a radio communication system, there is need for extensive knowledge of the refractivity and its variations. This work aims to determine the change in season with tropospheric surface ...refractivity of Ilorin, Kwara, Nigeria. The refractivity for both dry (1st quarter) and rainy (3rd quarter) seasons for 2000 - 2002 have been calculated using the meteorological data obtained from the Nigerian Meteorological Agency, Ilorin. The result shows that there is a variation between tropospheric surface refractivity during the dry and rainy seasons. High refractivity during the rainy season than in dry season is observed, mainly due to higher amount of water content in the atmosphere (troposphere) in the rainy season.
The novel coronavirus disease (COVID-19) is a highly pathogenic, transmittable and invasive pneumococcal disease caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which emerged ...in December 2019 and January 2020 in Wuhan city, Hubei province, China and fast spread later on the middle of February 2020 in the Northern part of Italy and Europe.
This study investigates the correlation between the degree of accelerated diffusion and lethality of COVID-19 and the surface air pollution in Milan metropolitan area, Lombardy region, Italy. Daily average concentrations of inhalable particulate matter (PM) in two size fractions PM2.5, PM10 and maxima PM10 ground level atmospheric pollutants together air quality and climate variables (daily average temperature, relative humidity, wind speed, atmospheric pressure field and Planetary Boundary Layer-PBL height) collected during 1 January–30 April 2020 were analyzed. In spite of being considered primarily transmitted by indoor bioaerosols droplets and infected surfaces, or direct human-to-human personal contacts, it seems that high levels of urban air pollution, weather and specific climate conditions have a significant impact on the increased rates of confirmed COVID-19 Total number, Daily New and Total Deaths cases, possible attributed not only to indoor but also to outdoor airborne bioaerosols distribution. Our analysis demonstrates the strong influence of daily averaged ground levels of particulate matter concentrations, positively associated with average surface air temperature and inversely related to air relative humidity on COVID-19 cases outbreak in Milan. Being a novel pandemic coronavirus (SARS-CoV-2) version, COVID-19 might be ongoing during summer conditions associated with higher temperatures and low humidity levels. Presently is not clear if this protein “spike” of the new coronavirus COVID-19 is involved through attachment mechanisms on indoor or outdoor airborne aerosols in the infectious agent transmission from a reservoir to a susceptible host in some agglomerated urban areas like Milan is.
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•COVID-19 daily New cases are positively related with PM and Air Quality Index.•Dry air supports COVID-19 virus transmission.•Warm season will not stop COVID-19 spreading.•Outdoor airborne aerosols might be possible routes of COVID-19 diffusion.
Root zone temperature is one of the most important soil characteristics, controlling many of the physical, chemical and biological processes in the soil. Temperature varies by soil depth, and exerts ...a profound impact on plant germination and growth. In this study, the accuracy of two artificial intelligence models including support vector regression (SVR) and elman neural network (ENN) and their hybrids with firefly algorithm (SVR-FA and ENN-FA) and krill herd algorithm (SVR-KHA and ENN-KHA) was assessed in estimating soil temperature (Ts) at 5, 10, 20, 30, 50 and 100 cm depths at Maragheh meteorological station in north-western Iran. The results of the models were evaluated under 5 scenarios with various inputs including the main meteorological parameters measured at the station (air temperature, sunshine hours, relative humidity, wind speed and saturation vapour pressure deficit). Daily Ts data recorded from January 1, 2006 to December 30, 2012 and from January 1, 2013 to December 30, 2015 were used for model training and testing, respectively. The results showed that error rates have decreased from 5 to 10 cm soil depth (root mean square error (RMSE) reduced by 2.97, 4.68 and 3.19% for the best scenarios of SVR, SVR-FA and SVR-KHA models, respectively), whereas error rates have been increasing from 10 to 100 cm soil depths (RMSE increased by 62.4, 80.9 and 73.6% for the best scenarios of SVR, SVR-FA and SVR-KHA models, respectively). For the best scenarios of ENN, ENN-FA and ENN-KHA models, RMSE values decreased by 2.1, 1.6 and 3.1% from 5 to 10 cm depth and increased by 61.1, 84.1 and 81.1% from 10 to 100 cm depth, so that all six models reached their best performance at 10 cm soil depth. Examination of the results in terms of under-estimation or over-estimation of Ts indicated that the lowest and highest differences in performance between under- and over-estimation sets were 0.01 °C (SVR-FA at 5 cm depth) and 1.64 °C (SVR at 100 cm depth) for SVR-based models and 0 °C (ENN at 10 cm depth) and 0.56 °C (ENN at 100 cm depth) for ELM-based models, respectively. According to the results from the best scenarios of SVR, SVR-FA and SVR-KHA models in the under-estimation set at 100 cm depth, all the three models have exhibited a poorer performance over the temperature range 15–25 °C (RMSE increased by 56.7, 47 and 61.3% for SVR, SVR-FA and SVR-KHA, respectively) compared to temperature values outside that range. Exactly the same trend was also observed for ELM-based models, where the mentioned increases in RMSE were about 37.7, 59.4 and 55.5% for ELM, ELM-FA and ELM-KHA, respectively. According to the results, bio-inspired metaheuristic optimisation algorithms based on SVR and ENN which use appropriate meteorological parameters as inputs can have a relatively satisfactory performance in estimating Ts under climatic conditions similar to our study area, especially in lower depths, and can be used as an alternative to direct measurement of this important parameter.
•Hybrid models improved Ts estimation compared to base models.•Especial improvement for Ts values <5 °C (5, 10 and 20 cm) and 15–25 °C (100 cm)•Bio-inspired metaheuristic optimisation algorithms reliably estimated Ts.•Estimation accuracy was reduced by soil depth.
Fine particulate matter (PM2.5) pollution in Eastern China (EC) has raised concerns due to its adverse effects on air quality, climate, and human health. This study investigated the long-term ...variation trend in satellite-derived PM2.5 concentrations and how it was related to pollutant emissions and meteorological parameters over EC and seven regions of interest (ROIs) during 1998–2016. Over EC, the annual mean PM2.5 increased before 2006 due to the enhanced emissions of primary PM2.5, NOx and SO2, but decreased with the reduced SO2 emissions after 2006 evidently in response to China's clean air policies. In addition, results from statistical analyses indicated that in the North China Plain (NCP), Northeast China (NEC), Sichuan Basin (SCB) and Central China (CC) planetary boundary layer height (PBLH) was the dominant meteorological driver for the PM2.5 decadal changes, and in the Pearl River Delta (PRD) wind speed is the leading factor. Overall, the variation in meteorological parameters accounted for 48% of the variances in PM2.5 concentrations over EC. The population-weighted PM2.5 over EC increased from 36.4 μg/m3 in 1998–2004 (P1) to 49.4 μg/m3 in 2005–2010 (P2) then decreased to 46.5 μg/m3 in 2011–2016 (P3). In the NCP and NEC, the percentages of the population living above the World Health Organization (WHO) Interim Target-1 (IT-1, 35 μg/m3) have risen steadily over the past 20 yr, reaching maxima of 97.3% and 78.8% in P3, respectively, but decreases of ∼30% from P2 to P3 were found for the SCB and PRD.
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•The joint effect of emission and meteorological determined the decadal trend of PM2.5•The changes in meteorological parameters explained 48% of the variances in PM2.5.•Planetary boundary layer height was the dominant driver for the decadal changes of PM2.5•Eastern China has experienced slight decreases in the population-weighted mean PM2.5 over the past 10 year.
The joint effect of emissions and meteorological determined the decadal trend in PM2.5. The decadal variation in meteorological parameters accounted for 48% of the variances in PM2.5 concentrations over Eastern China. Eastern China has experienced slight decreases in the population-weighted mean PM2.5 over the past 10 year.
Abstract
Experiments were performed to determine the effects of ergothioneine (ERG) on behavioural responses of stallions to exercise during hot-dry and rainy seasons. Eighteen healthy stallions were ...divided into three groups of six horses each. Group I (ERG + Exercise) was treated with ERG before exercise, group II was treated after exercise (Exercise + ERG), and group III (Exercise only) was not treated but subject to exercise. The stallions were subjected to a race of 2,000 m at maximum speed. The time spent standing by the horses in the ERG + Exercise and Exercise + ERG groups (1430.31 ± 30.73 s/30 min and 1403.32 ± 32.43 s/30 min, respectively) were higher (
P
< 0.0001) than the time spent standing in the Exercise-only group (1033.26 ± 21.19 s/30 min). The number of times the stallions bit their cribs per 30 min in the ERG + Exercise (0.38 ± 0.02/30 min) and Exercise + ERG (0.67 ± 0.0530 min) groups was lower (
P
< 0.0001) than that recorded in the Exercise-only group (3.51 ± 1.7730 min). It was concluded that ERG modulates behavioural responses to exercise in stallions, and the agent may be beneficial in alleviating exercise-induced stress responses and improving the welfare of horses post-exercise.
The creation of new working standards at the All-Russian Scientific Research Institute of Physicotechnical and Radio Engineering Measurements (VNIIFTRI) for metrological support of meteorological ...measuring instruments is mentioned in the work.
The measured data of global and diffuse solar radiation on a horizontal surface, the number of bright sunshine hours, mean daily ambient temperature, maximum and minimum ambient temperatures, ...relative humidity and amount of cloud cover for Jeddah (lat. 21°42′37′′N, long. 39°11′12′′E), Saudi Arabia, during the period (1996–2007) are analyzed. The monthly averages of daily values for these meteorological variables have been calculated. The data are then divided into two sets. The sub-data set I (1996–2004) are employed to develop empirical correlations between the monthly average of daily global solar radiation fraction (
H/
H
0) and the various weather parameters. The sub-data set II (2005–2007) are then used to evaluate the derived correlations. Furthermore, the total solar radiation on horizontal surfaces is separated into the beam and diffuses components. Empirical correlations for estimating the diffuse solar radiation incident on horizontal surfaces have been proposed. The total solar radiation incident on a tilted surface facing south
H
t
with different tilt angles is then calculated using both Liu and Jordan isotropic model and Klucher’s anisotropic model. It is inferred that the isotropic model is able to estimate
H
t
more accurate than the anisotropic one. At the optimum tilt angle, the maximum value of
H
t
is obtained as ∼36 (MJ/m
2
day) during January. Comparisons with 22
years average data of NASA SSE Model showed that the proposed correlations are able to predict the total annual energy on horizontal and tilted surfaces in Jeddah with a reasonable accuracy. It is also found that at Jeddah, the solar energy devices have to be tilted to face south with a tilt angle equals the latitude of the place in order to achieve the best performance all year round.
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