scholarly journals Generalized Additive Models Analysis of the Atmospheric Pollutants Response to the Emission Reduction and Meteorology During the COVID-19 Lockdown in the North of Africa (Morocco)

2021 ◽  
Author(s):  
salah eddine sbai ◽  
farida Bentayeb ◽  
Hao Yin
Keyword(s):  
Air Pollution ◽  
Air Pollutants ◽  
Emission Reduction ◽  
Meteorological Factors ◽  
Generalized Additive Models ◽  
Additive Models ◽  
Environmental Data ◽  
Atmospheric Pollutants ◽  
Photochemical Oxidation ◽  
The North

Abstract Climate and air quality change due to COVID 19 lockdown (LCD) are extremely concerned subjects of several research recently. The contribution of meteorological factors and emission reduction to air pollution change over the north of Morocco has been investigated in this study using the framework generalized additive models (GAM), that have been proved to be a robust technique for the environmental data sets, focusing on main atmospheric pollutants in the region including ozone (O3), nitrogen dioxide (NO2), sulfur dioxide (SO2), particulate matter (PM2.5 and PM10), secondary inorganic aerosols (SIA), nom-methane volatile organic compounds (NMVOC) and carbon monoxide (CO) from the regional air pollution dataset of the Copernicus Atmosphere Monitoring Service (CAMS). Our results indicate that secondary air pollutants (PM2.5, PM10 and O3) are more influenced by metrological factors and the other air pollutants reported by this study in comparison with primary air pollutants (NO2 and SO2). We found that meteorological factors contribute to O3, PM2.5, PM10 and SIA average mass concentration by 22%, 5%, 3% and 34% before LCD and by 28%, 19%, 5% and 42% during LCD respectively. The increase in meteorological factors effect during LCD shows the contribution of photochemical oxidation to air pollution due to increase in atmospheric oxidant (O3 and OH radical) during LCD, which can explain the response of PM to emission reduction. Our study indicates that PM (PM2.5, PM10) has more controlled by SO2 due to the formation of sulfate particles especially under high oxidants level. The positive correlation between westward wind at 10m (WW10M), Northward Wind at 10m (NW10M) and PM indicates the implication of sea salt particles transported from Mediterranean Sea and Atlantic Ocean. This study shows the contribution of atmospheric oxidation capacity to air pollution change.

scholarly journals Source contributions to sulfur and nitrogen deposition – an HTAP II multi-model study on hemispheric transport

2018 ◽  
Vol 18 (16) ◽  
pp. 12223-12240 ◽  
Author(s):  
Jiani Tan ◽  
Joshua S. Fu ◽  
Frank Dentener ◽  
Jian Sun ◽  
Louisa Emmons ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Pollutants ◽  
Emission Reduction ◽  
Open Ocean ◽  
Coastal Regions ◽  
The North ◽  
Source Regions ◽  
Low Emission ◽  
Air Flows ◽  
The Impact

Abstract. With the rising anthropogenic emissions from human activities, elevated concentrations of air pollutants have been detected in the hemispheric air flows in recent years, aggravating the regional air pollution and deposition issues. However, the regional contributions of hemispheric air flows to deposition have been given little attention in the literature. In this light, we assess the impact of hemispheric transport on sulfur (S) and nitrogen (N) deposition for six world regions: North America (NA), Europe (EU), South Asia (SA), East Asia (EA), Middle East (ME) and Russia (RU) in 2010, by using the multi-model ensemble results from the 2nd phase of the Task Force Hemispheric Transport of Air Pollution (HTAP II) with 20 % emission perturbation experiments. About 27 %–58 %, 26 %–46 % and 12 %–23 % of local S, NOx and NH3 emissions and oxidation products are transported and removed by deposition outside of the source regions annually, with seasonal variation of 5 % more in winter and 5 % less in summer. The 20 % emission reduction in the source regions could affect 1 %–10 % of deposition in foreign continental regions and 1 %–14 % in foreign coastal regions and the open ocean. Significant influences are found from NA to the North Atlantic Ocean (2 %–14 %), and from EA to the North Pacific Ocean (4 %–10 %) and to western NA (4 %–6 %) (20 % emission reduction). The impact on deposition caused by short-distance transport between neighboring regions (i.e., from EU to RU) occurs throughout the whole year (slightly stronger in winter), while the long-range transport (i.e., from EA to NA) mainly takes place in spring and fall, which is consistent with the seasonality found for hemispheric transport of air pollutants. Deposition in the emission-intensive regions such as US, SA and EA is dominated (∼80 %) by own-region emissions, while deposition in the low-emission-intensity regions such as RU is almost equally affected by foreign exported emissions (40 %–60 %) and own-region emissions. We also find that deposition of the coastal regions or the near-coastal open ocean is twice more sensitive to hemispheric transport than the non-coastal continental regions, especially for regions in the downwind direction of emission sources (i.e., west coast of NA). This study highlights the significant impacts of hemispheric transport of air pollution on the deposition in coastal regions, the open ocean and low-emission-intensity regions. Further research is proposed to improve the ecosystem and human health, with regards to the enhanced hemispheric air flows.

scholarly journals Effects of ambient air pollution on emergency room visits of children for acute respiratory symptoms

2020 ◽  
Author(s):  
Rashmi Yadav ◽  
Aditya Nagori ◽  
Aparna Mukherjee ◽  
Varinder Singh ◽  
Rakesh Lodha ◽  
...  
Keyword(s):  
Air Pollution ◽  
Emergency Room ◽  
Air Pollutants ◽  
Respiratory Symptoms ◽  
Generalized Additive Models ◽  
Ambient Air ◽  
Respiratory Illness ◽  
Additive Models ◽  
Ambient Air Pollution ◽  
Weather Variables

AbstractBackgroundData on the relation between the increase in ambient air pollution and acute respiratory illness in children are scarce. The present study aimed to explore the association between daily ambient air pollution and daily emergency room (ER) visits due to acute respiratory symptoms in children of Delhi.MethodsIn this epidemiological study, the daily counts of ER visits (ERV) of children (≤15 years) having acute respiratory symptoms from 1st June 2017 to 28th February 2019 were obtained from two general hospitals of Delhi. Simultaneously, data on daily average concentrations of particulate matter (PM10 and PM2.5), nitrogen dioxide (NO2), sulphur dioxide (SO2), carbon monoxide (CO), and ozone (O3), and weather variables were provided by Delhi Pollution Control Committee from their four continuous ambient air quality monitoring stations. We used K-means clustering with time-series approach to derive pollutant-derived clusters and the study period was categorized into high, moderate and low air pollution days. The combined effect of these air pollutants on acute respiratory ERV was assessed. Multi-pollutant generalized additive models (GAM) with Poisson link function was used to estimate the 0-6 day lagged change in daily ER visits with the change in multiple pollutants levels, adjusting for weather variables, days of the week and public holidays.ResultsIn 21 months, 132,029 children were screened at the ER of the participating hospitals. Of these 19,320 (14.6%) were eligible, and 19120 were enrolled with complete data collection. The study period could be divided into 3 pollutant-derived clusters with high (Cluster 1, 150 days), moderate (Cluster 2, 204 days) low (Cluster 3, 284 days) levels of air pollution. There was a 28.7% and 21% increase in ERV among children respectively, on high and moderate level pollution days (Cluster 1 and 2) compared to low pollution days (Cluster 3) on the same day of exposure to air pollutants. Similar results were found when the exposure to ambient air pollution of previous 1-6 days were taken into account. GAM analysis showed that the association of the acute respiratory ER visits with every 10 unit change of PM10, NO2, O3, CO and SO2 remained significant after adjusting for multi-pollutant and confounding variables effects. In contrast, no effect was seen for PM2.5. The ERVs for acute respiratory symptoms rose with increase in pollutants and the trends showed a percentage change (95% CI) 1.07% (0.32, 1.83) increase in ERVs for an increase of 10 micrograms per cubic meter of NO2 at previous day 1, 36.89% (12.24,66.95) for 10 milligrams per cubic meter of CO at previous day 3, and 12.77% (9.51, 16.12) for 10 micrograms per cubic meter of SO2 at same day while decrease of −0.18% (−0.32, - 0.03) for 10 micrograms per cubic meter of PM10 at same day, and −4.16 % (−5.18, −3.13) for O3 at previous day 3.ConclusionAn increase in the daily ER visits of children for acute respiratory symptoms was seen for 1-6 days after increase in daily ambient air pollution levels in Delhi.

scholarly journals Air Pollution and Hospital Admission for Epilepsy in Kerman, Iran

2021 ◽  
Author(s):  
Mohammad Amin Farahmandfard ◽  
Hossein Ali Ebrahimi ◽  
Moghaddameh Mirzaee ◽  
Prof Narges Khanjani
Keyword(s):  
Air Pollution ◽  
Environmental Protection Agency ◽  
Air Pollutants ◽  
Meteorological Data ◽  
Generalized Additive Models ◽  
Ambient Air ◽  
Additive Models ◽  
Relative Risks ◽  
Ambient Air Pollutants ◽  
Admission Data

Abstract Background: There is little information about air pollution and epilepsy attacks. The aim of this study was to investigate the relation between air pollution and epilepsy admission in Kerman, Iran.Methods: This was an ecological study, in which the concentrations of ambient air pollutants and meteorological data were inquired from the Kerman Environmental Protection Agency and the Kerman Meteorology Organization respectively, and epilepsy admission data were obtained from Kerman’s Shafa hospital Epilepsy Registry. Generalized Additive Models (GAM) with lags up to 7 days were used for estimating the Relative Risks (RR).Results: During 2008 until 2020, 894 epilepsy admission occurred in Kerman which 498 (55.7%) were male. The strongest relation between epilepsy admission was seen in the over 59 years group for CO in lag 0 (RR = 2.1455, 95% CI: 1.5823–2.9091), for NO2 in lag 0 (RR =1.0409, 95% CI: 1.0282–1.0537), and for PM2.5 in lag 5 (RR =1.0157, 95% CI: 1.0062–1.0252). Also for PM10 in the under 18 year's group in lag 2 (RR =1.0064, 95% CI: 1.0029–1.0098), for O3 in lag 0 (RR =0.9671, 95% CI: 0.9581–0.9761) and for SO2 in lag 5 (RR = 0.9937, 95% CI: 0.9891–0.9983).Conclusion: The findings of this study showed that CO, NO2, PM2.5, and PM10 air pollutants might be risk factors for epilepsy admission in Kerman.

scholarly journals Associations of Ambient Air Pollutants and Meteorological Factors With COVID-19 Transmission in 31 Chinese Provinces: A Time Series Study

2021 ◽  
Vol 58 ◽  
pp. 004695802110602
Author(s):  
Han Cao ◽  
Bingxiao Li ◽  
Tianlun Gu ◽  
Xiaohui Liu ◽  
Kai Meng ◽  
...  
Keyword(s):  
Air Pollution ◽  
Relative Humidity ◽  
Wind Velocity ◽  
Air Pollutants ◽  
Meteorological Factors ◽  
Meta Analysis ◽  
Ambient Air ◽  
Air Pollutant ◽  
Pollutant Concentrations ◽  
Air Pollutant Concentrations

Evidence regarding the effects of environmental factors on COVID-19 transmission is mixed. We aimed to explore the associations of air pollutants and meteorological factors with COVID-19 confirmed cases during the outbreak period throughout China. The number of COVID-19 confirmed cases, air pollutant concentrations, and meteorological factors in China from January 25 to February 29, 2020, (36 days) were extracted from authoritative electronic databases. The associations were estimated for a single-day lag as well as moving averages lag using generalized additive mixed models. Region-specific analyses and meta-analysis were conducted in 5 selected regions from the north to south of China with diverse air pollution levels and weather conditions and sufficient sample size. Nonlinear concentration–response analyses were performed. An increase of each interquartile range in PM2.5, PM10, SO2, NO2, O3, and CO at lag4 corresponded to 1.40 (1.37–1.43), 1.35 (1.32–1.37), 1.01 (1.00–1.02), 1.08 (1.07–1.10), 1.28 (1.27–1.29), and 1.26 (1.24–1.28) ORs of daily new cases, respectively. For 1°C, 1%, and 1 m/s increase in temperature, relative humidity, and wind velocity, the ORs were 0.97 (0.97–0.98), 0.96 (0.96–0.97), and 0.94 (0.92–0.95), respectively. The estimates of PM2.5, PM10, NO2, and all meteorological factors remained significantly after meta-analysis for the five selected regions. The concentration–response relationships showed that higher concentrations of air pollutants and lower meteorological factors were associated with daily new cases increasing. Higher air pollutant concentrations and lower temperature, relative humidity and wind velocity may favor COVID-19 transmission. Controlling ambient air pollution, especially for PM2.5, PM10, NO2, may be an important component of reducing risk of COVID-19 infection. In addition, as winter months are arriving in China, the meteorological factors may play a negative role in prevention. Therefore, it is significant to implement the public health control measures persistently in case another possible pandemic.

Environmental and geographical effects on fog occurrence

2021 ◽  
Author(s):  
Iva Hunova ◽  
Marek Brabec ◽  
Marek Malý ◽  
Alexandru Dumitrescu ◽  
Jan Geletič
Keyword(s):  
Air Pollution ◽  
Environmental Factors ◽  
Tensor Product ◽  
Generalized Additive Models ◽  
Additive Models ◽  
Low Rank ◽  
Seasonal Component ◽  
Explanatory Variables ◽  
The Individual

<p>Fog is a very complex phenomenon (Gultepe et al., 2007). In some areas it can contribute substantially to hydrological and chemical inputs and is therefore of high environmental relevance (Blas et al., 2010). Fog formation is affected by numerous factors, such as meteorology, air pollution, terrain (geomorphology), and land-use.</p><p>In our earlier studies we addressed the role of meteorology and air pollution on fog occurrence (Hůnová et al., 2018) and long-term trends in fog occurrence in Central Europe (Hůnová et al., 2020). This study builds on earlier model identification of year-to-year and seasonal components in fog occurrence and brings an analysis of the deformation of the above components due to the individual explanatory variables. The aim of this study was to indicate the geographical and environmental factors affecting the fog occurrence.</p><p>       We have examined the data on fog occurrence from 56 meteorological stations of various types from Romania reflecting different environments and geographical areas. We used long-term records from the 1981–2017 period. </p><p>       We considered both the individual explanatory variables and their interactions. With respect to geographical factors, we accounted for the altitude and landform. With respect to environmental factors,   we accounted for proximity of large water bodies, and proximity of forests. Geographical data from Copernicus pan-European (e.g. CORINE land cover, high resolution layers) and local (e.g. Urban Atlas) projects were used. Elevation data from EU-DEM v1.1 were source for morphometric analysis (Copernicus, 2020).</p><p>        We applied a generalized additive model, GAM (Wood, 2017; Hastie & Tibshirani, 1990) to address nonlinear trend shapes in a formalized and unified way. In particular, we employed penalized spline approach with cross-validated penalty coefficient estimation. To explore possible deformations of annual and seasonal components with various covariates of interest, we used (penalized) tensor product splines to model (two-way) interactions parsimoniously, Wood (2006).</p><p>       The fog occurrence showed significant decrease over the period under review. In general the selected explanatory variables significantly affected the fog occurrence and their effect was non-linear. Our results indicated that, the geographical and environmental variables affected primarily the seasonal component of the model. Of the factors which were accounted for, it was mainly the altitude showing the clear effect on seasonal component deformation (Hůnová et al., in press).</p><p>      </p><p> </p><p>References:</p><p>Blas, M, Polkowska, Z., Sobik, M., et al. (2010). Atmos. Res. 95, 455–469.</p><p>Copernicus Land Monitoring Service (2020). Accessed online at: https://land.copernicus.eu/.</p><p>Gultepe, I., Tardif, R., Michaelidis, S.C., Cermak, J., Bott, A. et al. (2007). Pure Appl Geophys, 164, 1121-1159.</p><p>Hastie, T.J., Tibshirani, R.J. (1990). Generalized Additive Models. Boca Raton, Chapman & Hall/CRC.</p><p>Hůnová, I., Brabec, M., Malý, M., Dumitrescu, A., Geletič, J. (in press) Sci. Total Environ. 144359.</p><p>Hůnová, I., Brabec, M., Malý, M., Valeriánová, A. (2018) Sci. Total Environ. 636, 1490–1499.</p><p>Hůnová, I., Brabec, M., Malý, M., Valeriánová, A. (2020) Sci. Total Environ. 711, 135018.</p><p>Wood, S.N. (2006) Low rank scale invariant tensor product smooths for generalized additive mixed models. Biometrics 62(4):1025-1036</p><p>Wood, S.N. (2017). Generalized Additive Models: An Introduction with R (2nd ed). Boca Raton, Chapman & Hall/CRC.</p><p> </p>

Accounting for responsive movement in line transect estimates of abundance

2001 ◽  
Vol 58 (4) ◽  
pp. 777-787 ◽  
Author(s):  
D L Palka ◽  
P S Hammond
Keyword(s):  
Animal Movement ◽  
Generalized Additive Models ◽  
Radial Distance ◽  
Additive Models ◽  
Line Transect ◽  
The North ◽  
Minke Whales ◽  
Orientation Density ◽  
Using Data ◽  
Animal Orientation

A method is developed to account for effects of animal movement in response to sighting platforms in line transect density estimates using data on animal orientation. Models of expected distributions of animal orientation show that presence of responsive movement is determined by the ratio of animal sightings with angles of orientation in the third quadrant relative to the first quadrant. The distance at which response began is estimated using logistic generalized additive models of the relationship between radial distance and orientation. Density corrected for responsive movement is estimated by applying the Buckland and Turnock two-team analysis method to data poststratified into regions "close" to and "far" from (beyond the distance that responsive movement began) the observation platform instead of the original stratification by observation team. For data collected in the North Atlantic, white-sided dolphins, harbor porpoises, and minke whales responded by avoiding the survey ship, and white-beaked dolphins were attracted to the ship. For these populations, our method to correct for responsive movement gave significantly higher estimates, from 1.4 to 2.7 times the uncorrected estimates.

scholarly journals Differential susceptibility according to gender in the association between air pollution and mortality from respiratory diseases

2011 ◽  
Vol 27 (9) ◽  
pp. 1827-1836 ◽  
Author(s):  
Marcio Sacramento de Oliveira ◽  
Antônio Ponce de Leon ◽  
Inês Echenique Mattos ◽  
Sérgio Koifman
Keyword(s):  
Air Pollution ◽  
Respiratory Diseases ◽  
Elderly Women ◽  
Generalized Additive Models ◽  
Differential Susceptibility ◽  
The Elderly ◽  
Additive Models ◽  
Male Population ◽  
Female Population ◽  
Increase In Risk

This study analyzed the association between air pollution and deaths from respiratory diseases, considering differential susceptibility according to gender. The authors used daily deaths from respiratory diseases (ICD-10, J00-J99), PM10, SO2, and O3 levels, and meteorological indicators in Volta Redonda, Rio de Janeiro State, Brazil, from January 2002 to December 2006. The association was estimated by Poisson regression using generalized additive models, where the increase in risk of deaths from PM10 to lag 1 was 10.01% (95%CI: 1.81-18.88%) in the total female population and 10.04% (95%CI: 0.90-20.02%) in elderly women. The increase in risk of deaths from PM10 to lag 9 was 8.25% in the total male population (95%CI: 0.86-16.18%) and 10.80% (95%CI: 2.18-20.15%) in elderly men. For exposure to SO2 and O3, the risk was significant in the total male population and the elderly, respectively. The results emphasize the need for further studies, focusing on modification of the effects of air pollution on health.

Diel variation of stomach contents of North Sea cod (Gadus morhua) during a 24-h fishing survey: an analysis using generalized additive models

2000 ◽  
Vol 57 (12) ◽  
pp. 2363-2367 ◽  
Author(s):  
Sara A Adlerstein ◽  
Henny C Welleman
Keyword(s):  
North Sea ◽  
Stomach Content ◽  
Gadus Morhua ◽  
Generalized Additive Models ◽  
Stomach Contents ◽  
Additive Models ◽  
Large Prey ◽  
Diel Variation ◽  
The North ◽  
The North Sea

Results show that the weight of cod (Gadus morhua) stomach contents sampled in the North Sea varies significantly within 24 h. To determine whether feeding varied with time, over 1100 cod stomachs were collected around the clock between 7 and 18 May 1984 in two areas in the central North Sea thought to be representative for feeding studies. Here we investigate temporal feeding patterns based on the analysis of stomach-content data, using generalized additive models (GAMs). Results show significant variation of content weight and indicate morning and evening peaks. The relative peak importance differed between and within areas. We propose that differences are due to diet composition, namely, prey size and diel availability. Cod fed primarily on molluscs, mainly ocean quahog (Cyprina islandica), crustaceans, sandeels (Ammodytes spp.), haddock (Melanogrammus aeglefinus), herring (Clupea harrengus), and several flatfish species. In one area, the diet was dominated by fish, relatively large prey that perform diel vertical migration, and in the other by invertebrates, smaller prey that are digested faster. The diel pattern was more pronounced where invertebrate prey were dominant. Generalisation of results and implications for predation-mortality estimates based on data from the North Sea Stomach Content Database, used to implement multispecies models in the region, are discussed.

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