Abundance and distribution of gaseous ammonia and particulate ammonium at Delhi, India

Abstract. This study reports abundance and distribution of gaseous NH3 and particulate NH4&plus; at Delhi. Gaseous NH3 and particulate NH4&plus; concentrations were measured during pre-monsoon, monsoon and post-monsoon seasons of the years 2010 and 2011. Average concentrations of gaseous NH3 during pre-monsoon, monsoon and post-monsoon seasons were recorded as 26.4, 33.2 and 32.5 μg m−3, respectively. Gaseous NH3 concentrations were the highest during monsoon, thought to be due to decay and decomposition of plants and other biogenic material under wet conditions, leading to increased NH3 emission. The results showed that particulate NH4&plus; was always lower than the gaseous NH3 during all the seasons. The concentrations of particulate NH4&plus; were recorded as 11.6, 22.9 and 8.5 μg m−3 during pre-monsoon, monsoon and post-monsoon seasons, respectively. The percent fraction of particulate NH4&plus; was noticed to be highest during the monsoon season, which is attributed to increased humidity levels favouring partitioning into the aerosol phase. On an average, 33.3% of total N-NHx was present as particulate NH4&plus;. Higher concentrations of NH3 noticed during night time may be due to stable atmospheric conditions. The study highlighted that, as compared with rural sites, urban sites showed higher concentrations of gaseous NH3 in India, which may be due to higher population density, human activities and poor sanitation arrangements.

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Abundance and distribution of gaseous ammonia and particulate ammonium at Delhi (India)

Biogeosciences Discussions ◽

10.5194/bgd-9-191-2012 ◽

2012 ◽

Vol 9 (1) ◽

pp. 191-207 ◽

Cited By ~ 1

Author(s):

S. Singh ◽

U. C. Kulshrestha

Keyword(s):

Monsoon Season ◽

Gaseous Ammonia ◽

Atmospheric Conditions ◽

Night Time ◽

Total N ◽

Biogenic Material ◽

Rural Sites ◽

Abundance And Distribution ◽

Urban Sites ◽

Particulate Ammonium

Abstract. This study reports abundance and distribution of gaseous NH3 and particulate NH4+ at Delhi. Gaseous NH3 and particulate NH4+ concentrations were measured during pre monsoon, monsoon and postmonsoon seasons of the years 2010 and 2011. Average concentrations of gaseous NH3 during premonsoon, monsoon and post monsoon seasons were recorded as 26.4, 33.2 and 32.5 μg m−3, respectively. Gaseous NH3 concentrations were the highest during monsoon due to decay and decomposition of plants and other biogenic material under wet conditions which emit NH3. The results showed that particulate NH4+ was always lower than the gaseous NH3 during all the seasons. The concentrations of particulate NH4+ were recorded as 11.6, 22.9 and 8.5 μg m−3 during premonsoon, monsoon and postmonsoon seasons, respectively. The percent fraction of particulate NH4+ was noticed highest during monsoon season due to increased humidity levels. On anaverage, 33.3 % of total N-NHx was present as particulate NH4+. Higher concentrations of NH3 noticed during night time may be due to stable atmospheric conditions. Study highlighted that as compared to rural sites, urban sites showed higher concentrations of gaseous NH3 in India which may be due to higher population density, human activities and poor sanitation arrangements.

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Seasonal variations of aerosol size distributions based on long-term measurements at the high altitude Himalayan site of Nepal Climate Observatory-Pyramid (5079 m), Nepal

Atmospheric Chemistry and Physics ◽

10.5194/acp-10-10679-2010 ◽

2010 ◽

Vol 10 (21) ◽

pp. 10679-10690 ◽

Cited By ~ 32

Author(s):

K. Sellegri ◽

P. Laj ◽

H. Venzac ◽

J. Boulon ◽

D. Picard ◽

...

Keyword(s):

Seasonal Variability ◽

Monsoon Season ◽

Number Concentration ◽

Residual Layer ◽

Research Station ◽

Free Troposphere ◽

Night Time ◽

High Accumulation ◽

Air Masses ◽

Post Monsoon

Abstract. The present paper investigates the diurnal and seasonal variability of the aerosol total number concentration, number and volume size distribution between 10 nm and 10 μm, from a combination of a scanning mobility particle sizer (SMPS) and an optical counter (OPC), performed over a two-year period (January 2006–February 2008) at the Nepal Climate Observatory-Pyramid (NCO-P) research station, (5079 m a.s.l.). The annual average number concentration measured over the two-year period at the NCO-P is 860 cm−3. Total concentrations show a strong seasonality with maxima during pre-monsoon and post-monsoon seasons and minima during the dry and monsoon seasons. A diurnal variation is also clearly observed, with maxima between 09:00 and 12:00 UTC. The aerosol concentration maxima are mainly due to nucleation processes during the post-monsoon season, as witnessed by high nucleation mode integrated number concentrations, and to transport of high levels of pollution from the plains by valley breezes during the pre-monsoon season, as demonstrated by high accumulation mode integrated number concentrations. Night-time number concentration of particles (from 03:00 to 08:00 NST) are relatively low throughout the year (from 450 cm−3 during the monsoon season to 675 cm−3 during the pre-monsoon season), indicating the of high altitudes background level, as a result of downslope winds during this part of the day. However, it was found that these background concentrations are strongly influenced by the daytime concentrations, as they show the same seasonal variability. If nighttime concentrations were presumed to be representative of free troposphere (FT)/residual layer concentrations, they would be found to be two times higher than at other lower altitudes European sites, such as the Jungfraujoch. However, BL intrusions might contaminate the free troposphere/residual layer even at this altitude, especially during regional air masses influence. Night-time measurements were subsequently selected to study the FT composition according to different air masses, and the effect of long range transport to the station.

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Week Day and Week End Air Ion Variability at Rural station Ramanandnagar (17° 4’ N 74° 25’E), India and At Different Atmospheric Sites in India

Global NEST Journal ◽

10.30955/gnj.000704 ◽

2013 ◽

Vol 13 (1) ◽

pp. 65-73

Keyword(s):

Urban Areas ◽

Transition Period ◽

Monsoon Season ◽

Pollution Index ◽

Negative Ion ◽

Rural Station ◽

Night Time ◽

Post Monsoon ◽

Post Monsoon Season ◽

The Government

Globalization and liberalization polices of the government of India have increased the number of road vehicles nearly 92.6% from 1980-81 to 2003-2004. Therefore to know whether there is effect of increase of industrialization in the urban areas like Pune (18° 32′N, 73° 51′E); Mumbai (18° 55' N, 72° 54' E) and at rural station like Ramanandnagar (17° 4′ N, 74° 25′ E); pollution index is measured. Pollution index which is ratio of average positive to negative small air ion ratio is plotted for week days and week end. At the rural station like Ramanandnagar Monday to Saturday are working days, while Sunday is holiday. It is observed that ratio of average positive to negative small ion ratio is maximum for all time periods during the week day as compared to week end. The data have been collected during the period from first 1 June 2007 to 31 May 2008; the period under analysis involves 8,040 hours shows that the peak of the positive to negative small air ion ratio is observed in winter, and dip is observed in post-monsoon season. As Ramanandnagar is surrounded by vegetation area, therefore due to plant transpiration of Radon and Thoron small air ion maximum are observed at noon time rather than night time. During the week end positive small air ion count is low as compared to week days. While during week end negative small air ion count is very high as compared to week days, which is observed in all the seasons. Post-monsoon is the transition period during which few thunder storms are observed. Due to these thunder storms additional amount negative ion are introduced and positively charged aerosols are cleared from the atmosphere. Therefore in the post-monsoon negative small air ion count is high as compared to all other seasons. Such type of diurnal variation of small air ion detected at rural station Ramanandnagar has never been observed elsewhere.

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Seasonal variations of aerosol size distributions based on long-term measurements at the high altitude Himalayan site of Nepal Climate Observatory-Pyramid (5079 m), Nepal

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-10-6537-2010 ◽

2010 ◽

Vol 10 (3) ◽

pp. 6537-6566 ◽

Cited By ~ 15

Author(s):

K. Sellegri ◽

P. Laj ◽

H. Venzac ◽

J. Boulon ◽

D. Picard ◽

...

Keyword(s):

Seasonal Variability ◽

Monsoon Season ◽

Number Concentration ◽

Research Station ◽

Scanning Mobility Particle Sizer ◽

Night Time ◽

High Accumulation ◽

Post Monsoon ◽

Post Monsoon Season ◽

Annual Average Number

Abstract. The present paper investigates the diurnal and seasonal variability of the aerosol total number concentration, number and volume size distribution between 10 nm and 10 μm, from a combination of a scanning mobility particle sizer (SMPS) and an optical counter (OPC), performed over a two-year period (May 2006–May 2008) at the Nepal Climate Observatory-Pyramid (NCO-P) research station, (5079 m a.s.l.). The annual average number concentration measured over the two-year period at the NCO-P is 860 cm−3. Total concentrations show a strong seasonality with maxima during pre-monsoon and post-monsoon seasons and minima during the dry and monsoon seasons. A diurnal variation is also clearly observed, with maxima between 09:00 and 12:00 UTC. The aerosol concentration maxima are mainly due to nucleation processes during the post-monsoon season, as witnessed by high nucleation mode integrated number concentrations, and to transport of high levels of pollution from the plains by valley breezes during the pre-monsoon season, as demonstrated by high accumulation mode integrated number concentrations. Night-time number concentration of particles (from 03:00 to 08:00 NST) are relatively low throughout the year (from 450 cm−3 during the monsoon season to 675 cm−3 during the pre-monsoon season), indicating the level of free_tropospheric background, as a result of downslope winds during this part of the day. However, it was found that these background concentrations are strongly influenced by the daytime concentrations, as they show the same seasonal variability. The resulting free troposphere (FT)/residual layer concentrations are found to be two times higher than at other lower altitudes European sites, such as the Jungfraujoch. Night-time measurements were subsequently selected to study the FT composition according to different air masses, and the effect of long range transport to the station.

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Aerosol fluxes and particle growth above managed grassland

Biogeosciences Discussions ◽

10.5194/bgd-6-341-2009 ◽

2009 ◽

Vol 6 (1) ◽

pp. 341-389 ◽

Cited By ~ 8

Author(s):

E. Nemitz ◽

J. R. Dorsey ◽

M. J. Flynn ◽

M. W. Gallagher ◽

A. Hensen ◽

...

Keyword(s):

Growth Rates ◽

Particle Deposition ◽

Scale Up ◽

Particle Growth ◽

Small Error ◽

N Budget ◽

Night Time ◽

Calcium Ammonium Nitrate ◽

Total N ◽

Nh3 Emission

Abstract. Particle deposition velocities (11–3000 nm diameter) measured above grassland by eddy covariance during the EU GRAMINAE experiment in June 2000 averaged 0.24 and 0.03 mm s−1 to long (0.75 m) and short (0.07 m) grass, respectively. After fertilisation with 108 kg N ha−1 as calcium ammonium nitrate, sustained apparent upward fluxes of particles were observed. Analysis of concentrations and fluxes of potential precursor gases, including NH3, HNO3, HCl and selected VOCs, shows that condensation of HNO3 and NH3 on the surface of existing particles is responsible for this effect. A novel approach is developed to derive particle growth rates at the field scale, from a combination of measurements of vertical fluxes and particle size-distributions. For the first 9 days after fertilization, growth rates of 11 nm particles of 3.5 nm hr−1 and 0.89 nm hr−1 were derived for day and night-time conditions, respectively. This implies total NH4NO3 production rates of 1.1 and 0.44 μg m−3 h−1, respectively. The effect translates into a small error in measured ammonia fluxes (0.06% day, 0.56% night) and a larger error in NH4+ and NO3- aerosol fluxes of 3.6% and 10%, respectively. By converting rapidly exchanged NH3 and HNO3 into slowly depositing NH4NO3, the reaction modifies the total N budget, though this effect is small (<1% for the 10 days following fertilization), as NH3 emission dominates the net flux. It is estimated that 3.8% of the fertilizer N was volatilised as NH3, of which 0.05% re-condensed to form NH4NO3 particles within the lowest 2 m of the surface layer. This surface induced process would at least scale up to a global NH4NO3 formation of ca. 0.21 kt N yr−1 from NH4NO3 fertilisers and potentially 45 kt N yr−1 from NH3 emissions in general.

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Assessment of Seasonal Variability in Soil Nutrients and Its Impact on Soil Quality under Different Land Use Systems of Lower Shiwalik Foothills of Himalaya, India

Sustainability ◽

10.3390/su13031398 ◽

2021 ◽

Vol 13 (3) ◽

pp. 1398

Author(s):

Tavjot Kaur ◽

Simerpreet Kaur Sehgal ◽

Satnam Singh ◽

Sandeep Sharma ◽

Salwinder Singh Dhaliwal ◽

...

Keyword(s):

Land Use ◽

Soil Quality ◽

Surface Soil ◽

Sandy Loam ◽

Monsoon Season ◽

Soil Layer ◽

Seasonal Effects ◽

Land Use Systems ◽

Post Monsoon ◽

Significant Difference

The present study was conducted to investigate the seasonal effects of five land use systems (LUSs), i.e., wheat–rice (Triticum aestivum—Oryza sativa) system, sugarcane (Saccharum officinarum), orange (Citrus sinensis) orchard, safeda (Eucalyptus globules) forest, and grassland, on soil quality and nutrient status in the lower Satluj basin of the Shiwalik foothills Himalaya, India. Samples were analyzed for assessment of physico-chemical properties at four soil depths, viz., 0–15, 15–30, 30–45, and 45–60 cm. A total of 120 soil samples were collected in both the seasons. Soil texture was found to be sandy loam and slightly alkaline in nature. The relative trend of soil organic carbon (SOC), macro- and micro-nutrient content for the five LUSs was forest > orchard > grassland > wheat–rice > sugarcane, in the pre- and post-monsoon seasons. SOC was highly correlated with macronutrients and micronutrients, whereas SOC was negatively correlated with soil pH (r = −0.818). The surface soil layer (0–15 cm) had a significantly higher content of SOC, and macro- and micro-nutrients compared to the sub-surface soil layers, due to the presence of more organic content in the soil surface layer. Tukey’s multiple comparison test was applied to assess significant difference (p < 0.05) among the five LUSs at four soil depths in both the seasons. Principle component analysis (PCA) identified that SOC and electrical conductivity (EC) were the most contributing soil indicators among the different land use systems, and that the post-monsoon season had better soil quality compared to the pre-monsoon season. These indicators helped in the assessment of soil health and fertility, and to monitor degraded agroecosystems for future soil conservation.

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EPID-07. ACCESS TO GLIOBLASTOMA CLINICAL TRIALS FOR RURAL PATIENTS IN THE UNITED STATES FROM 2010–2020

Neuro-Oncology ◽

10.1093/neuonc/noaa215.325 ◽

2020 ◽

Vol 22 (Supplement_2) ◽

pp. ii79-ii79

Author(s):

Kathryn Nevel ◽

Samuel Capouch ◽

Lisa Arnold ◽

Katherine Peters ◽

Nimish Mohile ◽

...

Keyword(s):

United States ◽

Clinical Trials ◽

Rural Communities ◽

The United States ◽

Interventional Treatment ◽

Phase Ii Trials ◽

Treatment Trials ◽

Rural Sites ◽

Rural Patients ◽

Urban Sites

Abstract BACKGROUND Patients in rural communities have less access to optimal cancer care and clinical trials. For GBM, access to experimental therapies, and consideration of a clinical trial is embedded in national guidelines. Still, the availability of clinical trials to rural communities, representing 20% of the US population, has not been described. METHODS We queried ClinicalTrials.gov for glioblastoma interventional treatment trials opened between 1/2010 and 1/2020 in the United States. We created a Structured Query Language database and leveraged Google application programming interfaces (API) Places to find name and street addresses for the sites, and Google’s Geocode API to determine the county location. Counties were classified by US Department of Agriculture Rural-Urban Continuum Codes (RUCC 1–3 = urban and RUCC 4–9 = rural). We used z-ratios for rural-urban statistical comparisons. RESULTS We identified 406 interventional treatment trials for GBM at 1491 unique sites. 8.7% of unique sites were in rural settings. Rural sites opened an average of 1.7 trials/site and urban sites 2.8 trials/site from 1/2010–1/2020. Rural sites offered more phase II trials (63% vs 57%, p= 0.03) and fewer phase I trials (22% vs 28%, p= 0.01) than urban sites. Rural locations were more likely to offer federally-sponsored trials (p< 0.002). There were no investigator-initiated or single-institution trials offered at rural locations, and only 1% of industry trials were offered rurally. DISCUSSION Clinical trials for GBM were rarely open in rural areas, and were more dependent on federal funding. Clinical trials are likely difficult to access for rural patients, and this has important implications for the generalizability of research as well as how we engage the field of neuro-oncology and patient advocacy groups in improving patient access to trials. Increasing the number of clinical trials in rural locations may enable more rural patients to access and enroll in GBM studies.

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Assessment of Trophic Responses of a Reservoir to Seasonal and Annual Variations in Monsoon

Water ◽

10.3390/w13152117 ◽

2021 ◽

Vol 13 (15) ◽

pp. 2117

Author(s):

Su-mi Kim ◽

Hyun-su Kim

Keyword(s):

Water Quality ◽

Trophic State ◽

Monsoon Season ◽

Phytoplankton Growth ◽

Phosphorus Loading ◽

Nutrient Concentrations ◽

Trophic State Index ◽

Post Monsoon ◽

Post Monsoon Season ◽

State Index

The variations in water quality parameters and trophic status of a multipurpose reservoir in response to changing intensity of monsoon rain was investigated by applying a trophic state index deviation (TSID) analysis and an empirical regression model to the data collected in two periods from 2014 to 2017. The reservoir in general maintained mesotrophic conditions, and Carlson’s trophic state index (TSIc) was affected most by TSITP. Nutrient concentrations, particularly phosphorus, did not show strong correlations with precipitation, particularly in the period with weak monsoon, and a significant increase in total phosphorus (TP) was observed in Spring 2015, indicating the possibility of internal phosphorus loading under decreased depth and stability of water body due to a lack of precipitation. TSIChl was higher than TSISD in most data in period 1 when a negligible increase in precipitation was observed in the monsoon season while a significant fraction in period 2 showed the opposite trend. Phytoplankton growth was not limited by nutrient limitation although nutrient ratios (N/P) of most samples were significantly higher than 20, indicating phosphorus-limited condition. TSID and regression analysis indicated that phytoplankton growth was limited by zooplankton grazing in the Spring, and that cell concentrations and community structure in the monsoon and post-monsoon season were controlled by the changing intensity of the monsoon, as evidenced by the positive and negative relationships between community size and cyanobacterial population with the amount of precipitation in the Summer, respectively. The possibility of contribution from internal loading and an increase in cyanobacterial population associated with weak monsoon, in addition to potential for nutrient enrichment in the post-monsoon season, implies a need for the application of more stringent water quality management in the reservoir that can handle all potential scenarios of eutrophication.

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Efficiency of Arsenic and Iron Removal Plants (AIRPs) for Groundwater Treatment in Rural Areas of Southwest Bangladesh

Water ◽

10.3390/w13030354 ◽

2021 ◽

Vol 13 (3) ◽

pp. 354

Author(s):

Md. Aminur Rahman ◽

Sazal Kumar ◽

A. S. M. Fazle Bari ◽

Abhishek Sharma ◽

Mohammad Mahmudur Rahman

Keyword(s):

Drinking Water ◽

Cancer Risk ◽

Monsoon Season ◽

Cancer Risk Assessment ◽

Future Research ◽

Treated Water ◽

Post Monsoon ◽

Drinking Water Standard ◽

Guideline Value ◽

Removal Efficiencies

Arsenic (As) removal plants were installed in As-endemic areas of Bangladesh to remove As from well water. In many cases, these removal plants did not perform satisfactorily. This study evaluated the efficiency of 20 As and iron (Fe) removal plants (AIRPs) during pre- and post-monsoon conditions in rural Bangladesh. Results revealed that As removal efficiencies ranged from 67% to 98% and 74 to 93% during the pre- and post-monsoons periods, respectively. In the post-monsoon season As removal at individual AIRP sites was on average (4.01%) greater than in the pre-monsoon season. However, two removal plants were unable to remove As below 50 µg L−1 (Bangladesh drinking water standard) during pre-monsoon, while 11 samples out of 20 were unable to remove As below the WHO provisional guideline value of 10 µg L−1. During post-monsoon, none of the samples exceeded 50 µg L−1, but eight of them exceeded 10 µg L−1. The Fe removal efficiencies of AIRPs were evident in more than 80% samples. Although As removal efficiency was found to be substantial, a cancer risk assessment indicates that hazard quotient (HQ) and carcinogenic risk (CR) of As in treated water for adults and children are above the threshold limits. Thus, additional reductions of As concentrations in treated water are needed to further reduce the excess cancer risk due to As in drinking water. Since 55% and 40% of the AIRPs were unable to remove As < 10 µg L−1 during pre-monsoon and post-monsoon, further improvement including changes in AIRP design, regular cleaning of sludge, and periodic monitoring of water quality are suggested. Future research is needed to determine whether these modifications improve the performance of AIRPs.

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A Study on Prevalence and Seasonal Distribution of Dengue at a Tertiary Care Centre of North India

Healthline ◽

10.51957/healthline_126_2020 ◽

2020 ◽

Vol 11 (2) ◽

pp. 100-107

Author(s):

Arti Agrawal ◽

Vikas Kumar ◽

Sanjeev Kumar ◽

Neha K Mani

Keyword(s):

Monsoon Season ◽

Dengue Infection ◽

Tertiary Care ◽

Seasonal Distribution ◽

North India ◽

Care Centre ◽

Tertiary Care Centre ◽

Post Monsoon ◽

Post Monsoon Season ◽

Male Preponderance

Introduction: Dengue virus infection is a major public health issue prevalent in tropical and sub-tropical countries all over the world mostly in urban and semi-urban areas. WHO estimates about 50-100 million dengue infections worldwide every year. The present study is aimed to assess the prevalence and seasonal distribution of dengue disease during three consecutive years from 2016-2018 at a tertiary care centre of North India. Method: This is an observational retrospective study conducted on total 6,481 clinical suspected cases referred from indoor and outdoor departments of Medicine and Pediatrics of one of the medical colleges of Agra during the period from 1st January 2016 to 31st December 2018. Results: The maximum positivity was recorded in the year 2016 (16.66%), followed by 2017 (14.07%) and 2018(13.56%).Our study shows male preponderance with maximum cases in the year 2018 was recorded in the month of October (22.75%) whereas the lowest in the month of May (1.96%). Most of the cases were in the age group 0-30 years with a male preponderance. The outbreak occurred during the months of August to November indicating vector transmission in the monsoon and post-monsoon season. Conclusion: From the analysis, this study reflects that the numbers of dengue cases in 2016 were maximum and outnumbered the dengue cases among three consecutive years from 2016 to 2018. The peak in dengue positivity was observed during September to October. As this disease affects the population in the monsoon and post monsoon months therefore continuous monitoring of dengue infection is important during the post-monsoon season.

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