Increasing Health Threat to Greater Parts of India Due to Crop Residue Burning

Rice crop residue burning during mid-October to November every year is becoming a serious health threat because of increased burning by farmers in the states of Punjab, Haryana, and western Uttar Pradesh in northern India. Crop residue burning started in the late 1980s with the start of mechanised harvesting in Punjab. Farmers found burning to be an economical way of cleaning crop stalk residues that are left over by mechanised harvesters. In doing so, farmers ignore the impact of this practice on health and air quality in the cities located in the Indo-Gangetic Plains. In the winter season, the severity of this problem increases as dispersion of smoke plumes is slowed down because of cold temperatures, whereas during the summer season the problem does not exist because of fast dispersion of plumes from burning. The practice of crop residue burning that started in Punjab has slowly spread to other adjoining states in northern India. We have found that the impact of crop residue burning on air quality is not restricted to cities in the Indo-Gangetic Plains alone, but is spreading to the far eastern parts of the Indo-Gangetic Plains and over central and southern parts of India, including parts of Bihar, Jharkhand, West Bengal, Madhya Pradesh, Chhattisgarh, Odisha, Telangana, and Maharashtra. We used diverse climate datasets derived from different NASA space platforms as well as global climate models and ground stations for our analysis

Assessment of Indoor & Outdoor Black Carbon Emissions Rural Areas of Indo-Gangetic Plain: Seasonal Characteristics, Source Apportionment and Radiative Forcing

Black Carbon (BC) has been widely recognized as the second largest source of territorial and global climate change as well as a threat to human health. There has been serious concern of BC emission and its impact in Indo-Gangetic Plains (IGP) due to the use of biomass and fossil fuels for cooking, transportation and industrial activities. An attempt has been made to study indoor (Liquefied Petroleum Gas- LPG & Traditional cookstoves users households) and outdoor concentrations; seasonal characteristics; radiative forcing and source of apportionment of BC in three districts (Sitapur, Patna and Murshidabad) of IGP during January to December 2016. The seasonal concentrations of BC in LPG (traditional cookstoves) users households were 3.79 ± 0.77 μgm−3 (25.36 ± 5.01 μgm−3) during the winter; 2.62 ± 0.60 μgm−3(16.36 ± 3.68 μgm−3) during the pre-monsoon; 2.02 ± 0.355 μgm−3(8.92 ± 1.98 μgm−3) during the monsoon and 2.19 ± 0.47 μgm−3(15.17 ± 3.31 μgm−3) during the post-monsoon seasons. However, the outdoor BC concentrations were 24.20 ± 4.46, 19.80 ± 4.34, 8.87 ± 1.83, and 9.14 ± 1.84 μgm−3 during winter, pre-monsoon, monsoon and post-monsoon seasons respectively. The negative radiative forcing (RF) at the surface suggests a cooling effect while a warming effect appears to be occurring at the top of the atmosphere. The atmospheric forcing of BC and aerosols also show a net warming effect in the selected study areas. The analysis of BC concentrations and fire episodes indicated that the emissions from biomass burning increases the pollution concentration. The backward trajectory analysis through the HYSPLIT model also suggests an additional source of pollutants during winter and pre-monsoon seasons from the northwest and northern region in the IGP

Crop Residue Burning in Northern India: Increasing Threat to Greater India

Crop residue burning (CRB) is a recurring problem, during October–November, in the northwestern regions (Punjab, Haryana, and western Uttar Pradesh) of India. The emissions from the CRB source regions spread in all directions through long-range transport mechanisms, depending upon the meteorological conditions. In recent years, numerous studies have been carried out dealing with the impact of CRB on the air quality of Delhi and surrounding areas, especially in the Indo-Gangetic Basin (also referred to as Indo-Gangetic Plain). In this paper, we present detailed analysis using both satellite- and ground-based sources, which show an increasing impact of CRB over the eastern parts of the Indo-Gangetic Basin and also over parts of central and southern India. The increasing trends of finer black carbon particles and greenhouse gases have accelerated since the year 2010 onward, which is confirmed by the observation of different wavelength dependent aerosol properties. Our study shows an increased risk to ambient air quality and an increased spatiotemporal extent of pollutants in recent years, from CRB, which could be a severe health threat to the population of these regions

Effect of Lockdown on HCHO and Trace Gases over India during March 2020

COVID-19 is one of the deadly Epidemics that has impacted people living in more than 200 countries. In order to mitigate the impact of COVID-19, India observed total lockdown in the first phase for a period of 21 days (24 March–13 May 2020), so that social distancing is maintained. However, this sudden decision severely affected the normal life of people. The air quality improved due to lockdown, some relaxation was given in different cities and within some areas in the city where the people were not affected by COVID-19. In this paper, we discuss results of detailed analysis of trace gases (HCHO, NO2, SO2, CH4, CO and O3) and particulate matter concentration using satellite and ground data in major metropolitan cities of India during 10–31 March, 2020 and compared with the same period in the year 2019, to study the impact of total lockdown. Our analysis suggests, pronounced qualitative changes in HCHO, NO2, SO2, CH4, CO, O3and PM2.5 concentration during complete lockdown period in the month of March 2020. We did not consider the period after 31 March 2020 to avoid influence of anthropogenic sources since the Government made relaxation in the lockdown periods after 31 March 2020

Dynamic Characteristics of Aerosol Optical Properties over Dibrugarh City in the North-Eastern Indian Region during 2018–2021

Aerosols play an important role in the earth\u27s environment across the globe through their involvement in various earth system cycles. The change in the aerosol properties may cause short and long-term impacts, the knowledge of such changes is useful in the estimation of the pollution sources of any region. We have carried out the analysis of the aerosols\u27 optical and radiative properties using AERONET station data from 2018 to 2021 in Dibrugarh City. The higher Aerosol Optical Depth (AOD) values during winter and pre-monsoon months indicate high anthropogenic activities, and biomass burning in Dibrugarh. The impact of various sources and daily meteorological parameters help in understanding the diurnal variations of the AOD, Ångström Exponent (AE), and column water (CW). Fine aerosol fractions dominate the aerosol volume, but sometimes the long-range transport of dust affects aerosol properties during pre-monsoon months (MAM). MODIS-derived AOD and AERONET AOD values show a good correlation, with R2 = 0.68. The highest volume of the aerosols reaches up to 0.11 µm3 µm–2 during pre-monsoon months, whereas it lies below 0.05 µm3 µm–2 in other seasons. SSA values indicate the presence of scattering aerosols but in 2020, a sudden decline in the SSA values shows a strong rise in the absorbing aerosols. Throughout the study period (2018–2021), the positive radiative forcing indicates a rise in atmospheric heating

Physico-Chemical Properties and Deposition Potential of PM2.5 during Severe Smog Event in Delhi, India

The present work studies a severe smog event that occurred in Delhi (India) in 2017, targeting the characterization of PM2.5 and its deposition potential in human respiratory tract of different population groups in which the PM2.5 levels raised from 124.0 µg/m3 (pre-smog period) to 717.2 µg/m3 (during smog period). Higher concentration of elements such as C, N, O, Na, Mg, Al, Si, S, Fe, Cl, Ca, Ti, Cr, Pb, Fe, K, Cu, Cl, P, and F were observed during the smog along with dominant organic functional groups (aldehyde, ketones, alkyl halides (R-F; R-Br; R-Cl), ether, etc.), which supported potential contribution from transboundary biomass-burning activities along with local pollution sources and favorable meteorological conditions. The morphology of individual particles were found mostly as non-spherical, including carbon fractals, aggregates, sharp-edged, rod-shaped, and flaky structures. A multiple path particle dosimetry (MPPD) model showed significant deposition potential of PM2.5 in terms of deposition fraction, mass rate, and mass flux during smog conditions in all age groups. The highest PM2.5 deposition fraction and mass rate were found for the head region followed by the alveolar region of the human respiratory tract. The highest mass flux was reported for 21-month-old (4.7 × 102 µg/min/m2), followed by 3-month-old (49.2 µg/min/m2) children, whereas it was lowest for 21-year-old adults (6.8 µg/min/m2), indicating babies and children were more vulnerable to PM2.5 pollution than adults during smog. Deposition doses of toxic elements such as Cr, Fe, Zn, Pb, Cu, Mn, and Ni were also found to be higher (up to 1 × 10−7 µg/kg/day) for children than adults

Coupling between Land–Ocean–Atmosphere and Pronounced Changes in Atmospheric/Meteorological Parameters Associated with the Hudhud Cyclone of October 2014

India is vulnerable to all kinds of natural hazards associated with land, ocean, biosphere, atmosphere, and snow/glaciers. These natural hazards impact large areas and the population living in the affected regions. India is surrounded by ocean on three sides and is vulnerable to cyclonic activities. Every year cyclones hit the east and west coasts of India, affecting the population living along the coasts and infrastructure and inland areas. The extent of the affected inland areas depends on the intensity of the cyclone. On 12 October 2014, a strong cyclone “Hudhud” hit the east coast of India that caused a high degree of devastation along the coast. The impact of this cyclone was seen up to the Himalayan region. Detailed analysis of satellite and ground data show a strong coupling between land-ocean-atmosphere associated with the Hudhud cyclone. The contrast between land and ocean temperature was found to be closely related with the formation of the cyclone in the ocean and its movements towards land. Pronounced changes in the ocean, land, atmospheric, and meteorological parameters with the development of the cyclone and its landfall have been observed. Changes in total column ozone (TCO), relative humidity (RH), and volume mixing ratio of CO (CO VMR), water mixing ratio (H2O MMR), surface latent heat flux (SLHF), and aerosol optical properties derived from satellite data show characteristic behavior of the Hudhud cyclone

Variability and linkages of aerosol properties between sub-urban and high altitude environments in Northern India

Atmospheric aerosol particles are linked to visibility reduction and adverse health effects, and radiation balance of the Earth— directly by reflecting and absorbing solar radiation and indirectly by influencing the cloud properties and processes and, possi-bly, by changing the heterogeneous chemistry of reactive gaseous species. Atmospheric aerosols are the most uncertain driver of global climate change. The South‒Asian region has been increasingly recognized as one of the global hotspots of aerosols; and Indo Gangetic Plains (IGP) is one among them with complex geography, heterogeneity in sources and varying atmospheric dynamics. These factors make IGP’s aerosol and pollution very difficult to characterize. So far, long-term regional observations of aerosol properties have been scarce in this region, but argued necessary in order to bring the knowledge of regional and global distribution of aerosols further. In this context, regional studies of aerosol properties their dynamics and atmospheric processes are very important areas of investigation to better estimate the climatic importance of submicron aerosol particles. Moreover regional studies over IGP-Himalayas domain are inevitable to know how trans-Himalayan valleys are acting as conduits for aerosol and pollution transport from the plains to the Himalayas. Therefore, in this thesis we studied these issues by applying basic to state-of-the-art instrumentation in two different envi-ronments, plains—Gual Pahari, and Himalayan foothills— Mukteshwar; to obtain physical and optical properties of submi-cron particles. Additionally, we used meteorological parameters, emissions and process modelling to determine local and region-al scale transport of atmospheric aerosols. The work carried out as part of the thesis infers four main conclusions, 1) Simultaneous long-term measurements at both the environments in Northern India region are useful to establish linkages between sub-urban environment and high altitude sites. One site represents a source region, while another characterize as a receiver site of atmospheric pollutants; 2) A distinct cycle of aerosol properties, both seasonal and diurnal, is present and provides information of driving factors of aerosol variability at both the sites; 3) The contribution of regional sources seem to dominate over the local /sub-urban sources, in the IGP region bounda-ry layer; 4) Aerosol properties and specific humidity “passive tracer” based analysis clearly reveal that the mountainous terrain sites are under the influence of air from the plains due to convective transport processes enhanced by local and mesoscale topography. The results presented in this thesis are particularly useful, first, when examining the linkages of aerosol properties variability between two different environments. The second, in determining for instance local versus regional influences, and pollutants reaching high altitude sites which can be explained by boundary layer dynamics processes, especially in the mountain terrain where the modelled mixing layer depths have uncertainties. This work outlines future direction of multi-points measurements on vertical profile of atmospheric particles and local boundary layer over mountainous terrain where the atmospheric structure becomes much more complicated. Additionally, investigations including isotope-based analysis and modelling work over the Himalayan region are desirable to be able to describe better the transport of atmospheric aerosols from IGP to high altitudes and further up to Himalayan ice-pack and glaciers where aerosol deposition could have serious environmental impacts

Ambient air quality and human health in India

700 million Indians have used solid fuels in their homes for the last 30 years, contributing substantially to air pollutant emissions. The Indian economy and industrial, power generation, and transport sectors have grown considerably over the last decade, increasing emissions of air pollutants. These air pollutant emissions have caused present-day concentrations of ambient PM2.5 and O3 in India to be amongst the highest in the world. Exposure to this air pollution is the second leading risk factor in India, contributing one-quarter of the global disease burden attributable to air pollution exposure. Air pollutant emissions are predicted to grow extensively over the coming years in India. Despite the importance of air quality in India, it remains relatively understudied, and knowledge of the sources and processes causing air pollution is limited. This thesis aims to understand the contribution of different pollution sources to the attributable disease burden from ambient air pollution exposure in India and the effects of future air pollution control pathways. The attributable disease burden from ambient PM2.5 exposure in India is substantial, where large reductions in emissions will be required to reduce the health burden due to the non-linear exposure-response relationship. The attributable disease burden from ambient O3 exposure is larger than previously thought and is of similar magnitude to that from PM2.5 in the future. Key sources contributing to the present day disease burden from ambient PM2.5 and O3 exposure are the emissions from the residential combustion of solid fuels, land transport, and coal combustion in power plants. The attributable disease burden is estimated to increase in the future due to population ageing and growth. Stringent air pollution control pathways are required to provide critical public health benefits in India in a challenging environment. A key focus should be to reduce the combustion of solid fuels