Quantification and assessment of hazardous mercury emission from industrial process and other unattended sectors in India: A step towards mitigation

Hazardous pollutants like Mercury (Hg) have emerged as a pressing challenge in recent times where the expanding industrial sector is regarded as the major source in developing country India. In this study, we are trying to identify all possible industrial sectors at district level to quantify Hg emission load across India for the year 2019 using IPCC methodology where the country-specific technological emission factors are used. We have included 5 major sectors out of which emission from coal combustion in thermal power plants accounts for 186.5 t/yr of Hg emission followed by non-ferrous metal production (88.3 t/yr), captive power plants (65.5 t/yr) and fly ash generation from various manufacturing industries (45.9 t/yr). A total of 459.4 t/yr of Hg is released into the ecosystem in 2019 with an uncertainty of ± 48%. This study also estimated that about 233 million people living in and around 10 km periphery of major industrial zones with as many as 17 million people residing near the 10 major hotspots are susceptible to hazardous Hg emissions directly or indirectly. This information would be quite useful in formulating future Hg emission control strategies in India. ENVIRONMENTAL IMPLICATIONS: Present study is the first-of-its-kind quantification of Hg emission load from the Industrial process and many unattended sectors over India, which will not only give an insight into potential hotspots regions across the country but also assess the population exposed to it. It will provide aid in tracking the mercury burden to match the international conventions. The findings suggest that about 233 million people are likely to be exposed to hazardous Hg emissions. It will also enlighten the government, policymakers, stakeholders and people about their mercury footprint and envision protecting the biomes and formulating future control strategies in India.

Assessment of hazardous radionuclide emission due to fly ash from fossil fuel combustion in industrial activities in India and its impact on public

Traditionally coal has been extensively used as a dominating fossil fuel in a wide range of industries due to its abundance. In India, industries like thermal power plants, cement industries, iron, and steel industries along with many captive power plants consume a huge quantity of coal each year to meet energy demand. Coal combustion releases blackish-grey colored fly ash waste is one of the most imperative sources of radionuclides like Radium (²²⁶Ra), Thorium (²³²Th), Potassium (⁴⁰K) and Uranium (²³⁸U). The estimated industrial fly ash is ∼308.416 Million Tonnes (MT) in 2019, considered as an emerging environmental problem. This study represents the first-ever radionuclide emission from Indian fly ash generated across various major industries. The results reveal that the estimated ²²⁶Ra, ²³²Th, ²³⁸U, and ⁴⁰K radionuclides were estimated to be ∼27.473 TBq, ∼44.351 TBq, ∼41.089 TBq, and ∼111.091 TBq respectively. The potential radionuclide hotspot regions across the nation are identified, which could be used as an important tool to assess its impact on the chronic exposure of millions of residents living near these sources. Cleaner or green energy could be the best alternative to combat the unseen health disaster. More effective and safe utilization of fly ash can minimize the hazardous effect of radionuclides emission.

Quantifying the high resolution seasonal emission of air pollutants from crop residue burning in India

Biomass burning, a recurring global phenomenon is also considered an environmental menace, making headlines every year in India with onset of autumn months. Agriculture is demographically the broadest economic sector and plays a significant role in the overall socio-economic fabric of India. Hence, disposal of crop residue is done mainly by burning leading to deterioration of air quality. Residue burning in parts of India is blamed for changing air quality in nearby cities. The spatial distribution of these emissions has always been a challenge due to various data constraints. We hereby present a comprehensive spatially resolved seasonal high resolution gridded (∼10 km × ∼10 km) emission inventory of major pollutants from crop residue burning source in India for the latest year 2018. The winter months contributes almost around ∼50% of total emission followed by summer (∼48%), which is the prime cause of changing air quality in nearby cities. Among all the crops; rice, wheat, maize and sugarcane accounts ∼90% of total PM₁₀ load in the country. The estimated emission for PM_2.5, PM₁₀, BC and OC, CO, NOx, SO₂, VOC, CH₄ and CO₂ are found to 990.68 Gg/yr, 1231.26 Gg/yr, 123.33 Gg/yr, 410.99 Gg/yr, 11208.18 Gg/yr, 484.55 Gg/yr, 144.66 Gg/yr, 1282.95 Gg/yr, 785.56 Gg/yr and 262051.06 Gg/yr respectively. The cropping pattern and its role in different geographic regions are analysed to identify all potential emission hotspots regions scattered across the country. The developed gridded emissions inventory is envisaged to serve as an important input to regional atmospheric chemistry transport model to better quantify its contribution in deteriorating air quality in various regions of India, paving the way to policy makers to better plan the mitigation and control strategies. The developed fundamental tool is likely to be useful for air quality management.

Establishing a link between fine particulate matter (PM2.5) zones and COVID -19 over India based on anthropogenic emission sources and air quality data

The spread of coronavirus disease of 2019 (COVID-19) pandemic around the globe is affecting people. The majority of Indian urban complexes are reeling under high emissions of deadly fine particulate matter PM_2.5 and resulting in poor air quality. These fine particles penetrate deep into the body and fuel inflammation in the lungs and respiratory tract, leading to the risk of having cardiovascular and respiratory problems, including a weak immune system. In the present study, we report the first national-scale study over India, which establishes a strong relationship between the PM_2.5 emission load and COVID-19 infections and resulting deaths. We find a significant correlation (R² = 0.66 & 0.60) between the states as well as districts having varied levels of PM_2.5 emissions with corresponding COVID-19 positive cases respectively, and R² = 0.61 between wavering air quality on a longer time scale and the number of COVID-19 related deaths till 5 November 2020. This study provides practical evidence that cities having pollution hotspot where fossil fuel emissions are dominating are highly susceptible to COVID-19 cases.

COVID-19 and environmental -weather markers: Unfolding baseline levels and veracity of linkages in tropical India

The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is rapidly spreading across the globe due to its contagion nature. We hereby report the baseline permanent levels of two most toxic air pollutants in top ranked mega cities of India. This could be made possible for the first time due to the unprecedented COVID-19 lockdown emission scenario. The study also unfolds the association of COVID-19 with different environmental and weather markers. Although there are numerous confounding factors for the pandemic, we find a strong association of COVID-19 mortality with baseline PM_2.5 levels (80% correlation) to which the population is chronically exposed and may be considered as one of the critical factors. The COVID-19 morbidity is found to be moderately anti-correlated with maximum temperature during the pandemic period (-56%). Findings although preliminary but provide a first line of information for epidemiologists and may be useful for the development of effective health risk management policies.