16 US EPA priority polycyclic aromatic hydrocarbons (PAHs) were quantified in total suspended ambient particulate matter (TSPM) collected from an industrial site in Agra (India) using gas ...chromatography. The major industrial activities in Agra are foundries that previously used coal and coke as fuel in cupola furnaces. These foundries have now switched over to natural gas. In addition, use of compressed natural gas has also been promoted and encouraged in automobiles. This study attempts to apportion sources of PAH in the ambient air and the results reflect the advantages associated with the change of fuel. The predominant PAHs in TSPM include high molecular weight (HMW) congeners BghiP, DbA, IP, and BaP. The sum of 16 priority PAHs had a mean value of 72.7 ± 4.7 ng m−3. Potential sources of PAHs in aerosols were identified using diagnostic ratios and principal component analysis. The results reflect a blend of emissions from diesel and natural gas as the major sources of PAH in the city along with contribution from emission of coal, coke, and gasoline.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Since their invention, conventional plastics have contributed in the betterment of the society in numerous ways, nevertheless their deleterious impacts on the natural ecosystems and living creatures ...is irrefutable. The management of plastic waste generated is a concern worldwide and therefore quest for the plastic alternates or bioplastics is imminent. Here, we explore the suitability of keratin from human hair waste as the candidate for the production of bioplastic films. Keratin extracted from hair was used to form the films or 'kertics' by solution casting and curing. Ethanediol, di-ethylene glycol and tri-ethylene glycol were used as novel plasticizers along with glycerol in the keratin film formation. The film prepared were of the thickness 190-220 µm with the area of about 4.54 ± 0.2 cm
. Water uptake by G100, ED100, DEG100 and TEG100 films was recorded to be 4.8, 6.2, 4.9 and 6.3% respectively. FESEM analysis revealed that the films with 100 µl of 1% glycerol (G100) had continuous surface morphology except few pits of 0.1 µm, also DEG100 and TEG100 films have the most uniform surface morphology with no evident pits, holes or bulges. X-ray diffractogram showed characteristic peak of keratin at 19.5° and the d-spacing value observed was 0.45 nm. The FTIR studies suggested that the films retained keratin in non degraded form, and possessed the characteristic Amide peaks. The films were also found to be biodegradable in studies involving keratinophilic fungal strain of A. oryzae. These films could found potential applications in packaging industry, disposable items manufacturing and biomaterial generation.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
In the present study, pollutants levels from 24^(th) March-31^(st) May in 2020 were compared with the same time period in 2019 to estimate the impact of lockdown on air pollutants levels in 39 ...different cities of India (including 10 Indian cities considered among the world's 20 most polluted cities). Data for air pollutants was obtained from the Central Pollution Control Board (CPCB) which was statistically analyzed. Tropospheric NO_2 column retrieved from Ozone Monitoring Instrument (OMI) were compared between 2019 and 2020 to compare the NO_2 levels. Impact of lockdown measures on Ghaziabad which is the world's most polluted city and Patiala which showed maximum reduction during the lockdown period in the present study was studied in detail. After the implementation of lockdown measures, air pollution decreased but with substantial variation among pollutants. The most significant reduction was observed for nitrogen dioxide (NO_2) (3-79%) and carbon monoxide (CO) (2-61%), pollutants which are mainly related to traffic emissions. Ozone (O_3) showed a mixed trend with increasing levels at some cities which may be attributed to lower titration of O_3 by NO. Maximum reduction observed in PM_(10) and PM_(2.5) was 58 and 57%, respectively during the lockdown period in 2020 as compared to the previous year. Air quality of the cities also improved in 2020. During the lockdown period in 2020, AQI of only 15% of cities was in the 'Unhealthy' category (151-200) while in 2019, 56% of cities were in the 'Unhealthy' category. In Ghaziabad and Patiala all the pollutants showed significant reduction after lockdown implementation except O_3. Diurnal patterns of PM_(10), PM_(2.5), CO and NO_2 showed lower values during lockdown period in 2020 with less distinct bimodal patterns as compared to 2019. The present study provides evidence that widespread implementation of air pollution measures can result in immediate air quality benefits.
Climate change plus ozone pollution is a lethal combination that adversely affects human health, agriculture productivity, ecosystems, and the world economy. Currently, there is a growing concern ...that climate change may aggravate ozone pollution even after reducing anthropogenic precursor source activities. Part of it may be due to temperature-enhanced natural precursor emissions of ozone, increased stratospheric–tropospheric exchange of ozone, more frequent periods with meteorologically stagnant conditions favouring pollution build-up, changes in wetland methane emissions, and enhanced concentrations of atmospheric carbon dioxide. The quantification of climate change and ozone levels involves complex chemical, radiative, biogenic, and transport processes and feedback that are difficult to fully comprehend. Further, the fact that ozone is a short-lived climate forcer and a potent greenhouse gas provides a feedback loop and makes climate-ozone links even more multifaceted. This review examines the up-to-date understanding of the processes regulating tropospheric ozone from regional to global scales and the associated climate connections. We explore the recent findings in ozone precursor emissions from natural sources, ozone formation chemistry, its transport on hemispheric scales, future plausible ozone concentrations in different shared socioeconomic pathways, and changes in the radiative forcing of ozone. The review demonstrates the challenges and limitations associated with climate-ozone linkages and their incorporation in models, which are due to uncertainties in magnitude and signs of projected precursor emissions in response to future climate change and also due to the difference in models.
The present study reports one year data of organic carbon (OC) and elemental carbon (EC) concentrations in total suspended particulates (TSP) at a suburban site. TSP concentrations varied from 80.0 ...to 396.2μgm−3 with an annual average of 216.3±80.7μgm−3. OC ranged from 2.5 to 91.0μgm−3 with an annual average of 25.4±19.8μgm−3 while EC ranged from 0.3 to 15.2μgm−3 with an annual average concentration of 3.3±3.0μgm−3. OC and EC contributed about 11.8% and 1.5% of TSP. Annual average of the OC/EC ratio was 8.7±6.5. Seasonally, OC and EC follow the trend: winter>post monsoon>summer>monsoon. High correlations were observed between OC and EC with correlation coefficient (r) ranging from 0.92 to 0.97 in the four seasons. OC concentrations in summer, winter and post monsoon were approximately three times higher than in monsoon. Total carbonaceous aerosols (TCA) accounted for 20.8±17.2% of TSP. In winter, percent contribution of TCA to TSP was high (33.2±24.4) as compared to other seasons. K+/EC and K+/OC ratios indicate biomass burning to be a source of carbonaceous aerosol at this site. Secondary organic carbon (SOC) fraction, estimated using the EC tracer method, was calculated to be 49.0 to 55.0% of OC at Dayalbagh. In winter, primary organic carbon (POC) concentration was almost twice the SOC concentration.
► TSP concentration was high in summer as compared to winter, monsoon and post monsoon. ► Average OC and EC concentrations were 25.4±19.8 and 3.3±3.0μgm−3. ► OC and EC showed high concentrations in winter due to increased heating sources. ► High OC/EC ratio (average=8.7±6.5) was observed due to biomass burning.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Airborne fine particulate matter PM2.5 was collected from May 2010 to December 2012 at Agra, a semi-urban site in north-central India. PM2.5 samples were chemically characterized for 16 polycyclic ...aromatic hydrocarbons by gas chromatography. PM2.5 values varied between 8.4 and 300 µg m(-3) with 55% of the values exceeding the 24h average NAAQ (National Ambient Air Quality) standard of 65 µg m(-3). Particle associated total PAHs ranged between 8.9 and 2,065 ng m(-3) with a mean value of 880.8 ng m(-3) during the sampling period, indicated an alarming level of pollution in Agra. Strong relationship was observed between PM2.5 and total PAHs (r=0.88), suggesting an increasing PAHs concentration with increasing PM2.5 mass. On a mass basis 3-ring and 4-ring compounds were dominant. Seasonal variation in mass concentration of PAHs was observed with high concentration in winter followed by post monsoon, summer and monsoon. This seasonal pattern could be attributed to differences in source strength and climatic conditions. PAHs concentration were also observed to be negatively correlated with the meteorological parameters i.e. temperature, solar radiation, relative humidity and wind speed. Molecular diagnostic ratios revealed vehicular emissions and combustion of wood and coal as the probable sources. The estimated carcinogenicity of PAHs in terms of benzo(a)pyrene toxic equivalency (BaPTEQ) was assessed and confirmed that benzoapyrene was the dominant PAH contributor (3.64%). Health risk of adults and children by way of PAHs was assessed by estimating the lifetime average daily dose (LADD) and corresponding incremental lifetime cancer risk (ILCR) using USEPA guidelines. The assessed cancer risk (ILCR) was found to be within the acceptable range (10(-6)-10(-4)). The particulate samples indicated the presence of both base pair and frame shift mutagens using TA98 and TA100 strains of Salmonella typhimurium. Enhanced mutagenic response was observed in the presence of enzyme activation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Ozone pollution is a growing problem in many developing countries posing challenges not only to air quality but also affecting agricultural productivity and human well-being. This is the first study ...in the Indo-Gangetic Plain exploring how the spatial variation and severity of tropospheric ozone affect both wheat yield and all-cause mortality. We estimated that ozone-related cumulative crop production loss for wheat in selected districts of IGP was 3.4 million tonnes during the study period (2019–2021), which amounted to 923 million USD. The production-weighted Relative Yield Loss (RYL) for wheat in the IGP was 9.3 % in 2019, 12.8 % in 2020, and 11.3 % in 2021. The losses incurred in 2021 could contribute to fulfilling the wheat requirements of 11.4 million people. We also assess the health and economic gains resulting from the attainment of the World Health Organization Air Quality Guidelines (WHO AQG) for ozone concentrations. It is estimated that interventions that achieve AQG would have averted 11,407 premature deaths in 2021 translating into an impressively large health and economic gain. The annual benefits in 2021 totaled to 34 billion USD. We observe that Uttar Pradesh experienced the highest losses, both in terms of crop damage and premature deaths. Our study observes that implementing policies to prepone the planting of wheat enhances food security by mitigating yield losses. Mitigating the health impact of ambient ozone necessitates a reduction in anthropogenic emissions and to attain this objective, we propose adopting an exposure-integrated source reduction approach.
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•Ozone pollution poses severe threat to food security and human health.•RYL for wheat 11.3 % in IGP for 2021•Economic Cost of 34 billion USD due to crop and health loss in 2021
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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