Particle and heavy metal accumulation by two plant species in a coal mining area of Odisha, India.

Mining activities lead to severe particulate matter (PM) pollution that consequently has a detrimental effect on ecosystem. A study was therefore conducted in a coal mining area of Odisha, India with an objective to assess the particulate matter pollution on the basis of differential aerodynamic size (PM10 and PM2.5) of the particles, the metallic (Zn and Fe) composition, and also to evaluate their nature of deposition on two identified plant species. The results suggest a significant variation in particle and heavy metal fractions in the ambient air of different sites (p < 0.05). Fe dominated the finer particle (PM2.5) fraction while Zn dominated the coarser counterpart (PM10) in the ambient air. When evaluated for the particle and heavy metal deposition on leaf surface, Shorea robusta performed better in trapping the coarser particles (PM10) while Holarrhena floribunda was found to be an efficient scrubber of the finer particles (PM2.5). Fe deposition on surface of leaves was comparatively higher than Zn irrespective of plant species or size fractions. Therefore, it is concluded that both S. robusta and H. floribunda should be planted in a schematic manner to tackle the particulate pollution in coal mining areas.

Altitude governs the air pollution tolerance and heavy metal accumulation in plants.

Plant response to changing air pollution is a function of various factors including meteorology, type of pollutants, plant species, soil chemistry, and geography. However, the impact of altitude on plant behavior has received little attention to date. A study was therefore conducted to evaluate the impact of altitude on the air pollution tolerance index (APTI), heavy metal accumulation, and deposition in plant species. The results favor the hypothesis of a definite impact of altitude on biochemical and heavy metal accumulation in plants. While a significant decline (p < 0.05) in the relative water content (RWC), APTI, and heavy metal accumulation with increasing altitude was evident in the studied plant species, the behavior of ascorbic acid, leaf extract pH, chlorophyll content, and the particle heavy metal deposition was erratic and did not display any statistically significant differences. The metal accumulation index was in the following order: Ni > Zn > Cu > Pb > Cd > Co. Similarly, the particle heavy metal deposition on the leaf surface (µg/cm2) displayed significant species variability (p < 0.05) and was in the order: Cu (0.303) > Pb (0.301) > Ni (0.269) > Zn (0.241) > Cd (0.044) > Co (0.025). The accumulated heavy metal and RWC showcased a significant positive correlation with the APTI, suggesting the dominant role of RWC in the plant's tolerance against air pollution in an altitudinal gradient. Future studies on the role of micrometeorological conditions in altering APTI may be fruitful in ascertaining these postulations.

Soil organic carbon fractionation of spoiled and unspoiled soils under different land use and land cover systems.

Alteration in land use and land cover is the key factor affecting the soil carbon fractions and its distribution. A study was carried out to estimate the carbon fractions in soils of agricultural, forest and pasture lands in two different areas separated on the basis of industrial activities (spoiled and unspoiled) to get an insight on the long-term soil carbon storage potential. The results showed that the mean values of the total organic carbon (TOC) and various fractions are significantly different between the land use types (p < 0.05). Irrespective of the land uses, the forest land showed significantly higher TOC (7.97) than agricultural land (6.98) and pasture lands (6.68). Further, evaluation of carbon management index (CMI) indicated that forest lands had highest CMI value compared to the other land uses. The spoiled area had significantly higher TOC and carbon fractions than their respective counterparts in the unspoiled area (p < 0.05) due to the negative industrial impact on soil biological processes. The PCA separates the sources of different carbon fractions and revealed an association of N (nitrogen) and K (potassium) with VL (very labile) and L (labile) fractions and the association of P (phosphorous) with stable R (recalcitrant) form. Therefore, it can be inferred from the present study that alterations in land use not only result in soil quality degradation but also trigger a reduction in potential for long term soil C sequestration.

Seedling growth and physicochemical transformations of rice nursery soil under varying levels of coal fly ash and vermicompost amendment.

Fly ash is an inevitable by-product from the coal-fired power plants in many developing countries including India that needs safe, timely and productive disposal. The addition of fly ash alters physicochemical properties of soil and hence could be used as a soil conditioner or modifier along with the appropriate level of vermicompost to support plant growth. Several studies have focalized sole use of fly ash and vermicompost in agricultural production systems lacking information on combined application effects. This work was carried out at Chiplima in the district of Sambalpur, Odisha, India, to ascertain the best suited combination of native soil, fly ash and vermicompost (from farmyard manure) for rice nursery based on the changing physicochemical properties and seedling growth. The experiment consisting of 21 treatment combinations of soil, fly ash and vermicompost at 0%, 20%, 40%, 60%, 80% and 100% by weight was laid out in a factorial complete randomized design with three replications. Fly ash and vermicompost at moderate concentrations significantly ameliorated the physical properties, viz., porosity, bulk and particle densities, water holding capacity, infiltration rate and the capillary rise of water in rice nursery soil that ultimately resulted in vigorous rice seedlings at 40 DAS through beneficial soil biota as well as better root and shoot development. The porosity, water holding capacity and infiltration rate significantly increased with the addition of vermicompost while fly ash addition substantially reduced them. Fly ash and vermicompost in moderate quantities smothered soil chemical properties like electrical conductivity and organic carbon that increased the availability of N, P, K, B, S and Zn. The pH did not differ significantly due to treatment effects owing to a marginal difference in pH of the substrates, whereas electrical conductivity increased significantly with only marginal addition of fly ash to vermicompost. Considering the economic feasibility and environmental impacts, 40% soil + 20% fly ash + 40% vermicompost may be recommend to the farmers for wet rice nursery raising and also for remediating the coal fly ash in agricultural production system.

Effect of fly ash and vermicompost amendment on rhizospheric earthworm and nematode count and change in soil carbon pool of rice nursery.

Fly ash application to the soil at lower doses with organic substrates has been advocated by researchers due to its beneficial soil ameliorative properties. But its xenobiotic effects in presence of vermicompost have not yet been studied fully. The hypothesis of the present study was to ascertain the ameliorative effects of fly ash and vermicompost amendment on the soil nematode and earthworm count and change in the soil carbon pool of the rice nursery. The native soil, fly ash, and vermicompost at 0%, 20%, 40%, 60%, 80%, and 100% combinations (by weight) in triplicate were investigated under a factorial complete randomized design. The fly ash affected the earthworm survivability to an extent that the earthworms could not survive in fly ash of concentration greater than 20%. On the contrary, the concentration of vermicompost positively influenced the earthworm and nematode count in the rice rhizosphere. The population of nematodes viz. Rhabditis terricola and Dorylaimids in the rhizosphere of rice nursery was positively linked with the vermicompost concentration, while fly ash had antagonistic effects. The absence of nematodes and earthworms at a higher concentration of fly ash could be linked to the xenobiotic effects of fly ash. However, on mild addition of fly ash and vermicompost (20% each) to the native soil, the carbon stock increased positively to the maximum extent due to the larger surface area of fly ash and its xenobiotic effects limiting respirational carbon loss.

Seasonality, atmospheric transport and inhalation risk assessment of polycyclic aromatic hydrocarbons in PM2.5 and PM10 from industrial belts of Odisha, India.

This study is the first attempt to assess the presence of 16 priority polycyclic aromatic hydrocarbons (PAHs) enlisted by the US Environmental Protection Agency in PM2.5 and PM10 from industrial areas of Odisha State, India. During 2017-2018, bimonthly sampling of PM10 and PM2.5 was carried out for 24 h in the industrial and mining areas of Jharsuguda and Angul in Odisha during the pre-monsoon, monsoon, and post monsoon seasons. Highest mean concentration of ∑16PAHs in PM2.5 was observed during the post monsoon (170 ng/m3) period followed by pre-monsoon (48 ng/m3) and monsoon (16 ng/m 3) periods, respectively. A similar trend of ∑16PAHs was also observed in PM10 with higher levels observed during post monsoon (286 ng/m3) followed by pre-monsoon (81 ng/m3) and monsoon (27 ng/m3) seasons. Diagnostic ratios and principal component analysis suggested diesel, gasoline and coal combustion as the major contributors of atmospheric PAH pollution in Odisha. Back trajectory analysis revealed that PAH concentration was affected majorly by air masses originating from the northwest direction traversing through central India. Toxic equivalents ranged between 0.24 and 94.13 ng TEQ/m3. In our study, the incremental lifetime cancer risk ranged between 10-5 and 10-3, representing potential cancer risk.

de novo transcriptome profile of two earthworms Lampito mauritii and Drawida calebi during regeneration.

Earthworms have remarkable ability to regenerate its tail and head region. However the list of genes expressed in this regeneration process has been less explored baring a few species. The current study involves the de novo transcriptome sequencing of intact tail and regenerating tail (15 day post amputation) of earthworms belonging to two different genera Lampito mauritii (Kinberg, 1867) and Drawida calebi (Gates, 1945). This study contains one de-novo and one reference based transcriptome analysis each from one genus of two earthworm genera. From a total of 119.92 million (150 × 2) reads, 112.95 million high quality adapter free reads were utilized in analysis. Assembly of high-quality reads was performed separately for Lampito mauritii (LM sample) and Drawida calebi (DC sample) that resulted in 66368 and 1,61,289 transcripts respectively. About 25.21% of transcripts were functionally annotated for DC sample and 38.27% for LM samples against Annelida sequences. A total of 239 genes were expressed exclusively in regenerated tissue compared to intact sample in DC whereas about 241 genes were exclusively expressed in regenerated tissue of LM compared to its intact sample. Majority of genes in Drawida and Lampito were dedicated to immune response, maintenance of cytoskeleton, resisting oxidative stress and promoting neuronal regeneration for cell-cell communication during tail regeneration.

Meteorology drives ambient air quality in a valley: a case of Sukinda chromite mine, one among the ten most polluted areas in the world.

The ambient air quality (AAQ) assessment was undertaken in Sukinda Valley, the chromite hub of India. The possible correlations of meteorological variables with different air quality parameters (PM10, PM2.5, SO2, NO2 and CO) were examined. Being the fourth most polluted area in the globe, Sukinda Valley has always been under attention of researchers, for hexavalent chromium contamination of water. The monitoring was carried out from December 2013 through May 2014 at six strategic locations in the residential and commercial areas around the mining cluster of Sukinda Valley considering the guidelines of Central Pollution Control Board (CPCB). In addition, meteorological parameters viz., temperature, relative humidity, wind speed, wind direction and rainfall, were also monitored. The air quality data were subjected to a general linear model (GLM) coupled with one-way analysis of variance (ANOVA) test for testing the significant difference in the concentration of various parameters among seasons and stations. Further, a two-tailed Pearson's correlation test helped in understanding the influence of meteorological parameters on dispersion of pollutants in the area. All the monitored air quality parameters varied significantly among the monitoring stations suggesting (i) the distance of sampling location to the mine site and other allied activities, (ii) landscape features and topography and (iii) meteorological parameters to be the forcing functions. The area was highly polluted with particulate matters, and in most of the cases, the PM level exceeded the National Ambient Air Quality Standards (NAAQS). The meteorological parameters seemed to play a major role in the dispersion of pollutants around the mine clusters. The role of wind direction, wind speed and temperature was apparent in dispersion of the particulate matters from their source of generation to the surrounding residential and commercial areas of the mine.