Efficient control of air pollution through plants, a cost-effective alternative: studies on Dalbergia sissoo Roxb

Quantitative assessment and mitigation measures of air pollution from crematoria in NCT of Delhi

The modernization of crematoria and replacement of existing fuel requirements for better air quality is a key challenge in view of the associated religious beliefs in India where conventional open pyre funeral practices are followed. Unlike developed nations, the lack of appropriate site selection criteria, combustion efficient crematorium oven designs, and pollution control devices at these facilities necessitates formulation of appropriate policy measures to reduce emissions. The existing practices do not address such localized sources that affects the micro air pollution patterns owing to their marginal contribution in the total air pollution load of the city. The present study is thus an attempt to estimate emissions from 51 cremation grounds identified in NCT of Delhi. The study considers both particulate and gaseous pollutants which are released due to burning of fuels like wood, CNG, and cow dung. It is estimated that cremation activities contributed 393 tons/year of PM_2.5, 142 tons/year of NO_x, 29 tons/year of SO₂, and 2686 tons/year of CO in year 2019. The maximum load was emitted from Central district as only Nigambodh Ghat crematoria receives on an average 60 bodies per day. Furthermore, air quality impact zone around crematoria has been demarcated using dispersion modelling considering crematorium with minimum and maximum number of bodies burnt in a day. The study also suggests control measures for reduction of pollution from cremation activities and delineates a buffer zone that could aid policymakers in establishing a site selection criterion to prevent the immediate population from likely exposure.

Selecting Biomonitors of Atmospheric Nitrogen Deposition: Guidelines for Practitioners and Decision Makers

Environmental pollution is a major threat to public health and is the cause of important economic losses worldwide. Atmospheric nitrogen deposition is one of the most significant components of environmental pollution, which, in addition to being a health risk, is one of the leading drivers of global biodiversity loss. However, monitoring pollution is not possible in many regions of the world because the instrumentation, deployment, operation, and maintenance of automated systems is onerous. An affordable alternative is the use of biomonitors, naturally occurring or transplanted organisms that respond to environmental pollution with a consistent and measurable ecophysiological response. This policy brief advocates for the use of biomonitors of atmospheric nitrogen deposition. Descriptions of the biological and monitoring particularities of commonly utilized biomonitor lichens, bryophytes, vascular epiphytes, herbs, and woody plants, are followed by a discussion of the principal ecophysiological parameters that have been shown to respond to the different nitrogen emissions and their rate of deposition.

Response of plant reflectance spectrum to simulated dust deposition and its estimation model

To quantitatively reflect the relationship between dust and plant spectral reflectance. Dust from different sources in the city were selected to simulate the spectral characteristics of leaf dust. Taking Euonymus japonicus as the research object. Prediction model of leaf dust deposition was established based on spectral parameters. Results showed that among the three different dust pollutants, the reflection spectrum has 6 main reflection peaks and 7 main absorption valleys in 350-2500 nm. A steep reflection platform appears in the 692-763 nm band. In 760-1400 nm, the spectral reflectance gradually decreases with the increase of leaf dust coverage, and the variation range was coal dust > cement dust > pure soil dust. The spectral reflectance in 680-740 nm gradually decreases with the increase of leaf dust coverage. In the near infrared band, the fluctuation amplitude and slope of its first derivative spectrum gradually decrease with the increase of leaf dust. The biggest amplitude of variation was cement dust. With the increase of dust retention, the red edge position generally moves towards short wave direction, and the red edge slope generally decreases. The blue edge position moved to the short wave direction first and then to the long side direction, while the blue edge slope generally shows a decreasing trend. The yellow edge position moved to the long wave direction first and then to the short wave direction (coal dust, cement dust), and generally moved to the long side direction (pure soil dust). The yellow edge slope increases first and then decreases. The R2 values of the determination coefficients of the dust deposition prediction model have reached significant levels, which indicated that there was a relatively stable correlation between the spectral reflectance and dust deposition. The best prediction model of leaf dust deposition was leaf water content index model (y = 1.5019x - 1.4791, R2 = 0.7091, RMSE = 0.9725).