Traffic-related metals in urban snow cover: A review of the literature data and the feasibility of filling gaps by field data collection.

A literature search on traffic related metals in polluted urban snow revealed a significant volume of references representing a substantive knowledge base. The frequently studied metals in urban snow included Zn, Cu, Pb, Cd and Ni. However, comparing metal concentrations across studies proves to be a complex effort due to the variations in site-specific factors among studies, such as traffic intensity, pavement conditions, hydrometeorological conditions, and research method aspects, such as sampling equipment and frequency, and laboratory analytical methods. The literature review indicated that among the commonly studied metals, Zn and Cu indicated potential environmental concerns, and that there was a lack of data on the occurrence and accumulation in snow of antimony (Sb), tungsten (W), and platinum group elements (PGEs). To partly mitigate this knowledge gap, a field study of these elements was carried out by sampling urban roadside snow at six locations with various land use and traffic intensities, focusing on accumulation of these elements in snowbanks along roadways. The results indicated that traffic related activities are the sources of PGEs, W and Sb in roadside snowbanks, as the concentrations of these metals increased with increasing traffic intensity. The mean concentrations of the studied metals followed this descending order: W (0.4 (Reporting limit-RL)-987 µg/l) > Sb (0.1 RL-33.2 µg/l) > Pd (0.02 (RL)-0.506 µg/l) > Rh (0.02 (RL)-0.053 µg/l). In laboratory melted snow, both W and Sb were mostly in the particulate-bound phase, with <25 % in the dissolved phase. For sites with metal concentrations above the detection limit, the regression analysis indicated linear trends in unit area deposition rates of W with time (snow age), described by R2 = 0.94.

Microplastics (MPs) in urban roadside snowbanks: Quantities, size fractions and dynamics of release.

The microplastics (MP) pollution has been receiving high attention in recent years, because of the massive amounts of plastics it contributes to the environment. Tyre wear and road wear particles (TWP and RWPs) were identified as major sources of MPs, but the observed data on these particles in urban snow deposits and snowmelt is scarce. To contribute to remediation of this situation, a study designed to quantify TWPs and RWPs in urban roadside snowbanks, and assess the MP occurrence in three size fractions, was conducted in the Luleå and Umeå municipalities in Northern Sweden. TWPs and RWPs were determined in three size fractions: 50-100 µm, 100-300 µm, and ≥300 µm, and their release from melting snow was investigated in the laboratory under controlled conditions. Among the MPs identified in snow and the associated snowmelt samples, a majority consisted of both types of particles (T&RWPs) with an average of 20,000 ± 48,000 number/L, whereas other MPs (fibres, fragments, flakes, and films of plastic) were much less plentiful with an average concentration of 24 ± 16 number/L. The largest proportion of T&RWPs was detected in the size fraction 50-100 µm (around 80%), and the smallest proportion was in the fraction ≥300 µm (about 2%). Of the T&RWPs, about 85% were black bitumen particles (RWPs), composed of bitumen, mineral material and polymer modifiers, and 15% were tyre wear particles (TWPs) composed of rubber. The laboratory snow melting experiments demonstrated that urban snow stored MPs, which were eventually released during snowmelt. The ultimate fate of released MPs would depend on snowmelt drainage; it may either drain away from the road pavement and infiltrate into the ground, or enter the road gutter and be conveyed to storm sewers discharging to the receiving waters.

A cross-sectional study of COVID-19 outbreak in Indian population.

Background: Presently India is the second most populous country in the world with an estimated population of 1.4 billion people and has recently been affected by COVID-19 pandemic and subsequent mutant viral outbreak. To date, India has administered its population with over 1.30 billion cumulative doses of COVID-19 vaccine. The consequences of COVID-19 vaccination on the outbreak in India has not been reported until now. Therefore, we probed to assess the impact of COVID-19 outbreak in India from December 2019 to December 2021. Methods: Indian COVID-19 related data were extracted from "ourworldindata.org" and "cowin.gov.in" databases. The incidence rate of COVID-19 per million people was calculated and other parameters such as new cases, positive rate, reproduction rate, new death and stringency index values were extracted from the database for statistical analysis. Results: Data indicate that the COVID-19 positive rate declined as the number of vaccinations rose over time. The Pearson correlation values between new cases and the cumulative percentage of vaccination or the percentage of fully vaccinated population showed no correlation (P < 0.01). COVID-19 vaccination has significantly decreased the R-value and positive rate of SARS-CoV-2 in India (P < 0.01). Furthermore, containment measures showed no correlation with the incidence rate of SARS-CoV-2 in India which may be in contradictory to the global trends. Conclusion: Vaccination against COVID-19 was efficacious in the control of the SARS-CoV-2 outbreak and the decrease in the positive rate. Further, the containment measures had no effect on the spread of COVID-19 infection in India, thus far.