Performance-based protocol for selection of economical portable sensor for air quality measurement.

An effective micro-level air quality management plan requires high-resolution monitoring of pollutants. India has already developed a vast network of air quality monitoring stations, both manual and real time, located primarily in urban areas, including megacities. The air quality monitoring network consists of conventional manual stations and real time Continuous Ambient Air Quality Monitoring Stations (CAAQMS) which comprise state-of-the-art analysers and instruments. India is currently in the early stages of developing and adopting economical portable sensor (EPS) in air quality monitoring systems. Protocols need to be established for field calibration and testing. The present research work is an attempt to develop a performance-based assessment framework for the selection of EPS for air quality monitoring. The two-stage selection protocol includes a review of the factory calibration data and a comparison of EPS data with a reference monitor, i.e. a portable calibrated monitor and a CAAQMS. Methods deployed include calculation of central tendency, dispersion around a central value, calculation of statistical parameters for data comparison, and plotting pollution rose and diurnal profile (peak and non-peak pollution measurement). Four commercially available EPS were tested blind, out of which, data from EPS 2 (S2) and EPS 3 (S3) were closer to reference stations at both locations. The selection was made by evaluating monitoring results, physical features, measurement range, and frequency along with examining capital cost. This proposed approach can be used to increase the usability of EPS in the development of micro-level air quality management strategies, other than regulatory compliance. For regulatory compliance, additional research is needed, including field calibration and evaluating EPS performance through additional variables. This proposed framework may be used as starting point, for such experiments, in order to develop confidence in the use of EPS.

Three-dimensional printing in the field of oral and maxillofacial surgery.

Advanced imaging techniques and modalities coupled with computer-assisted surgical planning and simulation has been in use in the field of medicine. However, it is worth noting that it is now being frequently used for the evaluation and exploration of the craniofacial structures. It had gained ingress in the planning as well as forecasting of the surgical outcomes of oral and maxillofacial surgical interventions. Numerous surgical guides and devices which are tailor-made can be fabricated using three-dimensional (3D) printing technology. The article is intended to put forth an overview of 3D printing technology and its applications in the field of oral and maxillofacial surgery.

Role of general anesthetic agents in postoperative nausea and vomiting: A review of literature.

Postoperative nausea and vomiting (PONV) is considered to be the most unpleasant experience associated with surgery and is believed to be one of the most common reasons for poor patient satisfaction in the postoperative period. It also results in prolonged hospitalization and increased use of resources such as intravenous fluids and drug supplements along with prolonged medical attention, all of which have psychological and financial implications. In addition to this, PONV can result in aspiration, laryngospasm, dehydration, electrolyte disturbances, gastric bleeding, increased intracranial pressure, increased intraocular pressure, and wound dehiscence particularly when the surgical intervention is performed through an intraoral approach. It is a well-known fact that there are many etiological factors as well as predisposing factors for PONV. Hence, this review is intended to evaluate as an individual factor what the role was played by the anesthetic agents used for GA in the incidence of PONV.

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 PM2.5, 142 tons/year of NOx, 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.

Identification of air pollution hotspots in urban areas - An innovative approach using monitored concentrations data.

Critical assessment of spatio-temporal variations in pollution levels is a crucial step for identifying and prioritizing air pollution hotspots (APH) in urban areas. There is no universally accepted methodology for defining and delineating air pollution hotspot which can be source-specific, pollutant-specific and time-specific. The present research article is an attempt to develop a protocol for identifying APH for any pollutant within a city where-in three criteria-based innovative methodology has been derived. The three criteria are frequency of exceedance (% of days), scale of exceedance and consistency in exceedance (consecutive number of days) to the specified standards that need to be met continuously for at least three years. The suggested methodology has been applied on a three-year database (2018-2021) of 37 continuous ambient air quality stations to identify PM2.5 specific APH. The analysis indicates 11 APH in April, 9 in May, 2 in June and almost the entire city during the October-February months. Given prioritization of implementation of control actions, the identified APH during summer has been further physically examined to map source activity types and their suitability for ambient air quality monitoring stations as per the guidelines. The APH can be the priority areas for the implementation of control actions by urban local bodies. The management of air pollution at these priority areas would be more effective instead of city-scale management practice, which is difficult to implement and monitor.

Understanding COVID-19 transmission, health impacts and mitigation: timely social distancing is the key.

COVID-19 is a highly infectious disease caused by SARS-CoV-2, first identified in China and spread globally, resulting into pandemic. Transmission of virus takes place either directly through close contact with infected individual (symptomatic/asymptomatic) or indirectly by touching contaminated surfaces. Virus survives on the surfaces from few hours to days. It enters the human body through nose, eyes or mouth. Other sources of contamination are faeces, blood, food, water, semen etc. Parameters such as temperature/relative humidity also play an important role in transmission. As the disease is evolving, so are the number of cases. Proper planning and restriction are helping in influencing the trajectory of the transmission. Various measures are undertaken to prevent infection such as maintaining hygiene, using facemasks, isolation/quarantine, social/physical distancing, in extreme cases lockdown (restricted movement except essential services) in hot spot areas or throughout the country. Countries that introduced various mitigation measures had experienced control in transmission of COVID-19. Python programming is conducted for change point analysis (CPA) using Bayesian probability approach for understanding the impact of restrictions and mitigation methods in terms of either increase or stagnation in number of COVID-19 cases for eight countries. From analysis it is concluded that countries which acted late in bringing in the social distancing measures are suffering in terms of high number of cases with USA, leading among eight countries analysed. The CPA week in comparison with date of lockdown and first reported case strongly correlates (Pearson's r = - 0.86 to - 0.97) to cases, cases per unit area and cases per unit population, indicating earlier the mitigation strategy, lesser the number of cases. The overall paper will help the decision makers in understanding the possible steps for mitigation, more so in developing countries where the fight against COVID-19 seems to have just begun.

Corona virus disease bring a new challenge for the dentistry: A review.

An outbreak of coronavirus disease 2019 (COVID-19) caused by the 2019 novel coronavirus (SARS-CoV-2) began in the city of Wuhan in China and has widely spread worldwide. While human strains of coronavirus (CoV) are associated with about 15% of cases of the common cold, the SARS-CoV-2 may present with varying degrees of severity, from flu-like symptoms to death. It is currently believed that this deadly CoV strain originated from wild animals at the Huanan market in Wuhan, a city in Hubei province. Bats, snakes, and pangolins have been cited as potential carriers based on the sequence homology of CoV isolated from these animals and the viral nucleic acids of the virus isolated from SARS-CoV-2 infected patients. Common clinical signs of the infection comprises of respiratory symptoms in the form of fever, cough, shortness of breath, and breathing difficulties. In more severe cases, infection results in pneumonia, severe acute respiratory syndrome, kidney failure, and even death. Standard recommendations advocated to prevent spread of infection consist of frequent hand washing, covering mouth and nose when coughing and sneezing. This article, based on our experience and relevant guidelines and research, introduces essential knowledge about CoV in dental settings and provides recommended management protocols for dental practitioners affected areas.

Assessment of the effectiveness of policy interventions for Air Quality Control Regions in Delhi city.

Government has implemented various scattered and un-quantified control actions in Delhi city to reduce the air pollution levels; however, it still exceeds the National Ambient Air Quality Standards (NAAQS). The present study has been designed to assess the air quality status, identify Air Quality Control Region (AQCR), and evaluate control strategies in the city. Out of eight selected locations, ambient PM10, PM2.5, and NO2 concentrations were found exceeding the daily as well as annual standards at selected AQCR with peak levels during post-monsoon than winter and summer. Anand Vihar was found to be most polluted and thus, selected as an AQCR. AERMOD performed satisfactorily in predicting pollutant concentration during winter and summer having an index of agreement in the range 0.54-0.80. PM10 and PM2.5 can be reduced substantially by increasing frequency of efficient mechanized cleaning of roads and sprinkling of water on the roads. Progressive decrease in NO2 concentrations can be achieved by restricting entry of truck in the study area through alternate path. The cumulative impact of all selected control strategies indicates a substantial decrease in air pollution within AQCR. The study also suggests a policy framework to manage the urban air quality through local scale air quality guidelines.

Urban local air quality management framework for non-attainment areas in Indian cities.

Increasing urban air pollution level in Indian cities is one of the major concerns for policy makers due to its impact on public health. The growth in population and increase in associated motorised road transport demand is one of the major causes of increasing air pollution in most urban areas along with other sources e.g., road dust, construction dust, biomass burning etc. The present study documents the development of an urban local air quality management (ULAQM) framework at urban hotspots (non-attainment area) and a pathway for the flow of information from goal setting to policy making. The ULAQM also includes assessment and management of air pollution episodic conditions at these hotspots, which currently available city/regional-scale air quality management plans do not address. The prediction of extreme pollutant concentrations using a hybrid model differentiates the ULAQM from other existing air quality management plans. The developed ULAQM framework has been applied and validated at one of the busiest traffic intersections in Delhi and Chennai cities. Various scenarios have been tested targeting the effective reductions in elevated levels of NOx and PM2.5 concentrations. The results indicate that a developed ULAQM framework is capable of providing an evidence-based graded action to reduce ambient pollution levels within the specified standard level at pre-identified locations. The ULAQM framework methodology is generalised and therefore can be applied to other non-attainment areas of the country.

The influence of odd-even car trial on fine and coarse particles in Delhi.

The odd-even car trial scheme, which reduced car traffic between 08.00 and 20.00 h daily, was applied from 1 to 15 January 2016 (winter scheme, WS) and 15-30 April 2016 (summer scheme, SS). The daily average PM2.5 and PM10 exceeded national standards, with highest concentrations (313 µg m-3 and 639 µg m-3, respectively) during winter and lowest (53 µg m-3 and 130 µg m-3) during the monsoon (June-August). PM concentrations during the trials can be interpreted either as reduced or increased, depending on the periods used for comparison purposes. For example, hourly average net PM2.5 and PM10 (after subtracting the baseline concentrations) reduced by up to 74% during the majority (after 1100 h) of trial hours compared with the corresponding hours during the previous year. Conversely, daily average PM2.5 and PM10 were higher by up to 3-times during the trial periods when compared with the pre-trial days. A careful analysis of the data shows that the trials generated cleaner air for certain hours of the day but the persistence of overnight emissions from heavy goods vehicles into the morning odd-even hours (0800-1100 h) made them probably ineffective at this time. Any further trial will need to be planned very carefully if an effect due to traffic alone is to be differentiated from the larger effect caused by changes in meteorology and especially wind direction.