Diurnal rail noise measurement, analysis, and evaluation of associated health impacts on residents living in the proximity of rail track area.

In India, railway is the major transportation mode for carrying goods and people. The tracks for the movement of the rail were initially constructed in the city for the pre-eminence and expediency of the vantage of the people. Rapid modernization and increasing population in the city crammed the area around the railway tracks. Moving rail on the tracks passing through the city is not compatible, which is creating problems for the nearby residents. In the urban and suburban regions, the railway noise has become a major problem. This study was conducted to examine the perception of the physiological and psychological effects of railway noise in the nearby areas of railway stations in Delhi, India. For this purpose, 10 sites near the railway station were selected for the study. To assess the impact of railway noise pollution on the health of humans, a questionnaire survey was conducted. The data of 344 individuals were collected through the questionnaire survey and analyzed to get the perception towards railway noise. Noise level was monitored by a Sound Level Meter (SLM) and the equivalent noise level (Leq) in dB(A) was used to compute the noise pollution in three shifts, i.e., morning, noon, and evening time. Results showed that 57.65% of female and 86.11% of male respondents in the survey reported the disturbance due to railway noise. The level of noise pollution was found higher in the evening time as compared to the noon and morning period, which exceeds the limit set by the Central Pollution Control Board (CPCB) at all the monitored locations. Findings of the study show that the primary cause of the health problems is railroad noise, which is negatively impacting the health of the residents, who are living in the proximity of the rail track region. The perception survey reported that headache, sleep disturbance, irritation, and stress are common health issues among the locals residing around the railway track proximity in Delhi.

Emission performance evaluation of urban passenger car fleet through field investigation data in a megacity.

Continued improvements in living standards and the economic well-being in the megacities have led to a huge surge in vehicular density. The worst environmental outcome of the same has been persistent unsafe urban air quality, thanks to vehicular emission. Further, the existing inspection and maintenance programs, conceived to check such emission remain largely ineffective, particularly in developing countries. This is due to the absence of a thorough assessment of the vehicle's compliance with the in-use emission norms generated through reliable field investigation data. To address this gap, the present comprehensive study collected real-time tailpipe emission data from 2040 cars in Delhi, India. Exhaust emission parameters, namely, CO (carbon monoxide), HC (hydrocarbon), and SE (smoke emission), were recorded from both petrol and diesel-driven cars of private ownership, in collaboration with the emission compliance test centers. The performance of cars was assessed in terms of their compliance with the in-use BS (Bharat Stage) emission norms. The one-of-its-kind study reported the petrol cars to be highly compliant toward the BS IV norm while faring even better toward BS II for both CO and HC emissions (80-90%). The conformance to the HC norm was found to be typically better than that for CO (85-90% versus 75-80%). For the diesel-driven cars, BS III compliance levels were reported relatively better compared to BS IV (90% in the case of the former against 80% in the latter's case). Further, the study puts forward a clear indication that the in-use emission norm and maintenance status of cars have a direct and negative relationship with tailpipe emission parameters. Cars of both overseas and domestic origin have almost equal degrees of compliance with the emission norms (over 80% in any case). The study recommends the incorporation of these two critical vehicular variables, i.e., maintenance status and in-use emission standard in the emission certification policy.

An in situ exploratory analysis of diesel cars' emission: way forward on policy evaluation.

Keeping in view the significant number of diesel-driven passenger cars in the existing light motor vehicle fleet in Delhi, India, a case study on smoke emission measurement from 460 number of such cars was conducted. Smoke exhaust data was collected from the diesel cars while the vehicles presented themselves for periodic renewal of pollution under control (PUC) certification at authorized emission testing centers across Delhi, India. Along with the smoke emission, various vehicle- and engine-related aspects, supposed to affect tailpipe smoke emission, were also recorded aiming at data analysis for two datasets, namely whole and top 5 makes. The smoke density under no-loading condition in the free acceleration test mode was measured. The study reported a strong correlation between vehicle parameters, such as age, mileage, maintenance category, emission norm, and engine aspiration; and the smoke emission (R2 values for vehicle age and mileage vs. smoke emission for whole dataset = 0.872 and 0.873, respectively). Top 5 make-wise correlations fared even better (R2 for age and mileage vs. emission in the range of 0.85-0.92 and 0.86-0.93, respectively). Further, the predictive emission equations using best-fit trendlines were also developed for both datasets. Such equations may be used by the car manufacturers to adopt a suitable strategy for tuning of engine or vehicle as such, to retain their cars in the longer state of compliance to the extant emission norms. Further, the study recommends to include vehicle mileage as an important factor in upgrading the existing inspection and maintenance programs, especially in the developing countries.

Ultrafine particle number concentration and its size distribution during Diwali festival in megacity Delhi, India: Are 'green crackers' safe?

Since the air pollution and noise generated from fireworks are related to air quality and human health, the regulatory bodies had implemented the eco-friendly "Green Crackers" in megacity Delhi, India, to celebrate Diwali 2019 with the permission of a specific time slot (8:00 p.m. to 10:00 p.m.). The present study was conducted on a residential educational institute campus to evaluate the particle number size distribution (PNSD) of green cracker emissions. During the Diwali event period, the high peak of particle number concentration (PNC) reached 1.7 × 105 # cm-3 with a geometric mean diameter (GMD) of ∼44 nm. The average PNC increment on Diwali day was 138% and 97% compared to pre (October 26, 2019) and post (October 28, 2019) Diwali period, respectively, including 468%, 142%, 65%, 75% on pre-Diwali and 485%, 110%, 32%, 26% on post- Diwali 2019 period in terms of Nucleation mode (10 nm < Dp < 20 nm), Small Aitken mode (20 nm < Dp < 50 nm), Large Aitken mode (50 nm < Dp < 100 nm), and Accumulation mode (100 nm < Dp < 1000 nm), respectively. Unlike traditional firework emissions, green crackers had a high UFP/Ntotal ratio of 0.72, including Nucleation mode-0.35, Aitken mode-0.30, and Accumulation mode 0.35, distinguishing it from other pre-and post-Diwali particle number size distribution-dN/dlogDp curves. These observations indicate that green crackers emit more particles with smaller diameters than traditional crackers. Recommendations for using green crackers for Diwali celebrations may be an option if lower size-diameter particle emission could be controlled by changing the material composition of the green crackers. More research studies need to be conducted to assess atmospheric emissions of green crackers and their health impacts to evaluate whether they are better or worse than traditional crackers.

Evaluation of water quality using water quality index, synthetic pollution index, and GIS technique: a case study of the river Gomti, Lucknow, India.

The river Gomti, one of India's most polluted rivers, passing through Lucknow, Uttar Pradesh, India, has been selected for this study. An attempt has been made to assess its water quality status by combining the water quality index (WQI) and synthetic pollution index (SPI). Further, the data integration with the geographic information system (GIS) along with twelve water quality parameters for the seven sampling stations (S1 to S7) over 5 years (2013-2017) has been performed. The study area showed a variation of WQI from 78.993 to 249.388 and SPI from 0.868 to 2.096 in 5 years. The map interpolated through GIS revealed that the WQI falls into the category of severely polluted (76-100) and unsuitable for human consumption (> 100), while SPI lies in the category of moderately polluted (0.5-1.0) and severally polluted (1.0-3.0). The BOD and COD were found to significantly influence the WQI and SPI scores. With the constant release of waste effluents into the river, all selected parameters increased from S1 to S7. Based on the study, effective wastewater management is immediately required to improve water quality and support any sustainable river restoration plan.

Assessment of the effect of the judicial prohibition on firecracker celebration at the Diwali festival on air quality in Delhi, India.

Diwali (the festival of lights and crackers) is celebrated grandly, resulting in a significant drop in the city's air quality. To study the impact of the judicial prohibition in Delhi to improve air quality, a comprehensive and comparative analysis was conducted over two consecutive years, namely 2015-2016 (when no significant regulations on the sale or usage of firecrackers were imposed) and 2017-2018 (when radically different regulations were implemented). Data on PM10, PM2.5, NOx, and CO were analysed, and their trends and levels with various regulations in place were compared. In 2017, the concentrations of PM10, PM2.5, NOx, and CO were reduced by 50%, 50%, 71%, and 64%, respectively, compared to 2016. However, in 2018, there was an increase of 32% in PM10 and PM2.5 concentrations, as well as a 25% increase in CO concentrations, with the exception of NOx, which decreased to 25% on Diwali day. The data was also examined in conjunction with the entire timeline of the various court rulings and regulations imposed in Delhi. The questionnaire survey study revealed that, despite the legislation in place, ambient air quality continued to deteriorate, necessitating a deeper dive into the policy's structure and implementation to fine-tune its feasibility and applications. Air pollution-related health effects were recognized by 82% of participants. Despite this, only 13% of people were observed without a mask, and only 12% of people were aware of green crackers as of 2018. To combat this deteriorating situation, the national capital must enact radical and well-thought-out legislation and regulations governing firecrackers, as well as raise public awareness amongst its citizens.

Comparative study on air quality status in Indian and Chinese cities before and during the COVID-19 lockdown period.

Amidst COVID-19 pandemic, extreme steps have been taken by countries globally. Lockdown enforcement has emerged as one of the mitigating measures to reduce the community spread of the virus. With a reduction in major anthropogenic activities, a visible improvement in air quality has been recorded in urban centres. Hazardous air quality in countries like India and China leads to high mortality rates from cardiovascular diseases. The present article deals with 6 megacities in India and 6 cities in Hubei province, China, where strict lockdown measures were imposed. The real-time concentration of PM2.5 and NO2 were recorded at different monitoring stations in the cities for 3 months, i.e. January, February, and March for China and February, March, and April for India. The concentration data is converted into AQI according to US EPA parameters and the monthly and weekly averages are calculated for all the cities. Cities in China and India after 1 week of lockdown recorded an average drop in AQIPM2.5 and AQINO2 of 11.32% and 48.61% and 20.21% and 59.26%, respectively. The results indicate that the drop in AQINO2 was instantaneous as compared with the gradual drop in AQIPM2.5. The lockdown in China and India led to a final drop in AQIPM2.5 of 45.25% and 64.65% and in AQINO2 of 37.42% and 65.80%, respectively. This study will assist the policymakers in devising a pathway to curb down air pollutant concentration in various urban cities by utilising the benchmark levels of air pollution.

A Retrospective Clinical Audit of Bracket Failure among Patients Undergoing Orthodontic Therapy.

OBJECTIVE: Bonding failure is a problem in orthodontic therapy and has been associated with orthodontic emergencies and delayed treatment time. The aim of this study is to determine the bracket failure rate among patients undergoing orthodontic therapy. MATERIALS AND METHODS: From the archives of posttreatment records, 200 total cases were selected, out of which 122 cases had detailed treatment records. Cases with incomplete records, large restorations, or enamel aberrations were excluded from the study. Descriptive statistics were applied to obtain sample characteristics, and a chi-square test was applied to compare the bracket failure between different categories. RESULT: Out of the 122 samples enrolled in the study, female and male patients comprised 71% and 29%, respectively. Class I malocclusions were the most common problem (56%), followed by Class II (41%) and Class III (3%). The bracket failure rate was 3.43%, and 32% of the patients had an incidence of bracket failure. There was no significant difference in bracket failure among genders (p=0.344), malocclusion types (p=0.191), or operators (p=0.188). The maxillary left quadrant was the most common site of bracket failure, followed by the mandibular right quadrant. CONCLUSION: Bracket failure is relatively uncommon. It is not affected by the gender or age of the patient or by malocclusion type. The maxillary left and mandibular right quadrants are the most common sites of bracket failure.

Analysis of Interarch Tooth Size Relationship in Nepalese Subjects with Normal Occlusion and Malocclusions.

INTRODUCTION: A proportional relationship between the maxillary and mandibular teeth size is required for achieving good finish with proper overjet and overbite postorthodontic treatment. The aims and objectives of this study were to determine the anterior and overall Bolton's ratio in Nepalese population, to compare Bolton's ratio between subjects with normal occlusion, Class I malocclusion, and Class II malocclusion, to compare these results with Bolton's norm, and to determine the frequency of clinically significant (beyond 2 SD) tooth size discrepancy compared to Bolton's norm. MATERIALS AND METHODS: The study models of the subjects with normal occlusion and Angle's Class I malocclusion and Class II malocclusion and fulfilling the inclusion criteria were retrieved from department archives. An electronic digital caliper was used to measure mesiodistal tooth size of the maxillary and mandibular teeth anterior to the second molars. The study sample of 120 study models consisted of the normal occlusion group (n = 31), Class I malocclusion group (n = 47), and Class II malocclusion group (n = 42). These measurements were then used to obtain Bolton's ratio in three groups of subjects. Bolton's ratio of study groups was compared with each other and with Bolton's original ratio. RESULTS: The differences in tooth size ratio of the study groups were not significant statistically, when the groups were compared on the basis of malocclusion or gender. Statistically significant differences were exclusively observed between the study groups and Bolton's original sample for the anterior ratio. The frequency of the clinically significant tooth size ratio discrepancy was lower for the overall ratio (9.1%) compared to the anterior ratio (22.5%). CONCLUSIONS: Bolton's analysis on the Nepalese population sample shows that there was no significant difference observed on the anterior and overall tooth size ratios when these were compared based on Angle's malocclusion classes or gender. The clinically significant anterior tooth size discrepancy was more prevalent than that of the overall ratio.