Substantial Changes in Selected Volatile Organic Compounds (VOCs) and Associations with Health Risk Assessments in Industrial Areas during the COVID-19 Pandemic.

During the COVID-19 pandemic, governments in many countries worldwide, including India, imposed several restriction measures, including lockdowns, to prevent the spread of the infection. COVID-19 lockdowns led to a reduction in gaseous and particulate pollutants in ambient air. In the present study, we investigated the substantial changes in selected volatile organic compounds (VOCs) after the outbreak of the coronavirus pandemic and associations with health risk assessments in industrial areas. VOC data from 1 January 2019 to 31 December 2021 were collected from the Central Pollution Control Board (CPCB) website, to identify percentage changes in VOC levels before, during, and after COVID-19. The mean TVOC levels at all monitoring stations were 47.22 ± 30.15, 37.19 ± 37.19, and 32.81 ± 32.81 µg/m3 for 2019, 2020, and 2021, respectively. As a result, the TVOC levels gradually declined in consecutive years due to the pandemic in India. The mean TVOC levels at all monitoring stations declined from 9 to 61% during the pandemic period as compared with the pre-pandemic period. In the current study, the T/B ratio values ranged from 2.16 (PG) to 26.38 (NL), which indicated that the major pollutant contributors were traffic and non-traffic sources during the pre-pandemic period. The present findings indicated that TVOC levels had positive but low correlations with SR, BP, RF, and WD, with correlation coefficients (r) of 0.034, 0.118, 0.012, and 0.007, respectively, whereas negative correlations were observed with AT and WS, with correlation coefficients (r) of -0.168 and -0.150, respectively. The lifetime cancer risk (LCR) value for benzene was reported to be higher in children, followed by females and males, for the pre-pandemic, pandemic, and post-pandemic periods. A nationwide scale-up of this study's findings might be useful in formulating future air pollution reduction policies associated with a reduction in health risk factors. Furthermore, the present study provides baseline data for future studies on the impacts of anthropogenic activities on the air quality of a region.

Temporary reduction in VOCs associated with health risk during and after COVID-19 in Maharashtra, India.

A novel coronavirus has affected almost all countries and impacted the economy, environment, and social life. The short-term impact on the environment and human health needs attention to correlate the Volatile organic compounds (VOCs) and health assessment for pre-, during, and post lockdowns. Therefore, the current study demonstrates VOC changes and their effect on air quality during the lockdown. The findings of result, the levels of the mean for total VOC concentrations were found to be 15.45 ± 21.07, 2.48 ± 1.61, 19.25 ± 28.91 µg/m3 for all monitoring stations for pre-, during, and post lockdown periods. The highest value of TVOCs was observed at Thane, considered an industrial region (petroleum refinery), and the lowest at Bandra, which was considered a residential region, respectively. The VOC levels drastically decreased by 52%, 89%, 80%, and 97% for benzene, toluene, ethylbenzene, and m-xylene, respectively, during the lockdown period compared to the previous year. In the present study, the T/B ratio was found lower in the lockdown period as compared to the pre-lockdown period. This can be attributed to the complete closure of non-traffic sources such as industries and factories during the lockdown. The Lifetime Cancer Risk values for all monitoring stations for benzene for pre-and-post lockdown periods were higher than the prescribed value, except during the lockdown period. Supplementary Information: The online version contains supplementary material available at 10.1007/s10874-022-09440-5.

Efficacy of dual use of Tc-99m-pertechnetate and Tc-99m-tetrofosmin scintigraphy for the assessment of thyroid nodules.

INTRODUCTION: Radioisotope methods have shown to be useful in the non-invasive diagnosis of thyroid nodules over the past years. The present prospective study aims to evaluate the efficacy of gamma imaging using single and dual tracer using Tc-99m pertechnetate and Tc-99m tetrofosmin for evaluation and management of thyroid nodules. METHODS: Dynamic (perfusion) imaging was performed after injecting 148-185 MBq (4-5 mCi) of Tc-99m pertechnetate followed by static imaging. A second, dynamic (perfusion) imaging study within same week was performed with 296-370MBq (8-10mCi) of Tc-99m tetrofosmin on same group of patients followed by early and delayed images. Results of radionuclide perfusion scan from both studies were compared qualitatively with postsurgical histopathology or fine needle aspiration cytology (FNAC). RESULTS: Total 65 nodules in 50 patients were included in the study. With single tracer, the specificity and accuracy of Tc-99m pertechnetate was 23% and 45% and for Tc-99m tetrofosmin scan was 40% and 49%. When dual tracers were evaluated for the same group of patients, the specificity was 56% and accuracy was 55%. CONCLUSION: Dual Tracer technique with Tc-99m pertechnetate and Tc-99m tetrofosmin could be helpful in selecting nodules need surgical intervention. This technique can be used for convenient and rapid diagnostic evaluation of thyroid nodules non-invasively. We suggest a combination of fine needle aspiration biopsy and dual use of Tc-99m-pertechnetate and Tc-99m-tetrofosmin as a routine diagnostic approach to thyroid nodules.

Role of Tc99m-Sestamibi scintimammography in assessing response to neoadjuvant chemotherapy in patients with locally advanced breast cancer.

INTRODUCTION: Neoadjuvant chemotherapy (NACT) is an essential part of multi-disciplinary management of locally advanced breast cancer (LABC). In this study, we aimed at evaluating the role of Tc99m-Sestamibi scinti-mammography in assessing response to NACT in patients with LABC. MATERIALS AND METHODS: A total of 42 patients of histologically proven LABC were enrolled in this prospective study. Imaging was performed according to pre-defined protocol at 10 min and 4 h after injection of tracer before the start of chemotherapy, 48 h after start of chemotherapy and at the end of chemotherapy. Quantitative parameters were obtained by calculating the ratio of activity in a region of interest (ROI) drawn over the tumor and the same sized ROI drawn in corresponding location in contra lateral breast. RESULTS: At the end of chemotherapy, 6 patients achieved complete response, 25 achieved partial response, 11 had stable disease. Various retention indices calculated at baseline, 48 h after first cycle of NACT, and at the end of chemotherapy showed statistically significant difference in responders and non-responders. By using 84.05 as cut-off point for retention index (RI) of tumor calculated 48 h after first cycle of NACT (RI 2) the positive predictive value and negative predictive value, were found to be 41.9% and 72.7% respectively in differentiating responders from non-responders. CONCLUSION: Early response assessment in patients with LABC to NACT with Tc99m-Sestamibi scintimammography is feasible and if confirmed by further studies can find routine clinical application in differentiating responders from non-responders.