ABSTRACT
The analysis of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) gene copy numbers in wastewater samples can provide quantitative information on Coronavirus Disease-19 (COVID-19) cases within a sewer catchment. However, many wastewater-based epidemiology (WBE) studies have neglected virus decay during the wastewater transportation process in sewers while back-calculating COVID-19 prevalence. Among various sewer condition parameters, wastewater temperature and dilution by fresh/saltwater infiltration may result in a significant change to the virus decay, in terms of both infectivity and Ribonucleic Acid (RNA). This paper reviewed the literature to identify and discuss the effects of temperature and water types (i.e., wastewater, freshwater, and seawater) on coronavirus decay based on the decay rate constants that were collected from published papers. To evaluate the importance of virus decay, a sensitivity analysis was then conducted with decay rates of SARS-CoV-2 RNA based on a WBE back-calculation equation. Finally, the decay rates of coronavirus in wastewater were also compared with those of other viruses to further understand the difference among virus species. The decay of SARS-CoV-2 RNA was found to be less impacted by temperature variation than viable coronaviruses. Nevertheless, WBE back-calculation was still sensitive to the RNA decay rates increased by warm wastewater (i.e., over 26 °C), which could lead to a two-times higher relative variance in estimated COVID-19 prevalence, considering the wastewater temperature variation between 4 and 37 °C in a sewer catchment with a 12-h hydraulic retention time. Comparatively, the sensitivity of the WBE estimation to the enveloped SARS-CoV-2 was greater than nonenveloped enteric viruses, which were less easily degradable in wastewater. In addition, wastewater dilution by stormwater inflow and accompanied cold weather might alleviate the decay of coronavirus infectivity, thus increasing the potential risk of COVID-19 transmission through wastewater. Overall, this paper aims to better understand the impact of in-sewer processes on coronavirus decay and its potential implications for WBE. The outcome could quantitatively inform WBE and improve awareness of the increased risk of COVID-19 infection via wastewater during heavy rainfall events. Given the identified scarcity of data available for coronavirus decay in salt water or with chemical additions, future research on the fate of SARS-CoV-2 subjected to chemical dosing for sewer or wastewater treatment plant operations is recommended. © 2023 by the authors.
ABSTRACT
Several epidemiological studies have examined the effect of temperature on health, such as tuberculosis (TB). Previous researches have used temperature data from local station sites but the temperature in an area is spatially variable. For example temperature in the urban area is normally higher than in the rural area because of the urban heat island. Satellite remote sensing data can provide area information and is, therefore useful to quantify the effect of environmental hazards on health in a wider region. To study the impact of temperature on TB, this study estimates Land Surface Temperature (LST) using Landsat 8 data in Yogyakarta City, Indonesia from 2016 to 2020 and analyzes the relationship between temperature and TB cases. The LST estimates were first verified by the temperature data obtained from the Meteorological, Climatological, and Geophysical Agency. Tuberculosis cases from 2016 until 2020 were collected from Public Health Office. The correlation patterns have also been examined before and after the COVID-19 pandemic. The result shows that the satellite-derived LST reasonably matches the ground measurement, and a negative correlation between TB cases and LST can be recognized: the cases number is higher in low LST while the cases number is lower when LST is higher. This can be explained that the increase of TB case number in the lower temperature is because ultraviolet radiation kills bacterium, which impedes the spread of TB in dwellings. However, this correlation cannot be observed after COVID-19 outbreak. The number of TB cases in 2020 (during COVID-19 pandemic) is generally lower than the previous year (2016-2019, before COVID-19 pandemic) in the study area. This study suggests that social restriction policy may potentially affect the spread of TB and thus shows the irrelevant relationship between LST and TB cases during COVID-19 pandemic. © ACRS 2021.All right reserved.
ABSTRACT
During the year 2020, the world witnessed the terror and threat of a new type of infection. The Corona Virus Disease (COVID19) was first identified in Wuhan, China, and spread worldwide. The infection was categorized as an acute respiratory syndrome and can cause causality amongst humans if timely treatment is not available. India is amongst the countries worst hit by COVID19. A country with a dense population and diversified weather conditions in different states is dealing with a highly contagious infection. Irregular ups and downs in the cases can be due to the changing temperature all around the year. This study aims to identify the relation between the temperature and the number of cases. For this purpose, the paper calculates the correlation coefficient between the temperate and the number of cases for different states of India. The study aims to analyze if the temperature of these states impacts the daily cases detected. A null hypothesis is subjected to the Pearson Product Moment Correlation Coefficient test for analysis, and the results are analyzed. © 2021 IEEE.