Analysis of the Effect and Role of Indoor Environmental Quality in the COVID-19 Transmission

Infectious diseases such as COVID-19 have some risk factors. One of the most important factors is the environment. This research focused on risk factors concerning the house environment. This study aimed to evaluate the parameters of the 'healthy house' environment in controlling the spread of COVID-19. This study used environmental quality, namely ventilation, humidity, brightness, temperature, and personal space area as house environment parameters. The location of the study is Coblong District, Bandung City. The χ 2 test of independence was used to show the significance between environmental parameters required for the healthy house and disease transmission. The study found that one house environment parameter (ventilation) are significantly related to indoor transmission rate in recovered patients' houses (p = 0.021). Pearson correlation coefficient r was also investigated for each element of environment factor on the indoor transmission rate. Ventilation was found to be the most significant parameter correlated with indoor transmission (r = –0.522, p = 0.002). Personal Space Area also observed to have a significant correlation with indoor transmission rate (r = 0.459, p = 0.008). Humidity, brightness, and temperature were observed to have no significant correlation with indoor transmission rate (p = 0.309, 0.735, and 0.953, respectively. Linear regression is used to further investigate and predict the indoor transmission rate with significant environmental parameter as predictor. The linear regression model showed that 27.3% of indoor transmission rate variability are caused by its relationship with ventilation, the predictor used in the model.


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19 risk factors when environmental parameters where people lives are in poor condition, supporting 48 the transmission of COVID-19. 49 The indoor environmental condition of houses in the same area varies significantly with the 50 ventilation system of the building. Temperature is one of the parameters controlled by a ventilation 51 system engineered by humans (Janssen, 1999). Indoor relative humidity, dependent on ambient 52 temperature, is also impacted by ventilation. Natural ventilation is also related to fresh air and 53 sunlight penetration to control pathogens' airborne transmission (Hobday and Dancer, 2013). 54 While in the laboratory setting, the relationship between environmental factors and SARS-CoV-55 2 can be determined, environmental effects may become harder to trace in epidemiological spatial 56 data and number of case monitoring. In other words, environmental factors that significantly affect 57 virus stability do not necessarily show a significant effect on disease transmission. For example, it 58 is confirmed that increasing temperature and humidity accelerate the inactivation of SARS-CoV-2 59 on surfaces (Biryukov et al., 2020). Still, a study involving epidemiological data in China found 60 that variation of environmental factors in question (ambient temperature and absolute humidity)

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3 did not limit the survival and transmission of the new virus. (Poirier et al., 2020). Thus, this study 62 used a more localized measure, namely, residential transmission, as a dependent variable. 63 Five parameters were investigated in this study: temperature, humidity, brightness, ventilation 64 size, and personal space area. These five parameters vary in each of the survivors' houses. Data 65 analysis was performed to demonstrate whether or not the parameters that significantly affect 66 SARS-CoV-2 stability (mainly temperature, humidity, and sunlight exposure) also play an essential 67 role in residential setting disease transmission. Indoor sunlight exposure is measured as natural 68 brightness (in lux, without indoor lighting) that correlates with indoor solar radiation (Imam et al.,69 2018). Additionally, ventilation size and personal space area were also measured and analyzed. 70 The two additional parameters are mainly associated with the design and size of a house. Therefore, 71 analysis on these two parameters may provide additional information of a good environmental 72 setting of a house in the COVID-19 pandemic situation.

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As the capital city of West Java Province, Bandung is often included in the top 5 cities with the 74 most active cases in West Java. Coblong District is often included in the top 5 districts in Bandung 75 City with the most active cases. Coblong is also a district with high recreational and educational 76 activities, with more than 50 schools and 20 universities in the area. Coblong District is chosen for 77 this study. The study aims to assess the effect and Role of Indoor Environmental Quality in the 78 COVID-19 transmission. District. The total area of the two subdistricts exceeded 50% of the total area of Coblong District.

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The population of the two subdistricts has exceeded 50% of the total population of Coblong District.

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The location study is shown in Figure 1. In addition, the dots pinpoint the exact locations of 96 survivors' houses that were visited.    found that the requirements for the ventilation and humidity parameters for a healthy house set in   The environmental parameters data are then further investigated. are generated and shown in Figure 3. It can be seen that outliers were presented in each parameters' data, except for temperature.

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Outliers in humidity and brightness data may be due to inevitable daily weather variations and 197 clouds. Measurement error might also happen to measure these variables involving using an 198 automatic digital instrument with its level of measurement accuracy. Unlike the outliers of 199 humidity and brightness data, the outliers in ventilation and personal space area data are more likely 200 due to variation of house design and variation within sample, and not due to measurement error for 201 only measuring tape was used to measure these two variables. In conclusion, outliers in humidity 202 and brightness variables are excluded for better results.  The correlation matrix for each pair of the relation of predictors and response variable in 218 question is displayed in Figure 5. While summarizes the correlation r, determination coefficient 219 R 2 , and significance value of each environmental parameter to indoor transmission rate shown in 220 Table 5.    is also a potential agent to other health conditions, such as the feeling of low energy or lethargy 249

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14 due to increased heat index (Sarmiento, 2016). In environmental epidemiology, this condition (i.e., 250 environmental changes cause the host to be more vulnerable) is one of the four ways an epidemic 251 can occur (Soemirat, 2000). The theory may explain the positive correlation, although the differing 252 result is more likely due to disturbance of other factors such as weather or measurement error, not 253 to mention the significance value indicating that humidity-transmission correlation is insignificant 254 here.