Table 2.
Relationships of viral payloads with environmental parameters.
| Environmental Parameter | Synthesized information | Reference |
|---|---|---|
| Daily minimum temperature with lagged effect of 5–7 days | Inverse relationship with numbers of daily SARS-CoV cases in Beijing and Hong Kong | Bi et al. (2007) |
| Air temperature at 4 °C and relative humidity (< 20% or > 80%) | Higher survival of payloads of transmissible gastroenteritis and mouse hepatitis viruses for extended days on surfaces in indoor environment | Casanova et al. (2010) |
| Temperatures of 22–25 °C and relative humidity of 40–50%, | Higher survival rates of SARS-CoV on smooth surfaces simulating typical air-conditioned environments | Chan et al. (2011) |
| Temperature at 38 °C, and relative humidity > 95% | Los of viability of SARS-CoV, simulating tropical climates | Chan et al. (2011) |
| Ambient temperature (16–28 °C) with 7-day time lag | Stimulated the growth of SARS-CoV | Tan et al. (2005) |
| Environmental temperature related to unexpected rapid spells of cold and warm days | Rise in SARS-CoV cases | Tan et al. (2005) |
| Low temperature/low humidity conditions even after 48 h (20 °C and 40% relative humidity) | More stable and viable payloads of MERS-CoV | van Doremalen et al. (2013) |
| Lower air temperatures (6 °C) and lower relative humidity (30%) than at higher relative humidity | Greater survival of coronaviruses in surfaces | Ijaz et al. (1985); Kim et al. (2007) |
| Lower air temperatures (6 °C) | Enhanced viral survival | Harper (1961) |
| Diurnal temperature | Positive relationship of daily death counts of SARS-CoV patients | Park et al. (2019) |
| Low temperatures in the absence of ultraviolet light and different relative humidity | Slowest inactivation of influenza virus | Kormuth et al. (2018); Lowen et al. (2007); McDevitt et al. (2012); Skinner and Bradish (1954); Yang et al. (2012) |
| Temperature and humidity during the winter season in temperate countries, in the rainy season, or where there were sudden seasonal changes in tropical countries | Strong association of transmission rate of the influenza virus | Biswas et al. (2014); Chowell et al. (2012); Hemmes et al. (1962); Viboud et al. (2006) |
| Absolute humidity | Negative association with daily survival counts of Influenza patients | Metz and Finn (2015) |
| Cold temperature and low relative humidity | Stimulate Influenza transmission | Lowen et al. (2007) |
| Temperature at 30 °C and at all humidity | No association with Influenza transmission | Lowen et al. (2008) |
| Absolute humidity | Wintertime increase in influenza virus transmission and influenza virus survival | Shaman and Kohn (2009) |
| Absolute humidity | No strong correlation with airborne transmission of Influenza virus | Tang et al. (2010) |
| Temperature and relative humidity | Strong correlation with airborne transmission of Influenza virus | Tang et al. (2010) |
| Sunlight | Negative relationship with survival and infectivity of various viruses | Nelson et al. (2018); Rzeżutka and Cook (2004); Tang (2009); Qiao et al. (2018) |
| Natural and simulated sunlight | Significant loss of infectivity of influenza virus in liquid suspensions and aerosols | Schuit et al. (2020); Skinner and Bradish (1954) |
| Natural and simulated sunlight | High sensitivity of SARS-CoV survival | Tseng and Li (2007); WHO (2004) |
| Natural sunlight and UV radiation | Decay the viability of SARS-CoV | Karapiperis et al. (2020) |
| 60 min of exposure to > 90 W/cm2 of UV-C light at a distance of 80 cm | Loosing viability of SARS-CoV | Duan et al. (2003) |
| 15 min of exposure to UV-C light (> 90 W/cm2) at a closer distance (< 80 cm) | High efficiency of inactivation of SARS-CoV | Darnell et al. (2004) |
| Inadequate indoor ventilation | Enhanced infection risk of SARS-CoV in makeshift hospitals | WHO (2009) |
| With > 12 air changes per hour (ACH) (e.g., equivalent to > 80 L/s for a 24 m3-room) and controlled direction of airflow | Low risk of infectivity of viral diseases in an airborne precaution room | AIA (2001); Mayhall (2004); Wenzel (2003); WHO (2007) |
| Negative pressure of > 2.5 Pa, an airflow having a difference between the exhaust to supply > 125 cfm (56 L/s), clean-to-dirty airflow, > 12 ACH for a new building, and > 6 ACH in existing buildings for an old building, and exhaust to the outside, or a HEPA-filter if room air is recirculated | Low risk of infectivity in an airborne infection isolation room | CDC (2003) |
| Ambient temperature (< 3 °C) | Positive association of daily number of SARS-CoV-2 cases | Zhu and Xie (2020) |
| Average daily ambient temperature | Significant negative correlation with SARS-CoV-2 for northern hemisphere countries | Tosepu et al. (2020) |
| Minimum temperature, maximum temperature, relative humidity, and amount of rainfall | No significant correlation with SARS-CoV-2 | Tosepu et al. (2020) |
| Increasing ambient daily average temperature up to around 13 °C | Negative association of daily number of SARS-CoV-2 cases | Oliveiros et al. (2020); Wang et al. (2020b) |
| Diurnal temperature and absolute humidity | Positive and negative associations with daily death counts of COVID-19 patients | Ma et al. (2020) |
| Poor ventilation (approximately 150 m3 per hour per person) | High infectives in makeshift hospitals in Hubei Province, China | Chen and Zhao (2020) |
| Increase of temperature and humidity | No marked relationship with SARS-CoV-2 cases in the northern hemisphere in spring and summer months | Poirier et al. (2020) |
| High temperature and high humidity | Reduced Reproductive number (R) of COVID-19 in China and USA | Wang et al. (2020a) |
| Changes in temperature | No significant correlation with SARS-CoV-2 cases transmitted, deaths or recovered | Stanam et al. (2020) |
| Temperature and humidity | Association of infectivity of SARS-CoV-2 with temperature but no association with humidity | Gupta (2020) |
| Humidity | Direct and positive correlation with COVID-19 mortality | Li (2020) |
| Ambient temperature and relative humidity | Impacted on the growth rate of COVID-19 outbreaks | Chaudhuri et al. (2020) |
| Temperature, humidity, and UV-B radiation | Higher transmission risks for COVID-19 | Liu et al. (2020a) |
| Increased temperature and humidity | Partially suppressed COVID-19 incidences | Wu et al. (2020) |
| Air pollutants (PM2.5, PM10, SO2, CO, NO2 and O3) | Short-term exposure to air pollutants (PM2.5, PM10, CO, NO2 and O3) is associated with increased risk of COVID-19 infection; short-term exposure to a higher concentration of SO2 is associated to decreased risk of COVID-19 infection | Zhu et al. (2020) |