Person-to-person spread of coronavirus more dominant than weather conditions: University of Texas

Washington, US:

University of Texas at Austin recently conducted a research to understand the effects of weather on the spread of coronavirus.

The findings in the International Journal of Environmental Research and Public Health suggest that hot, cold or humid weather does not impact the transmission of the virus from person to person.

Factors such as mobility and human behaviour, dominates the causes for human to human transmission of the virus.

“The effect of weather is low and other features such as mobility have more impact than the weather. In terms of relative importance, the weather is one of the last parameters,” said Dev Niyogi, a professor at UT Austin’s Jackson School of Geosciences and Cockrell School of Engineering who led the research

Co-authors of the study are Sajad Jamshidi, a research assistant at Purdue University, and Maryam Baniasad, a doctoral candidate at Ohio State University.

The study defined weather as “equivalent air temperature,” which unites temperature and humidity into a single value.

The researchers then analysed the monitored this new hybrid single value with coronavirus spread in different areas from March to July 2020.

Their scale constituted U.S. states, countries and the world at large. The study made detailed observations concerning travelling habits in the country and state by tracking cell phone data.

They also investigated the relation linking human behaviour and coronavirus spread. Although the study did not attempt to connect human behaviour with weather patterns.

Across the variable scales, scientists discovered that the weather had nearly no influence when compared against other factors using a statistical metric.

The weather’s relative contribution at the county scale was less than 3 per cent, with no observations supporting the previous hypothesis of a specific weather galvanizing the spread over another.

In fact, the data pointed out the clear influence of human behaviour. The outsized influence of taking trips and spending time away from home. Followed by pollution and urban density.

The former two being the top two contributing factors to Covid-19 growth, with a relative importance of about 34% and 26% respectively.

The latter comprises with a relative importance of about 23 per cent and 13 per cent respectively.

“We shouldn’t think of the problem as something driven by weather and climate. We should take personal precautions, be aware of the factors in urban exposure,” said Jamshidi.

Baniasad, a biochemist and pharmacist, said that the the assumptions linking the coronavirus spread to the weather prevail due to previous studies conducted in laboratory settings on similar viruses.

“When you study something in the lab, it’s a supervised environment. It’s hard to scale up to society. This was our first motivation to do a more broad study,” she said.

Marshall Shepherd, an atmospheric sciences professor at the University of Georgia, said that the research offers significant insights about weather and coronavirus across scales.

“This important work clarifies some of the innuendoes about weather-Covid-19 connections and highlights the need to address science challenges at the appropriate scales,” said Shepherd. Shepherd was not one of the co-authors of the study.

Highlighting the key lessons of the coronavirus pandemic, Niyogi pressed on the importance of analysing phenomena at the “human scale”.

“The scale at which humans live their day-to-day lives.” He said that this research is an example of this type of perspective.

“Covid, it is claimed, could change everything. We have been looking at weather and climate outlooks as a system that we scale down, down, down and then seeing how it might affect humans,” Niyogi said.

“Now, we are flipping the case and upscaling, starting at human exposure scale and then going outwards. This is a new paradigm we will need for studying virus exposure and human environmental modelling systems involving new sensing and AI-like techniques,” Niyogi added.