dpa/GNA – A higher pollen count can lead to a greater risk of catching Covid-19, research by scientists in Germany indicates.
A team at the Technical University of Munich (TUM) noticed that higher pollen counts correlate with higher coronavirus infection numbers, according to the study published in the Proceedings of the National Academy of Sciences (PNAS).
The researchers and other experts said however that the results – which measured pollen counts and Covid-19 infections in 31 countries across five continents – should not be undue cause for alarm, as spring blooms in much of the northern hemisphere.
According to the study, infection rates in areas without a local lockdown go up by an average of four per cent when the amount of pollen in the air increases by 100 per cubic metre.
In data from some German cities analysed in the study, pollen rates rose to 500 per cubic metre, and infection rates rose by 20 per cent.
The daily pollen counts and infections rates correlated both in areas with and without lockdown measures in place. But if residents were confined to their homes, infections increased at only half of the rate seen when people were able to freely move around.
“We found that pollen, sometimes in synergy with humidity and temperature, explained, on average, 44 per cent of the infection rate variability. Lockdown halved infection rates under similar pollen concentrations,” the study said.
There was no evidence for airborne pollen grains themselves being carriers of virus particles, it said.
A spokesman for the Germany society for clinical immunology, Joerg Kleine-Tebbe, cautioned that the effect the researchers had noticed was only “defined to a limited extent.”
“This is not an extreme result,” he told dpa.