High levels of air contamination could raise the risk of dying from Covid-19, two research studies recommend.
Dr Maria Neira, of the World Health Organization (WHO), told BBC News nations with high pollution levels, many in Latin America, Africa and Asia, must increase their preparations.
Those with underlying pollution-related conditions have established serious Covid-19 in countries with high levels.
But medical professionals say it is prematurely to prove a direct relationship.
” We will be doing a map of most polluted cities based on our database to support national authorities in these regions so that they can prepare their epidemic reaction plan accordingly,” Dr Neira said.