Moss, a “bioindicator”, responds to pollution or drought-stress by changing shape, density or by disappearing, allowing scientists to calculate atmospheric alterations, said Yoshitaka Oishi, associate professor at Fukui Prefectural University. The study showed severe drought-stress tended to occur in areas with high levels of nitrogen pollution, which it said raised concerns over the impact on health and biodiversity. The World Health Organisation says 88% of city dwellers are exposed to annual pollution levels that exceed its air quality guidelines. South-east Asia and the eastern Mediterranean have the worst air quality, followed by countries in Latin America and Africa. “We believe this method can contribute to the evaluation of atmospheric pollution in other areas,” said Oishi.

Source: The Guardian August 21, 2017 17:15 UTC