https://www.theguardian.com/environment/2017/aug/21/moss-may-prove-cheap-city-pollution-monitor-study-finds
Delicate mosses found on rocks and trees in cities around the world can be used to measure the impact of atmospheric change and could prove a low-cost way to monitor urban pollution, according to Japanese scientists.
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.
He said: “This method is very cost effective and important for getting information about atmospheric conditions.
“Mosses are a common plant in all cities so we can use this method in many countries ... they have a big potential to be bioindicators,” said Oishi, who analysed nearly 50 types of moss for the study.
Oishi said humid cities where moss thrives could benefit most from using bryophytes – a collective term for mosses, hornworts and liverworts – as bioindicators, adding moss could be monitored in its natural environment or cultivated for analysis.
In a research paper published in the Landscape and Urban Planning journal, Oishi and a colleague described how they studied the effect of nitrogen pollution, air quality and drought-stress on moss found over a 1.9 sq mile (3 sq km) area in Hachioji City in north-west Tokyo.
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.
However, the scientists could not effectively measure air purity which affects the number of moss types as pollution levels in the sample area were not high enough, said Oishi. “If the air pollution is severe, the purity is also evaluated by moss ... the change of the moss is very diverse according to the environmental problem.”
Bioindicators such as mosses, which generally absorb water and nutrients from their immediate environments, were often cheaper to use than other methods of environmental evaluation and can also reflect changes to ecosystems, said the scientists.
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.
Since you’re here …
… we have a small favour to ask. More people are reading the Guardian than ever but advertising revenues across the media are falling fast. And unlike many news organisations, we haven’t put up a paywall – we want to keep our journalism as open as we can. So you can see why we need to ask for your help. The Guardian’s independent, investigative journalism takes a lot of time, money and hard work to produce. But we do it because we believe our perspective matters – because it might well be your perspective, too.
I appreciate there not being a paywall: it is more democratic for the media to be available for all and not a commodity to be purchased by a few. I’m happy to make a contribution so others with less means still have access to information.Thomasine F-R.
If everyone who reads our reporting, who likes it, helps to support it, our future would be much more secure.
沒有留言:
張貼留言