Can Aromatherapy Counter Pollution?

Can Aromatherapy Counter Pollution?

A recent study found toxic air was linked to “extremely high mortality” in people with mental disorders; and earlier work linked it to increased mental illness in children; while another analysis found those living near busy roads had an increased risk of dementia


The new work, published in the journal Proceedings of the National Academy of Sciences (
http://www.pnas.org/content/early/2018/08/21/1809474115 ), analyzed language & arithmetic tests conducted as part of the China Family Panel Studies on 20,000 people across the nation between 2010 and 2014.

 
The scientists compared the test results with records of nitrogen dioxide & sulphur dioxide pollution. They found the longer people were exposed to dirty air, the bigger the damage to intelligence, with language ability more harmed than mathematical ability and men more harmed than women. The researchers said this may result from differences in how male & female brains work.

Derrick Ho, at the Hong Kong Polytechnic University, said the impact of air pollution on cognition was important and his group had similar preliminary findings in their work. “It is because high air pollution can potentially be associated with oxidative stress, neuroinflammation, & neurodegeneration of humans” Derrick Ho said.

Chen said air pollution was most likely to be the cause of the loss of intelligence, rather than simply being a correlation. 

The study followed the same individuals as air pollution varied from one year to the next, meaning that many other possible causal factors such as genetic differences are automatically accounted for. The scientists also accounted for the gradual decline in cognition seen as people age and ruled out people being more impatient or uncooperative during tests when pollution was high. Air pollution was seen to have a short-term impact on intelligence as well and Chen said this could have important consequences, for example for students who have to take crucial entrance exams on polluted days.

“But there is no shortcut to solve this issue. Governments really need to take concrete measures to reduce air pollution. That may benefit human capital, which is one of the most important driving forces of economic growth.” Chen said.

In China, air pollution is declining but remains 3 times above World Health Organisation (WHO) limits. According to the WHO, 20 of the world’s most polluted cities are in developing countries. China, home to several of those cities, has been engaged in a “war against pollution” for the past 5 years.

"The results would apply around the world. The damage to intelligence was likely to be incremental. With a 1mg rise in pollution over 3 years, equivalent to losing more than a month of education. Small pollution particles are known to be especially damaging. That is the same wherever you live. As human beings we have more in common than is different.” Chen added.