The Puyehue volcano

Travelling round town yesterday in a taxi I noted that the sky looked a bit weird, the day seemed to have gone grey (typical for this time of year, you might say)  a little while before, however, skies were blue and the sun was shinning). Now the day was duller than dull and the sun looked as if it were behind clouds, but no clouds were to be seen.
The taxi driver must have noticed my befuddled look and started to talk about the amount of volcanic ash in Buenos Aires and whether or not it was harmful. He mentioned that earlier he had seen some people wearing masks and thought it rather ridiculous......
Being an asthma sufferer and having needed my puff more than usual over the last few days,  i decided to find out just how ridiculous this was.....
First, I thought it would be a good idea to find out what  volcanic ash is made of, why it was dangerous to aeroplanes and whether or not i should be walking round town wearing a mask... this is what i found out after reading several articles on the internet-

Ash particles are also know as tephra and are made of fragments of rocks, minerals and volcanic glasses(yes, glass not gas!)apparently this is because gas bubbles are released into the magma of the eruption as it wells up and as the magma cools and solidifies the gas bubbles are trapped and during an eruption the gas in these particles gets heated to such an extent that solidified mass explodes creating the glass shards..,,,,yeah i know a bit technical----
so what exactly are we inhaling???       According to what i have read, the ash particles become corrosive (due to the formation of sulfuric and hydrocloric acid when the ash becomes hydrated) and this is why it is dangerous for aeroplanes as it can cause chemical corrosion but more dangerous still to aeroplanes is the molten material which can choke the cooling vents which leads to engine failure.,,,,,
so back to the question about whether or not the ash is harmful to us....ummm most people seem to believe that inhaling volcanic ash is less harmful than smoking or air pollution.... and that during a short period of time has no adverse effects... below are number of sypmtoms one may come accross and if you are like me and have asthma are  or have any kind of respiratory disease then you may consider looking ridiculous and wearing a mask..... (masks in the area of the volcano are apparently in great demand and cost around $8 each!!!!!!!!!)
Acute respiratory symptoms commonly reported by people during and after ash falls (Blong, 1984, p. 83-91):

• nasal irritation and discharge (runny noses)
• throat irritation and sore throat, sometimes accompanied by dry coughing
• people with pre-existing chest complaints have developed severe bronchitic symptoms which lasted some days beyond exposure to ash (for example, hacking cough, production of sputum, wheezing, or shortness of breath)
• airway irritation of people with asthma or bronchitis; common complaints of people with asthma include shortness of breath, wheezing, and coughing
• breathing becomes uncomfortable

These short-term effects are not considered harmful for people without existing respiratory conditions. People should take steps to minimize their exposure to breathing ash

http://volcanoes.usgs.gov/ash/health/index.html
http://www.brighthub.com/environment/science-environmental/articles/71452.aspx