A three-year study performed in Iceland revealed that toxic gases associated with geothermal drilling can be dangerous to human health. The study found a link between underground-originating hydrogen sulfide (the rotten eggs-smelling substance) and asthma and various respiratory diseases.
The hydrogen sulfide had been measured next to a busy intersection in Reykjavik, from March 2006 to December 2009, where about 70,000 cars passed through every day. They also counted the amounts of ozone, nitrogen dioxide and particulate matter of up to 10 micrometers emitted by diesel exhausts.
Eventually the scientists observed that spike increases in typical traffic pollution led to more asthma medications prescriptions, and increases in the daily averages for hydrogen sulfide also saw increases in the frequency of prescriptions. All of these occurred 3 to 5 days after the increased exposures to the pollutants.
You’ll be saying that Reykjavik is one of the most polluted cities in Europe – well, it’s actually not. All of these pollutants had actually been lower than the limits imposed by the regulatory authority in Iceland, and the effects had been seen even for low concentrations. Higher doses, however, led mainly to people having neurologic effects.
The study ultimately showed that peaks in air pollutants are more harmful than constant average pollution.