As night falls, thick clouds of black smoke cover Greece's sky, making it hard to breathe outside. The familiar winter smell of wood burning in fireplaces has turned into a public health threat, with cash-strapped Greek households turning to firewood for heat .
Smog has long plagued Athens. But the problems reported in the 1990s were largely the consequence of an economic boom, when an average family in the capital owned more than one car and industrial production was at its peak. But time around, it is a consequence of the financial crisis.
Central Athens, GreeceEco Images | Universal Images Group | Getty Images
The Greek government increased tax on heating oil to bring it in line with taxes on motor fuel, sending prices up 30 percent. At 1.30 euro per liter, many people chose not to buy heating oil and turn to cheaper solutions.
(Read more: Greece to exit bailout plan in 2014: Prime Minister)
Maria, 65, lives in a block of flats in Aghia Paraskevi, a suburb of Athens. Her neighbors refuse to bear the shared cost for heating oil used for the building's central heating, so she has to use other ways to keep her flat warm this winter. "I actually do have the money for oil, but I cannot pay for the whole block of flats, so I have to light up the fireplace or use an electric heater."
Other people are in a far worse situation, and don't even have the money to pay for electricity or wood. So they burn scrap wood and garbage, releasing carcinogenic substances in the air. "At night, everything is blurry outside, a bit like fog, and it smells so badly that you feel you are choking. It smells like burned wood, like a fireplace burning, but on a much larger scale.", says 25-year old Evangelia, who lives in Athens. "Even if you are driving in your car and all the windows are shut, you can still smell it.", she says.