As air quality across Macedonia goes deep into unsafe territory again, with the start of the winter months, a father and son from Skopje are promoting their cheap filter that they say can prevent much of the air pollution caused by dirty heating fuels.

Engineer Pando Petkovski demonstrated the system to Sitel TV. It contains a filter using porous bronze and activated charcoal.

This is a dry filter which captures the PM10 particles. The device directs the smoke from burning fuel, captures the PM10 particles and collects them so they can be easily removed, said Petkovski.

His father even demonstrated how clean the air is by inhaling it directly from the filter. The device recently received a bronze medal in Taiwan, in competition against 1.500 innovations. Burning wood, coal and waste for heating is the main source of air pollution in Macedonia over the winter months when the PM10 particles concentration spikes to levels which are among the worst in the world.