Professor Nikos Thomaidis of Analytical Chemistry at the University of Athens has raised alarm over the toxic smoke cloud blanketing Thessaloniki following a major fire at a recycling plant in Orfeas — a municipality located just southeast of the city. The blaze, which involved plastics and other organic materials, released thousands of chemical compounds into the atmosphere — many of them highly toxic or carcinogenic.
A Complex Mix of Hazardous Substances
In an interview with ERT, Professor Thomaidis explained that the smoke contains polycyclic aromatic hydrocarbons (PAHs), dioxins, volatile organic compounds (VOCs), heavy metals, and other dangerous pollutants. ‘The combustion of such materials produces thousands of substances,’ he said. ‘Some categories are classified as highly toxic; others are known carcinogens.’
PM2.5 Particles Pose Greatest Health Risk
He emphasized that fine particulate matter — specifically PM2.5 — represents the most immediate and serious health threat. These inhalable particles can penetrate deep into the lungs and even enter the bloodstream. ‘PM2.5 is the primary and most significant burden on human health,’ Thomaidis noted.
Vulnerable Groups Urged to Avoid Exposure
The professor sounded the alarm for vulnerable populations, particularly those with pre-existing respiratory conditions. ‘People with serious respiratory problems — and vulnerable groups in general — must avoid any contact with this kind of smoke,’ he stressed.
He advised residents to remain indoors with windows closed and to use air conditioning units only in recirculation mode — never drawing in outside air. ‘If air conditioners bring in external air, polluted air may enter homes, increasing citizens’ exposure to harmful pollutants.’
Smoke Spreads Across Greece
According to Thomaidis, the smoke cloud is not confined to Thessaloniki. It has already reached Attica, where elevated particle levels have been detected. He expects the plume to disperse across much of the Aegean Sea, Central Greece, and Southern Greece — with pollutant concentrations gradually decreasing the farther they travel from the fire’s origin in Orfeas.
Early Warning Signs: Odor and Irritation
On health effects, Thomaidis outlined early symptoms of exposure: a strong, unusual odor followed by irritation — especially of the eyes, nose, and throat. ‘Irritation is the first symptom. The smell itself is our warning — it tells us we need protection. Once irritation begins, it means we’ve already entered a phase of serious exposure.’