A fire at an oil terminal in the port of Tuapse, which has been burning for three consecutive days, has covered the Black Sea coastline in dense smoke and has already reached the Russian city of Sochi.

Environmental specialists are warning of serious environmental and health risks linked to the incident, The Caspian Post reports, citing The Moscow Times.

Experts explain that large volumes of combustion products, including nitrogen and sulfur oxides, are being released into the atmosphere. When these substances become saturated with water vapor, they transform into nitric, sulfuric, or sulfurous acids and fall back to the ground in the form of acid rain.

One specialist noted that residents are already reporting what they describe as “oil rain,” with streets covered by an oily film and black spherical particles resembling oil residues or spill fragments.

Ecologist Yevgeny Vitishko described the current situation as “the largest environmental disaster in the region in recent memory,” warning that it could have long-term negative consequences for the environment for several years unless urgent measures are taken.

Russia’s consumer health watchdog, Rospotrebnadzor, has urged residents to remain indoors whenever possible and to keep windows closed to reduce exposure. However, the agency also stated that no exceedances of harmful substance levels in the air had been detected at this stage.

Alongside the air pollution, an oil slick covering an area of approximately 10,000 square meters has been discovered in the Black Sea near the port. Authorities have deployed containment booms and sent six vessels to carry out cleanup operations. Similar response efforts are also underway at the mouth of the Tuapse River.

The fire, which reportedly began following Ukrainian drone strikes on April 20, is still being extinguished. The operational task force in the Kuban region reported that 276 personnel and 77 pieces of equipment are involved in firefighting and containment operations, including units from the Main Directorate of the Ministry of Emergency Situations for Krasnodar Krai.