Mysterious strong odor of gas smothers southern Athens for hours

From the coastal areas to densely populated districts of the basin, citizen reports were continuous, with dozens of calls to emergency services and critical infrastructure management companies. Despite long-term investigations, the origin of the odor remained unclear until late at night, leaving open questions about what exactly caused the phenomenon.

Checks on energy infrastructure and gas networks

The first burden of the investigations fell on energy facilities, as the nature of the odor initially created fears of a possible leak of natural gas or fuel derivatives. The focus was on DESFA's infrastructure, with the company categorically denying the scenarios linking the smell to its facilities in Revithoussa, noting that the inspections did not reveal any indication of an incident. At the same time, ENAON EDA, as manager of the natural gas distribution network in Attica, mobilized technical teams that carried out on-site and preventive inspections in areas where most reports were recorded. Special high-sensitivity leak detection vehicles were even used, without any indication of damage or technical problem.

As announced by Enaon EDA on Wednesday morning, "following the calls received yesterday by the Emergency Response Center regarding an odor in the atmosphere in areas of Attica, the inspection process was completed yesterday at 22:30 and no Natural Gas leak was detected nor was there any finding related to the distribution network".

The first technical assessments converged more on the possibility that the odor was related to hydrocarbons, LPG or some petroleum compound, rather than a typical natural gas leak. For this reason, the investigations were extended to other energy facilities connected to fuels and storage infrastructures. The refineries were also put under the microscope, which also denied any possible involvement in the incident, as there was no indication of a leak or other technical incident that would implicate their facilities in the Thriasio field. Despite successive cross-checks of data, none of the main energy scenarios was confirmed.

Port, maritime transport and Psyttalia under scrutiny 

The geographical spread of the phenomenon and the strong presence of the odor in coastal zones led the authorities to investigate even scenarios of marine pollution. The possibility of the involvement of passing ships transporting gases or other cargoes moving in the Saronic Gulf was considered, but no incident was reported by the port authorities.

At the same time, environmental management facilities were also included in the picture. Particular emphasis was given to the Psyttalia Urban Wastewater Treatment Center, one of the largest urban waste management systems in the country, as some estimates linked the strong odor to possible emissions or operational issues from the unit. However, sources from EYDAP, which is responsible for the operation of the relevant infrastructure, categorically ruled out any connection between the incident and the Psyttalia facilities.

Thus, both the energy and environmental infrastructures that were checked did not provide a clear clue as to the source of the phenomenon.

Unanswered questions and scientific investigation

Despite the massive mobilization and the successive cross-checking of data, the main difficulty for the authorities was that possible scenarios were constantly being ruled out, without a documented explanation emerging.

As citizen reports began to decrease in the afternoon, the crews remained on alert, while the investigation also moved to a scientific level. Experts were tasked with examining the chemical composition of the odor and determining whether it was volatile organic compounds, hydrocarbon residues or other atmospheric pollution.

Until there are firm conclusions, the case remains open. The only thing certain is that the authorities have put critical infrastructures under the microscope—DESFA, Enaon EDA, the refineries, Psyttalia, EYDAP, and maritime transport in the Saronic Gulf—without so far identifying the source of the mysterious odor that has disturbed the southern suburbs.