The shutdown of the Cepsa refinery in Santa Cruz de Tenerife in 2013 has led to a 76% decrease in radioactivity levels in the island’s capital, according to research conducted by the Laboratory of Medical Physics and Environmental Radioactivity (FIMERALL) at the University of La Laguna (ULL).
The investigation, which involved 1,105 measurements of surface aerosols, examined the changes in total alpha activity from 2001 to 2022 and its relationship with other pollutants stemming from the oil industry, including carbon monoxide (CO), sulphur dioxide (SO₂), nitrogen monoxide (NO), nitrogen dioxide (NO₂), benzene, toluene, and xylene.
These pollutants and radionuclides are associated with the extraction, processing, and combustion of petroleum products, which adversely impacts both air quality and levels of environmental radioactivity, as noted by the University of La Laguna.
Findings from this study indicated that significant events, such as the global economic downturn of 2008—which resulted in a reduction of refinery operations—and its final closure in 2013, correlated with a substantial decline in the levels of these pollutants.
In addition to total alpha activity, other atmospheric pollutants, including PM10, SO₂, NO₂, and volatile organic compounds (VOCs), exhibited similar reductions.
Advanced statistical methods determined that 84% of the variations observed in total alpha activity levels could be attributed to factors associated with industrial activities.
Currently, the ULL research team highlights that despite the variations recorded, none of the total alpha activity levels posed a radiological risk to the residents of Santa Cruz de Tenerife.
Nevertheless, the acquired results “emphasize the significance of prolonged environmental monitoring to comprehend and address the repercussions of radioactive and chemical pollution in urban settings impacted by industrial operations.”
Regarding the Santa Cruz refinery, they assert that its closure along with the “marked reduction” in associated pollution levels provide “clear evidence of the influence that industrial activities exert on public health and the environment.”
The ULL stresses that environmental pollution is among the most significant challenges of the 21st century, and although greenhouse gases like carbon dioxide (CO₂), methane (CH₄), and nitrogen oxides (N₂O) are “well recognised,” other less acknowledged contaminants, such as radiation, also represent “a danger.”
“In normal circumstances,” public exposure to radiation remains minimal and predominantly originates from natural sources.
However, certain industries, such as oil extraction, can elevate the levels of naturally occurring radionuclides in the environment, known as Enhanced Naturally Radioactive Material (TENORMs).
The findings of this research were recently shared in an article published in the ‘Journal of Environmental Management,’ authored by Pedro Salazar Carballo, Antonio Catalán Acosta, Francisco Hernández, and María López Pérez, affiliated with the laboratory and other institutions at the University of La Laguna.
