A recently published study assessed diesel exhaust particulate matter (DEPM) emissions from two midsize domestic generators operating in Beirut and examined their cytotoxicity in vitro.

Results showed that 87% of emitted particles are quasi-ultrafine (<0.33 microns), meaning they can not only reach the deepest regions of the lungs but also get absorbed into the bloodstream and affect distant organs.

The study also revealed high emissions of a wide range of highly potent substances, including genotoxic heavy metals like titanium; WHO-classified carcinogens such as polycyclic aromatic hydrocarbons; and known endocrine-disrupting compounds and cancer promoters like dioxins, furans, and dioxin-like polychlorinated biphenyls (all classified as persistent organic pollutants by the Stockholm Convention), marking their ability to penetrate the food chain.

These alarming findings were published in Atmospheric Pollution Research (Elsevier) as part of an investigation led by Dr. Hassan R. Dhaini, toxicologist and associate professor at the Faculty of Health Sciences (FHS) at the American University of Beirut (AUB), in collaboration with Dr. Wassim Abou-Kheir, professor at the Faculty of Medicine at AUB; Dr. Charbel Afif, professor at Université Saint-Joseph; and other scientists from The Cyprus Institute and Université du Littoral Côte d'Opale in Dunkirk, France.