How cigarette waste fuels antimicrobial resistance

As described in the study by Fang et al., from Dr. Uli Klümper’s research group at Technische Universität Dresden, Germany, cigarette smoke, ash, and used filters can promote the spread of antibiotic resistance genes (ARGs) in both lung and environmental microbiomes. Resistomap supported the study by conducting high-throughput qPCR analysis to quantify ARGs, mobile genetic elements (MGEs), and the presence of Klebsiella pneumoniae in microbial communities colonising cigarette filters.

Smoke increases gene transfer

In artificial lung sputum medium, exposure to cigarette smoke condensate (CSC) led to more than a two-fold increase in plasmid-mediated gene transfer between bacteria. This effect was linked to increased production of reactive oxygen species (ROS), a known trigger of horizontal gene transfer. When ROS was neutralised, the increase in gene transfer disappeared.

Ash has a similar effect

Cigarette ash solution (CAS) caused a four-fold increase in gene transfer rates and a significant rise in ROS. This pattern was observed in both Pseudomonas putida and Escherichia coli.

Filters carry resistance and pathogens

Used cigarette filters submerged in wastewater developed microbial communities significantly richer in:

• ARGs across 10 antibiotic classes
• MGEs
• Human pathogens, including elevated levels of Klebsiella pneumoniae

These communities differed substantially from those on unused filters.

Filters travel, and persist

The study estimates that over 1.57 × 10¹¹ cigarette filters enter waterways globally each year. These filters can float for long periods (up to 10 years) and act as vehicles for transporting resistant bacteria and genes across different environments. Their buoyancy and mobility allow them to travel to high-exposure locations, including beaches and children’s playgrounds, where contact with humans and animals is likely.

Combined with the evidence of enhanced gene transfer and enriched resistance genes, these findings show that cigarette filters are not just environmental litter, they are mobile reservoirs of antimicrobial resistance. As the study concludes, cigarette-derived compounds and waste products represent a dual threat, promoting resistance both inside the human lung and throughout the environment.