RESUMEN
Tobacco is a well-documented threat to human health. However, its environmental impact has only recently been considered. Metals can interact with cigarette butts (CBs) being transported in the marine environment and reaching organisms. To understand this mechanism, a series of metal(loid)s were analyzed in cigarette filters (virgin, artificially smoked, leached in seawater and aged in beach and harbour) as well as in artificially contaminated oyster tissues. Smoked filters showed higher levels of metals compared to the virgin ones showing enrichment factors up to 90, probably associated with tobacco metal content. Once the CBs are delivered to the environment, metals can be leached to seawater until reaching equilibrium, which may be dependent on initial metal levels in the water. Copper was the element with the highest percentage of desorption (91 ± 3%) while strontium showed the lowest percentage (40 ± 0%). CBs revealed a great capacity to accumulate metals from the environment when weathered in contaminated areas. A chemical impact derived from CBs contamination might exist as they serve as a carrier for metals in the marine environment. The release of metals from CBs or the ingestion of metal loaded CBs may pose a toxicological risk for marine organisms via accumulation in their tissues.