Cigarette butt leachates induce alterations in gene expression and damage in health status of tropical oysters

Author(s)

Rosa, Hytalo de Souza ; Moreno, Beatriz Barbosa ; Zanardi-Lamardo, Eliete ; Griz, Julia de Aragao Soares ; Moreira, Lucas Buruaem ; Medeiros, Igor Dias ; Castro, Italo Braga

• Document type: Journal article
• Source: Marine Pollution Bulletin; v. 215, p. 10-pg., 2025-06-01.

Abstract

Cigarette butts (CB) are among the most frequent debris in marine litter collected in coastal areas. They are potential sources of chemical contamination by leaching process, posing risks to biota. This study aimed to evaluate the short-term impacts of CB leachates on the oyster Crassostrea brasiliana. The animals were exposed in the laboratory to different leached dilutions and assessed for bioaccumulation of polycyclic aromatic hydrocarbons (PAHs), their general health status by neutral red retention time (NRRT), and variation in expression of genes related to xenobiotic biotransformation. The results showed that CB leachates at very low dilutions impaired the general health status of oysters, with significant reductions in NRRT at 24 h (dilution 0.1 %), and that persisted at 96 h (dilution 0.01 %). Therefore, a single cigarette butt was able to make toxic 250 l of seawater after 24 h release, and 2500 l after 96hs. The gene expression indicated a decrease in gill transcripts (CYP2-like, GST Omega, and HSP70) of C. brasiliana exposed for 24 h, with no marked trend at 96 h. Despite the low PAHs bioaccumulation, the damages observed in lysosomal membranes followed by the decreased expression of key genes involved in xenobiotic biotransformation, and the protection of protein stability, represent evidence of early effects caused by cigarette residues on marine organisms from tropical environments. (AU)

• FAPESP's process: 20/00068-8 - Whole transcriptome analysis of benthic organisms as models to estimate toxic effects of contaminated sediments in marine environments
• Grantee: Lucas Buruaem Moreira
• Support Opportunities: BIOTA-FAPESP Program - Young Investigators Grants
• FAPESP's process: 21/08471-9 - Whole transcriptome analysis of benthic organisms as models to estimate toxic effects of contaminated sediments in marine environments
• Grantee: Lucas Buruaem Moreira
• Support Opportunities: Scholarships in Brazil - BIOTA - Young Researchers
• FAPESP's process: 19/13750-4 - Occurrence, partitioning, toxicity and degradation to cigarette butts in coastal areas
• Grantee: Ítalo Braga de Castro
• Support Opportunities: Regular Research Grants