Caracterização, particionamento e toxicidade de bitucas de cigarro em zonas costeiras
Arquivos
Data
2020-04-24
Autores
Lima, Christiane Freire 
Orientadores
Castro, Ítalo Braga
Tipo
Dissertação de mestrado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
O descarte inadequado de lixo no mar tem sido motivo de crescente preocupação uma vez que gera inúmeros impactos sociais, econômicos e ambientais. Neste contexto, as bitucas de cigarro são o item mais reportado em ações de limpeza e estudos de abundância e composição do lixo marinho. Os objetivos deste estudo foram realizar a caracterização qualitativa das bitucas encontradas em praias de Santos - SP, analisar em qual compartimento ambiental esses resíduos particionam preferencialmente e avaliar a toxicidade do lixiviado de bitucas sobre o crustáceo Nitokra sp verificando a taxa de fecundidade após 96 horas (água) e 10 dias (sedimento) de exposição. Os resultados mostraram que a bituca foi o primeiro e segundo item mais encontrado nas coletas de verão e inverno representando cerca de 51% e 34% dos resíduos coletados, respectivamente. Os testes de sedimentação em condições estáticas e de agitação mostraram que as bitucas permaneceram na coluna d’água por período variável e superior a 3 dias. Entretanto, os tempos de sedimentação em ambos os tratamentos não apresentaram relação com a salinidade sugerindo que outros parâmetros, como a porosidade dos materiais, podem influenciar a flutuabilidade das bitucas. Os ensaios de toxicidade indicaram que pequenas quantidades de bitucas de cigarro podem ser suficientes para induzir efeitos deletérios sobre a reprodução de Nitokra sp. Os testes em meio aquoso apresentaram CE50 – 96h = 10,736% ± 6,145, CENO = 6,25% e CEO = 12,5%. Os resultados dos ensaios com sedimento apontaram maior toxicidade em relação aos testes de água. A CE50 - 10 dias foi de 0,2384% e CEO = 0,78%. Considerando que as bitucas de cigarro constituem uma mistura complexa de substâncias químicas e que podem ser descartadas em ambientes marinhos e costeiros, organismos aquáticos podem estar sob potencial ameaça. Diante deste cenário, estudos adicionais para compreender outros aspectos do comportamento de bitucas em ambientes aquáticos bem como ensaios ecotoxicológicos que envolvam outros grupos tróficos são altamente recomendados.
The marine litter has been a motive of concern since it generates several impacts in social, economic and environmental fields. Cigarette butts are the most reported item in cleaning actions and studies on the abundance and composition of marine waste. The present study carried out a qualitative characterization of cigarette butts sampled on the beach of Santos - SP, investigating in which environmental compartment these residues preferentially partition. In addition, toxicity tests of the leachates prepared from cigarette butts on the crustacean Nitokra sp were assessed. In this regard, we checked fertility rates after 96 hours (water) and 10 days (sediment) of exposure. The results showed that cigarette butts were the first and second most found items in the summer and winter sample campaigns, representing about 51% and 34% of the collected waste, respectively. The sedimentation tests under static and agitation conditions showed that cigarette butts remained in the water column for a variable period and longer than 3 days. However, the sedimentation time in both treatments were not related to salinity, suggesting that other parameters, such as the material porosity, could influence the buoyancy of these residues. Toxicity assays indicated that small amounts of cigarette butts may be enough to induce harmful effects on the reproduction of Nitokra sp. Tests held via water exposure showed EC50 - 96h = 10.736% ± 6.145, NOEC = 6.25% and LOEC = 12.5%. The results of the sediment tests showed higher toxicity than water exposure. The EC50 - 10 days was 0.2384% and LOEC = 0.78%. Considering that cigarette butts are a complex mixture of chemicals and can be discarded in marine and coastal environments, aquatic organisms may be under potential threat. Based on this scenario, further studies to understand other aspects of the behavior of cigarette butts in aquatic environments as well as ecotoxicological tests over other trophic groups are highly recommended.
The marine litter has been a motive of concern since it generates several impacts in social, economic and environmental fields. Cigarette butts are the most reported item in cleaning actions and studies on the abundance and composition of marine waste. The present study carried out a qualitative characterization of cigarette butts sampled on the beach of Santos - SP, investigating in which environmental compartment these residues preferentially partition. In addition, toxicity tests of the leachates prepared from cigarette butts on the crustacean Nitokra sp were assessed. In this regard, we checked fertility rates after 96 hours (water) and 10 days (sediment) of exposure. The results showed that cigarette butts were the first and second most found items in the summer and winter sample campaigns, representing about 51% and 34% of the collected waste, respectively. The sedimentation tests under static and agitation conditions showed that cigarette butts remained in the water column for a variable period and longer than 3 days. However, the sedimentation time in both treatments were not related to salinity, suggesting that other parameters, such as the material porosity, could influence the buoyancy of these residues. Toxicity assays indicated that small amounts of cigarette butts may be enough to induce harmful effects on the reproduction of Nitokra sp. Tests held via water exposure showed EC50 - 96h = 10.736% ± 6.145, NOEC = 6.25% and LOEC = 12.5%. The results of the sediment tests showed higher toxicity than water exposure. The EC50 - 10 days was 0.2384% and LOEC = 0.78%. Considering that cigarette butts are a complex mixture of chemicals and can be discarded in marine and coastal environments, aquatic organisms may be under potential threat. Based on this scenario, further studies to understand other aspects of the behavior of cigarette butts in aquatic environments as well as ecotoxicological tests over other trophic groups are highly recommended.
Descrição
Citação
LIMA, Christiane Freire. Caracterização, particionamento e toxicidade de bitucas de cigarro em zonas costeiras. 2020. 70 f. Dissertação (Mestrado em Biodiversidade Marinha e Costeira) - Instituto do Mar, Universidade Federal de São Paulo, Santos, 2020