ABSTRACT
Polycyclic aromatic hydrocarbons (PAHs) and the trophic structure of polychaete assemblages were studied in sediments at 28 stations in Todos os Santos Bay. Total PAH concentrations varied from 8 to 4163 ng g(-1) dry weight. The indexes used for the determination of PAH origin suggested both pyrolytic and petrogenic sources. A total of 397 individuals of polychaetes was recorded which were classified in three trophic groups. The PCA ordination resulted in the formation of three groups of stations, Group I characterised by sandy sediments, low organic content, low total PAH concentration and percentage of potentially harmful PAH was dominated by subsurface deposit-feeders. The other two groups (IIa and IIb), showed similar percentages of silt and clay, however, Group IIb formed by those stations with high total organic carbon, total nitrogen, sulphur contents, high total PAH concentration and percentage of potentially harmful PAH was dominated by carnivores. Trophic changes could be explained by the level of exposure to PAH effects relative to differences in the life style and feeding strategies between deposit-feeders and carnivores.
Subject(s)
Food Chain , Polychaeta , Polycyclic Aromatic Hydrocarbons/poisoning , Water Pollutants, Chemical/poisoning , Aluminum Silicates , Animals , Brazil , Clay , Diet , Geologic Sediments , Population DynamicsABSTRACT
Os valores maximos de mercurio encontrados na Baixada Santista foram os seguintes: agua: 1,35 microgramo/l; sedimentos: 1,7 microgramo/g; peixes: 4,80 microgramo/g (musculatura) e 1,17 microgramo/g (visceras). As especies de peixes que apresentaram teores mais elevados foram: Micropogonias furnieri, Netuma barba, Stellifer rastrifer, Arius spixil, Mugil brasiliensis, Achirus sp e Eucinostomus gula. As especies que apresentaram fatores de acumulacao mais elevado (> 5000) foram: Netuma barba (5944), Micropogonias furnieri (5611) e Mugil brasiliensis (5444)
Subject(s)
Fishes , Mercury Poisoning , Sanitation , BrazilABSTRACT
O fenomeno ocorrido em 1978, inicialmente na Praia de Hermenegildo, e que se extendeu ate Tramandai (RS), foi provavelmente devido a um episodio de tipo de mare vermelha. A favor dessa hipotese sao levantadas evidencias quimicas, biologicas. toxicologicas e oceanograficas
Subject(s)
Humans , Air Pollution , Respiratory Tract Diseases , Seawater , Water Pollution , BrazilABSTRACT
Le malattie più comuni, anche quelle sulle quali sembra non vi sia più nulla da notare e registrare, quando assumono una diffusione eccezionale possono essere ricche di insegnamenti pratici ed a volte anche dottrinali. Così è avvenuto per la pandemia di Scabbia che la attuale guerra, con tutte le conseguenze che tanto a fondo hanno inciso sulla popolazione civile, ha portanto nel nostro disgraziato Paese.