Persistent toxic substances in the Brazilian Amazon: contamination of man and the environment

The organochlorine insecticide DDT was extensively used in Brazil since 1945, both for agricultural purposes and for vector control measures. In 1986 its uses were forbidden in agriculture and in 1997 it was also phased-out in vector controls programs. However, the presence of DDT in urban and forested soils, breast milk and aquatic biota is still common, especially at the Amazon region. The results gathered since the middle of the 90s indicate that environmental contamination with this pesticide is still relatively high. Due to the high fish consumption by traditional riverside populations, human breast milk may represent an important source of DDT exposure to newborns. New results on DDT and PCBs in red dolphin (Inia geoffrensis), an endemic aquatic mammal of the Amazon region, is also reported

Trophic dynamics of methylmercury and trace elements in a remote Amazonian Lake.

peer reviewedInformation on pollutant trophodynamics can be crucial for public health, as contaminated food consumption may lead to deleterious effects. This study was performed in Puruzinho Lake, a remote body of water in the Brazilian Amazon from which a riparian human population obtains an important part of its animal protein intake. Samples from 92 individuals, comprising 13 species and four trophic guilds (iliophagous, planktivorous, omnivorous, and piscivorous fish) were analysed for the determination of trace elements (Fe, Cr, Mn, Ni, Zn, Ca, Sr, Cd, Sn, Tl and Pb) and methylmercury concentrations. Samples from the same individuals had already been analysed for stable isotope (SI) measurements (δ13C and δ15N) in a previous investigation and the SI data have been statistically treated with those generated in this study for the evaluation of trophic dynamics of contaminants. Methylmercury was the only analyte that biomagnified, presenting TMF values of 4.65 and 4.55 for total and resident ichthyofauna, respectively. Trace elements presented either trophic dilution or independence from the trophic position, constituting a behaviour that was coherent with that found in the scientific literature. The similarity between Ni behaviour through the trophic web to that of essential elements contributes to the discussion on the essentiality of this metal to fish. Considering the Non-cancer Risk Assessment, the calculated Target Hazard Quotient (THQ) values were higher than 1.0 for all analysed individuals for methylmercury, as well as for only one individual for nickel. No other analyte rendered THQ values higher than 1.0.14. Life below wate

High Accumulation of Perfluorooctane Sulfonate (PFOS) in Marine Tucuxi Dolphins (Sotalia guianensis) from the Brazilian Coast

Perfluorooctane sulfonate (PFOS) and other perfluoroalkyl compounds (PFCs) were measured in liver samples from 29 marine tucuxi dolphins from Rio de Janeiro state (RJ), Brazil. PFC measurement combined liquid chromatography and mass spectrometry, using a CapLC system connected to a Quadrupole- LIT mass spectrometer. PFOS was the only PFC detected and it was so in all samples. PFOS concentrations (ng ·g-1 dw) of dolphins (n)23) from the highly contaminated Guanabara Bay (in RJ) varied between 43 and 2431 as well as between 76 and 427 from areas of RJ other than the quoted bay (n ) 6). Concentrations of three fetuses and one neonate varied between 664 and 1590. Fetus/mother ratios were calculated in two situations (2.75 and 2.62). It seems that mother-to-calf transference plays important role for relationships between PFOS and age. When a one-year-old male calf presenting 2431 ng ·g-1 dw was excluded from the test, significant correlations were observed between PFOS concentrations and both age and total length. Despite the placental transference, PFOS concentrations were not significantly lower in females than in males. PFOS levels in marine tucuxi dolphins from Guanabara Bay are among the highest detected to date in cetaceans, andthismayrepresentathreat to the small population concerned

Comportamento do boto-cinza (sotalia guianensis)(cetacea: delphinidae): amostragem, termos e definições

The marine tucuxi (Sotalia guianensis Van Bénéden, 1864) is a small delphinidae currently under investigation by several different research groups along the Brazilian coast. Due to its habit of swimming in murky waters and to some morphological characteristics, studying the behavior of this animal is difficult, yet behavioral studies with S. guianensis are becoming more frequent in Brazil. However, the methods employed by different studies, including sampling techniques and terminology are not standardized, thus hindering comparisons of the results and general conclusions of such studies. This paper reviews the current state of knowledge about the behavior of this species while attempting to revise the terms, definitions and methods employed by different studies.O boto-cinza (Sotalia guianensis Van Bénéden, 1864), um pequeno delfinídeo pertencente à ordem dos cetáceos, tem sido alvo de diferentes estudos ao longo da costa brasileira. Devido à sua distribuição em águas de baixa visibilidade e às características morfológicas da espécie, S. guianensis é um objeto de estudo difícil em pesquisa de comportamento animal. Apesar das dificuldades, os estudos de comportamento de S. guianensis são cada vez mais numerosos no Brasil. Porém, não existe uma padronização dos métodos utilizados, dos intervalos de registro do comportamento ou da classificação das atividades comportamentais, dificultando comparações dos resultados e um melhor conhecimento do comportamento da espécie. O presente trabalho apresenta informações sobre o comportamento de S. guianensis e faz uma revisão dos termos, definições e metodologias aplicadas em estudos de comportamento do boto-cinza na costa brasileira

Anthropogenic and naturally-produced organobrominated compounds in marine mammals from Brazil

Liver samples from 51 cetaceans, comprising 10 species, stranded between 1994 and 2006 in a highly industrialized and urbanized region in Southeast Brazil, were analyzed for polybrominated diphenyl ethers (PBDEs) and methoxylated-PBDEs (MeO-PBDEs). A concentration range of PBDEs (3-5960 ng/g lw) similar to that observed in Northern Hemisphere dolphins was found. MeO-PBDE concentrations in continental shelf (CS) dolphins from Brazil are among the highest detected to date in cetaceans (up to 250 µg/g lw). Higher [Sigma]MeO-PBDE concentrations were measured in CS and oceanic dolphins than in estuarine dolphins. The [Sigma]PBDE/[Sigma]MeO-PBDE ratio varied significantly ranging from a mean value of 7.12 to 0.08 and 0.01 for estuarine, CS and oceanic species, respectively. A positive correlation was observed between [Sigma]PBDE and year of stranding of male estuarine dolphins (Sotalia guianensis), which suggests temporal variation in the exposure. Placental transfer of organobrominated compounds was also evidenced in S. guianensis