Eating tropical fruit reduces mercury exposure from fish consumption in the Brazilian Amazon.

This study aimed to examine the influence of the consumption of traditional foods on the relationship between fish consumption and mercury (Hg) exposure. A 12-month prospective dietary survey was carried out with 26 adult women from a fish-eating community in the Brazilian Amazon. Food ingestion was determined using a daily food diary, and total hair Hg levels were assessed for each month through sequential analyses using cold vapor atomic absorption spectrometry. Simple and multiple regression analyses showed that the strong relationship between fish consumption and Hg exposure was significantly modified by fruit consumption: for the same number of fish meals, those who ate more tropical fruits had lower hair mercury levels. The findings of this study indicate different ways of maintaining fish consumption while reducing Hg exposure in the Amazon. A number of phytochemicals and nutritional fibers present in fruits might be interacting with Hg in several ways: absorption and excretion, transport, binding to target proteins, metabolism, and sequestration. More studies are required on larger populations to further elucidate the extent and public health implications of the use of fruits to counteract the toxic action of methylmercury.

Presence of oOrganophosphate Insecticides in fish of the Amazon River

Trace levels of three organophosphate insecticides (OPI) were detected in eight fish species from the region of Santarém, State of Pará, Brazil. Individual concentrations of OPI in fish ranged from less than the detection limit to 2,1 ppb. Mean concentrations of chlorpyrifos, malathion, and methyl-parathion were 0,3 ± 0,3, 0,1 ± 0,1, and 0,3 ± 0,3 ppb, respectively. Pellona flavipinnis, the largest and fattest piscivorous species analyzed, was the most contaminated. Since an inhabitant of this Amazonian region consumes 220 g of fish per day on average, ingested doses of chlorpyrifos, malathion, and methyl-parathion may reach up to 308, 220, and 462 ng·d-1, respectively. Compared to acceptable daily intakes (ADI), quantities of OPI absorbed via fish consumption on a daily basis are far below deleterious levels. We estimated that even considering the highest OPI contents detected, the average daily fish consumption of anadult of 60 kg would have to increase by ca. 1 950, 5 450, and 2 600 times to reach ADI of chlorpyrifos, malathion, and methyl-parathion, respectively. Neither fish diet nor fish lipid content enabled us to completely explain the interspecific differences observed.

As concentrações de três inseticidas organofosforados (IOF) foram determinadas em oito espécies de peixes da região de Santarém, Estado do Pará, Brasil. As concentrações individuais de IOF dos peixes situam-se entre abaixo da limite de detecção e 2,1 ppb. As concentrações médias de clorpirifós, malathion e metil parathion foram respectivamente de 0,3 ± 0,3, 0,1 ± 0,1 e 0,3 ± 0,3 ppb. Pellom Flavipinnis, a espécie piscívora de maior tamanho e mais gordurosa, apresentou as concentrações mais elevadas. Considerando que um morador dessa região da Amazônia brasileira consome em média 220 g de peixe por dia, as doses de clorpirifós, malathion e metil parathion podem atingir respectivamente 308, 220 e 462 ng·d-1. Tendo em conta as "doses diárias aceitáveis" (acceptable daily intakes - ADI), as quantidades diárias de IOF absorvidas via consumo de peixe estão muito abaixo dos níveis perigosos para a saúde humana. Nós estimamos que mesmo com o teor mais elevado de IOF detectado, o consumo diário médio de peixe de um adulto de 60 kg teria que aumentar cerca de 1 950, 5 450 e 2 600 vezes para atingir as respectivas ADI de clorpirifós, malathion e metil parathion. Nem o hábito alimentar dos peixes e nem o seu teor de gorduras podem explicar completamente as diferenças interespecíficas observadas.