Maria João Botelho

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The re-emergence of Gymnodinum catenatum blooms after a 10 year hiatus of absence initiated the present investigation. This study aims to evaluate the exposure of small pelagic fishes to paralytic shellfish toxins (PST) during blooms of G. catenatum. Sardines (Sardina pilchardus) were selected as a representative fish species. In order to assess toxin(More)
The presence of paralytic shellfish poisoning (PSP) toxins has not been recorded in the Portuguese coast since 1995. A bloom of Gymnodinium catenatum occurred in the NW coast of Portugal in the autumn of 2005, and PSP profiles were determined in several inshore and offshore shellfish species by HPLC after pre-column oxidation. Most of the species studied(More)
Lichens are one of the most useful environmental biomonitors, due to their ability to clearly reflect atmospheric deposition of pollutants. Dioxin and furan (PCDD/F) emissions have been reported to be decreasing in North European countries as a consequence of European regulations. This reduction has been perceptible across several environmental matrices,(More)
The swimming crab Polybius henslowii may play an important role in the movement of the amnesic shellfish toxin, domoic acid (DA), through the marine food chain. High DA concentrations have been determined in crab samples harvested along the Portuguese coast during the summer of 2002, reaching a level of 323.1 microg DA/g crab tissue. Toxin distribution in(More)
Emissions from Portland cement manufacturing facilities may increase health risks in nearby populations and are thus subject to stringent regulations. Direct testing of pollutant concentrations in exhaust gases provides the best basis for assessing the extent of these risks. However, these tests (i) are often conducted under stressed, rather than typical,(More)
Cement kilns are known to emit polychlorinated dibenzo(p)dioxins and furans (PCDD/Fs; "dioxins"), but estimates of the amounts and patterns of these emissions vary widely. These variations may stem from a combination of factors, including the design and operating conditions of the kiln, and the fuels and raw materials fed into the kiln. The goal of this(More)
In an area with multiple sources of air pollution, it is difficult to evaluate the spatial impact of a minor source. Here, we describe the use of lichens to track minor sources of air pollution. The method was tested by transplanting lichens from a background area to the vicinity of a cement manufacturing plant that uses alternative fuel and is located in a(More)
Concentrations of the paralytic shellfish toxins C1+2, C3+4, GTX5, GTX6, dcGTX2+3, dcSTX, dcNEO, GTX2+3, GTX1+4, STX and NEO were determined by LC-FLD in composite samples of digestive glands and gills of Cerastoderma edule cockle. The specimens were sampled in Aveiro lagoon, Portugal, under natural depuration conditions (days 0, 8, 12, 14, 19, 21 and 25)(More)
During the last few years the occurrence of a high percentage of esters of diarrhetic shellfish poisoning (DSP) toxins has been observed in shellfish from the Portuguese coast. Most of the commercial bivalves contain DSP toxins in ester forms, either acyl derivatives of okadaic acid (OA) or of dinophysistoxin-2 (DTX-2). The stability of these toxins in(More)