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Toxin Levels (toxin + level)
Selected AbstractsNodularin uptake by seafood during a cyanobacterial bloomENVIRONMENTAL TOXICOLOGY, Issue 6 2001P. G. Van Buynder Abstract The problem of blue-green algal toxin contamination of recreational waters and drinking water catchments is well described, as is the potential contamination of associated seafood. Algal contamination of Victorian waterways is now a widespread annual occurrence and, in some regions, the intersection of blooms and commercial fishing threatens the food safety of large numbers of people. Toxin levels which produce no observed adverse effect in animal studies were used to derive safe tolerable daily intake levels. These ,acceptable levels' were then modified to protect against potential acute health risks associated with short-term exposures. National food surveys were used to derive likely seafood intakes and thus, in combination with ,safe toxin levels', health alert levels for seafood were formulated. During the summer of 2001 a bloom of Nodularia spumigena occurred in the Gippsland Lakes area of Southern Victoria. During the bloom, seafood samples were collected and nodularin concentrations were estimated. Nodularin concentrations reached levels of concern in mussels and in prawn viscera at cell counts as low as 30,000 cells/ml. Nodularin concentrations in the flesh of finfish remained low. Boiling the seafood redistributed toxin between viscera and flesh. The results were used to restrict some seafood harvesting. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 468,471, 2001 [source] FUNGI AND PATULIN IN APPLES AND THE ROLE OF PROCESSING ON PATULIN LEVELS IN JUICES: A STUDY ON NATURALLY CONTAMINATED APPLESJOURNAL OF FOOD SAFETY, Issue 2 2010JULIANE ELISA WELKE ABSTRACT The purpose of this study was to determine the predominant fungal species, including toxigenic strains, patulin levels in apples used for juice production and in produced juices. The possibility of use of apple highly contaminated with patulin to produce juice with lower patulin levels than the limit permitted by Codex Alimentarius was also checked. Sixteen lots of apples and juices were analyzed. The most prevalent fungal population was Penicillium spp. (93%) followed by the Aspergillus spp. (3.5%) and the Rhizopus spp. (3.5%). The mycoflora of apples was composed mainly of species that produce patulin. P. expansum was identified as the most frequently isolated species (66%). Species able to produce patulin were P. expansum and P. griseofulvum. Patulin levels in apples from cold storage ranged from 254.6 to 653.4 µg/kg. Apple juice processing caused average reduction of 95% in patulin levels. Patulin levels ranged from 14.3 to 46.7 µg/L in apple juices. In all samples were found patulin levels lower than the limit of 50 µg/L considered acceptable by the Codex Alimentarius Commission. PRACTICAL APPLICATIONS This study was performed to define the mycoflora of apples and patulin levels in apples that were used for juice production. This approach is useful to evaluate the quality of apples and the effect of processing on patulin to determine if the toxin level can be managed through postharvest procedures. Besides, information about patulin levels in juices is important to contribute for establishing national regulation. [source] HOW BRIGHT AND HOW NASTY: EXPLAINING DIVERSITY IN WARNING SIGNAL STRENGTHEVOLUTION, Issue 3 2007Michael P. Speed The conspicuous displays that warn predators of defenses carried by potential prey have been of interest to evolutionary biologists from the time of Wallace and Darwin to the present day. Although most studies implicitly assume that these "aposematic" warning signals simply indicate the presence of some repellent defense such as a toxin, it has been speculated that the intensity of the signal might reliably indicate the strength of defense so that, for example, the nastiest prey might "shout loudest" about their unprofitability. Recent phylogenetic and empirical studies of Dendrobatid frogs provide contradictory views, in one instance showing a positive correlation between toxin levels and conspicuousness, in another showing a breakdown of this relationship. In this paper we present an optimization model, which can potentially account for these divergent results. Our model locates the optimal values of defensive traits that are influenced by a range of costs and benefits. We show that optimal aposematic conspicuousness can be positively correlated with optimal prey toxicity, especially where population sizes and season lengths vary between species. In other cases, optimal aposematic conspicuousness may be negatively correlated with toxicity; this is especially the case when the marginal costs of aposematic displays vary between members of different populations. Finally, when displays incur no allocation costs there may be no single optimum value for aposematic conspicuousness, rather a large array of alternative forms of a display may have equal fitness. [source] 41 Incidence of paralytic shellfish toxin in bivalve mollusc tissue from the oregon coastJOURNAL OF PHYCOLOGY, Issue 2003R. C. Everroad Saxitoxin and domoic acid sequestration by bivalve molluscs occurs periodically along the Oregon coast, presumably as a result of harmful algal blooms (HABs). Since 1958 and more continuously since 1979, the Oregon Shellfish Program (OSP) has assayed toxin levels in these molluscs as part of a monitoring program for paralytic (PSP) and amnesic (ASP) shellfish poisoning. We have created a working data base for all PSP sampling by the OSP between 1958 and 2001 and have examined the data for spatial and temporal trends in the appearance of toxin in shellfish, amount of toxin, and apparent duration of toxic events. In this report, we examine the data from the five stations with the longest record of continuous sampling (1979,2000) for evidence of correlation with El Niño events, upwelling, and/or a pattern of increasing frequency or intensity of toxic events. We also compare the pattern of appearance of toxin at open coast stations with the timing of first appearance of toxin in shellfish at adjacent estuarine stations. This is an important analysis because, in Oregon, shellfish closures due to PSP occur frequently in mussel beds on the open coast and the source of toxin-producing organisms is unknown. [source] Nodularin uptake by seafood during a cyanobacterial bloomENVIRONMENTAL TOXICOLOGY, Issue 6 2001P. G. Van Buynder Abstract The problem of blue-green algal toxin contamination of recreational waters and drinking water catchments is well described, as is the potential contamination of associated seafood. Algal contamination of Victorian waterways is now a widespread annual occurrence and, in some regions, the intersection of blooms and commercial fishing threatens the food safety of large numbers of people. Toxin levels which produce no observed adverse effect in animal studies were used to derive safe tolerable daily intake levels. These ,acceptable levels' were then modified to protect against potential acute health risks associated with short-term exposures. National food surveys were used to derive likely seafood intakes and thus, in combination with ,safe toxin levels', health alert levels for seafood were formulated. During the summer of 2001 a bloom of Nodularia spumigena occurred in the Gippsland Lakes area of Southern Victoria. During the bloom, seafood samples were collected and nodularin concentrations were estimated. Nodularin concentrations reached levels of concern in mussels and in prawn viscera at cell counts as low as 30,000 cells/ml. Nodularin concentrations in the flesh of finfish remained low. Boiling the seafood redistributed toxin between viscera and flesh. The results were used to restrict some seafood harvesting. © 2001 John Wiley & Sons, Inc. Environ Toxicol 16: 468,471, 2001 [source] | ||||||||||