RESUMO

Acetylcholinesterase (AChE) activity levels can be used as an indicator for AChE inhibition due to pesticide poisoning in bird species. We assessed the comparative brain cholinesterase (AChE) activity level of five bird species inhabiting pesticide exposed croplands and Protected Area i.e. Deva Vatala National Park (DVNP), Bhimber by using a spectrophotometric method. AChE activity levels ranged from 56.3 to 85.9 µmol/min/g of brain tissue of birds representing DVNP. However, AChE activity levels ranged from 27.6 to 79.9 µmol/min/g of brain tissue of birds representing croplands. AChE activity levels observed in Jungle babbler, Common babbler, and Red-vented bulbul showed significant differences (P 0.05). Maximum inhibition was recorded in Jungle babbler (53%) followed by Common babbler (35%), Red-vented bulbul (18%), White wagtail (15%), and Black drongo (7%). The brain cholinesterase inhibition levels under-protected ecosystems (DVNP, Bhimber) and agricultural landscape suggest insecticidal contamination and its impact on avifauna diversity. The study also emphasizes on the importance of pesticide-free zones to protect the biodiversity of birds.

Os níveis de atividade da acetilcolinesterase (AChE) podem ser usados como um indicador para a inibição da AChE devido ao envenenamento por pesticidas em espécies de aves. Avaliamos o nível de atividade comparativa da colinesterase cerebral (AChE) de cinco espécies de aves que habitam áreas cultivadas expostas a pesticidas e Área Protegida, ou seja, Deva Vatala National Park (DVNP), Bhimber, usando um método espectrofotométrico. Os níveis de atividade da AChE variaram de 56,3 a 85,9 µmol / min / g de tecido cerebral de aves representando DVNP. No entanto, os níveis de atividade da AChE variaram de 27,6 a 79,9 µmol / min / g de tecido cerebral de aves representando áreas de cultivo. Os níveis de atividade de AChE observados no tagarela da selva, tagarela comum e bulbul vermelho exalado mostraram diferenças significativas (P 0,05). A inibição máxima foi registrada no tagarela da selva (53%), seguido pelo tagarela comum (35%), bulbul vermelho (18%), alvéola branca (15%) e drongo preto (7%). Os níveis de inibição da colinesterase cerebral nos ecossistemas subprotegidos (DVNP, Bhimber) e na paisagem agrícola sugerem contaminação por inseticida e seu impacto na diversidade da avifauna. O estudo também enfatiza a importância das zonas livres de pesticidas para proteger a biodiversidade das aves.

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RESUMO

Acetylcholinesterase (AChE) activity levels can be used as an indicator for AChE inhibition due to pesticide poisoning in bird species. We assessed the comparative brain cholinesterase (AChE) activity level of five bird species inhabiting pesticide exposed croplands and Protected Area i.e. Deva Vatala National Park (DVNP), Bhimber by using a spectrophotometric method. AChE activity levels ranged from 56.3 to 85.9 µmol/min/g of brain tissue of birds representing DVNP. However, AChE activity levels ranged from 27.6 to 79.9 µmol/min/g of brain tissue of birds representing croplands. AChE activity levels observed in Jungle babbler, Common babbler, and Red-vented bulbul showed significant differences (P < 0.05) at two sites. However, White wagtail and Black drongo demonstrated non-significant differences (P > 0.05). Maximum inhibition was recorded in Jungle babbler (53%) followed by Common babbler (35%), Red-vented bulbul (18%), White wagtail (15%), and Black drongo (7%). The brain cholinesterase inhibition levels under-protected ecosystems (DVNP, Bhimber) and agricultural landscape suggest insecticidal contamination and its impact on avifauna diversity. The study also emphasizes on the importance of pesticide-free zones to protect the biodiversity of birds.(AU)

Os níveis de atividade da acetilcolinesterase (AChE) podem ser usados como um indicador para a inibição da AChE devido ao envenenamento por pesticidas em espécies de aves. Avaliamos o nível de atividade comparativa da colinesterase cerebral (AChE) de cinco espécies de aves que habitam áreas cultivadas expostas a pesticidas e Área Protegida, ou seja, Deva Vatala National Park (DVNP), Bhimber, usando um método espectrofotométrico. Os níveis de atividade da AChE variaram de 56,3 a 85,9 µmol / min / g de tecido cerebral de aves representando DVNP. No entanto, os níveis de atividade da AChE variaram de 27,6 a 79,9 µmol / min / g de tecido cerebral de aves representando áreas de cultivo. Os níveis de atividade de AChE observados no tagarela da selva, tagarela comum e bulbul vermelho exalado mostraram diferenças significativas (P < 0,05) em dois locais. No entanto, alvéola branca e drongo preto demonstraram diferenças não significativas (P > 0,05). A inibição máxima foi registrada no tagarela da selva (53%), seguido pelo tagarela comum (35%), bulbul vermelho (18%), alvéola branca (15%) e drongo preto (7%). Os níveis de inibição da colinesterase cerebral nos ecossistemas subprotegidos (DVNP, Bhimber) e na paisagem agrícola sugerem contaminação por inseticida e seu impacto na diversidade da avifauna. O estudo também enfatiza a importância das zonas livres de pesticidas para proteger a biodiversidade das aves.(AU)

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The concentrations of recognized or suspected genotoxic and carcinogenic agents found in the air of large cities and, in particular, developing countries, have raised concerns about the potential for chronic health effects in the populations exposed to them. The biomonitoring of environmental genotoxicity requires the selection of representative organisms as "sentinels," as well as the development of suitable and sensitive assays, such as those aimed at assessing DNA damage. The aim of this study was to evaluate DNA damage levels in erythrocytes from Columba livia living in the metropolitan area of Monterrey, Mexico, compared with control animals via comet assay, and to confirm the results via Micronuclei test (MN) and DNA breakage detection-fluorescence in situ hybridization (DBD-FISH). Our results showed a significant increase in DNA migration in animals from the area assayed compared with that observed in control animals sampled in non-contaminated areas. These results were confirmed by MN test and DBD-FISH. In conclusion, these observations confirm that the examination of erythrocytes from Columba livia via alkaline comet assay provides a sensitive and reliable end point for the detection of environmental genotoxicants.

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A mortality event caused by exposure to the carbamate insecticide methomyl was diagnosed in several hundred pigeons fed treated corn kernels in a city park. A cholinesterase inhibitor insecticide was initially suspected based on clinical signs and a significant inhibition (P < 0.05) of brain cholinesterase (ChE) activity compared with normal values for the species. However, brain ChE activity was within the normal range in birds subsequently submitted in an advanced stage of autolysis. Two groups of 10 healthy pigeons were allocated into a control group and an experimental group, which was offered corn samples retrieved from the incident site. Within minutes of ingesting the contaminated corn, the birds became immobile, had transient wing fluttering, and developed profuse salivation immediately followed by death. Plasma ChE activity at death had declined by more than 95% of preexposure levels (0.04 +/- 0.02 vs. 1.56 +/- 0.23 micromol/min per milliliter). Brain activity in the sagittal brain sections that were immediately frozen after death was inhibited by > or =50% of control birds (13.5 +/- 2.2 vs. 27.5 +/- 1.8 micromol/min per gram). However, the sagittal sections left for 1.5 days at ambient temperature of 25 degrees C had normal or higher activity, an effect that was attributed to a combination of spontaneous reactivation and dehydration. After incubation of both plasma and brain homogenates for 1 hr at 37 degrees C, ChE activity recovered by 2- and 1.46-fold, respectively. An organophosphorus and carbamate screen conducted by 2 independent laboratories identified and quantified methomyl in treated kernels at 400 ppm. These results indicate that spontaneous reactivation and dehydration can mask previous reductions in ChE activity.

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Poisoning of waterfowl due to ingestion of lead pellets is a worldwide problem in areas that are subject to hunting. No studies have assessed exposure of waterbirds to this heavy metal in Argentina, in spite of intense hunting activity, and the fact that only lead ammunition is commercially available. The objective of this study was to evaluate duck exposure to lead by examining gizzard and bone samples collected from 30 wild ducks, 16 Rosy-billed Pochard (Netta peposaca), and 14 Fulvous Whistling-Duck (Dendrocygna bicolor), provided by hunters in northern Santa Fe Province, Argentina, in July 2007. Radiographs, followed by dissection of the gizzards, showed that 31% of the Rosy-billed Pochards and 29% of the Fulvous Whistling-Ducks had ingested lead pellets (between one and four per animal). Lead in bone was found at concentrations associated with detrimental health effects. In spite of the small number of samples in this project, these results indicate high levels of lead exposure (both recent and chronic) in these species. This is the first report of a problem in Argentina that could represent a threat to the health and conservation of native aquatic species, their predators, and the wetlands they inhabit.

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Petroleum pollution is a problem for seabirds along the Southwest Atlantic coast. Twenty-five groups from Salvador, Brazil (12 degrees 58'S) to San Antonio Oeste, Argentina (40 degrees 43'S) survey or rehabilitate sick or oiled seabirds. Four groups, one each in Brazil and Uruguay, and two in Argentina, kept counts of birds found alive and in need of rehabilitation. An average of 63.7% of the seabirds found were Magellanic penguins (Spheniscus magellanicus), with 3869 reported since 1987. Mainly adult penguins were found in Argentina (1605 of 2102 penguins of known age class) and Uruguay (158 of 197). Juveniles were most common in Brazil (234 of 325). Oil fouling was the most frequent cause of injury or sickness. The number of oiled penguins reported in their wintering range has greatly increased since the early 1990s and is strongly correlated with petroleum exports from Argentina. Our results show that chronic petroleum pollution is a problem for wildlife from Southern Brazil through Northern Argentina, and regulations and enforcement are failing to protect living resources.

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Domoic acid was found to be responsible for an isolated event involving the massive death of brown pelicans (Pelecanus occidentalis) in January 1996, at the tip of the Baja California peninsula. The death of these sea birds was the result of feeding on mackerel (Scomber japonicus) contaminated by domoic acid-producing diatoms (Pseudonitzschia sp.). The number of dead birds (150 animals) found during a period of 5 days caused alarm and called for a governmental task force that would help to implement emergency measurements to protect other species of bird. Also, local canneries were inspected to verify the safety of their recent production and prevent the toxin entering the human market. Fortunately, the timing, response and coordination of this task force enabled identification of the origin and nature of the toxin that provoked such a phenomenon. Future monitoring is recommended to avoid a larger impact of domoic acid spreading and the occurrence of similar toxic events.

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