RESUMO
Background: Haemagogus janthinomys is a primary sylvan vector of yellow fever virus and the emerging Mayaro virus. However, despite its medical importance, there is a dearth of data on the molecular taxonomy of this mosquito species. Methods: In this study, DNA barcoding analysis was performed on 64 adult female mosquitoes from Trinidad morphologically identified as Hg. janthinomys. The mitochondrial cytochrome c oxidase I (COI) gene and ribosomal DNA internal transcribed spacer 2 (ITS2) region of the mosquitoes were PCR amplified and sequenced, and molecular phylogenies inferred. Results: The BLASTN analysis showed that only 20% (n = 13/66) of COI sequences had high similarity (>99% identity) to Hg. janthinomys and the remaining sequences had low similarity (<90% identity) to reference GenBank sequences. Phylogenetic analysis of COI sequences revealed the presence of four strongly supported groups, with one distinct clade that did not align with any reference sequences. Corresponding ITS2 sequences for samples in this distinct COI group clustered into three clades. Conclusions: These molecular findings suggest the existence of a putative new Haemagogus mosquito species and underscore the need for further, more in-depth investigations into the taxonomy and classification of the Haemagogus genus.
Assuntos
Culicidae , Animais , Feminino , Código de Barras de DNA Taxonômico/veterinária , Mosquitos Vetores/genética , Mosquitos Vetores/anatomia & histologia , Filogenia , Trinidad e TobagoRESUMO
The use of lure-and-kill, large-volume ovitraps to control Aedes aegypti and Aedes albopictus populations has shown promise across multiple designs that target gravid females (adulticidal) or larvae post-oviposition (larvicidal). Here we report on a pilot trial to deploy 10 L yeast-baited ovitraps at select sites in Curepe, Trinidad, West Indies during July to December, 2019. Oviposition rates among ovitraps placed in three Treatment sites were compared to a limited number of traps placed in three Control areas (no Aedes management performed), and three Vector areas (subjected to standard Ministry of Health, Insect Vector Control efforts). Our goal was to gain baseline information on efforts to saturate the Treatment sites with ovitraps within 20-25 m of each other and compare oviposition rates at these sites with background oviposition rates in Control and Vector Areas. Although yeast-baited ovitraps were highly attractive to gravid Aedes females, a primary limitation encountered within the Treatment sites was the inability to gain access to residential compounds for trap placement, primarily due to residents being absent during the day. This severely limited our intent to saturate these areas with ovitraps, indicating that future studies must include plans to account for these inaccessible zones during trap placement.
Assuntos
Aedes , Animais , Feminino , Controle de Mosquitos , Mosquitos Vetores , Oviposição , Saccharomyces cerevisiae , Trinidad e TobagoRESUMO
Currently, there are increasing concerns about the possibility of a new epidemic due to emerging reports of Mayaro virus (MAYV) fever outbreaks in areas of South and Central America. Haemagogus mosquitoes, the primary sylvan vectors of MAYV are poorly characterized and a better understanding of the mosquito's viral transmission dynamics and interactions with MAYV and other microorganisms would be important in devising effective control strategies. In this study, a metatranscriptomic based approach was utilized to determine the prevalence of RNA viruses in field-caught mosquitoes morphologically identified as Haemagogus janthinomys from twelve (12) forest locations in Trinidad, West Indies. Known insect specific viruses including the Phasi Charoen-like and Humaiata-Tubiacanga virus dominated the virome of the mosquitoes throughout sampling locations while other viruses such as the avian leukosis virus, MAYV and several unclassified viruses had a narrower distribution. Additionally, assembled contigs from the Ecclesville location suggests the presence of a unique uncharacterized picorna-like virus. Mapping of RNA sequencing reads to reference mitochondrial sequences of potential feeding host animals showed hits against avian and rodent sequences, which putatively adds to the growing body of evidence of a potentially wide feeding host-range for the Haemagogus mosquito vector.
Assuntos
Culicidae/virologia , Vírus de RNA/isolamento & purificação , Viroma , Infecções por Alphavirus/epidemiologia , Infecções por Alphavirus/virologia , Animais , Sequência de Bases , Aves , Culicidae/microbiologia , Surtos de Doenças , Reservatórios de Doenças/virologia , Geografia Médica , Especificidade de Hospedeiro , Insetos Vetores/virologia , Filogenia , Proteobactérias/genética , Vírus de RNA/classificação , Vírus de RNA/genética , RNA Bacteriano/genética , RNA Bacteriano/isolamento & purificação , RNA Viral/genética , RNA Viral/isolamento & purificação , Roedores , Togaviridae/genética , Togaviridae/isolamento & purificação , Trinidad e Tobago/epidemiologia , Viroma/genéticaRESUMO
A suitable optimized digestion method for lipsticks and powders for the analysis of As, Hg, Cd, Cr, Ni and Pb by Hydride Generation Atomic Absorption Spectrophotometry (HG-AAS), Cold Vapor Atomic Absorption Spectrophotometry (CV-AAS) and Flame Atomic Absorption Spectrophotometry (FAAS) was developed using common acid digestion methods enhanced by the use of Triton X-100. The three acid digestion methods used in this study were Method A (nitric acid and hydrogen peroxide), Method B (nitric acid and hydrochloric acid) and Method C (nitric acid, hydrochloric acid and hydrogen peroxide). Triton X-100 was added to each of these and the effects were studied. The acid digestion method that was determined to be the most suitable and efficient for lipsticks and powders was Method A-1 (nitric acid and hydrogen peroxide with 5% Triton X-100 at 95 °C for 3 h). The range of percentage recoveries obtained were; powders (98.50% to 92. 61%) and lipsticks (100.96% to 99.41%) for As, Cd, Cr, Pb, Hg and Ni. The addition of Triton X-100 significantly improved the efficiency of the method.â¢Triton X-100 improves the efficiency of acid digestion of fatty hydrophobic samples by dispersing the sample throughout the acid digestant.
RESUMO
Dengue, Zika, chikungunya and yellow fever viruses continue to be a major public health burden. Aedes mosquitoes, the primary vectors responsible for transmitting these viral pathogens, continue to flourish due to local challenges in vector control management. Yeast interfering RNA-baited larval lethal ovitraps are being developed as a novel biorational control tool for Aedes mosquitoes. This intervention circumvents increasing issues with insecticide resistance and poses no known threat to non-target organisms. In an effort to create public awareness of this alternative vector control strategy, gain stakeholder feedback regarding product design and acceptance of the new intervention, and build capacity for its potential integration into existing mosquito control programs, this investigation pursued community stakeholder engagement activities, which were undertaken in Trinidad and Tobago. Three forms of assessment, including paper surveys, community forums, and household interviews, were used with the goal of evaluating local community stakeholders' knowledge of mosquitoes, vector control practices, and perceptions of the new technology. These activities facilitated evaluation of the hypothesis that the ovitraps would be broadly accepted by community stakeholders as a means of biorational control for Aedes mosquitoes. A comparison of the types of stakeholder input communicated through use of the three assessment tools highlighted the utility and merit of using each tool for assessing new global health interventions. Most study participants reported a general willingness to purchase an ovitrap on condition that it would be affordable and safe for human health and the environment. Stakeholders provided valuable input on product design, distribution, and operation. A need for educational campaigns that provide a mechanism for educating stakeholders about vector ecology and management was highlighted. The results of the investigation, which are likely applicable to many other Caribbean nations and other countries with heavy arboviral disease burdens, were supportive of supplementation of existing vector control strategies through the use of the yeast RNAi-based ovitraps.
Assuntos
Aedes/fisiologia , Controle de Mosquitos/instrumentação , Mosquitos Vetores/virologia , RNA Interferente Pequeno/genética , Saccharomyces cerevisiae/genética , Viroses/prevenção & controle , Aedes/virologia , Animais , Feminino , Humanos , Controle de Mosquitos/métodos , Oviposição , Participação dos Interessados , Trinidad e Tobago , Viroses/epidemiologia , Viroses/transmissãoRESUMO
RNA interference (RNAi), a technique used to investigate gene function in insects and other organisms, is attracting attention as a potential new technology for mosquito control. Saccharomyces cerevisiae (baker's yeast) was recently engineered to produce interfering RNA molecules that silence genes required for mosquito survival, but which do not correspond to genes in humans or other non-target organisms. The resulting yeast pesticides, which facilitate cost-effective production and delivery of interfering RNA to mosquito larvae that eat the yeast, effectively kill mosquitoes in laboratory and semi-field trials. In preparation for field evaluation of larvicides in Trinidad, a Caribbean island with endemic diseases resulting from pathogens transmitted by Aedes mosquitoes, adult residents living in the prospective trial site communities of Curepe, St. Augustine, and Tamana were engaged. Open community forums and paper surveys were used to assess the potential acceptability, societal desirability, and sustainability of yeast interfering RNA larvicides. These assessments revealed that Trinidadians have good working knowledge of mosquitoes and mosquito-borne illnesses. A majority of the respondents practiced some method of larval mosquito control and agreed that they would use a new larvicide if it were proven to be safe and effective. During the community engagement forums, participants were educated about mosquito biology, mosquito-borne diseases, and the new yeast larvicides. When invited to provide feedback, engagement forum attendees were strongly supportive of the new technology, raised few concerns, and provided helpful advice regarding optimal larvicide formulations, insecticide application, operational approaches for using the larvicides, and pricing. The results of these studies suggest that the participants are supportive of the potential use of yeast interfering RNA larvicides in Trinidad and that the communities assessed in this investigation represent viable field sites.
Assuntos
Aedes/genética , Engenharia Genética/métodos , Controle de Mosquitos/métodos , Interferência de RNA , Saccharomyces cerevisiae/genética , Adulto , Animais , Feminino , Humanos , Larva/genética , Masculino , Pessoa de Meia-Idade , Mosquitos Vetores/genética , Controle Biológico de Vetores/métodos , RNA Interferente Pequeno/genética , Características de Residência , Inquéritos e Questionários , Trinidad e TobagoRESUMO
There is a global lack of data concerning shark consumption trends, consumer attitudes, and public knowledge regarding sharks. This is the case in Trinidad and Tobago, where shark is a popular culinary delicacy. A Knowledge, Attitudes, and Practices (KAP) survey was conducted in Trinidad and Tobago. Six hundred and seven questionnaires were administered. Univariate and stepwise multivariate logistic regressions were performed to test the association between KAP and demographic categories. The response rate was 93.4% with 567 questionnaires returned (473 from Trinidad and 94 from Tobago). Two hundred and seventeen (38.3%) participants were knowledgeable, 422 (74.4%) displayed attitudes in favour of shark conservation and sustainable use, and 270 (47.6%) displayed practices promoting shark conservation and sustainable use. Island (AOR = 2.81, CI = 1.78, 4.46) and tertiary education (AOR = 2.31, CI = 1.20, 4.46) significantly influenced knowledge level. Gender (AOR = 1.50, CI = 1.02, 2.20) and island (AOR = 0.56, CI = 0.35, 0.90) significantly influenced attitude. Gender (COR = 1.59, CI = 1.14, 2.22) was significantly associated with practices. Over 70% of respondents ate shark, and 54.7% ate shark infrequently enough to avoid risks from heavy metal toxicity. Our results may be useful to develop public awareness and practice improvement initiatives in order to improve KAP regarding shark meat consumption.
Assuntos
Preferências Alimentares , Conhecimentos, Atitudes e Prática em Saúde , Tubarões , Inquéritos e Questionários , Adulto , Animais , Feminino , Humanos , Masculino , Carne , Pessoa de Meia-Idade , Alimentos Marinhos , Sorogrupo , Trinidad e TobagoRESUMO
ABSTRACT: Arsenic contamination in chicken is a cause of concern because of the potential health problems that may arise. In Trinidad and Tobago, chicken consumption averages about 53.8 kg per person per year, and chicken accounts for 85% of all the meat consumed locally. Fourteen chicken samples of imported, locally grown, and local organically farmed chickens were obtained from poultry depots and local supermarkets and were analyzed in triplicate. The concentration of total arsenic in the imported chicken ranged from below the method detection limit (MDL) to 512.50 µg/kg, and the concentration in the locally produced chicken ranged between Assuntos
Arsênio/análise
, Galinhas/metabolismo
, Contaminação de Alimentos/análise
, Animais
, Carne/análise
, Medição de Risco
, Trinidad e Tobago
RESUMO
The Mayaro virus disease (MAYVD) is an emerging mosquito borne zoonosis that was first reported on the island of Trinidad in 1954. The viral agent for this disease is known to presently be endemic to Central and South America. The enzootic cycle of the Mayaro virus (MAYV) is not fully characterized, though primates are thought to be the main reservoir with Haemagogus species of mosquitoes as the primary vector. This virus has been responsible for several sporadic cases of infections and limited outbreaks, but it is postulated that the MAYVD will become a major epidemic in the future, following in the steps of the recent pandemics caused by Chikungunya and Zika viruses. Mitigating possible major outbreaks of MAYVD in the future would require effective strategies for vector control, for which knowledge on the ecology and distribution of the Haemagogus mosquitoes would be vitally important. In Trinidad, Haemagogus species have only been reported in the northwestern peninsula of the island based on studies up to 1995. However, no recent investigations have been completed to determine the status of this important vector on the island. The aim of this study was to investigate the current spatial distribution of Haemagogus species in the island of Trinidad, West Indies. Adult Haemagogus (Hag.) mosquitoes and larvae were surveyed during a twenty-month period using human bait trapping and ovitraps in major forested areas on the island. Mosquito species were identified using classical taxonomic keys. Haemagogus species were widespread and found in all forest types surveyed. Hag. janthinomys (85.7%) was the most widely distributed and dominant species on the island. Lower levels of Hag. leucocelaneus (7.3%), Hag. equinus (6.4%) and Hag. celeste (0.6%) were also collected. Overall, the proportion of mosquitoes collected in the wet season (June-December) was 3.5 times more than in the dry season (January-May). Mangroves, young secondary forests, semi-evergreen and evergreen forest types had relatively high mean abundance levels of Haemagogus species as compared to deciduous and montane forests. Proximity analysis suggests that population settlements within a 1â¯km buffer of the forest peripherals may be at risk for any emerging arboviral disease associated with these mosquito vectors. Haemagogus species showed a much wider distribution in Trinidad as compared to previous reports from up to 20 years ago and were prevalent in areas with no known presence of non-human primates. Since the MAYV has been previously implicated in causing infections in vertebrate hosts like rodents, birds and small mammals, the findings of this study suggest that there may be alternative hosts and reservoirs of this virus in the sylvatic cycle in Trinidad, other than primates. This has significant epidemiological implications for mosquito-borne viral infections in the region.
Assuntos
Infecções por Alphavirus/transmissão , Culicidae , Mosquitos Vetores , Animais , Culicidae/virologia , Demografia , Humanos , Trinidad e TobagoRESUMO
The chemical vapor generation atomic absorption spectrometry technique is extremely popular for trace analysis specifically hydride generation continuous flow systems for arsenic, antimony, selenium and cold vapor for mercury. Optimizing the instrument parameters as well as the hydride generating reactions will improve the sensitivity and reliability of the results obtained. The advantage of optimizing these conditions increases the production of hydrides or vapor species formed thereby improving recoveries. In addition this helps to reduce chemical interferences from other species that may compete with the analyte of interest for hydride formation. Parameters optimized include: â¢Reagent flow rateâ¢Sample flow rateâ¢Argon flow rateâ¢Acetylene/Air ratioâ¢Concentration of reagentsâ¢Read delay time For the analytical procedure the flow rate of the reagents and sample was affected by the tension on the peristaltic pump and the size of the tubing. The optimized flow rate for all reagents was between 0.9-1.0 mL/min and between 6-7 mL/min for the sample when both conditions were applied. The optimized type and concentrations of the reducing agent for Arsenic, Antimony and Selenium were NaBH4 (0.6% w/v), NaBH4 (0.7% w/v) and NaBH4 (0.1% w/v) in NaOH (0.5% w/v) respectively and SnCl2 (25% w/v) in HCl (20% v/v) for Mercury. The concentration and type of acid that produced the optimum signals for Arsenic, Antimony and Selenium were 5, 10 and 10 mol/dm-3 respectively. The flow rates for the carrier gas (Argon) for Arsenic, Antimony, Selenium and Mercury were optimized at 0.2, 0.2, 2.0 and 2.0 mL/min respectively. The optimized flow rate for fuel gas (Acetylene) for all the metals except Mercury was 2.5 mL/min. The optimized Instrument Read Delay Time for Mercury was 70 s and 20 s for Arsenic, Antimony and Selenium.
RESUMO
A simple, efficient and cost effective method was developed and optimized for the digestion of fish tissue for the determination of Lead, Cadmium, Mercury, Antimony, Arsenic and Selenium by FAAS, CVAAS and HGAAS. Three of the more common classical open tubed acid digestion procedures were explored with the purpose of optimizing the variables and selecting the single most efficient, convenient and inexpensive digestion method. The effect of parameters such as digestion media, digestion time and digestion temperature on the efficiency of extraction of heavy metals from fish tissue was examined. Concentrated nitric acid was determined to be the most efficient digestion media for all the metals studied. â¢Efficient extraction of Arsenic, Selenium, Antimony, Lead and Cadmium was achieved at a digestion temperature of 100 °C for 120 min.â¢Optimum extraction of Mercury in fish tissue was achieved at 85 °C for 120 min since at higher temperatures, mercury was lost due to volatilization.
RESUMO
Sharks are long-lived apex predators which can accumulate toxic metals such as mercury and arsenic. Samples of Sphyrna lewini and Carcharinus porosus were collected from two commercial fish landing sites in Trinidad. Heavy metal concentrations were determined in the muscle, dorsal fin, vertebrae and liver using atomic absorption spectrometric. The provisional tolerable weekly intake (PTWI) and target hazard quotient (THQ) were determined to assess the potential health risks to consumers. Mercury levels ranged between 74-1899µg/kg in S. lewini and 67-3268µg/kg in C. porosus. Arsenic levels ranged between 144-2309µg/kg in S. lewini and 762-6155µg/kg in C. porosus. Cadmium levels generally ranged between 0.27-27.29mg/kg in S. lewini and 0.6-29.89mg/kg in C. porosus. Lead levels generally ranged between 0.14 and 208.81mg/kg in S. lewini while C. porosus levels ranged between 0.30 and 459.94mg/kg. The PTWI and THQ values suggest that consumption of these shark species can therefore be a major source of exposure to lead, cadmium, arsenic and mercury in humans and is likely to have potential health risk over long term exposure.
Assuntos
Contaminação de Alimentos , Metais Pesados/análise , Tubarões , Animais , Arsênio , Cádmio , Humanos , Chumbo , Mercúrio , Risco , Alimentos Marinhos , Trinidad e TobagoRESUMO
Dietary exposure to polycyclic aromatic hydrocarbons (PAHs) may pose serious threats to human health. However, within the Caribbean, quantitative assessments regarding the risks associated with dietary PAH exposure remain sparse. This study investigated PAH presence in edible biota from the Caroni Swamp and quantitatively assessed the potential health threat to human consumers. Mangrove oysters (Crassostrea rhizophorae) and Madamango sea catfish (Cathorops spixii) collected from seven sites in the Caroni Swamp were analysed for 16 priority PAHs. Total PAH levels ranged from 109 ± 18.4 to 362 ± 63.0 ng/g dry wt. in Crassostrea rhizophorae and 7.5 ± 0.9 to 43.5 ± 25.5 ng/g dry wt. in Cathorops spixii (average ± standard deviation). Benzo[a]pyrene levels in Crassostrea rhizophorae at all sites exceeded international guidelines from British Colombia (Canada) and the European Union (EU). Incremental lifetime cancer risk (ILCR) values based on the ingestion of Crassostrea rhizophorae ranged from 8.4 × 10(-6) to 1.6 × 10(-5) and slightly exceeded the commonly used 1 × 10(-6) acceptable level of risk. Information from this study is important in understanding the potential health risks posed by PAHs, it is critical towards the protection of public health, and it serves as a useful baseline for comparison with future work.
Assuntos
Crassostrea/química , Contaminação de Alimentos/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Alimentos Marinhos/análise , Animais , Peixes-Gato/metabolismo , Qualidade de Produtos para o Consumidor , Crassostrea/metabolismo , Humanos , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Índias Ocidentais , Áreas AlagadasRESUMO
Metals can have significant impacts on inhabitants of mangrove swamps as well as consumers of mangrove-associated fauna. Yet, for several Caribbean islands, assessments regarding the impact of metals on such ecosystems are particularly sparse. The present study investigated the distribution and potential impact of Cd, Cr, Cu, Ni, Pb and Zn in the Caroni Swamp, Trinidad and Tobago's largest mangrove ecosystem. Surface sediments and mangrove oysters (Crassostrea rhizophorae) from 10 sites in the swamp were analysed for the 6 identified metals. The concentration ranges (in µg/g dry wt.) of metals in sediments from Caroni Swamp were: Zn (113.4-264.6), Cr (27-69.7), Ni (10.7-41.1) and Cu (11-40.7). Based on Canadian Sediment Quality Guidelines (CSQGs), metals in sediments posed a low to medium risk to aquatic life. The concentration ranges (in µg/g wet wt.) for metals in Crassostrea rhizophorae tissues were: Zn (123.2-660), Cu (4.2-12.3), Ni (0.1-5.5), Pb (0.1-0.9), Cr (0.2-0.3) and Cd (0.1-0.2). Multiple evaluations indicated that zinc posed a potential threat to the health of oyster consumers. Information from this study is vital for managing the Caroni Swamp, safeguarding the health of consumers of shellfish on this Caribbean island and serving as a useful baseline for future local and regional risk assessments.
Assuntos
Crassostrea/metabolismo , Monitoramento Ambiental , Sedimentos Geológicos/química , Metais/metabolismo , Poluentes Químicos da Água/metabolismo , Áreas Alagadas , Animais , Metais/análise , Trinidad e Tobago , Poluentes Químicos da Água/análiseRESUMO
Concentrations of heavy metals were determined in nearshore marine sediments and fish tissue from Sea Lots area on the west coast, at Caroni Lagoon National Park, and in the Point Lisas harbor, Trinidad. The most dominant metals found in sediments were Al, Fe and Zn with mean concentrations highest at Sea Lots (Al-39420 µg/g; Fe-45640 µg/g; Zn-245 µg/g), when compared to sediments from Point Lisas (Al-11936 µg/g; Fe-30171 µg/g; Zn-69 µg/g) and Caroni (Al-0400 µg/g; Fe-19000 µg/g; Zn-32 µg/g), High concentration of Cu, Al, Fe and Zn were also detected in fish tissue from Point Lisas and Caroni. Metal concentrations in fish tissue showed significant correlation with sediment metals concentration, which suggests that tissue levels are influenced by sediment concentration. Of the metals, only Zn, Hg and Cu had a bioaccumulation factor (BAF) greater than one, which suggests a high bioaccumulation potential for these metals.
Assuntos
Monitoramento Ambiental , Peixes/metabolismo , Sedimentos Geológicos/química , Metais/análise , Poluentes Químicos da Água/análise , Animais , Metais/metabolismo , Metais/normas , Água do Mar/química , Trinidad e Tobago , Poluentes Químicos da Água/metabolismo , Poluentes Químicos da Água/normas , Poluição Química da Água/estatística & dados numéricosRESUMO
This study was conducted to determine the effects of increased water temperatures on the development of Aedes aegypti immatures under laboratory conditions in Trinidad, West Indies using temperature regulated water baths to cover a range of temperatures from 24-25°C to 34-35°C at a relative humidity of 80%. Two experiments were designed: (1) at constant temperature regimens and (2) under diurnal temperature regimens ranging from 24-25°C to 34-35°C. At 24-25°C egg hatching success was 98% at 48 h, however at 34-35°C egg hatching rates declined to 1.6% after 48 h. Ae. aegypti larvae reared under constant temperature regimens showed pupation on day 4 with highest pupation occurring at 30°C (78.4%) However, under diurnal temperature regimens, pupation began on day 4 but only at the higher temperatures of 30-35°C. Under diurnal temperature regimens ranging from 24°C to 35°C significantly more females emerged at higher temperatures, than males. In contrast, at constant temperatures of 24-35°C no significant difference in M/F ratios were observed. The body size of Ae. aegypti reared at constant temperature regimens was significantly larger than males and females larvae reared under diurnal temperature regimens of 25-30°C. The results of this study are discussed in the context of changing or increasing water temperatures, seasonal changes in vector populations and vector competence. Using these key factors control strategies are recommended to manage vector populations as expected increases in temperatures impact the Caribbean region.
Assuntos
Aedes/crescimento & desenvolvimento , Temperatura , Asas de Animais/crescimento & desenvolvimento , Animais , Mudança Climática , Feminino , Insetos Vetores , Larva/crescimento & desenvolvimento , Masculino , Óvulo/fisiologia , Pupa/crescimento & desenvolvimento , Estações do Ano , Razão de Masculinidade , ÁguaRESUMO
Concentrations of polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were determined in nearshore marine surficial sediments from three locations in Trinidad. Sediments were sampled at Sea Lots on the west coast, in south Port-of-Spain Harbor, south of Sea Lots at Caroni Lagoon National Park, and on Trinidad's east coast at Manzanilla. Total PCB concentrations in Sea Lots sediments ranged from 62 to 601ng/g (dry weight {dw}), which was higher than at Caroni and Manzanilla, 13 and 8ng/g dw, respectively. Total OCP concentrations at Sea Lots were ranged from 44.5 to 145ng/g dw, compared with 13.1 and 23.8n/g (dw), for Caroni and Manzanilla respectively. The concentrations of PCBs and of some OCPs in sediments from Sea Lots were above the Canadian interim sediment quality guidelines. To date, this data is the first report on the levels of PCBs and other organochlorine compounds from Trinidad and Tobago.
Assuntos
Sedimentos Geológicos/química , Hidrocarbonetos Clorados/análise , Praguicidas/análise , Bifenilos Policlorados/análise , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Trinidad e Tobago , Poluição Química da Água/estatística & dados numéricosRESUMO
Organochlorine compounds are a class of pollutants considered toxic to humans, fish and wildlife, and show great potential for accumulation and persistence in the environment. In May 1995, the United Nations Environmental Program (UNEP) Governing Council adopted Decision 18/32 (GC18/32) on persistent organic pollutants (POPs), the goal of which was to initiate an expeditious assessment process, initially beginning with twelve priority POPs: polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs or dioxins), polychlorinated dibenzofurans (PCDFs), aldrin, dieldrin, DDT, endrin, chlordane, hexachlorobenzene (HCB), mirex, toxaphene and heptachlor. In 1997, based on recommendations from the Intergovernmental Forum on Chemical Safety (IFCS), UNEP decided that immediate international action should be initiated to protect human health and the environment by reducing and/or eliminating emissions and discharges of the twelve persistent organic pollutants (the dirty dozen) specified by GC18/32. UNEP decision GC19/13C proposed a series of immediate action responses based on the IFCS recommendations: (1) general awareness of POPs; (2) information exchange between countries and organizations; and (3) improved availability of information and expertise on alternatives to POPs (UNEP, 2001 UNEP. 2001. The Stockholm Convention on Persistent Organic Pollutants.
Assuntos
Animais , Humanos , Inseticidas Organoclorados , Poluentes da Água/toxicidade , Poluentes Químicos da Água/toxicidade , Poluentes Ambientais/toxicidade , Trinidad e TobagoRESUMO
In recent times, bioprospecting for plants that show bioactive properties has yielded many chemicals that can be used in controlling mosquitoes. Crude extracts of 4 terrestrial and 3 mangrove plants were assayed against 2-3 larval instars of Aedes aegypti. Among the plants tested, Cordia curassavica showed the highest levels of activity for all the extracts tested. Azadirachta indica showed the least activity, whereas the 2 cultivars of Mangifera indica showed substantial activity for the aqueous extracts. The mangrove species proved to be relatively nontoxic to Ae. aegypti larvae when compared to the terrestrial plants. The results of this study suggest that some common plants in Trinidad may be highly effective in controlling the urban vector of yellow fever and dengue fever, Ae. aegypti.