Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Cancer Educ ; 30(3): 490-6, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25420766

RESUMO

Multiple factors contribute to disparities in head and neck cancer prevalence across the sociodemographic spectrum, including a lack of screening efforts in mostly underserved minority communities. African Americans and other ethnic minorities are at greater risk for late-stage diagnoses due to the lack of routine screenings and examinations. Advanced stage diagnosis profoundly limits treatment options, disease recovery, and survivorship. Differential access to care is frequently cited as contributing to delayed diagnosis in minority patients. Access to care is a complex concept that includes not only insurance status but also the equitable spatial distribution of health-care services. Recognizing this complexity, we explored the distribution of head and neck cancer cases seen at Grady Health System from 2010 to 2012 in order to identify geographic trends in disease prevalence compared to the distribution of oral health-care providers at the zip code level. We identified 53 cases of head and neck cancer spread across 36 zip codes primarily in the metropolitan Atlanta region. Geographic information systems analysis showed a spatial mismatch: increased disease prevalence and provider shortage in the mostly minority zip codes, and decreased disease prevalence and greater provider presence in the majority zip codes.


Assuntos
Neoplasias de Cabeça e Pescoço/epidemiologia , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Disparidades nos Níveis de Saúde , Área Carente de Assistência Médica , Acidentes por Quedas/estatística & dados numéricos , Adulto , Idoso , Idoso de 80 Anos ou mais , Assistência Odontológica/estatística & dados numéricos , Feminino , Sistemas de Informação Geográfica , Mapeamento Geográfico , Georgia/epidemiologia , Neoplasias de Cabeça e Pescoço/etnologia , Hospitais Urbanos/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Grupos Minoritários , Prevalência , Fatores Socioeconômicos
2.
Environ Pollut ; 343: 123157, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38142808

RESUMO

In coastal waters, higher concentrations of microplastics (MPs) are generally related to densely populated and industrialized areas, but intense upwelling and offshore transport in the Eastern Boundary Upwelling Systems (EBUS) may influence this pattern. The Humboldt Current System (HCS) along the coast of northern-central Chile represents a perfect model to test whether the abundance of MP at the sea surface decreases with distance from land-based sources, e.g., river mouths, harbors, and submarine wastewater outfalls. The sea surface was sampled with a manta trawl to examine the abundance, composition, and distribution of floating MPs, and Generalized Additive Mixed Models (GAMMs) were performed to examine the relationship between MP abundance (particles km-2) and the distance to putative sources. MPs were found in all 57 net tows, with an average of ⁓120,000 MP km-2 and maximum values of ⁓1,500,000 MP km-2. The composition of MPs was dominated by fragments (>50% of the total count) and over 80% of all MPs were ≥1 mm. The combined effect of the various sources, spatially concentrated in urban areas, makes it difficult to distinguish their relative contributions, but the MP composition suggested that rivers are more important sources, followed by submarine wastewater outfalls and then harbors. A significant and steep negative relationship with the "distance to source" explained 15.2% of the variance of "MP abundance", suggesting rapid offshore displacement within the HCS. This is the first study to report this pattern along the edges of the South Pacific Subtropical Gyre (SPSG), revealing that continuous offshore transport of microplastic from land-based sources is occurring over large scales and contributing to the accumulation of microplastics in the center of the SPSG. However, the findings additionally suggested that processes at meso- and submeso-spatial scales (driven by geographic and seasonal variables) are disrupting the general pattern.


Assuntos
Microplásticos , Poluentes Químicos da Água , Plásticos , Águas Residuárias , Poluentes Químicos da Água/análise , Monitoramento Ambiental
3.
Hepatology ; 56(4): 1223-30, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22488513

RESUMO

UNLABELLED: Treatment of chronic hepatitis C infection (HCV(+) ) has historically been shown to be less effective in patients with a heavy drinking history. The effect of moderate and heavy alcohol use on treatment with pegylated interferon-alpha and ribavirin (P/R) in an insured household population has not been previously reported. We investigated the effect of alcohol on treatment outcome in a cohort of 421 treatment-naïve HCV(+) patients, members of an integrated health care plan treated with P/R between January 2002 and June 2008. A detailed drinking history was obtained for 259 (61.5%) eligible patients. Regular drinking was reported by 93.1% of patients before HCV diagnosis, by 30.9% between HCV diagnosis and treatment, by 1.9% during treatment, and 11.6% after the end of treatment. Heavy drinking patterns were reported by 67.9%, 63.5% of patients drank more than 100 kg of ethanol before initiating HCV treatment, and 29.3% reported abstaining less than the required 6 months before treatment. Despite these reports of heavy drinking, sustained virological responses (SVRs) were obtained in 80.2% of patients with HCV genotypes 2 or 3 and 45.1% of patients with genotypes 1, 4, or 6. Pretreatment drinking patterns and total alcohol intake were both unrelated to SVR rates. Abstaining less than 6 months before treatment was related to lower SVR rates in moderate, but not heavy, drinkers. HCV treatment relapse was unrelated to drinking after treatment ended. CONCLUSION: The amount of alcohol consumed before HCV treatment did not have a negative effect on treatment outcomes in our population. A history of heavy drinking should not be considered a deterrent to HCV treatment in members of an integrated health care plan who are closely monitored.


Assuntos
Consumo de Bebidas Alcoólicas/efeitos adversos , Prestação Integrada de Cuidados de Saúde/economia , Hepatite C/tratamento farmacológico , Interferon-alfa/uso terapêutico , Polietilenoglicóis/uso terapêutico , Ribavirina/uso terapêutico , Adulto , Idoso , Consumo de Bebidas Alcoólicas/economia , Antivirais/economia , Antivirais/uso terapêutico , California , Estudos de Coortes , Intervalos de Confiança , Quimioterapia Combinada , Feminino , Seguimentos , Hepatite C/diagnóstico , Hepatite C/economia , Humanos , Seguro Saúde/economia , Interferon-alfa/economia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Polietilenoglicóis/economia , Setor Privado/economia , Proteínas Recombinantes/economia , Proteínas Recombinantes/uso terapêutico , Estudos Retrospectivos , Ribavirina/economia , Medição de Risco , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento
4.
PLoS One ; 18(3): e0281596, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36888681

RESUMO

As global awareness, science, and policy interventions for plastic escalate, institutions around the world are seeking preventative strategies. Central to this is the need for precise global time series of plastic pollution with which we can assess whether implemented policies are effective, but at present we lack these data. To address this need, we used previously published and new data on floating ocean plastics (n = 11,777 stations) to create a global time-series that estimates the average counts and mass of small plastics in the ocean surface layer from 1979 to 2019. Today's global abundance is estimated at approximately 82-358 trillion plastic particles weighing 1.1-4.9 million tonnes. We observed no clear detectable trend until 1990, a fluctuating but stagnant trend from then until 2005, and a rapid increase until the present. This observed acceleration of plastic densities in the world's oceans, also reported for beaches around the globe, demands urgent international policy interventions.


Assuntos
Smog , Poluentes Químicos da Água , Poluentes Químicos da Água/análise , Plásticos , Monitoramento Ambiental , Oceanos e Mares , Resíduos/análise
5.
Chemosphere ; 308(Pt 3): 136449, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36115477

RESUMO

Microscopy is often the first step in microplastic analysis and is generally followed by spectroscopy to confirm material type. The value of microscopy lies in its ability to provide count, size, color, and morphological information to inform toxicity and source apportionment. To assess the accuracy and precision of microscopy, we conducted a method evaluation study. Twenty-two laboratories from six countries were provided three blind spiked clean water samples and asked to follow a standard operating procedure. The samples contained a known number of microplastics with different morphologies (fiber, fragment, sphere), colors (clear, white, green, blue, red, and orange), polymer types (PE, PS, PVC, and PET), and sizes (ranging from roughly 3-2000 µm), and natural materials (natural hair, fibers, and shells; 100-7000 µm) that could be mistaken for microplastics (i.e., false positives). Particle recovery was poor for the smallest size fraction (3-20 µm). Average recovery (±StDev) for all reported particles >50 µm was 94.5 ± 56.3%. After quality checks, recovery for >50 µm spiked particles was 51.3 ± 21.7%. Recovery varied based on morphology and color, with poorest recovery for fibers and the largest deviations for clear and white particles. Experience mattered; less experienced laboratories tended to report higher concentration and had a higher variance among replicates. Participants identified opportunity for increased accuracy and precision through training, improved color and morphology keys, and method alterations relevant to size fractionation. The resulting data informs future work, constraining and highlighting the value of microscopy for microplastics.


Assuntos
Microplásticos , Poluentes Químicos da Água , Monitoramento Ambiental , Humanos , Microscopia , Plásticos/análise , Polímeros , Cloreto de Polivinila/análise , Água/análise , Poluentes Químicos da Água/análise
6.
Sci Total Environ ; 759: 143545, 2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33203559

RESUMO

The hyper-oligotrophic waters of the South Pacific Subtropical Gyre (SPSG) and the productive coastal Humboldt Current System (HCS) constitute an extreme nutrient gradient in the eastern South Pacific Ocean. Rich and dense fouling communities are known from floating objects in the HCS, but they have not been studied in the SPSG and it is not known which factors are influencing their richness and abundance. Here we present the first extensive study of rafting by marine invertebrates on floating anthropogenic debris in the eastern SPSG. We compared the effect of 9 raft-related categorical predictors on epibiont richness and fouling cover. Raft complexity was the most important predictor of richness. Fouling was dominated by thin crusts and biofilms, with more advanced communities only observed on few items. Fouling cover could not be predicted by any of the categorical factors tested. However, when tested as continuous predictors, raft volume and surface area were significantly correlated with both cover and richness. The most frequently encountered epibionts were common pelagic rafters, particularly Lepas spp., Planes spp., and Jellyella spp. Low fouling cover suggests that the SPSG's hyper-oligotrophic conditions strongly limit fouling growth, while the low frequency of coastal taxa points to the HCS/SPSG nutrient gradient acting as a filter for such organisms.


Assuntos
Thoracica , Animais , Organismos Aquáticos , Oceano Pacífico , Plásticos
7.
J Environ Monit ; 12(12): 2226-36, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21042605

RESUMO

Floating marine plastic debris was found to function as solid-phase extraction media, adsorbing and concentrating pollutants out of the water column. Plastic debris was collected in the North Pacific Gyre, extracted, and analyzed for 36 individual PCB congeners, 17 organochlorine pesticides, and 16 EPA priority PAHs. Over 50% contained PCBs, 40% contained pesticides, and nearly 80% contained PAHs. The PAHs included 2, 3 and 4 ring congeners. The PCBs were primarily CB-11, 28, 44, 52, 66, and 101. The pesticides detected were primarily p,p-DDTs and its metabolite, o,p-DDD, as well as BHC (a,b,g and d). The concentrations of pollutants found ranged from a few ppb to thousands of ppb. The types of PCBs and PAHs found were similar to those found in marine sediments. However, these plastic particles were mostly polyethylene which is resistant to degradation and although functioning similarly to sediments in accumulating pollutants, these had remained on or near the ocean surface. Particles collected included intact plastic items as well as many pieces less than 5 mm in size.


Assuntos
Plásticos , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Resíduos de Alimentos , Oceano Pacífico
8.
Environ Res ; 108(2): 131-9, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18949831

RESUMO

Synthetic polymers, commonly known as plastics, have been entering the marine environment in quantities paralleling their level of production over the last half century. However, in the last two decades of the 20th Century, the deposition rate accelerated past the rate of production, and plastics are now one of the most common and persistent pollutants in ocean waters and beaches worldwide. Thirty years ago the prevailing attitude of the plastic industry was that "plastic litter is a very small proportion of all litter and causes no harm to the environment except as an eyesore" [Derraik, J.G.B., 2002. The pollution of the marine environment by plastic debris: a review. Mar. Pollut. Bull. 44(9), 842-852]. Between 1960 and 2000, the world production of plastic resins increased 25-fold, while recovery of the material remained below 5%. Between 1970 and 2003, plastics became the fastest growing segment of the US municipal waste stream, increasing nine-fold, and marine litter is now 60-80% plastic, reaching 90-95% in some areas. While undoubtedly still an eyesore, plastic debris today is having significant harmful effects on marine biota. Albatross, fulmars, shearwaters and petrels mistake floating plastics for food, and many individuals of these species are affected; in fact, 44% of all seabird species are known to ingest plastic. Sea turtles ingest plastic bags, fishing line and other plastics, as do 26 species of cetaceans. In all, 267 species of marine organisms worldwide are known to have been affected by plastic debris, a number that will increase as smaller organisms are assessed. The number of fish, birds, and mammals that succumb each year to derelict fishing nets and lines in which they become entangled cannot be reliably known; but estimates are in the millions. We divide marine plastic debris into two categories: macro, >5 mm and micro, <5 mm. While macro-debris may sometimes be traced to its origin by object identification or markings, micro-debris, consisting of particles of two main varieties, (1) fragments broken from larger objects, and (2) resin pellets and powders, the basic thermoplastic industry feedstocks, are difficult to trace. Ingestion of plastic micro-debris by filter feeders at the base of the food web is known to occur, but has not been quantified. Ingestion of degraded plastic pellets and fragments raises toxicity concerns, since plastics are known to adsorb hydrophobic pollutants. The potential bioavailability of compounds added to plastics at the time of manufacture, as well as those adsorbed from the environment are complex issues that merit more widespread investigation. The physiological effects of any bioavailable compounds desorbed from plastics by marine biota are being directly investigated, since it was found 20 years ago that the mass of ingested plastic in Great Shearwaters was positively correlated with PCBs in their fat and eggs. Colonization of plastic marine debris by sessile organisms provides a vector for transport of alien species in the ocean environment and may threaten marine biodiversity. There is also potential danger to marine ecosystems from the accumulation of plastic debris on the sea floor. The accumulation of such debris can inhibit gas exchange between the overlying waters and the pore waters of the sediments, and disrupt or smother inhabitants of the benthos. The extent of this problem and its effects have recently begun to be investigated. A little more than half of all thermoplastics will sink in seawater.


Assuntos
Ecossistema , Monitoramento Ambiental , Plásticos , Poluentes Químicos da Água , Poluição da Água/prevenção & controle , Animais , Praias/economia , Praias/legislação & jurisprudência , Praias/normas , Biodegradação Ambiental , Monitoramento Ambiental/legislação & jurisprudência , Monitoramento Ambiental/métodos , Monitoramento Ambiental/normas , Biologia Marinha , Oceanos e Mares , Plásticos/química , Plásticos/toxicidade , Eliminação de Resíduos/economia , Eliminação de Resíduos/legislação & jurisprudência , Eliminação de Resíduos/normas , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade
9.
Mar Pollut Bull ; 54(8): 1230-7, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17532349

RESUMO

Thermoplastic resin pellets are melted and formed into an enormous number of inexpensive consumer goods, many of which are discarded after a relatively short period of use, dropped haphazardly onto watersheds and then make their way to the ocean where some get ingested by marine life. In 2003 and 2004 pre-production thermoplastic resin pellets and post-consumer plastic fragments were collected and analyzed for contamination for persistent organic pollutants (POPs). Samples were taken from the North Pacific Gyre, and selected sites in California, Hawaii, and from Guadalupe Island, Mexico. The total concentration of PCBs ranged from 27 to 980 ng/g; DDTs from 22 to 7100 ng/g and PAHs from 39 to 1200 ng/g, and aliphatic hydrocarbons from 1.1 to 8600 microg/g. Analytical methods were developed to extract, concentrate and identify POPs that may have accumulated on plastic fragments and plastic pellets. The results of this study confirm that plastic debris is a trap for POPs.


Assuntos
Meio Ambiente , Monitoramento Ambiental , Plásticos/química , Poluentes da Água/análise , Praias , Hidrocarbonetos/análise , Indústrias , Oceano Pacífico
10.
PLoS One ; 9(12): e111913, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25494041

RESUMO

Plastic pollution is ubiquitous throughout the marine environment, yet estimates of the global abundance and weight of floating plastics have lacked data, particularly from the Southern Hemisphere and remote regions. Here we report an estimate of the total number of plastic particles and their weight floating in the world's oceans from 24 expeditions (2007-2013) across all five sub-tropical gyres, costal Australia, Bay of Bengal and the Mediterranean Sea conducting surface net tows (N = 680) and visual survey transects of large plastic debris (N = 891). Using an oceanographic model of floating debris dispersal calibrated by our data, and correcting for wind-driven vertical mixing, we estimate a minimum of 5.25 trillion particles weighing 268,940 tons. When comparing between four size classes, two microplastic <4.75 mm and meso- and macroplastic >4.75 mm, a tremendous loss of microplastics is observed from the sea surface compared to expected rates of fragmentation, suggesting there are mechanisms at play that remove <4.75 mm plastic particles from the ocean surface.


Assuntos
Oceanos e Mares , Plásticos , Poluição da Água , Hidrodinâmica , Modelos Lineares , Modelos Teóricos , Vento
11.
Mar Pollut Bull ; 64(10): 2190-2, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22954615

RESUMO

Laysan Albatrosses (Phoebastria immutabilis) and Black-footed Albatrosses (P. nigripes) ingest plastic debris, as evidenced by studies showing plastic in the digestive contents of their chicks, but there is little documentation of the frequency and amount of ingested plastics carried in foraging adults. In this study, we quantify plastics among the digestive contents of 18 Laysan Albatrosses and 29 Black-footed Albatrosses collected as by-catch in the North Pacific Ocean. We found ingested plastic in 30 of the 47 birds examined, with Laysan Albatrosses exhibiting a greater frequency of plastic ingestion (83.3% n=18) than Black-footed Albatrosses (51.7% n=29) (X(2)=4.8, df=1, P=0.03). Though the mass of ingested plastic in both species (mean±SD=0.463g±1.447) was lower than previously noted among albatross chicks, the high frequency of ingested plastic we found in this study suggests that long-term effects, e.g. absorption of contaminants from plastics, may be of concern throughout the population.


Assuntos
Aves , Plásticos/análise , Poluentes Químicos da Água/análise , Animais , Ingestão de Alimentos , Monitoramento Ambiental , Conteúdo Gastrointestinal/química , Oceano Pacífico , Poluição Química da Água/estatística & dados numéricos
12.
Mar Pollut Bull ; 62(8): 1683-92, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21719036

RESUMO

To understand the spatial variation in concentrations and compositions of organic micropollutants in marine plastic debris and their sources, we analyzed plastic fragments (∼10 mm) from the open ocean and from remote and urban beaches. Polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), dichloro-diphenyl-trichloroethane and its metabolites (DDTs), polybrominated diphenyl ethers (PBDEs), alkylphenols and bisphenol A were detected in the fragments at concentrations from 1 to 10,000 ng/g. Concentrations showed large piece-to-piece variability. Hydrophobic organic compounds such as PCBs and PAHs were sorbed from seawater to the plastic fragments. PCBs are most probably derived from legacy pollution. PAHs showed a petrogenic signature, suggesting the sorption of PAHs from oil slicks. Nonylphenol, bisphenol A, and PBDEs came mainly from additives and were detected at high concentrations in some fragments both from remote and urban beaches and the open ocean.


Assuntos
Praias , Monitoramento Ambiental , Plásticos/análise , Água do Mar/análise , Poluentes Químicos da Água/análise , Compostos Benzidrílicos , Cidades , Éteres Difenil Halogenados/análise , Oceanos e Mares , Fenóis/análise , Plásticos/química , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Água do Mar/química
13.
Mar Pollut Bull ; 60(12): 2275-8, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21067782

RESUMO

A significant amount of marine debris has accumulated in the North Pacific Central Gyre (NPCG). The effects on larger marine organisms have been documented through cases of entanglement and ingestion; however, little is known about the effects on lower trophic level marine organisms. This study is the first to document ingestion and quantify the amount of plastic found in the gut of common planktivorous fish in the NPCG. From February 11 to 14, 2008, 11 neuston samples were collected by manta trawl in the NPCG. Plastic from each trawl and fish stomach was counted and weighed and categorized by type, size class and color. Approximately 35% of the fish studied had ingested plastic, averaging 2.1 pieces per fish. Additional studies are needed to determine the residence time of ingested plastics and their effects on fish health and the food chain implications.


Assuntos
Peixes , Plásticos/análise , Poluentes Químicos da Água/análise , Animais , Dieta , Monitoramento Ambiental , Cadeia Alimentar , Conteúdo Gastrointestinal/química , Oceano Pacífico , Plâncton , Estômago/química , Movimentos da Água
14.
Philos Trans R Soc Lond B Biol Sci ; 364(1526): 1973-6, 2009 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-19528049

RESUMO

Within the last few decades, plastics have revolutionized our daily lives. Globally we use in excess of 260 million tonnes of plastic per annum, accounting for approximately 8 per cent of world oil production. In this Theme Issue of Philosophical Transactions of the Royal Society, we describe current and future trends in usage, together with the many benefits that plastics bring to society. At the same time, we examine the environmental consequences resulting from the accumulation of waste plastic, the effects of plastic debris on wildlife and concerns for human health that arise from the production, usage and disposal of plastics. Finally, we consider some possible solutions to these problems together with the research and policy priorities necessary for their implementation.


Assuntos
Meio Ambiente , Poluentes Ambientais/economia , Poluentes Ambientais/toxicidade , Plásticos/toxicidade , Política Pública , Gerenciamento de Resíduos/métodos , História do Século XX , Plásticos/história
15.
Philos Trans R Soc Lond B Biol Sci ; 364(1526): 1999-2012, 2009 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-19528052

RESUMO

Plastic debris has significant environmental and economic impacts in marine systems. Monitoring is crucial to assess the efficacy of measures implemented to reduce the abundance of plastic debris, but it is complicated by large spatial and temporal heterogeneity in the amounts of plastic debris and by our limited understanding of the pathways followed by plastic debris and its long-term fate. To date, most monitoring has focused on beach surveys of stranded plastics and other litter. Infrequent surveys of the standing stock of litter on beaches provide crude estimates of debris types and abundance, but are biased by differential removal of litter items by beachcombing, cleanups and beach dynamics. Monitoring the accumulation of stranded debris provides an index of debris trends in adjacent waters, but is costly to undertake. At-sea sampling requires large sample sizes for statistical power to detect changes in abundance, given the high spatial and temporal heterogeneity. Another approach is to monitor the impacts of plastics. Seabirds and other marine organisms that accumulate plastics in their stomachs offer a cost-effective way to monitor the abundance and composition of small plastic litter. Changes in entanglement rates are harder to interpret, as they are sensitive to changes in population sizes of affected species. Monitoring waste disposal on ships and plastic debris levels in rivers and storm-water runoff is useful because it identifies the main sources of plastic debris entering the sea and can direct mitigation efforts. Different monitoring approaches are required to answer different questions, but attempts should be made to standardize approaches internationally.


Assuntos
Ecossistema , Monitoramento Ambiental/estatística & dados numéricos , Poluentes Ambientais/análise , Plásticos , Resíduos/análise , Movimentos da Água , Praias/estatística & dados numéricos , Oceanos e Mares
16.
Philos Trans R Soc Lond B Biol Sci ; 364(1526): 2153-66, 2009 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-19528062

RESUMO

Plastics have transformed everyday life; usage is increasing and annual production is likely to exceed 300 million tonnes by 2010. In this concluding paper to the Theme Issue on Plastics, the Environment and Human Health, we synthesize current understanding of the benefits and concerns surrounding the use of plastics and look to future priorities, challenges and opportunities. It is evident that plastics bring many societal benefits and offer future technological and medical advances. However, concerns about usage and disposal are diverse and include accumulation of waste in landfills and in natural habitats, physical problems for wildlife resulting from ingestion or entanglement in plastic, the leaching of chemicals from plastic products and the potential for plastics to transfer chemicals to wildlife and humans. However, perhaps the most important overriding concern, which is implicit throughout this volume, is that our current usage is not sustainable. Around 4 per cent of world oil production is used as a feedstock to make plastics and a similar amount is used as energy in the process. Yet over a third of current production is used to make items of packaging, which are then rapidly discarded. Given our declining reserves of fossil fuels, and finite capacity for disposal of waste to landfill, this linear use of hydrocarbons, via packaging and other short-lived applications of plastic, is simply not sustainable. There are solutions, including material reduction, design for end-of-life recyclability, increased recycling capacity, development of bio-based feedstocks, strategies to reduce littering, the application of green chemistry life-cycle analyses and revised risk assessment approaches. Such measures will be most effective through the combined actions of the public, industry, scientists and policymakers. There is some urgency, as the quantity of plastics produced in the first 10 years of the current century is likely to approach the quantity produced in the entire century that preceded.


Assuntos
Conservação dos Recursos Naturais/tendências , Poluição Ambiental/efeitos adversos , Poluição Ambiental/prevenção & controle , Plásticos , Saúde Pública/tendências , Política Pública , Gerenciamento de Resíduos/métodos , Carga Corporal (Radioterapia) , Poluição Ambiental/estatística & dados numéricos , Humanos , Medição de Risco/métodos
17.
Philos Trans R Soc Lond B Biol Sci ; 364(1526): 2027-45, 2009 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-19528054

RESUMO

Plastics debris in the marine environment, including resin pellets, fragments and microscopic plastic fragments, contain organic contaminants, including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons, petroleum hydrocarbons, organochlorine pesticides (2,2'-bis(p-chlorophenyl)-1,1,1-trichloroethane, hexachlorinated hexanes), polybrominated diphenylethers, alkylphenols and bisphenol A, at concentrations from sub ng g(-1) to microg g(-1). Some of these compounds are added during plastics manufacture, while others adsorb from the surrounding seawater. Concentrations of hydrophobic contaminants adsorbed on plastics showed distinct spatial variations reflecting global pollution patterns. Model calculations and experimental observations consistently show that polyethylene accumulates more organic contaminants than other plastics such as polypropylene and polyvinyl chloride. Both a mathematical model using equilibrium partitioning and experimental data have demonstrated the transfer of contaminants from plastic to organisms. A feeding experiment indicated that PCBs could transfer from contaminated plastics to streaked shearwater chicks. Plasticizers, other plastics additives and constitutional monomers also present potential threats in terrestrial environments because they can leach from waste disposal sites into groundwater and/or surface waters. Leaching and degradation of plasticizers and polymers are complex phenomena dependent on environmental conditions in the landfill and the chemical properties of each additive. Bisphenol A concentrations in leachates from municipal waste disposal sites in tropical Asia ranged from sub microg l(-1) to mg l(-1) and were correlated with the level of economic development.


Assuntos
Aves/metabolismo , Poluentes Ambientais/análise , Cadeia Alimentar , Modelos Teóricos , Plásticos/química , Água do Mar/química , Resíduos/análise , Adsorção , Animais , Compostos Benzidrílicos , Aves/fisiologia , Disruptores Endócrinos/análise , Poluentes Ambientais/farmacocinética , Comportamento Alimentar/fisiologia , Éteres Difenil Halogenados/análise , Cinética , Praguicidas/análise , Petróleo/análise , Fenóis/análise , Poliquetos/metabolismo , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise
18.
Mar Pollut Bull ; 58(10): 1437-46, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19635625

RESUMO

Samples of polyethylene pellets were collected at 30 beaches from 17 countries and analyzed for organochlorine compounds. PCB concentrations in the pellets were highest on US coasts, followed by western Europe and Japan, and were lower in tropical Asia, southern Africa and Australia. This spatial pattern reflected regional differences in the usage of PCBs and was positively correlated with data from Mussel Watch, another monitoring approach. DDTs showed high concentrations on the US west coast and in Vietnam. In Vietnam, DDT was predominant over its metabolites (DDE and DDD), suggesting the principal source may be current usage of the pesticide for malaria control. High concentrations of pesticide HCHs were detected in the pellets from southern Africa, suggesting current usage of the pesticides in southern Africa. This study demonstrates the utility and feasibility of the International Pellet Watch approach to monitor POPs at a global scale.


Assuntos
DDT/análise , Monitoramento Ambiental/estatística & dados numéricos , Poluentes Ambientais/análise , Hidrocarbonetos Halogenados/análise , Bifenilos Policlorados/análise , Polietileno/química , Praias/estatística & dados numéricos , Monitoramento Ambiental/métodos , Cromatografia Gasosa-Espectrometria de Massas , Geografia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA