Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 47
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
Environ Toxicol Chem ; 40(6): 1726-1739, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33646628

RESUMEN

We explored metal concentrations in wasps from 4 sites near Harare, Zimbabwe, on a 106 km west-east transect. We found elevated concentrations at 2 presumed-polluted sites (a platinum [Pt] mine and a known polluted lake) located near a metal-enriched geological feature (the Great Dyke). A site in urban Harare and a nature reserve served as reference. Only wasps from the 2 presumed-polluted sites had quantifiable Pt. For Cr, Ni, Mg, Se, Fe, Mn, and V, we report the highest concentrations in wasps yet published. Wasps from the presumed-polluted sites had significantly higher concentrations of most metals when compared with wasps from the reference sites, suggesting pollution as a source. Geology, however, differs between the sites. It is probable, therefore, that both geology and pollution contributed to the differences in metal concentrations. Because of its long and narrow dimensions (550 km long and 4-11 km wide), the Great Dyke offers opportunities for comparative studies. Because wasps form a complex part of the food web and ecology, studies on the transfer of metals to wasps' predators are needed, especially given that some birds specialize in feeding on hymenopterans. The rich diversity of wasps (>145 000 species worldwide) occupying multiple different trophic levels is a good indicator, and wasps have a rich potential to join other invertebrates as terrestrial indicators. Environ Toxicol Chem 2021;40:1726-1739. © 2021 SETAC.


Asunto(s)
Metales Pesados , Avispas , Animales , Monitoreo del Ambiente/métodos , Invertebrados , Metales , Metales Pesados/análisis , Zimbabwe
2.
Sci Total Environ ; 771: 145348, 2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-33540163

RESUMEN

We report the concentrations of persistent organic pollutants (POPs) in seabird eggs from St. Brandon's Atoll, a tropical island system in the western Indian Ocean. Ten eggs each of sooty terns (Onychoprion fuscatus), fairy terns (Gygis alba), and common noddies (Anous stolidus) were collected from the atoll. For a terrestrial reference, we analysed three feral chicken (Gallus gallus domesticus) eggs from the same location. Sooty tern eggs contained the highest mean concentrations of three chemical classes: Æ©CHL3 (0.21 ng/g wm; wet mass), Æ©PCB10 (1.5 ng/g wm), and Æ©PBDE6 (1.1 ng/g wm). Fairy tern eggs contained the highest mean concentrations of HCB (0.68 ng/g wm) and Æ©CHB5 (0.83 ng/g wm). The chicken eggs contained the highest mean concentrations of Æ©DDT3 (2.6 ng/g wm), while common noddy eggs contained the highest mean concentrations of Æ©HCH2 (0.5 ng/g wm). We surmise that the differences in chemical composition between species reflect different pollutant compositions in prey from the bird's different foraging ranges. The sooty terns foraging offshore contained higher POPs concentrations than the nearshore-foraging common noddies. Fairy tern eggs contained intermediate concentrations, commensurate with their intermediate foraging. Inter-island differences in contaminant concentrations were seen between eggs of the common noddies from St. Brandon's Atoll and Rodrigues Island, 520 km to the south-east. Concentrations of contaminants found in this study were lower than values quantified by other studies, making St. Brandon's Atoll an ideal reference site to monitor background concentrations of POPs in the tropical Indian Ocean.


Asunto(s)
Contaminantes Ambientales , Contaminantes Orgánicos Persistentes , Animales , Aves , Monitoreo del Ambiente , Contaminantes Ambientales/análisis , Océano Índico , Islas
3.
Environ Sci Pollut Res Int ; 28(7): 7691-7709, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33400105

RESUMEN

Chlorine (Cl) in the terrestrial environment is of interest from multiple perspectives, including the use of chloride as a tracer for water flow and contaminant transport, organochlorine pollutants, Cl cycling, radioactive waste (radioecology; 36Cl is of large concern) and plant science (Cl as essential element for living plants). During the past decades, there has been a rapid development towards improved understanding of the terrestrial Cl cycle. There is a ubiquitous and extensive natural chlorination of organic matter in terrestrial ecosystems where naturally formed chlorinated organic compounds (Clorg) in soil frequently exceed the abundance of chloride. Chloride dominates import and export from terrestrial ecosystems while soil Clorg and biomass Cl can dominate the standing stock Cl. This has important implications for Cl transport, as chloride will enter the Cl pools resulting in prolonged residence times. Clearly, these pools must be considered separately in future monitoring programs addressing Cl cycling. Moreover, there are indications that (1) large amounts of Cl can accumulate in biomass, in some cases representing the main Cl pool; (2) emissions of volatile organic chlorines could be a significant export pathway of Cl and (3) that there is a production of Clorg in tissues of, e.g. plants and animals and that Cl can accumulate as, e.g. chlorinated fatty acids in organisms. Yet, data focusing on ecosystem perspectives and combined spatiotemporal variability regarding various Cl pools are still scarce, and the processes and ecological roles of the extensive biological Cl cycling are still poorly understood.


Asunto(s)
Cloro , Ecosistema , Cloruros/análisis , Cloro/análisis , Halogenación , Suelo
4.
Chemosphere ; 262: 127716, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32799137

RESUMEN

For the first time the occurrence of 25 organic micropollutants (OMPs) including; 11 personal care products (PCPs), six phthalate ester plasticizers (PEPs) and eight organophosphorus flame retardants (OPFRs) was investigated in 72 water samples obtained from five bays in the Uganda sector of Lake Victoria. In addition, an assessment of the potential ecotoxic risk of the target OMPs to aquatic organisms was conducted. Water samples were analyzed for the target OMPs using gas chromatography coupled with mass spectrometry (GC/MS). All the target PCPs were found in all the water samples with the exception of musk ketone and 2,6-di-tert-butylphenol. Triclosan (89-1400 ng L-1), benzophenone (36-1300 ng L-1), and 4-methylbenzylidine camphor (21-1500 ng L-1) were the most predominant PCPs. All the six plasticizers were found in all the water samples with dibutyl phthalate (350-16 000 ng L-1), and bis-(2-ethylhexyl) phthalate (210-23 000 ng L-1) detected at the highest concentrations. Five OPFRs out of the eight targeted were found in all the water samples. Tricresyl phosphate (25-8100 ng L-1), tris-(2-chloroethyl) phosphate (24-6500 ng L-1) and triphenyl phosphate (54-4300 ng L-1) were the most dominant OPFRs. The highest concentrations of OMPs were recorded in Murchison and Thurston Bays, presumably due to industrial wastewater effluents from the highly industrialized localities of the two Bays. Ecotoxicological risk assessment showed that PCPs (triclosan, musk ketone, and 4-MBC), plasticizers (dibutyl phthalate, bis-(2-ethylhexyl) adipate and bis-(2-ethylhexyl) phthalate) and OPFRs (tricresyl phosphate, triphenyl phosphate and tris-(2-chloroethyl) phosphate) pose a high ecotoxic risk to lives of aquatic organisms (risk quotients, RQ > 1).


Asunto(s)
Cosméticos/análisis , Retardadores de Llama/análisis , Lagos/análisis , Compuestos Organofosforados/análisis , Plastificantes/análisis , Contaminantes Químicos del Agua/análisis , Animales , Cosméticos/toxicidad , Ecotoxicología/métodos , Retardadores de Llama/toxicidad , Cromatografía de Gases y Espectrometría de Masas/métodos , Compuestos Organofosforados/toxicidad , Plastificantes/toxicidad , Medición de Riesgo , Análisis Espacio-Temporal , Uganda , Aguas Residuales/química , Contaminantes Químicos del Agua/toxicidad
5.
Mar Environ Res ; 156: 104916, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32174336

RESUMEN

Shallow shipwrecks, can have severe ecological and toxicological impacts on coral atolls. In 2012, a tuna longliner ran aground on the reef crest of St Brandon's Atoll, Mauritius, broke up into three pieces which was moved by currents and storms into the lagoon. In the months following the grounding, the coral around the wreck became dead and black. Down-current from the wreck, a dense bloom of filamentous algae (Ulva sp.) attached to coral occurred. To determine the ecological effects of the wreck on the system, the marine biota around the wreck, in the algal bloom, and fish reference zones were counted in 2014. Metal concentrations in reference and affected coral was determined using inductively coupled plasma mass spectrometry (ICP/MS). A pronounced difference was seen in the metal concentration pattern between coral from the wreck- and algal zones, and the coral reference zone. While the wreck zone contained the highest abundance of fish, the fish reference zone had the highest species diversity but with fewer fish. We also counted eleven Critically Endangered hawksbill sea turtles Eretmochelys imbricata and significantly more sea cucumbers in the algal zone than the reference zones. The effects of shipwrecks on coral reefs must be considered a threat over periods of years and should be studied further.


Asunto(s)
Antozoos , Arrecifes de Coral , Navíos , Animales , Biodiversidad , Quelantes/análisis , Monitoreo del Ambiente , Peces , Océano Índico , Mauricio , Ulva/crecimiento & desarrollo , Contaminantes Químicos del Agua/análisis
6.
Chemosphere ; 239: 124642, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31521936

RESUMEN

The occurrence of 24 pharmaceuticals (including 15 antibiotics, three analgesic/anti-inflammatory drugs, three anti-epileptic/antidepressant drugs, two beta blockers, and one lipid regulator) was investigated in 75 water samples collected from four bays in the Ugandan part of Lake Victoria. In addition, the potential environmental risk of the target pharmaceutical compounds to aquatic organisms in the aquatic ecosystem of Lake Victoria was assessed. Water samples were extracted using solid phase extraction and analyzed for pharmaceuticals using high-performance liquid chromatography coupled with triple quadrupole mass spectrometry (LC/MS/MS). Eighteen of the 24 pharmaceuticals occurred at quantifiable concentrations. Sulfamethoxazole (1-5600 ng L-1), trimethoprim (1-89 ng L-1), tetracycline (3-70 ng L-1), sulfacetamide (1-13 ng L-1), and ibuprofen (6-780 ng L-1) occurred at quantifiable concentrations in all water samples. Sulfamethazine (2-50 ng L-1), erythromycin (10-66 ng L-1), diclofenac (2-160 ng L-1), and carbamazepine (5-72 ng L-1) were only quantifiable in water samples from Murchison Bay. The highest concentrations of pharmaceuticals were found in Murchison Bay, the main recipient of sewage effluents, industrial and municipal waste from Kampala city via the Nakivubo channel. Ecotoxicological risk assessment showed that sulfamethoxazole, oxytetracycline, erythromycin, and diclofenac pose a high toxic risk to aquatic organisms in the lake, while ciprofloxacin, norfloxacin, and ibuprofen pose a medium risk. This study is the first of its kind to report the levels and ecotoxic risks of pharmaceutical compounds in Lake Victoria waters, of Uganda, and East Africa as a whole.


Asunto(s)
Monitoreo del Ambiente/métodos , Lagos/química , Preparaciones Farmacéuticas/análisis , Aguas del Alcantarillado/química , Contaminantes Químicos del Agua/análisis , Antagonistas Adrenérgicos beta/análisis , Antibacterianos/análisis , Antiinflamatorios no Esteroideos/análisis , Organismos Acuáticos/efectos de los fármacos , Cromatografía Liquida , Ciudades , Diclofenaco/análisis , Ecosistema , Ecotoxicología , Medición de Riesgo , Extracción en Fase Sólida , Espectrometría de Masas en Tándem , Uganda
7.
Water Res ; 155: 182-192, 2019 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-30849732

RESUMEN

Disinfection of drinking water using chlorine can lead to the formation of genotoxic by-products when chlorine reacts with natural organic matter (NOM). A vast number of such disinfection by-products (DBPs) have been identified, making it almost impossible to routinely monitor all DBPs with chemical analysis. In this study, a bioanalytical approach was used, measuring oxidative stress (Nrf2 activity), genotoxicity (micronucleus test), and aryl hydrocarbon receptor (AhR) activation to evaluate an innovative water treatment process, including suspended ion exchange, ozonation, in-line coagulation, ceramic microfiltration, and granular activated carbon. Chlorination was performed in laboratory scale after each step in the treatment process in order to investigate the effect of each treatment process to the formation of DBPs. Suspended ion exchange had a high capacity to remove dissolved organic carbon (DOC) and to decrease UV absorbance and Nrf2 activity in non-chlorinated water. High-dose chlorination (10 mg Cl2 L-1) of raw water caused a drastic induction of Nrf2 activity, which was decreased by 70% in water chlorinated after suspended ion exchange. Further reduction of Nrf2 activity following chlorination was achieved by ozonation and the concomitant treatment steps. The ozonation treatment resulted in decreased Nrf2 activity in spite of unchanged DOC levels. However, a strong correlation was found between UV absorbing compounds and Nrf2 activity, demonstrating that Nrf2 inducing DBPs were formed from pre-cursors of a specific NOM fraction, constituted of mainly aromatic compounds. Moreover, high-dose chlorination of raw water induced genotoxicity. In similarity to the DOC levels, UV absorbance and Nrf2 activity, the disinfection-induced genotoxicity was also reduced by each treatment step of the innovative water treatment technique. AhR activity was observed in the water produced by the conventional process and in the raw water, but the activity was clearly decreased by the ozonation step in the innovative water treatment process.


Asunto(s)
Agua Potable , Contaminantes Químicos del Agua , Purificación del Agua , Daño del ADN , Desinfección , Estrés Oxidativo
8.
Environ Sci Pollut Res Int ; 26(8): 7305-7314, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29492811

RESUMEN

The occurrence of disinfection by-products (DBPs) in drinking water has become an issue of concern during the past decades. The DBPs pose health risks and are suspected to cause various cancer forms, be genotoxic, and have negative developmental effects. The vast chemical diversity of DBPs makes comprehensive monitoring challenging. Only few of the DBPs are regulated and included in analytical protocols. In this study, a method for simultaneous measurement of 20 DBPs from five different structural classes (both regulated and non-regulated) was investigated and further developed for 11 DBPs using solid-phase extraction and gas chromatography coupled with a halogen-specific detector (XSD). The XSD was highly selective towards halogenated DBPs, providing chromatograms with little noise. The method allowed detection down to 0.05 µg L-1 and showed promising results for the simultaneous determination of a range of neutral DBP classes. Compounds from two classes of emerging DBPs, more cytotoxic than the "traditional" regulated DBPs, were successfully determined using this method. However, haloacetic acids (HAAs) should be analyzed separately as some HAA methyl esters may degrade giving false positives of trihalomethanes (THMs). The method was tested on real water samples from two municipal waterworks where the target DBP concentrations were found below the regulatory limits of Sweden.


Asunto(s)
Cromatografía de Gases/métodos , Desinfectantes/análisis , Agua Potable/química , Monitoreo del Ambiente/métodos , Halógenos/análisis , Contaminantes Químicos del Agua/análisis , Abastecimiento de Agua , Desinfección/métodos , Halogenación , Humanos , Suecia , Trihalometanos/análisis , Purificación del Agua/métodos
9.
Environ Pollut ; 229: 688-695, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28711567

RESUMEN

The production and use of pentachlorophenol (PCP) was recently prohibited/restricted by the Stockholm Convention on persistent organic pollutants (POPs), but environmental data are few and of varying quality. We here present the first extensive dataset of the continent-wide (Eurasia and Canada) occurrence of PCP and its methylation product pentachloroanisole (PCA) in the environment, specifically in pine needles. The highest concentrations of PCP were found close to expected point sources, while PCA chiefly shows a northern and/or coastal distribution not correlating with PCP distribution. Although long-range transport and environmental methylation of PCP or formation from other precursors cannot be excluded, the distribution patterns suggest that such processes may not be the only source of PCA to remote regions and unknown sources should be sought. We suggest that natural sources, e.g., chlorination of organic matter in Boreal forest soils enhanced by chloride deposition from marine sources, should be investigated as a possible partial explanation of the observed distributions. The results show that neither PCA nor total PCP (ΣPCP = PCP + PCA) should be used to approximate the concentrations of PCP; PCP and PCA must be determined and quantified separately to understand their occurrence and fate in the environment. The background work shows that the accumulation of airborne POPs in plants is a complex process. The variations in life cycles and physiological adaptations have to be taken into account when using plants to evaluate the concentrations of POPs in remote areas.


Asunto(s)
Anisoles/análisis , Monitoreo del Ambiente , Contaminantes Ambientales/análisis , Pentaclorofenol/análisis , Pinus/química , Canadá , Suelo/química
10.
Sci Total Environ ; 583: 64-71, 2017 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-28100418

RESUMEN

Persistent organic pollutants (POPs) continue to cycle through the atmosphere and hydrosphere despite banned or severely restricted usages. Global scale analyses of POPs are challenging, but knowledge of the current distribution of these compounds is needed to understand the movement and long-term consequences of their global use. In the current study, air and seawater samples were collected Oct. 2007-Jan. 2008 aboard the Icebreaker Oden en route from Göteborg, Sweden to McMurdo Station, Antarctica. Both air and surface seawater samples consistently contained α-hexachlorocyclohexane (α-HCH), γ-HCH, hexachlorobenzene (HCB), α-Endosulfan, and polychlorinated biphenyls (PCBs). Sample concentrations for most POPs in air were higher in the northern hemisphere with the exception of HCB, which had high gas phase concentrations in the northern and southern latitudes and low concentrations near the equator. South Atlantic and Southern Ocean seawater had a high ratio of α-HCH to γ-HCH, indicating persisting levels from technical grade sources. The Atlantic and Southern Ocean continue to be net sinks for atmospheric α-, γ-HCH, and Endosulfan despite declining usage.

11.
Endeavour ; 40(2): 131-4, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26995448

RESUMEN

What is science? Or, more pertinently, what is good science? This question is central for all practitioners of science and one of the most important to convey to our students. For those of us working in interdisciplinary settings - my own department covers everything from humanities to political and natural science - the question becomes even more complicated when traditions from different disciplines collide. For me personally, whenever I think too highly of my own research and risk deviating into bad scientific practices, I think of my paternal grandmother, Elsa. Although long dead, she brings me back into the fold of good science - or so I hope - by urging me to take another turn at critically evaluating how I perform research and to keep my arrogance in check.

12.
Mar Environ Res ; 114: 58-64, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26763686

RESUMEN

Isolated coral atolls are not immune from marine debris accumulation. We identified Southeast Asia, the Indian sub-continent, and the countries on the Arabian Sea as most probable source areas of 50 000 items on the shores of St. Brandon's Rock (SBR), Indian Ocean. 79% of the debris was plastics. Flip-flops, energy drink bottles, and compact fluorescent lights (CFLs) were notable item types. The density of debris (0.74 m(-)(1) shore length) is comparable to similar islands but less than mainland sites. Intact CFLs suggests product-facilitated long-range transport of mercury. We suspect that aggregated marine debris, scavenged by the islands from currents and gyres, could re-concentrate pollutants. SBR islets accumulated debris types in different proportions suggesting that many factors act variably on different debris types. Regular cleaning of selected islets will take care of most of the accumulated debris and may improve the ecology and tourism potential. However, arrangements and logistics require more study.


Asunto(s)
Monitoreo del Ambiente , Plásticos/análisis , Residuos/análisis , Contaminación del Agua/análisis , Islas del Oceano Índico
13.
Environ Sci Technol ; 49(23): 13844-52, 2015 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-26196214

RESUMEN

The Arctic has been contaminated by legacy organochlorine pesticides (OCPs) and currently used pesticides (CUPs) through atmospheric transport and oceanic currents. Here we report the time trends and air-water exchange of OCPs and CUPs from research expeditions conducted between 1993 and 2013. Compounds determined in both air and water were trans- and cis-chlordanes (TC, CC), trans- and cis-nonachlors (TN, CN), heptachlor exo-epoxide (HEPX), dieldrin (DIEL), chlorobornanes (ΣCHBs and toxaphene), dacthal (DAC), endosulfans and metabolite endosulfan sulfate (ENDO-I, ENDO-II, and ENDO SUL), chlorothalonil (CHT), chlorpyrifos (CPF), and trifluralin (TFN). Pentachloronitrobenzene (PCNB and quintozene) and its soil metabolite pentachlorothianisole (PCTA) were also found in air. Concentrations of most OCPs declined in surface water, whereas some CUPs increased (ENDO-I, CHT, and TFN) or showed no significant change (CPF and DAC), and most compounds declined in air. Chlordane compound fractions TC/(TC + CC) and TC/(TC + CC + TN) decreased in water and air, while CC/(TC + CC + TN) increased. TN/(TC + CC + TN) also increased in air and slightly, but not significantly, in water. These changes suggest selective removal of more labile TC and/or a shift in chlordane sources. Water-air fugacity ratios indicated net volatilization (FR > 1.0) or near equilibrium (FR not significantly different from 1.0) for most OCPs but net deposition (FR < 1.0) for ΣCHBs. Net deposition was shown for ENDO-I on all expeditions, while the net exchange direction of other CUPs varied. Understanding the processes and current state of air-surface exchange helps to interpret environmental exposure and evaluate the effectiveness of international protocols and provides insights for the environmental fate of new and emerging chemicals.


Asunto(s)
Contaminantes Atmosféricos/análisis , Hidrocarburos Clorados/análisis , Plaguicidas/análisis , Contaminantes Químicos del Agua/análisis , Regiones Árticas , Clordano/análisis , Clordano/química , Endosulfano/análogos & derivados , Endosulfano/análisis , Endosulfano/química , Monitoreo del Ambiente/métodos , Gases/análisis , Gases/química , Hidrocarburos Clorados/química , Océanos y Mares , Plaguicidas/química , Agua de Mar/análisis , Agua de Mar/química , Contaminantes del Suelo/análisis , Volatilización
14.
Chemosphere ; 90(1): 28-35, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22921435

RESUMEN

A screening of metals, persistent organic pollutants, pharmaceuticals and personal care products (PPCPs), and other organic contaminants in sludge from seven Swedish sewage treatment plants (STPs) was performed in this study. This extensive screening provides information on mass flows of 282 compounds used in the Swedish society to sewage sludge. It reveals constant relative contaminant concentrations (ng mg kg(-1) d.w.), except for some pesticides and perfluorinated compounds, indicating that these originate from broad usage and diffuse dispersion rather than (industrial) point sources. There was a five order of magnitude difference in the sum concentrations of the most and least abundant species (metals and polychlorinated dibenzo-p-dioxins and -furans, respectively). Lower total concentrations were found in sludge from STPs processing primarily food industry or household sewage. Proportions of the amounts used (in Sweden) found in sludge were lower for compounds that are present in consumer goods or are diffusely dispersed into the environment (0.01-1% recovered in sludge) than for compounds used as detergents or PPCPs (17-63%). In some cases, the recovery seemed to be affected by evaporation (e.g. octamethylcyclotetrasiloxane) or biotransformation (e.g. adipates) losses, while polychlorinated alkanes and brominated diphenyl ethers were recovered to disproportionately high degree (ca. 4%); likely due to incomplete statistics for imported goods.


Asunto(s)
Monitoreo del Ambiente/métodos , Aguas del Alcantarillado/química , Eliminación de Residuos Líquidos , Contaminantes Químicos del Agua/análisis , Benzofuranos/análisis , Dioxinas/análisis , Éteres Difenilos Halogenados/análisis , Productos Domésticos/análisis , Productos Domésticos/estadística & datos numéricos , Metales/análisis , Plaguicidas/análisis , Suecia , Contaminación Química del Agua/estadística & datos numéricos
15.
Environ Sci Technol ; 46(20): 10982-9, 2012 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-22992198

RESUMEN

The partitioning of α- and γ-hexachlorocyclohexane between air and the moss Hylocomium splendens and the lichen Cladina stellaris were studied under laboratory conditions. After cultivation of the sample material to obtain a common starting point free from outside influence, the material was divided into four different treatment categories with different hydration/desiccation regimes. The concentrations of the analytes were 3-5 times higher in the hydrated moss or lichen than in the desiccated material. The results are in contrast to how these compounds are taken up by pine needles in which there is a continuous accumulation, more rapid during periods with high temperatures and dry weather. In general, the different adaptations to water economy is a more important explanatory factor for the concentration of airborne hydrophobic pollutants in mosses, lichens, and vascular plants than their designation as "plants" in a broad sense. It is, therefore, not advisible to mix data from different organism groups for monitoring or modeling purposes.


Asunto(s)
Contaminantes Atmosféricos/análisis , Ascomicetos/química , Bryopsida/química , Hexaclorobenceno/análisis , Hexaclorociclohexano/análisis , Contaminantes Atmosféricos/metabolismo , Contaminación del Aire/estadística & datos numéricos , Ascomicetos/metabolismo , Bryopsida/metabolismo , Monitoreo del Ambiente , Hexaclorobenceno/metabolismo , Hexaclorociclohexano/metabolismo , Líquenes/química , Líquenes/metabolismo
16.
Environ Pollut ; 170: 63-70, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22766005

RESUMEN

We investigated presence and levels of DDT in 163 breast milk samples from four South African villages where, in three of them, malaria is controlled with DDT-sprayed indoors. Mean ΣDDT levels in breast milk were 18, 11, and 9.5 mg/kg mf (milk fat) from the three DDT-sprayed villages, respectively, including the highest ΣDDT level ever reported for breast milk from South Africa (140 mg/kg mf). Understanding the causes for these differences would be informative for exposure reduction intervention. The Provisional Tolerable Daily Intake (PTDI) for DDT by infants, and the Maximum Residue Limit (MRL) were significantly exceeded. DDT had no effect on duration of lactation. There were indications (not significant) from DDT-sprayed villages that first-born female infants drink milk with more ΣDDT than first-born male infants, and vice versa for multipara male and female infants, suggesting gender involvement on levels of DDT in breast milk - requiring further investigation.


Asunto(s)
Lactancia Materna/estadística & datos numéricos , DDT/metabolismo , Exposición a Riesgos Ambientales/estadística & datos numéricos , Insecticidas/metabolismo , Leche Humana/metabolismo , Residuos de Plaguicidas/metabolismo , Adolescente , Adulto , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Factores Sexuales , Sudáfrica , Adulto Joven
17.
Environ Res ; 118: 53-64, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22694834

RESUMEN

We report for the first time levels of persistent organic pollutants in marine bird eggs from an oceanic island in the Indian Ocean, the world's third largest ocean. Ten eggs each of the Common Noddy, also known as the Brown Noddy (Anous stolidus), and Sooty Tern (Sterna fuscata) were collected from Ile Cocos off the coast of the island of Rodrigues, located 560 km east of the island of Mauritius. ΣPCBs had the highest levels (2.2 and 2.6n g/g wm, wet mass; 20 and 19 ng/g lm, lipid mass) for common Noddy and Sooty Tern, respectively (and following), then ΣDDT (1.9 and 3.1 ng/g wm; 17 and 23 ng/g lm), and mirex (0.96 and 0.69 ng/g wm; 8.7 and 5.0 ng/gl m). ΣChlordanes (0.094 and 0.15 ng/g wm; 0.48 and 0.73 ng/g lm) and Σtoxaphenes (0.26 and 0.61 ng/g wm; 2.4 and 5.9 ng/g lm) are rare data for these compounds from this ocean. Brominated flame retardants were low (0.08 and 0.07 ng/g wm; 0.7 and 0.7 ng/g lm). Multivariate analyses indicated different contamination patterns in the prey items as Sooty Terns had significantly higher levels of mean Σchlordanes and Σtoxaphenes, as well as CB105, -108 and -157. p,p'-DDE had an association with thinner eggshells in the Sooty Tern. Although the contaminant levels were in all respects low, industrialisation, development on the periphery, commercial exploitation of the marine environment, and pollutants transferred over long distances by marine debris is likely to add to chemical pressure in this region. Monitoring changes in background levels of pollutants in remote regions will indicate such trends, and marine bird eggs from Rodrigues would be an excellent site.


Asunto(s)
Aves , Huevos/análisis , Contaminantes Ambientales/análisis , Hidrocarburos Bromados/análisis , Hidrocarburos Clorados/análisis , Biología Marina , Animales , Geografía , Océano Índico , Análisis Multivariante , Especificidad de la Especie
18.
Environ Sci Technol ; 46(11): 5815-23, 2012 Jun 05.
Artículo en Inglés | MEDLINE | ID: mdl-22548373

RESUMEN

We report here on the spatial distribution of C(4), C(6), and C(8) perfluoroalkyl sulfonates, C(6)-C(14) perfluoroalkyl carboxylates, and perfluorooctanesulfonamide in the Atlantic and Arctic Oceans, including previously unstudied coastal waters of North and South America, and the Canadian Arctic Archipelago. Perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS) were typically the dominant perfluoroalkyl acids (PFAAs) in Atlantic water. In the midnorthwest Atlantic/Gulf Stream, sum PFAA concentrations (∑PFAAs) were low (77-190 pg/L) but increased rapidly upon crossing into U.S. coastal water (up to 5800 pg/L near Rhode Island). ∑PFAAs in the northeast Atlantic were highest north of the Canary Islands (280-980 pg/L) and decreased with latitude. In the South Atlantic, concentrations increased near Rio de la Plata (Argentina/Uruguay; 350-540 pg/L ∑PFAAs), possibly attributable to insecticides containing N-ethyl perfluorooctanesulfonamide, or proximity to Montevideo and Buenos Aires. In all other southern hemisphere locations, ∑PFAAs were <210 pg/L. PFOA/PFOS ratios were typically ≥1 in the northern hemisphere, ∼1 near the equator, and ≤1 in the southern hemisphere. In the Canadian Arctic, ∑PFAAs ranged from 40 to 250 pg/L, with perfluoroheptanoate, PFOA, and PFOS among the PFAAs detected at the highest concentrations. PFOA/PFOS ratios (typically ≫1) decreased from Baffin Bay to the Amundsen Gulf, possibly attributable to increased atmospheric inputs. These data help validate global emissions models and contribute to understanding of long-range transport pathways and sources of PFAAs to remote regions.


Asunto(s)
Ácidos Alcanesulfónicos/análisis , Fluorocarburos/análisis , Regiones Árticas , Océano Atlántico , Canadá , Caprilatos/análisis , Geografía , Laboratorios , Modelos Químicos , Navíos , América del Sur , Contaminantes Químicos del Agua/análisis
19.
Environ Pollut ; 163: 142-8, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22325442

RESUMEN

Chlorinated paraffins (CPs) were found in the biodegradable fraction of source separated waste from Uppsala, Sweden. We identified and quantified the CPs by multivariate evaluation of gas chromatography-electron capture detection chromatograms. Using principal component analyses (PCA) we identified different types of CP-formulations and also obtain quantitative data. PCA yielded better identifications of individual CP-formulations than visual comparison of chromatograms. Partial least squares regression gave good calibration curves of the standards, but did not work for the waste samples. No source of CPs could be identified in the waste collection chain, and as the waste samples seemed to contain at least two different CP-formulations the source was probably to be found in the waste material itself. The method was used to determine CPs in additional environmental samples, demonstrating that multivariate methods may be developed into a powerful tool for identification and quantification of complex mixture.


Asunto(s)
Contaminantes Ambientales/química , Hidrocarburos Clorados/química , Parafina/química , Residuos/estadística & datos numéricos , Biodegradación Ambiental , Cromatografía de Gases , Monitoreo del Ambiente , Contaminantes Ambientales/análisis , Hidrocarburos Clorados/análisis , Análisis Multivariante , Parafina/análisis , Análisis de Componente Principal , Eliminación de Residuos , Suecia
20.
Environ Sci Technol ; 46(6): 3135-40, 2012 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-22369049

RESUMEN

Brominated diphenyl ethers (BDE47, 99, 100, and 209) were measured in air, snow and sea ice throughout western Antarctica between 2001 and 2007. BDEs in Antarctic air were predominantly associated with aerosols and were low compared to those in remote regions of the northern hemisphere, except in Marguerite Bay following the fire at Rothera research station in Sept 2001, indicating that this event was a local source of BDE209 to the Antarctic environment. Aerosol BDE47/100 reflects a mixture of commercial pentaBDE products; however, BDE99/100 is suggestive of photodegradation of BDE99 during long-range atmospheric transport (LRAT) in the austral summer. BDEs in snow were lower than predicted based on snow scavenging of aerosols indicating that atmospheric deposition events may be episodic. BDE47, -99, and -100 significantly declined in Antarctic sea ice between 2001 and 2007; however, BDE209 did not decline in Antarctic sea ice over the same time period. Significant losses of BDE99 and -100 from sea ice were recorded over a 19 day period in spring 2001 demonstrating that seasonal ice processes result in the preferential loss of some BDEs. BDE47/100 and BDE99/100 in sea ice samples reflect commercial pentaBDE products, suggesting that photodegradation of BDE99 is minimal during LRAT in the austral winter.


Asunto(s)
Contaminantes Ambientales/análisis , Éteres Difenilos Halogenados/análisis , Aerosoles , Regiones Antárticas , Monitoreo del Ambiente , Hielo/análisis , Nieve/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA