Metal(loid) bioaccessibility of atmospheric particulate matter from mine tailings at Zimapan, Mexico.

Metal(loid)s are contaminants of concern emitted as particulate matter (PM) from several pollution sources. The objective was to characterize potential exposure from local airborne metal(loid)s in a community in proximity to mine tailings. Air samples were collected weekly at five sites around the municipal mine tailings using two Hi-volume samplers for simultaneously collecting PM10 and PM2.5. Total suspended particulates (TSP), concentrations, speciation, and bioaccessibility of metal(loid)s were quantified. The size and form of particles were determined by scanning electron microscopy. The concentration of TSP (µg m-3) in the airborne samples ranged from 21.2 to 64.6 for PM2.5 and 23.6 to 80.1 for PM10. The profiles of analyzed quasi-total metal(loid) concentration from all sampling sites were similar between these aerosols PM sizes except at site 2 for Cd, at site 3 for Cu, and site 4 for Zn. The order of quasi-total metal(loid) concentration, in the airborne samples for both PM sizes, was As > Zn > Fe > Pb > Cu > Mn > Cd. As speciation included As-sulfite, As(III)-O, and As(V)-O with less concentration of As(III)-O in both PM sizes. Bioaccessible metal(loid) concentrations were very high and represented a great percentage from the quasi-total airborne concentrations, for instance, 10% and 37% for Pb and 8% and 6% for As in pulmonary and gastric bioaccessible concentrations, respectively. Knowing the toxic effects of these pollutants, there is an urgent need to establish environmental regulation of bioaccessible pollutant concentrations from PM dislodged from uncovered metal(loid) mine tailings affecting not only nearby human populations but also possible long-distance ecosystem transport.

Review: ecotoxicity of organic and organo-metallic antifouling co-biocides and implications for environmental hazard and risk assessments in aquatic ecosystems.

Hazard assessments of Irgarol 1051, diuron, 2-(thiocyanomethylthio)benzothiazole (TCMTB), dichloro-octylisothiazolin (DCOIT), chlorothalonil, dichlofluanid, thiram, zinc pyrithione, copper pyrithione, triphenylborane pyridine (TPBP), capsaicin, nonivamide, tralopyril and medetomidine were performed to establish robust environmental quality standards (EQS), based on predicted no effect concentrations (PNECs). Microalgae, zooplankton, fish and amphibians were the most sensitive ecological groups to all the antifoulants evaluated, especially in the early life stages. No differences were identified between freshwater and seawater species. The use of toxicity tests with non-standard species is encouraged because they increase the datasets, allowing EQS to be derived from probabilistic-based PNECs whilst reducing uncertainties. The global ban of tributyltin (TBT) has been heralded as a major environmental success; however, substitute antifoulants may also pose risks to aquatic ecosystems. Environmental risk assessments (ERAs) have driven decision-makings for regulating antifouling products, but in many countries there is still a lack of regulation of antifouling biocides which should be addressed.

Aspectos críticos da transição para um modelo de regulação ambiental voltado à sustentabilidade: proposta taxonômica / Critical aspects of the transition to a sustainability driven environmental regulatory model: a taxonomy proposition

Dentre os pesquisadores da área socioambiental, é reconhecido que a solução dos problemas ambientais passa pelas políticas de governo, que devem corrigir distorções do mercado e promover avanços rumo à sustentabilidade por meio de uma reforma regulatória. Esta, no entanto, não tem sido estudada e implantada de modo sistemático, principalmente nos países em desenvolvimento. O presente artigo visa a contribuir para esta discussão, estabelecendo uma taxonomia dos principais aspectos dessa mudança apontados pela literatura internacional. Utilizando a metodologia de revisão bibliográfica, os principais argumentos foram selecionados e ordenados segundo uma taxonomia criada para esse fim, composta de 33 categorias de ação ("objetivos" de regulação), agrupadas em seis "aspectos" da transição de modelos. Ao final, é realizada uma breve discussão e conclusões, que não pretendem encerrar o assunto, mas, sim, estabelecer uma contribuição a futuros estudos que verifiquem como esses aspectos têm sido praticados no caso brasileiro(AU)

Among the socioenvironmental researchers, it is recognized that the solution to environmental problems relies on government policies, which should correct market distortions and promote progress towards sustainability by means of a regulatory reform. This, however, has not been studied and implemented in a systematic way, especially in developing countries. The present article aims to contribute to this discussion, establishing a taxonomy of the main aspects of this transition as described by the international literature. Using literature review as methodology, the main arguments have been selected and arranged in a taxonomy consisting of 33 categories of action (regulation "objectives"), which were grouped into six transition "aspects". In the end, a brief discussion is held, and conclusions are made in order to contribute to future studies on how these aspects have been practiced in Brazil(AU)

Aspectos críticos da transição para um modelo de regulação ambiental voltado à sustentabilidade: proposta taxonômica / Critical aspects of the transition to a sustainability driven environmental regulatory model: a taxonomy proposition

Dentre os pesquisadores da área socioambiental, é reconhecido que a solução dos problemas ambientais passa pelas políticas de governo, que devem corrigir distorções do mercado e promover avanços rumo à sustentabilidade por meio de uma reforma regulatória. Esta, no entanto, não tem sido estudada e implantada de modo sistemático, principalmente nos países em desenvolvimento. O presente artigo visa a contribuir para esta discussão, estabelecendo uma taxonomia dos principais aspectos dessa mudança apontados pela literatura internacional. Utilizando a metodologia de revisão bibliográfica, os principais argumentos foram selecionados e ordenados segundo uma taxonomia criada para esse fim, composta de 33 categorias de ação ("objetivos" de regulação), agrupadas em seis "aspectos" da transição de modelos. Ao final, é realizada uma breve discussão e conclusões, que não pretendem encerrar o assunto, mas, sim, estabelecer uma contribuição a futuros estudos que verifiquem como esses aspectos têm sido praticados no caso brasileiro.

Among the socioenvironmental researchers, it is recognized that the solution to environmental problems relies on government policies, which should correct market distortions and promote progress towards sustainability by means of a regulatory reform. This, however, has not been studied and implemented in a systematic way, especially in developing countries. The present article aims to contribute to this discussion, establishing a taxonomy of the main aspects of this transition as described by the international literature. Using literature review as methodology, the main arguments have been selected and arranged in a taxonomy consisting of 33 categories of action (regulation "objectives"), which were grouped into six transition "aspects". In the end, a brief discussion is held, and conclusions are made in order to contribute to future studies on how these aspects have been practiced in Brazil.

A one-year study on carbon, water and nutrient relationships in a tropical C3 -CAM hemi-epiphyte, Clusia uvitana Pittier.

Diel (24 h) courses of CO2 and water-vapour exchange of leaves of hemi-epiphytic plants of Clusia uvitana Pittier (Clusiaceae) were measured under natural tropical conditions in the semi-evergreen moist forest of Barro Colorado Island, Panama, from January 1991 until January 1992. Plants were studied at two sites, in the crown of a 47-m tall tree (Ceiba pentandra) and on the shore of Lake Gatun, at a height of about 2-4 m. The following results were obtained: (1) Diel carbon gain was mainly a function of photosynthetic photon fluence rate (PPFR) on individual days. PPFR also strongly affected CAM activity. A leafless period of the host tree Ceiba pentandra resulted in higher incident PPFRs and slightly lower nighttime temperatures in the canopy of C uvitana; this led to increases in both daytime and nighttime CO2 fixation. (2) In fully mature sun leaves from the two sites, nocturnal net uptake of atmospheric CO2 occurred on almost all of the 71 days measured and nocturnal carbon gain was enhanced during the dry season. (3) In C. uvitana at the Lake site, 24-h carbon gain during the wet and dry season was similar to C. uvitana at the Ceiba site during the leafless period of the host tree. Overall CAM activity was lower at the Lake site. (4) Recycling of respiratory CO2 was a major route for nocturnal acid synthesis. Nocturnal net uptake of atmospheric CO2 was closely correlated with changes in titratable acidity, but accounted for only about 30% of the nocturnal increase in organic acids. (5) Mature shade leaves performed CAM only during the dry season, whereas in the wet season they showed atmospheric CO2 uptake exclusively in the light. (6) Independent of exposure or season, leaves less than about 12 wk old showed a C3 pattern of diel gas exchange and the level of titratable acidity was high day and night. (7) The annual carbon budget of outer canopy leaves of C uvitana in the Ceiba site was 1780 g CO2 m-2 a-1 and the average long-term water-use efficiency was 23 × 10-3 g CO2 g-1 H2 O. (8) Vegetative growth was strongly seasonal. Branch length increment and leaf area development was much higher in the wet season. Mineral element contents in these evergreen plants showed no age-related changes, but a significant proportion of elements was retrieved before abscission.