Gaseous and particulate atmospheric mercury concentrations in the Campinas Metropolitan Region (Sao Paulo State, Brazil)

The concentrations of Total Gaseous Mercury (TGM) and Total Particulate Mercury (TPM) were monitored during the 2002-2003 rainy and dry seasons at two sampling points (industrial and residential areas) of the Campinas Metropolitan Region. No significant difference was observed between the concentrations found at the two sampling areas and the mean values were 7.0 +/- 5.8 ng M-3 (TGM) and 0.4 +/- 0.3 ng m(-3) (TPM). The analysis of the diel variability showed higher TGM concentrations during the day, which could be related to more intense anthropogenic activity during the day. Atmospheric dispersion processes could also explain some seasonal variation observed in TGM concentrations. For TPM concentrations a decreasing trend was observed during the rainy season, which could be explained by the removal of particles by wet deposition. The concentrations of TGM and TPM found in this study were of the same order of magnitude of those recorded in some highly industrialized regions of the northern hemisphere. These data show that emissions from the most industrialized Brazilian regions, and probably from similar regions in other countries of the southern hemisphere, should also be assessed and integrated into the global anthropogenic mercury emission assessment.17588689

Methylmercury exposure in a subsistence fishing community in Lake Chapala, Mexico: an ecological approach

<p>Abstract</p> <p>Background</p> <p>Elevated concentrations of mercury have been documented in fish in Lake Chapala in central Mexico, an area that is home to a large subsistence fishing community. However, neither the extent of human mercury exposure nor its sources and routes have been elucidated.</p> <p>Methods</p> <p>Total mercury concentrations were measured in samples of fish from Lake Chapala; in sections of sediment cores from the delta of Rio Lerma, the major tributary to the lake; and in a series of suspended-particle samples collected at sites from the mouth of the Lerma to mid-Lake. A cross-sectional survey of 92 women ranging in age from 18-45 years was conducted in three communities along the Lake to investigate the relationship between fish consumption and hair mercury concentrations among women of child-bearing age.</p> <p>Results</p> <p>Highest concentrations of mercury in fish samples were found in carp (mean 0.87 ppm). Sediment data suggest a pattern of moderate ongoing contamination. Analyses of particles filtered from the water column showed highest concentrations of mercury near the mouth of the Lerma. In the human study, 27.2% of women had >1 ppm hair mercury. On multivariable analysis, carp consumption and consumption of fish purchased or captured from Lake Chapala were both associated with significantly higher mean hair mercury concentrations.</p> <p>Conclusions</p> <p>Our preliminary data indicate that, despite a moderate level of contamination in recent sediments and suspended particulate matter, carp in Lake Chapala contain mercury concentrations of concern for local fish consumers. Consumption of carp appears to contribute significantly to body burden in this population. Further studies of the consequences of prenatal exposure for child neurodevelopment are being initiated.</p

Hydride generation using a metallic atomizer after microwave-assisted extraction for inorganic arsenic speciation in biological samples

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The present speciation method reports the determination of inorganic arsenic forms, using metallic furnace hydride generation atomic absorption spectrometry. The inorganic As speciation is carried out using mild conditions for hydride formation, such as slightly acid pH media (4.50) and low tetrahydridoborate(1-) concentration (0.1% (w/v)). Limits of detection and quantification of 2.0 and 6.6 mu g L-1 of iAs(III) are obtained using optimized conditions. Additionally, microwave-assisted extraction using water as solvent is carried out to provide the appropriate environment for As species extraction as well as impeding inter-conversion between species. With these analytical strategies, As was accurately determined (at 99.9% confidence level) in water and plankton samples. (C) 2012 Elsevier B.V. All rights reserved.104187192Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Rainfall chemistry composition in two ecosystems in the northeastern Brazilian Amazon (Amapa State)

The rainfall chemical composition in two Amazonian ecosystems, a "terra firme" forest (dense tropical rain forest) and the "cerrado" (savanna) are presented. Both areas are located in the northeast Brazilian Amazon (Amapa State). This study evaluated the statistical differences in the rainfall chemistry, as well as the deposition through rainfall, for each ecosystem. The chemical species evaluated in the rainwater were Na+, K+, Mg2+, Ca2+, NH4+, Cl-, NO3-, SO42-, Fe3+, Al3+, Zn2+, and Mn2+ for both ecosystems. Factor analysis for the terra fume ecosystem indicated that there is a significant difference between the dry and wet periods in the rainfall chemical composition, indicating a biomass-burning signature (K+ in association with Zn2+. High deposition of solutes, except for Mn2+ and Cl+, was also observed during the dry period. Comparison between the terra fume and cerrado rainfall chemistry showed statistical differences in concentration for the marine species (Nac and CU and for the soil dust species (Al3+, Fe3+, and Mn2+. The sea-salt and biogenic sources of chemical species in terra fume forest rainwater are equally important. The site nearer to the sea (cerrado) has rainfall chemistry dominated by species having marine origins. The terra firme forest also has rainfall chemistry dominated by marine origin species, although the biogenic and soil dust origin species are highly significant at this site. Also in the terra firme a biomass-burning signature was observed. The amount of sea salt deposited was more than 50% larger in the cerrado owing to its proximity to the shore.105D23288952890

A simple voltammetric procedure for speciation and evaluation of As removal from water

Here, we show a fast and sensitive method for the determination of inorganic arsenic in natural waters using differential pulse cathodic stripping voltammetry. All the arsenite determinations were done in 2.0 mol L-1 HCl + 3.15 x 10(-4) mol L-1 Cu(II) supporting electrolyte. 1 x 10(-3) mol L-1 sodium thiosulphate was used as As(V) reducing agent. The detection limit was 0.5 mu g L-1 for both species. The method has been applied to water samples collected in an arsenic-contaminated region of Brazil, in particular, to verify the efficiency of the solar oxidation and removal of arsenic process applied to these waters.5313714

Mercury emissions from forest burning in southern Amazon

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Several recent studies have indicated that forest fires are likely to re-emit important quantities of atmospherically deposited mercury (Hg) to the atmosphere. Although the Amazon forest accounts for approximately 25% of the world's total rainforest, few data are available about these emissions. The emissions of mercury from prescribed fires of two 4-ha plots of Amazon forest were investigated. Hg concentration and Hg burden were determined for vegetation, litter and soil before and after the fires. The data show that only Hg present in the aboveground vegetation and in the O-horizon was volatilised; no significant soil emission was observed. Before the fire, the Hg stored in the vegetation (logs, branches, leaves and litter) ranged from 3.7 to 4.0 g ha(-1) while 1.8 g ha(-1) was found in the O-horizon. The mass balance calculations of the present work indicate an average Hg emission of 3.5 g ha(-1) due to forest fires, with 1.6 ha(-1) originating from O-horizon and 1.9 from above ground vegetation. On the base of the average annual deforestation rate of the Brazilian Amazon between 2000 and 2008, an annual Hg emission of 6.7 Mg yr(-1) was estimated. Citation: Michelazzo, P. A. M., A. H. Fostier, G. Magarelli, J. C. Santos, and J. A. d. Carvalho Jr. (2010), Mercury emissions from forest burning in southern Amazon, Geophys. Res. Lett., 37, L09809, doi: 10.1029/2009GL042220.O TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE FEVEREIRO DE 2015.37Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [04/01122-3, 03/07822-4, 02/08964-4

Mercury fluxes in a natural forested Amazonian catchment (Serra do Navio, Amapa State, Brazil)

Mercury (I-Ig total) fluxes were calculated for rainwater, throughfall and stream water in a small catchment located in the northeastern region of the Brazilian Amazon (Serra do Navio, Amapa State), whose upper part is covered by a natural rainforest and lower part was altered due to deforestation and activities related to manganese mining. The catchment area is 200 km from the nearest gold mining (garimpo). Minimum and maximum Hg concentrations were measured monthly from October 1996 to September 1997 and were 3.5-23.4 ng l(-1) for rainwater, 16.5-82.7 ng l(-1) for throughfall (March-August 1997) and 1.2-6.1 and 4.2-18.8 ng l(-1) for stream water, in natural and disturbed areas, respectively. In the natural area, the inputs were 18.2 mu g m(-2) year(-1) in rainwater and 72 mu g m(-2) year(-1) in throughfall. This enrichment was attributed to dry deposition. The stream output of 2.9 mu g m(-2) year(-1) indicates that Hg is being recycled within the forest as other chemical species or is being retained by the soil system, as confirmed by the cumulative Hg burden in the 0-10 cm surface layer, which was 36 480 mu g m When the disturbed area of the catchment was included, the stream output was 9.3 mu g m(-2), clearly indicating the impact of the deforestation of the lower part of the basin on the release of mercury. The Hg burden in the disturbed area was 7560 mu g m(-2) for the 0-10 cm surface layer. (C) 2000 Elsevier Science B.V. All rights reserved.2604169920121