An in situ post tsunami study was conducted to assess the effect of water management and rainfalls in soil properties and water quality at a low-lying coastal area of central Chile affected by Mw8.8 Earthquake Tsunami the night of 27 February 2010. Soil samples were taken at two depths (0 to 20 and 20 to 40 cm) during 2010 and late 2012. Water quality in a local shallow well was also monitored in 2010 and 2012. High soil salinity was recorded 2 months later than tsunami occurs, closely associated to water-soluble chloride and cations (Cl- >> Na+ >> Ca2+> Mg2+> K+), ionic toxicities, and vegetal inhibition (Vasconcellea pubescens) by less available water to plants. An initial reduction in soil pH due to ionic strength and coarse-textured class of soil was observed and the sodium adsorption ratio (SAR) in soil varied between 5.7 and 11.2 (mmol L-1)(0.5) showing to be saline. Although SARw values are very high (> 18 (mmol L-1) 0.5), it does not exist risks of reduction on soil infiltration rates according to ECw (> 5 dS m(-1)) obtained. After 2 years, soil salinity was drastically reduced in the affected areas due to high soil permeability and natural attenuation (rainfalls and leaching effects), with sulfate and bicarbonate concentrations showing excessive values. Further, irrigation water quality returned to pre-tsunami situation, with only levels of sodium slightly exceeding desirable range from health point of view. Finally, it is suggested a proper design of irrigation systems before implementing other management practices

An in situ post tsunami study was conducted to assess the effect of water management and rainfalls in soil properties and water quality at a low-lying coastal area of central Chile affected by Mw8.8 Earthquake Tsunami the night of 27 February 2010. Soil samples were taken at two depths (0 to 20 and 20 to 40 cm) during 2010 and late 2012. Water quality in a local shallow well was also monitored in 2010 and 2012. High soil salinity was recorded 2 months later than tsunami occurs, closely associated to water-soluble chloride and cations (Cl⁻ > > Na⁺ > > Ca²⁺ > Mg²⁺ > K⁺), ionic toxicities, and vegetal inhibition (Vasconcellea pubescens) by less available water to plants. An initial reduction in soil pH due to ionic strength and coarse-textured class of soil was observed and the sodium adsorption ratio (SAR) in soil varied between 5.7 and 11.2 (mmol L⁻¹)⁰.⁵ showing to be saline. Although SARw values are very high (>18 (mmol L⁻¹)⁰.⁵), it does not exist risks of reduction on soil infiltration rates according to ECw (>5 dS m⁻¹) obtained. After 2 years, soil salinity was drastically reduced in the affected areas due to high soil permeability and natural attenuation (rainfalls and leaching effects), with sulfate and bicarbonate concentrations showing excessive values. Further, irrigation water quality returned to pre-tsunami situation, with only levels of sodium slightly exceeding desirable range from health point of view. Finally, it is suggested a proper design of irrigation systems before implementing other management practices.

peer reviewed | The concentrations of mercury (Hg), selenium (Se) and metallothioneins (MT) were evaluated in fetuses, calves, juveniles and adults of the endangered coastal Franciscana dolphin (Pontoporia blainvillei) from Argentina. Mercury concentrations varied among analyzed tissues (liver, kidney, muscle and brain), with liver showing the higher concentrations in all specimens. An age-dependent accumulation was found in liver, kidney and brain. No significant relationship between Hg and MT concentrations was found for all tissues analyzed. Hepatic Hg molar concentrations were positively correlated with those of Se, indicating a great affinity between these two elements. Furthermore, dark granules of HgSe were observed in Kupffer cells in the liver by electron microscopy, suggesting the role of this macrophage in the detoxification of Hg. A transfer of Hg through placenta was proved. The presence of Hg in brain in all age classes did not show concentrations associated with neurotoxicity.

The concentrations of mercury (Hg), selenium (Se) and metallothioneins (MT) were evaluated in fetuses, calves, juveniles and adults of the endangered coastal Franciscana dolphin (Pontoporia blainvillei) from Argentina. Mercury concentrations varied among analyzed tissues (liver, kidney, muscle and brain), with liver showing the higher concentrations in all specimens. An age-dependent accumulation was found in liver, kidney and brain. No significant relationship between Hg and MT concentrations was found for all tissues analyzed. Hepatic Hg molar concentrations were positively correlated with those of Se, indicating a great affinity between these two elements. Furthermore, dark granules of HgSe were observed in Kupffer cells in the liver by electron microscopy, suggesting the role of this macrophage in the detoxification of Hg. A transfer of Hg through placenta was proved. The presence of Hg in brain in all age classes did not show concentrations associated with neurotoxicity.

Mercury (Hg) concentrations in freshwater fish relates to aquatic Hg concentrations, which largely derives from soil stores of accumulated atmospheric deposition. Hg in catchment soils as a source for aquatic Hg is poorly studied. Here we test if i) peatland soils produce more methylmercury (MeHg) than forest soils; ii) total Hg (THg) concentrations in top soils are determined by atmospheric inputs, while MeHg is produced in the soils; and iii) soil disturbance promotes MeHg production. In two small boreal catchments, previously used in a paired-catchment forest harvest manipulation study, forest soils and peatlands were sampled and analysed for Hg species and additional soil chemistry. In the undisturbed reference catchment, soils were sampled in different vegetation types, of varying productivity as reflected in tree density, where historical data on precipitation and throughfall Hg and MeHg fluxes were available. Upper soil THg contents were significantly correlated to throughfall inputs of Hg, i.e. lowest in the tree-less peatland and highest in the dense spruce forest. For MeHg, top layer concentrations were similar in forest soils and peatlands, likely related to atmospheric input and local production, respectively. The local peatland MeHg production was documented through significantly higher MeHg-to-THg ratios in the deeper soil layer samples. In the disturbed catchment, soils were sampled in and just outside wheeltracks in an area impacted by forest machinery. Here, MeHg concentrations and the MeHg-to-THg ratios in the upper 5 cm were weakly significantly (p = 0.07) and significantly (p = 0.04) different in and outside of the wheeltracks, respectively, suggesting that soil disturbance promotes methylation. Differences in catchment Hg and MeHg streamwater concentrations were not explained by soil Hg and MeHg information, perhaps because hydrological pathways are a stronger determinant of streamwater chemistry than small variations in soil chemistry driven by disturbance and atmospheric inputs of Hg. | acceptedVersion

Mercury (Hg) concentrations in freshwater fish relates to aquatic Hg concentrations, which largely derives from soil stores of accumulated atmospheric deposition. Hg in catchment soils as a source for aquatic Hg is poorly studied. Here we test if i) peatland soils produce more methylmercury (MeHg) than forest soils; ii) total Hg (THg) concentrations in top soils are determined by atmospheric inputs, while MeHg is produced in the soils; and iii) soil disturbance promotes MeHg production. In two small boreal catchments, previously used in a paired-catchment forest harvest manipulation study, forest soils and peatlands were sampled and analysed for Hg species and additional soil chemistry. In the undisturbed reference catchment, soils were sampled in different vegetation types, of varying productivity as reflected in tree density, where historical data on precipitation and throughfall Hg and MeHg fluxes were available. Upper soil THg contents were significantly correlated to throughfall inputs of Hg, i.e. lowest in the tree-less peatland and highest in the dense spruce forest. For MeHg, top layer concentrations were similar in forest soils and peatlands, likely related to atmospheric input and local production, respectively. The local peatland MeHg production was documented through significantly higher MeHg-to-THg ratios in the deeper soil layer samples. In the disturbed catchment, soils were sampled in and just outside wheeltracks in an area impacted by forest machinery. Here, MeHg concentrations and the MeHg-to-THg ratios in the upper 5 cm were weakly significantly (p = 0.07) and significantly (p = 0.04) different in and outside of the wheeltracks, respectively, suggesting that soil disturbance promotes methylation. Differences in catchment Hg and MeHg streamwater concentrations were not explained by soil Hg and MeHg information, perhaps because hydrological pathways are a stronger determinant of streamwater chemistry than small variations in soil chemistry driven by disturbance and atmospheric inputs of Hg.

The aim of this study was to identify primary flow paths involved in the chlordecone (CLD) river contamination and quantify the CLD fluxes to assess CLD pollution levels and duration according to a typical catchment of the banana cropping area in the French Indies (Guadeloupe): the Perou Catchment (12 km(2)) characterized by heavy rainfall (5686 mm year(-1)). Three sub-catchments (SC1, SC2 and SC3) were studied during the hydrological year 2009-2010: a pedological survey combined with a spatialized hydrochemical approach was conducted. The average soil concentration is higher in the Perou Catchment (3400 mu g kg(-1)) than in the entire banana cropping area in Guadeloupe (2100 mu g kg(-1)). The results showed that CLD stocks in soils vary largely among soil types and farming systems: the weakest stocks are located upstream in SC1 (5 kg ha(-1)), where a majority of the area is non-cultivated; medium stocks are located in Nitisols downstream in SC3 (9 kg ha(-1)); and the greatest stocks are observed in SC2 on Andosols (12 kg ha(-1)) characterized by large farms. The annual water balance and the hydro-chemical analysis revealed that the three sub-catchments exhibited different behaviors. Perou River contamination was high during low flows, which highlighted that contamination primarily originated from groundwater contributions. The results showed that only a small part of the catchment (SC2), contributing little to the water flow, comprises a major CLD contribution, which is in agreement with the highly contaminated andosol soils observed there. Another significant result considers that at least 50 years would be required to export the totality of the actual CLD soil stocks retained in the topsoil layer. The actual time for soil remediation will however be much longer considering (i) the necessary time for the chlordecone to percolate and be stored in the shallow aquifers and (ii) its travel time to reach the river.rights reserved.

The aim of this study was to identify primary flow paths involved in the chlordecone (CLD) river contamination and quantify the CLD fluxes to assess CLD pollution levels and duration according to a typical catchment of the banana cropping area in the French Indies (Guadeloupe): the Pérou Catchment (12 km2) characterized by heavy rainfall (5686 mm year?1). Three sub-catchments (SC1, SC2 and SC3) were studied during the hydrological year 2009–2010: a pedological survey combined with a spatialized hydrochemical approach was conducted. The average soil concentration is higher in the Pérou Catchment (3400 ?g kg?1) than in the entire banana cropping area in Guadeloupe (2100 ?g kg?1). The results showed that CLD stocks in soils vary largely among soil types and farming systems: the weakest stocks are located upstream in SC1 (5 kg ha?1), where a majority of the area is non-cultivated; medium stocks are located in Nitisols downstream in SC3 (9 kg ha?1); and the greatest stocks are observed in SC2 on Andosols (12 kg ha?1) characterized by large farms. The annual water balance and the hydro-chemical analysis revealed that the three sub-catchments exhibited different behaviors. Pérou River contamination was high during low flows, which highlighted that contamination primarily originated from groundwater contributions. The results showed that only a small part of the catchment (SC2), contributing little to the water flow, comprises a major CLD contribution, which is in agreement with the highly contaminated andosol soils observed there. Another significant result considers that at least 50 years would be required to export the totality of the actual CLD soil stocks retained in the topsoil layer. The actual time for soil remediation will however be much longer considering (i) the necessary time for the chlordecone to percolate and be stored in the shallow aquifers and (ii) its travel time to reach the river. (Résumé d'auteur)