Effect of groundwater flow on forming arsenic contaminated groundwater in Sonargaon, Bangladesh

Three-dimensional groundwater flow in Sonargaon, Bangladesh is numerically simulated in order to evaluate the flow paths of As-contaminated drinking groundwater in the Holocene aquifer of the Ganges-Blamaptra-Meghna delta plain over a recent 30-year period. The model indicates that vertical infiltration of surface groundwater into the shallow Holocene aquifer occurs frequently in the Ganges-Blamaptra-Meghna delta plain. It predicts that the water recharged from ground surface moves approximately 10-20 m vertically downward beneath the flood plain, with a gradually increasing horizontal flow, toward the underlying Pleistocene middle mud layer (aquitard). The model also predicts that groundwaters containing highest As concentrations (>700 mu g/L) are formed on the vertical groundwater flow paths where surface water recharges the Holocene aquifer and not on the horizontal flow paths. Combining with the groundwater chemistry, reducing groundwater condition is not essential for the As-contaminated groundwater of the studied area in the Ganges delta plain.ArticleJOURNAL OF HYDROLOGY. 409(3-4):724-736 (2011)journal articl

Costa Rica Rift hole deepened and logged

During Leg 111 of the Ocean Drilling Program, scientists on the drilling vessel JOIDES Resolution studied crustal structure and hydrothermal processes in the eastern equatorial Pacific. Leg 111 spent 43 days on its primary objective, deepening and logging Hole 5048, a deep reference hole in 5.9-million-year-old crust 200 km south of the spreading axis of the Costa Rica Rift. Even before Leg 111 , Hole 5048 was the deepest hole drilled into the oceanic crust, penetrating 274.5 m of sediments and 1,075.5 m of pillow lavas and sheeted dikes to a total depth of 1,350 m below sea floor (mbsf). Leg 111 deepened the hole by 212.3 m to a total depth of 1,562.3 mbsf (1,287.8 m into basement), and completed a highly successful suite of geophysical logs and experiments, including sampling of borehole waters

Prospective Study on the Association between Harm Avoidance and Postpartum Depressive State in a Maternal Cohort of Japanese Women

BACKGROUND: Recent studies have displayed increased interest in examining the relationship between personality traits and the onset, treatment response patterns, and relapse of depression. This study aimed to examine whether or not harm avoidance (HA) was a risk factor for postpartum depression measured by the Edinburgh Postnatal Depression Scale (EPDS) and the state dependency of HA. METHODS: Pregnant women (n=460; mean age 31.9±4.2 years) who participated in a prenatal program completed the EPDS as a measure of depressive state and the Temperament and Character Inventory (TCI) as a measure of HA during three periods: early pregnancy (T1), late pregnancy (around 36 weeks), and 1 month postpartum (T2). Changes in EPDS and HA scores from T1 to T2 were compared between the non depressive (ND) group and the postpartum depressive (PD) group. RESULTS: There was no significant difference in the level of HA between the ND and PD groups at T1. In the ND group, EPDS and HA scores did not change significantly from T1 to T2. In the PD group, both scores increased significantly from T1 to T2 (EPDS, p<0.0001; HA, p<0.048). In the ND and PD groups, a significant positive correlation was observed in changes in EPDS and HA scores from T1 to T2 (r=0.31, p=0.002). CONCLUSIONS: These results suggest that HA cannot be considered a risk factor for the development of postpartum depression measured by EPDS. Furthermore, HA may be state dependent

Arsenic cycling in the Earth’s crust and hydrosphere: interaction between naturally occurring arsenic and human activities

Abstract Field-based research on naturally occurring arsenic contamination of surface waters and groundwaters and the mechanisms of contamination are reviewed. The distribution of arsenic is strongly related to areas of active plate tectonics, magmatism and associated hydrothermal activity, and high rates of erosion. Sources of arsenic contamination are mainly hydrothermal water, sulfide and arsenide minerals, volcanic ash, and iron oxyhydroxide/oxide as weathering products. The promotion of the reduction and oxidation of arsenic source minerals by in situ microbial activity is an important secondary mechanism that often determines arsenic levels in groundwater. Anthropogenic activities, such as geothermal and mining operations, as well as excess pumping of shallow groundwaters, disperse arsenic in the environment, thereby expanding areas of arsenic contamination