Metal accumulation in the tissues and shells of the Rapanine Whelk Indothais gradata along an acidified estuarine gradient

Human ImpactsPoster presentation: P-74Acidification of estuaries results from microbial CO2 generation, acid sulphate groundwater discharge, and anthropogenic activities, in the context of weak buffering potential of hyposaline waters. The resulting acidification introduces an additional yet poorly studied factor influencing the ecology and distributions of biological populations and species. Furthermore, it has a complex influence on estuarine chemistry, including altering the speciation of metals and potentially their availability to the biotic component. With the aim of providing baseline information for metal accumulation in the shells and tissues of organisms inhabiting acidified turbid tropical Asian estuaries, we studied the rapanine whelk Indothais gradata from the mineral-acidified Sungai ...postprin

Sustained use of a household-scale water filtration device in rural Cambodia.

The effectiveness of point-of-use water treatment may be limited by declining use over time, particularly when water treatment is introduced via targeted intervention programmes. In order to evaluate the long-term uptake and use of locally produced ceramic water filters in rural Cambodia, we visited households that had received filters as part of NGO-subsidized distribution programmes over a 4 year period from 2002 to 2006. Of the more than 2,000 filters distributed, we visited 506 randomly selected households in 13 villages spanning three provinces to assess filter time in use and to collect data on factors potentially correlated with long-term use. Results indicate that filter use declined at the rate of approximately 2% per month after implementation, largely owing to breakages, and that, controlling for time since implementation, continued filter use over time was most closely positively associated with: related water, sanitation and hygiene practices in the home; cash investment in the technology by the household; and use of surface water as a primary drinking water source

Escherichia coli in household drinking water and diarrheal disease risk: evidence from Cambodia.

Escherichia coli counts in household drinking water may or may not reliably indicate the presence of diarrheogenic pathogens originating in feces. The extent to which a bacterial indicator like E. coli predicts risks from all classes of pathogens (viruses and parasites as well as bacteria), especially in tropical waters, is uncertain. To investigate the association between E. coli in household drinking water and diarrheal diseases in Cambodia, we conducted a 22 week cohort study in a rural village in Kandal Province. Episodes of diarrhea (all) and bloody diarrhea (dysentery), water quality, water sources, and other covariates were monitored biweekly in 180 households. Households used a variety of water treatment, storage, and handling practices.Results suggest a weak but positive association between E. coli counts in household drinking water and diarrhea and for diarrhea with blood (dysentery), after adjusting for clustering within households and within individuals over time. Compared to households with 1,000 E. coli per 100 ml sample (LPR = 1.2, 95% CI 1.1-1.2 for diarrheal disease; LPR = 1.2, 95% CI 1.0-1.3 for dysentery). Unlike the results of some previous studies, diarrheal disease risks did not increase progressively in magnitude with increasing concentration of E. coli in drinking water