Johnston, R. B., Hanchett, S., & Hoque Khan, M. (2010). The socio-economics of arsenic removal. Nature Geoscience, 3, 2-3. https://doi.org/10.1038/ngeo735
Nearly an eighth of the population in Bangladesh relies on arsenic-contaminated drinking water. Arsenic-removal filters could help to reduce exposure, but their price is high for the poor and their maintenance is cumbersome.