Earth and Planetary Sciences · Geochemistry and Petrology
A study of spring, river, volcanic vapor and underground heated waters at Japan’s Kussharo Caldera found that hot-spring water includes water from the subducting Pacific Plate. The finding provides direct evidence linking volcanic water beneath the caldera to the slab, alongside water from rainfall and other surface sources.
A filter combining bone char and hydroxyapatite removed high levels of fluoride from groundwater in laboratory tests and an Ethiopian field study. In the village trial, it lowered fluoride from 9.46 to 0.14 milligrams per liter and more than doubled the time between adsorbent replacements.
A study of 34 public boreholes in Ghana found a 69% modeled dry-season probability of fluoride-related health-risk thresholds being exceeded for children. The researchers recommend confirmatory testing and site-specific responses at high-risk boreholes, while noting that the screening approach needs testing with larger, year-round datasets.
