An investigation into the potential toxicological effects of fracking sand dust (FSD), collected from unconventional gas drilling sites, has been undertaken, along with characterization of their chemical and biophysical properties. Using intratracheal instillation of nine FSDs in rats and a whole body 4-d inhalation model for one of the FSDs, i.e., FSD 8, and related in vivo and in vitro experiments, the effects of nine FSDs on the respiratory, cardiovascular and immune systems, brain and blood were reported in the preceding eight tandem papers. Here, a summary is given of the key observations made in the organ systems reported in the individual studies. The major finding that inhaled FSD 8 elicits responses in extra-pulmonary organ systems is unexpected, as is the observation that the pulmonary effects of inhaled FSD 8 are attenuated relative to forms of crystalline silica more frequently used in animal studies, i.e., MIN-U-SIL®. An attempt is made to understand the basis for the extra-pulmonary toxicity and comparatively attenuated pulmonary toxicity of FSD 8.

The U.S. Global Climate Change Research Program has identified climate change as a growing public health threat. We investigated the potential effects of changes in ambient daily maximum temperature on hyperthermia and cardiovascular emergency department (ED) visits using records for patients age 64 and younger from a private insurance database for the May-September period for 2005-2012. We found a strong positive relationship between daily maximum temperatures and ED visits for hyperthermia but not for cardiovascular conditions. Using the fitted relationship from 136 metropolitan areas, we calculated the number and rate of hyperthermia ED visits for climates representative of year 1995 (baseline period), as well as years 2050 and 2090 (future periods), for two climate change scenarios based on outcomes from five global climate models. Without considering potential adaptation or population growth and movement, we calculate that climate change alone will result in an additional 21,000-28,000 hyperthermia ED visits for May to September, with associated treatment costs between $6 million and $52 million (2015 U.S. dollars) by 2050; this increases to approximately 28,000-65,000 additional hyperthermia ED visits with treatment costs between $9 million and $118 million (2015 U.S. dollars) by 2090. The range in projected additional hyperthermia visits reflects the difference between alternative climate scenarios, and the additional range in valuation reflects different assumptions about per-case valuation.