Following the mysterious death of seven cattle near an oil field in Kansas, public health authorities are investigating whether oil drilling could be the cause. In late December, seven dead cattle were found near an oil field in the Cimarron National Grassland, Kansas, and authorities believe that cows inhaled something toxic, prompting them to deny public access to the 2,500-acre Cimarron National Grassland until at least May. Six of the cattle were discovered together in a low-lying area, while a seventh was found a short distance away, with local veterinarians identifying the ingestion or inhalation of something toxic leading to...