During tests conducted from June 10 to August 5, 2008, the Monterey Bay (California) Unified Air Pollution Control District reported high levels of chromium VI, also known as hexavalent chromium, a cancer causing chemical agent, at an elementary school and fire department in Davenport, California. Chromium VI is the contaminant that inspired the movie, "Erin Brockovich". The toxic substance apparently originated from dust emitted by the Cemex Cement plant in Davenport, as the levels of Chromium VI measured eight times the air district's acceptable level at Pacific Elementary School and 10 times at the Davenport Fire Department. Both are located less than a half-mile from CEMEX. Chromium VI may have been unwittingly produced at the CEMEX plant in Davenport for the last seven years. According to Ed Kendig, the executive director of the Monterey Bay Unified Air Pollution Control District, it's "highly possible" that Chromium VI continues to be produced across the country as an accidental, previously unknown byproduct of the cement-making process.