Viz Vol hike locationsAMC Viz Vols have been reporting ozone levels from their hikes using ozone detector cards since 2003.  The map shows locations by year of Viz Vol hikes on or adjacent to the Appalachian Trail.

Volunteers have led 389 Viz Vol hikes on which over 1,500 people participated.

The table below shows the number of hikes at different reported ozone levels for 2005 as reported by Viz Vols and as reported by nearby EPA/State monitors (View current ozone levels in eastern mountains).

Viz Vol Results - 2005

Ozone Detector Card Ratings Key (10 minute average)

  • Rating 1: No or very little ozone pollution (10 - 45 ppb)
  • Rating 2: Normal ozone pollution on sunny days (45 - 75 ppb)
  • Rating 3: Potentially Unhealthy. Children, asthmatics and people with other respiratory diseases should limit prolonged outdoor exertion (75 - 105 ppb)
  • Rating 4: Unhealthy. Children, asthmatics, and people with other respiratory diseases should avoid outdoor exertion; everyone else should limit outdoor exertion ( >105 ppb)

EPA AQI Key (8-hour average)

  • Good: No health impacts are expected when air quality is in this range (< 65 ppb)
  • Moderate: Unusually sensitive people should consider limiting prolonged outdoor exertion (65 - 84 ppb)
  • Unhealthy for sensitive groups: Active children and adults, and people with respiratory disease, such as asthma, should limit prolonged outdoor exertion (85 - 104 ppb)
  • Unhealthy: Active children and adults, and people with respiratory disease, such as asthma, should limit prolonged outdoor exertion; everyone else, especially children, should limit prolonged outdoor exertion (105- 124 ppb)
  • Very Unhealthy: Active children and adults, and people with  respiratory disease, such as asthma, should avoid all outdoor exertion; everyone else, especially children, should limit outdoor exertion (>125 ppb)