- What is sulfur dioxide?
- How can sulfur dioxide affect your health?
- Who is at risk?
- How can I avoid unhealthy exposure?
- What are the NPS sulfur dioxide health advisories?
- How does sulfur dioxide affect national parks?
The main sources of sulfur dioxide emissions are from fossil fuel combustion and natural volcanic activity. Hawai'i Volcanoes National Park (NP) is unique in the national park system because it sometimes has extremely high concentrations of sulfur dioxide — far higher than any other national park, or even most urban areas.
People sensitive to sulfur dioxide include:
- People with lung diseases, such as asthma, chronic bronchitis, and emphysema will generally have more serious health effects at higher SO2 levels.
- Children are at higher risk from SO2 exposure because their lungs are still developing. They are also more likely to have asthma, which can get worse with SO2 exposure.
- Older adults may be more affected by SO2 exposure, possibly because they are more likely to have pre-existing lung or cardiovascular disease.
- Active people of all ages who exercise or work outdoors have higher exposure to sulfur dioxide than people who are less active.
When possibly unhealthy sulfur dioxide pollution happens, your chances of being affected increase with high levels of activity and the length of time you are active outdoors. If your planned activity has long or heavy physical exertion and the sulfur dioxide levels are high, you may want to limit or stop your activity. For recommended ways to protect yourself at high levels of sulfur dioxide, consult the Health Advisory Table. NPS SO2 health advisories for Hawai'i Volcanoes NP help you understand what local air quality means to your health. The air quality index is divided into six levels of health concern:
Understanding Sulfur Dioxide Health Advisory Levels
- Good (0–0.1 ppm)
No cautionary statement.
- Moderate (0.1–0.2 ppm)
Unusually sensitive people should consider reducing prolonged or heavy exertion outdoors.
- Unhealthy for Sensitive Groups (0.2–1.0 ppm)
Active children and adults, and people with lung disease, such as asthma, should reduce prolonged or heavy exertion outdoors.
- Unhealthy (1.0–3.0 ppm)
Active children and adults, and people with lung disease, such as asthma, should avoid prolonged or heavy exertion outdoors. Everyone else, especially children, should reduce prolonged or heavy exertion outdoors.
- Very Unhealthy (3.0–5.0 ppm)
Active children and adults, and people with lung disease, such as asthma, should avoid all outdoor exertion. Everyone else, especially children, should avoid prolonged or heavy exertion outdoors.
- Hazardous ( > 5.0 ppm)
Triggers health warnings of emergency conditions. Entire population is more likely to be affected. Avoid outdoor activities & remain indoors. Leave the area if directed by Civil Defense.