Exposure to volcanic ashfall rarely endangers human life directly, except where very thick falls cause structural damage to buildings (e.g. roof collapse) or indirect casualties such as those sustained during ash clean-up operations or in traffic accidents. Short-term effects commonly include irritation of the eyes and upper airways and exacerbation of pre-existing respiratory disease such as asthma; serious health problems are rare. In addition, affected communities may experience increased levels of psychological distress. This is particularly the case when eruptions cause social and economic disruption.
People should avoid unnecessary exposure to ash and wear an effective face mask when outside to reduce inhalation of ash particles. People with existing respiratory problems should take special care to avoid exposure to airborne ash and should carry their medication with them.
Medical services can expect an increased number of patients with respiratory and eye symptoms during and after ashfall. People will generally be very concerned about the effects of ash, and questions commonly arise about the characteristics of the ash and the implications for their health.
For information relating to animal health, read the Animal (livestock) section of this website.
The International Volcanic Health Hazards Network (IVHHN)is an umbrella organisation for all research and information on volcanic health hazards. IVHHN has produced guidelines and databases on volcanic health issues.
NEW IVHHN guidelines on Protection from Breathing Ash
Pamphlets on Guidelines on Preparedness Before, During and After an Ashfall (English version) and Health Hazards of Volcanic Ash-A Guide for the Public may be downloaded from the IVHHN website. These Preparedness and Health Pamphlets are available many languages including: English, Japanese, French, Spanish, Swahili, Portuguese, Indonesian and Icelandic. A version in Italian is in preparation.| Impact on Health | Monitoring | Preventive Measures | |
| Respiratory | |||
| Inhalation of ash <100 µm diameter | <100 µm: Irritation of the upper airways. <10 µm: Exacerbation of pre-existing lung diseases (e.g. asthma, bronchitis) | Syndromic surveillance of acute respiratory health symptoms Monitoring of PM10 concentrations | Initiate cleanup of ashAdvise public to reduce their exposure and wear an approved maskProtect homes and workplaces from ash ingress |
| Inhalation of respirable crystalline silica | Prolonged exposure may raise risk of silicosis or other chronic lung diseases | Determine free crystalline silica content of bulk ash samplesAir sampling to determine respirable crystalline silica (for exposure monitoring for high-exposure occupations or individuals) | Initiate cleanup of ashAdvise public to reduce their exposure and wear an approved maskProtect homes and workplaces from ash ingress |
| Ocular (eye) | |||
| Foreign bodies in eyes | Corneal abrasion, conjunctivitis | Syndromic surveillance of ocular symptoms | Advise public to reduce exposure and wear goggles |
| Mechanical | |||
| Roof collapse due to ash accumulation | Trauma, including death | Syndromic surveillance of emergency department admissions | Advise public to prevent excessive accumulation of ash on roofs |