Institute of Occupational Medicine pesticides from food and other sources. This work demonstrated that although it is likely that most people are exposed to low levels of a wide variety of pesticide compounds it is unlikely that such exposure would have measurable effects on the health of the population. In 1995 the Soufriere Hills volcano on the Caribbean island of Montserrat erupted, spewing volcanic ash containing large amounts of the crystalline silica mineral cristobalite over the surrounding area. IOM scientists investigated the health of people who lived on the island. In general the exposure of the residents was low, because most people lived well
Volcano in Germany, Shiprock in New Mexico, and Zuidwal volcano in the Netherlands. Edinburgh Castle in Scotland is famously located atop an extinct volcano. Otherwise, whether a volcano is truly extinct is often difficult to determine. Since "supervolcano" calderas can have eruptive lifespans sometimes measured in millions of years, a caldera that has not produced an eruption in tens of thousands of years is likely to be considered dormant instead of extinct. Some volcanologists refer to extinct volcanoes as inactive, though the term is now more commonly used for dormant volcanoes once thought to be extinct. It is difficult to distinguish