Volcanos! Run!

So, if you have been watching the news lately you would have notice some volcanos disasters around the globe. Volcanos intereste me so I thought I would do a little research about them. Here are some questions that I had about volcanos....
Which gases are emitted before and during a volcanic eruption, and what effects can they have on people, animals, plant life near a volcano? How could the gas kill trees? Is it realistic that squirrel might die all over the place, but not humans, like in Dante’s Peak? Are all volcanic gases visible? Yellow? Smelly? Can gas emissions occur without a big volcanic eruption happening at the same time?
The gases are released from magma that is located under ground and then eventually surfaces. Gases can also rise through soil and other volcanic vents. These gases start to create tiny bubbles which over time tend to increase in size. After a volcano erupts the gases are carried by the wind then spreading acid aerosols (tiny acid fragments) to the ground.
There are many types of volcanic gases the most common volcanic acid that is released into the atmosphere is water vapor (H20), carbon dioxide (S02). Also volcanoes release other smaller gases know as Hydrogen sulfide (H2S), hydrogen (H2), carbon monoxide (CO), hydrogen chloride (HCL), hydrogen fluoride (HF), and helium (HE).
There was another question about if these gases are harmful to people humans and animals the answer is yes. Volcanic gases are the greatest potential hazard to people, animals, agriculture, and property. These hazards are carbon dioxide, sulfur dioxide, and hydrogen dioxide. Once these toxins are emitted into the atmosphere can turn into acid rain. If a large explosion takes place it can inject a tremendous volume of sulfur aerosols into the air causing lower surface temperatures and cause damage to the earth ozone layer. Carbon dioxide is a heavier toxin which can lower itself in to the earth soil causing soil decontamination. The carbon dioxide gas in these areas can be deadly to people, animals, and vegetation. A few historic eruptions have released sufficient flouring-compounds to deform or kill animals that eat on vegetation.
Sulfur dioxide is another deadly toxin to humans and wild life. This toxin is a colorless gas with a horrible order that irritates skin and the tissues and mucous membranes of the eyes, nose and throat.
Hydrogen sulfide is another colorless gas that is emitted when a volcanic eruption happens. This toxin is flammable with a very strong odor. This toxin can cause respiratory tract and, dizziness, excitement, staggering gait, and diarrhea. Some of these gases are visible to the human eye but some are not. Hydrogen Fluoride is a pale yellow colored gas that attaches to fine ash particles, covers grass, and pollutes streams and lakes. There are many deadly effects caused by this toxin, skin irritation, bone degeneration and mottling of teeth. Animals that eat vegetation that coated with fluorine-tainted ash are poisoned. Well, some of the gases can be detected like sulfur while others like carbon dioxide cannot. So the views and ideas shown in Dante’s Peak seem to be accurate and logical. Remember to always be aware of your surrounding when