Chemicals are the most likely source of air contamination. An accident at a plant or factory or a train wreck might release large amounts of a hazardous chemical into the air, for instance. A terrorist attack could involve the deliberate release of a toxic chemical or gas.
In a bioterror attack, bacteria or viruses causing diseases such as anthrax, pneumonic plague, smallpox, or tularemia could be released in an aerosol form. Anyone who inhaled the substance could be affected.
Although air itself does not become radioactive, the release of radiation into the environment can create radioactive dust and dirt (fallout) that can make the air unsafe. A "dirty bomb" could work in this manner, causing a relatively minor explosion but doing its real damage by releasing radioactive materials into the environment.
What you can do
You cannot do much in advance to protect yourself from a hazardous substance released into the air. If there hasn't been an obvious explosion or a known terrorist attack, the air could become contaminated without anyone knowing it until people or animals start to have symptoms.
As with other potential emergencies, it makes sense to have a disaster kit with water, food, first aid items, tools, and other essentials. Concern over terrorist threats has prompted some people to consider adding the following items to their supplies:
- Duct tape and plastic sheeting for "sheltering in place." Sheltering in place involves temporarily sealing yourself inside a room in your home or another indoor location and shutting off sources of ventilation so that outside air doesn't get in.
- Masks. Different kinds of masks are available, such as surgical masks and gas masks. A surgical mask can help protect against some infections (such as SARS). But it will not protect against many other substances. A gas mask can protect against many toxic gases and other harmful substances in the air. But gas masks are expensive and hard to use. In general, masks are helpful only if you know how and when to use them and if they are properly fitted. They are not recommended for the general public. You do not need to purchase or wear any kind of protective mask unless civil or health authorities in your area tell you to do so.
- Potassium iodide tablets. Potassium iodide, also known as KI, helps protect your thyroid gland from the harmful effects of radioactive iodine, which could be released as a result of a dirty bomb, an explosion at a nuclear power plant, or any other nuclear incident. The KI is taken up by your thyroid gland and prevents the radioactive iodine from accumulating there. Potassium iodide does not protect against any other radioactive substances.