that asbestos was found to be a health hazard. In the 1900s, only miners and workers in industrial manufacturing plants were believed to be affected by asbestos. As research continued into the 1900s, asbestos was discovered to be the main cause of asbestosis, a generic term for a wide range of asbestos-related disorders and mesothelioma. Mesothelioma, at one time, was a rare form of lung cancer. It is presently occurring much more frequently among people exposed to asbestos dust particles.

There are three terms associated with asbestos dust particle length that you need to know. These terms are nicron, nanometer, and angstrom. To give you an idea of their size, in 1 meter, there are 1 million microns, 1 billion nanometers, and 10 billion angstroms.

It was not until the advent of the transmission electron microscope and the scanning electron microscope in the latter part of the 1950s that the true size (200 to 250 angstroms) of an asbestos particle was discovered. Within this size range, air that appears to be dust-free can contain millions of disease-producing asbestos particles. These minuscule asbestos particles have led to many laws, regulations, and cleanup problems. Although these particles cannot be seen, they can remain suspended in the air for months. In working to solve this problem, you must take air samples to ascertain the severity of the situation. To remove these particles, the air must be scrubbed with a special air filtration machine.

The Navy's guidance for asbestos use, demolition, and disposal is covered by the Navy Occupational Safety and Health (NAVOSH) Program Manual, 0PNAVINST 5100.23 series. However, you should also learn the local laws and restrictions pertinent to the area in which you work. These federal, state, and local laws or ordinances are extremely important. In an overseas location, you need to research and clearly understand the pollution laws of the host country. It is inevitable that somewhere in the disposal cycle, transporting of this type of material to a disposal site will take place over

In all cases, you must constantly research the laws governing asbestos. If you are continually involved with asbestos, you need to stay informed of current regulations and laws. Asbestos laws are constantl changing and being updated. At the present time, legislation is proposed to outlaw all forms and uses of asbestos.

Pesticides

There are also numerous chemicals and pesticides that release harmful and deadly fumes into the air. It is important for you to become familiar with all the materials used by shop personnel within your jurisdiction. Normally, toxic substances have warning labels affixed to them. Once the chemicals being used are identified, you can obtain supplemental information from the unit environmental protection office or from the local safety office.

POLYCHLORINATED BIPHENYLS (PCBs)

There are other hazardous substance classes of chemicals that you, as a first class petty officer, must be aware of. These chemicals, polychlorinated biphenyls, better known as PCBs, are a group of toxic chemicals belonging to the chlorinated hydrocarbon family.

PCBs have been used extensively as insulators and coolers in electrical equipment. PCBs have been used primarily in electrical transformers, especially in and around buildings where the danger of fire exists. PCBs have also been used in capacitors, fluorescent light ballasts, electrical appliances, and motors.

PCBs can cause irritation to the eyes, skin, and lungs. PCBs also are suspected of being a cause of cancer. To date, there is still not enough evidence to prove PCBs cause cancer in humans. PCBs accumulate in the environment; more specifically, they accumulate in human fat tissue. PCBs are stable and slow to break down.

Naturally after reading this information, you are asking yourself, how do I recognize containers or equipment that may contain PCBs? To begin with, PCBs were manufactured and used in a variety of electrical and mechanical applications from the early 1930s until regulated by the Toxic Substances Control Act in 1977. They continue to be used today, but only in enclosed systems.

If you are designated as a project supervisor or petty officer in charge (POIC) of a project, you must be aware of items that contain PCBs if these items are to be serviced, modified, or removed from service. If such items exist, you must stop site work secure the site, and notify the activity environmental coordinator and the EPA branch or division. For further information on the PCB program, consult the PCB Program Management Guide, NEESA 20.2-028B. roads not directly under Navy control.