1. Control of Airborne Respirable Dust Hazards: A Training Program for Underground Coal Miners The Penn State Miner Training Program University Park, PA 16802 Raja V. Ramani, Ph.D., P.E, C.M.S.P. Mark C. Radomsky, Ph.D. MPA, C.M.S.P. Joseph P. Flick, M.S., C.M.S.P. March 31, 2003 Penn State

2. CENTERS FOR DISEASE CONTROL AND PREVENTION NATIONAL INSTITUTE FOR OCUPATIONAL SAFETY AND HEALTH GENERIC MINERAL TECHNOLOGY CENTER ON RESPIRABLE DUST PENNSYLVANIA BUREAU OF DEEP MINE SAFETY

3. RESPIRABLE DUST TRAINING PROGRAM Section 2 HUMAN RESPIRATORY SYSTEM

4. Breathing Process  Breathing is essential for living  Humans at rest breathe about 10 to 12 times per minute  Air we breathe in mines  must contain at least 19.5% Oxygen  must not contain more than 0.5% Carbon Dioxide  has limits on many other gases and dusts found in the mines

5. Human Respiratory System  Is a very complex system consisting of the nose and mouth, windpipe, bronchial tubes, lungs, bronchioles and alveoli. Alveoli are surrounded by arteries and veins where gas exchange takes place.  Breathing substances that are harmful or in amounts not ordinarily encountered in the atmosphere can cause injuries to the system.

6. The main function of the lungs is to provide oxygen to the body, and eliminate carbon dioxide. The average person breathes in about eight liters of air per minute The average person uses about 250 milliliters of oxygen per minute Liters Milliliters

7. Air is breathed in through the nose and/or mouth  Air enters the windpipe (trachea)  Air passes down the windpipe (trachea) to the lungs. Air In Trachea Breathing Basics

8.  The trachea divides into two bronchial tubes, and a bronchial tube enters each lung  The bronchial tube in each lung divides and branches out many times forming progressively smaller bronchial tubes called bronchioles Bronchial Tubes Bronchioles

9. Breathing Basics  At the end of the bronchioles are small air sacs called alveoli  There are millions of alveoli in the human lungs  The alveoli are surrounded by very tiny arteries and veins  This is where oxygen is given to the bloodstream Alveoli

10. Breathing Basics  Oxygen is given to the blood stream to be used, and carbon dioxide enters the alveoli to be exhaled out of the body  The oxygen given to the blood stream is carried to various cells and organs.  This process is known as “Oxygen Transport”

11. Without Oxygen… Without oxygen transport, we would die in minutes Oxygen in Carbon Dioxide out

12. Respiratory System Defensive Mechanisms  Nose, Mouth, Trachea, and Bronchial Tubes all play a major role in evacuating inhaled dust and preventing it from reaching the alveoli  Special Cells in Alveoli (Macrophages) engulf and try to digest the smallest particles that enter this region

13.  The nose regulates (warms/cools) the temperature of inhaled air  The nose moisturizes inhaled air  Small hairs in the nose trap particles for evacuation Respiratory System Defensive Mechanisms The respiratory system has an elaborate defense network to try and allow only clean air to reach the lungs

14. Respiratory System Defensive Mechanisms The nose, trachea, and larger bronchial tubes have cells with tiny hair-like fibers called “Cilia” that sweep in an upward direction to try and evacuate inhaled particles The nose, trachea, and larger bronchial tubes are lined with a mucus material which traps inhaled particles. This mucus is moved by the cilia to try and evacuate inhaled particles. Cilia

15. Respiratory System Defensive Mechanisms  The process of the cilia and the mucus working together to sweep and transport inhaled particles upward is called the “Mucociliary Escalator”  It works much like a human respiratory conveyor belt Dust is Ingested or Evacuated Dust

16.  There are special cells in the alveoli called “Macrophages” that engulf and try to digest the very smallest particles that have eluded all defense networks  Some substances, like coal and silica, can damage the macrophages Be kind to your macrophages! Don’t overload them with dust! Respiratory System Defensive Mechanisms

17.  Only the very smallest particles can actually enter the alveoli  A small particle size is measured in microns. A micron is expressed as (u m)  The smallest particle that the human eye can see is about 40 microns  A human hair is about 50-70 microns thick Respiratory System Defensive Mechanisms

18. Respirable dust: <1 micron to approximately 10 microns. Capable of being inhaled deep into the respiratory tract and alveoli. Invisible to the human eye. Visible dust: approximately 40 microns. <10 microns 40+ microns Respirable Versus Visible Particle Size

19. The particles that can cause illness and disease are so small that you can't see them!

20. Proceed to Section 3 Health Hazards of Coal Mine Dust