Some researchers believe that different health hazards accompany different types of asbestos and should, therefore, be regulated separately. The fiber bundles of asbestos easily separate into long, thin individual fibers when disturbed. Once breathed into the lungs, a fiber must be able to endure the lung fluids in order to stay intact, accumulate, and cause harm. While the durability of the different types of asbestos is being studied, all are under suspicion and should be handled with care. It is generally considered best to leave asbestos material that is undamaged alone and to only have it removed by qualified contractors.