The cartilage rings are C-shaped because the back of the trachea presses against the esophagus. The cartilage opens at the esophagus and is replaced by connective tissue and muscle. This gives the esophagus space to allow food to be swallowed easily. The rings of the trachea are stacked one on top of the other, with a small space between them.
In 2014, a survey of the Australian working population revealed that the most common carcinogenic exposures in the workplace were solar ultraviolet radiation, diesel engine exhaust, environmental tobacco (second-hand) smoke, benzene, lead and silica.
asbestos exposure cancer exposure to asbestos is known to the medical field as one of the main causes of several types of cancer one the most common forms of asbestos cancer are known as mesothelioma and it affects 30000 people each year world widesbestos exposure cancer exposure to asbestos is known to the medical field as one of the main causes of several types of cancer one the most common forms of asbestos cancer are known as mesothelioma and it affects 30000 people each year world wide