The average typing speed is 38-40 words per minute (wpm) for adults  in a professional working environment (despite many incorrect  reports on the web that it is 50-60 wpm).
Chronic Health Effects The following chronic (long-term) health effects can occur at some time after exposure to Mica and can last for months or years: Cancer Hazard * Some Silicas have been shown to cause cancer in animals. The risk of cancer in humans from Mica is unclear at this time.
Mica is a naturally occurring mineral dust often used in makeup foundations, as filler in cement and asphalt, and as insulation material in electric cables. Workers in cosmetic manufacturing factories are at high risk of mica exposure through inhalation.