About a million. According to the 2001 census data, 1,003,810 out of a total national workforce of 15,872,070 Canadians chose science-related careers. That's 6.3%. Based on earlier studies this level of science participation is similar to countries such as France, USA and Germany, but lags behind England, Sweden and Japan. You can view the details at Statistics Canada's Website. NOTE: Male/Female ratio is 79% male, 21% female scientists in Canada.