Particle generation from humans is a severe problem when working in cleanrooms and other controlled environments. Data regarding the number of particles generated by humans are few and there are no detailed references as to how these studies have been performed. An experimental method to determine the particle release from a human being in a cleanroom was developed and used to describe the variation of particle concentration with time, in regards to both physical activity as well as the protective garment used. The particle strength of source for a human being was studied during different activities and when wearing two different types of clothing. Results from this study could not be directly compared to data found in the literature, due to the lack of historical information. However, it was found that the cleanroom garment used is much more efficient, when greater movements were performed by the test subject.