Chirkin AV, Reducing the harmful effects of polluted air at workplaces using respiratory PPE
“ Measurements in the workplace showed that the average rates of protection of one employee (using the same respirator) may differ a hundred times on different days; and the average rates of protection of different employees (using exactly the same respirators) are very different. So, it is difficult to identify the causes of breathing polluted air workers, and prevents reasonable to require the issuance of more reliable respirators. The reason is that in some cases the proportion of workers using respirators insufficiently effective, such respirators provide protection yet. ”
