There are three patterns of acute sinusitis:  Persistent cold symptoms. If symptoms get better in 10 days, the infection is probably viral. âBut if thereâs no improvement after 10 days, itâs likely to be bacterial at that stage,â Dr. Rosenfeld said.
Electric Tools Employees using electric tools must be aware of several dangers. Among the most serious hazards are electrical burns and shocks. Electrical shocks, which can lead to injuries such as heart failure and burns, are among the major hazards associated with electric-powered tools.
Hazard substitution. Hazard substitution is a hazard control strategy in which a material or process is replaced with another that is less hazardous. Substitution is the second most effective of the five members of the hierarchy of hazard controls in protecting workers, after elimination. Substitution and elimination are most effective early in the design process, when they may be inexpensive and simple to implement, while for an existing process they may require major changes in equipment and procedures. The concep