It used to be that almost all bug repellents contained DEET, a chemical developed during World War II used by U.S. troops in jungle warfare. It became available to consumers in 1957 and has been used ever since. Unfortunately, many people apply bug repellents containing DEET without understanding the consequences to their bodies.
Experts now recommend that products containing DEET should never be used on infants under two months old; and children, seniors, and those with weakened immune systems should be extremely cautious using it. In children, the most common side effects reported to poison control centers are lethargy, headaches, seizures, tremors, and involuntary movements. In addition, experts believe that frequent use of this chemical can cause brain deficits in children.
In addition, laboratory testing and studies from Duke University using DEET on animals and human cells have shown that this chemical can actually cause damage to DNA. In these studies, it led to brain cell death and behavioral changes in its subjects.
Heavy exposure to DEET has been linked to a variety of side effects, including psychological effects such as altered mental state or severe agitation. Some of the physical problems linked to the frequent use of DEET are headaches, memory loss, muscle and joint pain, shortness of breath, dizziness, and fatigue.