If they're hospitalized or sick, they're not in school. Other insect-related diseases and illness are increasing as well. Goddard reports a rise in the number of tick and mosquito-borne diseases, and concerns about head lice are reaching epidemic proportions in some areas. Koehler notes the lack of any new product chemistries in the last 15-20 years has allowed lice to become resistant to the one pesticide that is most often used to treat head lice. Likewise, a sound pesticide registration system means new products to curb insect-related health problems must be proven safe before they are made available to the public.
Products go through a rigorous process before they are approved for use.