Currently 64,805 households occupy FEMA travel trailers and mobile homes in Alabama, Louisiana, Mississippi and Texas.
Ninety-seven percent of these units are located in Louisiana and Mississippi.
A fact sheet will be distributed by FEMA on Saturday to provide basic information about formaldehyde, its possible medical effects and contacts for further assistance.
FEMA said similar information was provided to residents of all FEMA trailers in the Gulf last year.
FEMA said, over the last two months, it has significantly increased its focus on formaldehyde-related health concerns raised by Gulf Coast disaster victims.
These individuals reside in FEMA-provided travel trailers and mobile homes in the Gulf States.
Formaldehyde is a common indoor air pollutant that can be found in nearly all homes and buildings. It is a colorless gas that is released into the home from a variety of indoor sources.
Formaldehyde can also be found in a variety of materials used in home construction and products for everyday living. FEMA has received a relatively small but meaningful number of inquiries from residents of FEMA trailers who have had medical symptoms possibly related to formaldehyde fumes.
The new brochure is also available at www.fema.gov.