[shebantam]

Older trailers will have formaldaydes, late last decade that all changed when Congress pssed a bill limiting Formalahydes.
I had had a conversation by phone with the owner of Aliner Northwest Industries a few years back when I ran the same test in My 2005 Cabin A that FEMA and Sierra club ran on the hurricane Catriona Trailers. I had a sick camper and it made me very sick.
bottom line, I added a fantastic fan to both my Cabin A and the Bantam. This made a world of difference for my breathing. Newer models have a low VOC rating.
Glues that were used, flooring, paneling all have Formalahydes, as well as the particle board.
Aliner cut me a check to reimburse me for the Fantastic Fan. All newer Aliner come standard with one.
try adding a two way fan to the roof vent, especially if it is an Older trailer.