You're correct. It is the adhesives, as well as the myriad of other chemicals and synthetics used in the construction of the trailer. This is a common problem with RVs and mobile homes, and even some new homes (carpeting is the big culprit here). The smells will dissipate with time and ventilation. Keep the windows open and the rooftop vent fan running whenever you can. Elevated temperatures hasten the escape of these chemicals into the air, thus they're more noticeable in warm weather. I've heard that you can keep a few bowls of white vinegar on the countertops to help disguise and neutralize the chemical smells. Unless you are very allergic to these odors, they should do you no harm.
