Could be mold. Could be you are cooking some creature that came along for the trip. Could be whatever they used in the cleanup and refurbishment.
I'd suggest a look inside. If it is truely making you sick contact the seller and ask about a return.
Bought a Sony PC about a month ago and it is still emitting a very unpleasant odor,it is stuffy and almost like dirty laundry bacteria type odor.
It is not the brand new computer or burning odor.
I bought it manufactor refurbished on ubid,works well but the odor is too strong and I think it is toxic because I get a sore throat when I wake up.
Would like to know if anyone had a similar problem.Thank you.