The study was conducted at a newly built modern TDI polyurethane foam factory in Eastern Europe with an on-site health clinic. The entire initial production workforce (N=49) was recruited to participate in the study following a brief informational session, during which employees learned about the study and informed consent was obtained. Workers completed an interviewer-administered questionnaire, underwent spirometry testing, and provided peripheral blood for serology pre-employment and at 6 and 12 months after employment. The human subjects study protocol was approved by oversight committees at the authors’ respective home institutions; the Human Investigations Committee at Yale University, New Haven, CT, USA, and the Institutional Review Board at Environmental Health Center, Cluj- Napoca, Romania