Lacrimation | definition of lacrimation by Medical dictionary. The acute effects of exposure can be caused by inhalation of formaldehyde vapors, which irritate the respiratory tract and eyes and cause lacrimation, burning of the nose and throat, dyspnea, and headache and can result in pulmonary edema and pneumonitis (Kurose, Kodera, Aoyama, & Kawamata, 2004).