Respiratory Symptoms due to Occupational Exposure to Formaldehyde and MDF Dust in a MDF Furniture Factory in Eastern Thailand

Table 5

Factors associating irritation and allergy symptoms among workers exposed to formaldehyde (ppm).

Variables	Irritation				Allergy
	Crude		Adjusted OP; OR 95% (CI)		Crude		Adjusted; 95% CI (lower, upper)
	OR 95% (CI)	value			OR 95% (CI)	value
Education
Primary school	3.354 (1.648, 6.827)	0.001	3.238	(1.541, 6.801)	3.284 (1.614, 6.684)	0.001	3.615	(1.506, 6.652)
Elementary school	3.209 (1.581, 6.512)	0.001	2.853	(1.359, 6.987)	3.209 (1.581, 6.512)	0.001	2.852	(1.358, 5.988)
University	Ref	Ref	Ref	Ref	Ref	Ref	Ref	Ref
Atopic eczema, allergic rhinitis history
No	Ref	Ref	Ref	Ref	Ref	Ref	Ref	Ref
Yes	4.77 (2.499, 9.091)	0.000	4.552	(2.350, 8.820)	4.818 (2.526, 9.189)	0.000	4.601	(2.375, 8.914)
Family allergic history
No	Ref	Ref	Ref	Ref	Ref	Ref	Ref	Ref
Yes	2.872 (1.345, 6.135)	0.006	2.686	(1.294, 6.358	2.901 (1.358, 6.197)	0.006	2.898	(1.307, 6.425)
Formaldehyde (ppm)
<0.75	Ref	Ref	Ref	Ref	Ref	Ref	Ref	Ref
0.75	0.362 (1.581, 6.512)	0.002	0.365	(0.188, 0.707)	0.358 (1.89, 0.677)	0.007	0.361	(0.186, 0.700)

Note: the respiratory irritation symptoms: (1) coughing in the morning when they wake up; (2) coughing during the daytime or night-time; (3) coughing during the daytime or night-time for >3 months over a period of 1 year; (4) having phlegm regularly on waking; (5) having phlegm frequently during the daytime or night-time; (6) having phlegm for about 3 months over a 1-year period; and (7) having a stuffy nose, chest discomfort, or inflammation in the nose when the temperature is low. The allergic symptom: (1) difficulty breathing after being exposed to MDF dust; (2) chest discomfort when exposed to MDF dust; (3) being more exhausted than people of the same age when walking on a flat surface; (4) having wheezing during the daytime or night-time.