The effect of occupational exposure to formaldehyde on blood platelets of employees in a wood industry company

Existing literatures indicate that occupational exposure to formaldehyde may decrease blood platelets. In this study، the influences of occupational exposure to formaldehyde on the number of blood plateletsand clinical symptoms were studied while determining the occupational exposure of employees of a wood industry to formaldehyde. In a case study، the occupational exposure to formaldehyde was determined among 30 workers from production line and 30 administrative staffs of a wood company using US-NIOSH method No 2541. The number of blood platelets was determined using the normal blood count method and related indices. Demographic data as well as the clinical symptoms of exposure to formaldehyde were collected using a standard questionnaire. The smokers and those using drugs interacting with similar symptoms and blood characteristics were excluded from the study. Ethical principles for medical research involving human subjects announced in Helsinki declaration were considered. The research proposal had been approved by the university committee of ethics prior to its execution. Details of tests were explained for all subjects and a written consent was signed by each subject. Occupational exposure of workers in various parts of particle board production line ranged from 0. 5 ppm to 1. 52 ppm which was higher than the ceiling level (0. 3 ppm) recommended by US-ACGIH. The prevalence of all studied symptoms from formaldehyde exposure in workers was significantly higher than the administrative staffs. In case group، tearing rate was the highest average 8. 98 while the chest pain with an average rate of 3. 20 was the lowest. In control group، the prevalence of coughing with an average rate of 6. 62 was the highest and the chest pain with an average rate of 5. 53 was the lowest. The average number and standard deviation of blood platelets of workers in production line and staffs were statistically different with the range 207. 33±41. 79 and 254. 60±71. 05، respectively. The statistical tests showed no relationship between the level of occupational exposure to formaldehyde and the number of blood platelets (p>0. 05). This means that، increasing the exposure level would not lead to a further reduction in the number of platelets. Occupational exposure to formaldehyde significantly changed the number of blood platelets.