Morphometric alterations of the rat spleen following formaldehyde exposure

Formaldehyde is commonly used in the production of various industrial and medical products. At room temperature formaldehyde easily evaporates. Exposure to formaldehyde can be hazardous to human health. Studies show that the vapour can be the cause of clinical symptoms such as throat, eye, skin and nasal irritation. It can also decrease the production of IgM in the spleen cells. This study was designed to determine the morphometric changes to the spleen in rats when samples were exposed to formaldehyde for 18 weeks. A total of 28 albino Wistar rats aged 6-7 postnatal weeks were divided into the following three case groups according to their exposure to formaldehyde: E1 (2 h/day, 2 days/week), E2 (2 h/day, 4 days/week), E3 (4 h/day, 4 days/week) and one control group. When the exposure period had expired the animals were anaesthetised with chloroform. After cervical dislocation, the abdomen was dissected and spleen specimens were taken. These were sectioned and stained with the haematoxylin and eosin technique for morphometric study. Data was obtained from an Olympus light microscope and then analysed with SPSS (version 11.5) and one-way ANOVA test. The white pulp area and diameter and the marginal zone diameter were greater in group E3 than those in the other groups. The germinal centre area and diameter and the diameter of the periarterial lymphoid sheaths (PALS) were greater in group E2 than in other groups, although there was no significant difference between groups in the area of white pulp and the PALS diameter (p<0.05). This study showed that formaldehyde vapour can cause morphometric changes in the white pulp of the spleen in rats.