Effects of Sub-Acute Rice Dust Inhalation Exposure on Hematological Parameters in Albino Wistar Rats

Background and Objectives: Occupational exposure to rice mill dust is associated with respiratory disease, but systemic hematological effects are not well characterized. This study evaluated the effect of subacute rice dust inhalation on white blood cell (WBC), platelet, red blood cell (RBC), packed cell volume (PCV), and hemoglobin (Hb) in albino Wistar rats. Methods: Fifteen adult albino Wistar rats (150–200 g) were randomly assigned to three groups (n=5): control exposed to filtered air, RD50 exposed to 50 mg/m³ rice dust, and RD100 exposed to 100 mg/m³ rice dust. Rice dust was sourced from an active mill in Katagum LGA, Bauchi State. Rats were exposed in a whole-body inhalation chamber for 1 hour/day, for 14 days. Blood was collected 24 hours post-exposure and WBC, platelet, RBC, PCV, and Hb were determined using an automated analyzer. Data were analyzed using one-way ANOVA followed by Tukey’s post hoc test. Significance was set at p < 0.05. Results: Rice dust exposure significantly increased WBC count in RD50 (33.16 ± 9.42 ×10⁹/L) and RD100 (65.76 ± 0.00 ×10⁹/L) compared with control (21.30 ± 0.70 ×10⁹/L), with a dose-dependent increase. Platelet count was significantly elevated in RD100 (264.40 ± 172.00 ×10⁹/L) compared with control (55.80 ± 18.61 ×10⁹/L). Conversely, RBC count significantly decreased in RD50 (2.33 ± 1.95 ×10¹²/L) and RD100 (1.07 ± 0.21 ×10¹²/L) compared with control (6.72 ± 1.75 ×10¹²/L). PCV also decreased significantly, particularly in RD100 (5.56 ± 0.61%) compared with control (36.06 ± 3.95%). Hb concentration showed no significant difference among groups. Conclusion: Subacute rice dust inhalation produced a mixed hematological response with concentration-dependent increases in WBC and platelet counts with significant reductions in RBC count and PCV, and relative preserved Hb. This suggests concurrent inflammatory and erythrosuppressive effects with relevance to occupationally exposed workers.