Fig. 5.

Splenic natural killer cell activity was assessed in adult female B6C3F1 mice following oropharyngeal aspiration exposure to CBN 3 geogenic dust samples from NDRA each week for 28 days. Data are presented as mean lytic unit ± standard deviation. Sample size for each group was 5–6 animals. Data presented represent one replicate. The (*) indicates data significantly different from the 0 mg/kg group (p < 0.05).