diff --git a/cara/montecarlo.py b/cara/montecarlo.py
index 60ed82ae..c4bd5526 100644
--- a/cara/montecarlo.py
+++ b/cara/montecarlo.py
@@ -20,6 +20,13 @@ weibull_parameters = [((0.5951563631241763, 0.027071715346754264),          # em
 beta_parameters = ((0.0, 0.0558823529411764, 0.40785196091099885, 0.6465433589950477),              # Breathing
                    (0.00735294117647056, 0.094485294117647, 0.5381693341323044, 1.055612645201782)) # Breathing (fast-deep)
 
+# (csi, lamb)
+lognormal_parameters = ((0.10498338229297108, -0.6872121723362303),     # BR, seated
+                        (0.09373162411398223, -0.5742377578494785),     # BR, standing
+                        (0.09435378091059601, 0.21380242785625422),     # BR, light exercise
+                        (0.1894616357138137, 0.551771330362601),        # BR, moderate exercise
+                        (0.21744554768657565, 1.1644665696723049))      # BR, heavy exercise
+
 log_viral_load_frequencies = ((1.880302953, 2.958422139, 3.308759599, 3.676921581, 4.036604757, 4.383770594,
                                4.743136608, 5.094658141, 5.45613857, 5.812946142, 6.160090835, 6.518505362,
                                6.866918705, 7.225333232, 7.574148314, 7.923640008, 8.283027166, 8.641758855,