Figure 2

The Borgwaldt RM20S 8 syringe smoking machine. The dilutor syringes work independently, with the capability of delivering an extensive smoke dilution range (1:2 -1:4,000 [smoke:air, v/v]) and delivering up to eight different doses of whole smoke simultaneously. A - cigarette smoke generator; Bi - original 4-syringe unit; Bii - additional 4-syringe unit enabling 8 concurrent dilutions in a single run; C - a single BAT exposure chamber housed in an incubator at 37°C attached to smoke generator and media (up to 9 chambers can be installed in the incubator shown, one connected to each syringe plus an air control); D - cell culture media maintained at 37°C in an incubator, supplied to chambers using a pump; E - airflow fan controller.