Comparison of the inhalation toxicity of kretek (clove cigarette) smoke with that of American cigarette smoke. I. One day exposure

Abstract

The comparative acute toxicity of a branded American cigarette and kreteks (Indonesian cigarettes containing approximately 60% tobacco and 40% ground clove buds) was assessed by exposure of groups of ten male and ten female rats to three different but equivalent (in terms of total particulate matter) concentrations of smoke from each type of cigarette. The smoke was delivered “nose only” using an HRC Rodent Smoking Machine (Mark IV) within a single 1-h period, with a total delivery of 30 min smoke and a 15 min air-breathing period between the two smoke exposures. Comparison of the immediate response to smoke exposure was made by monitoring respiration during exposure and by observation of the animals immediately following exposure. At this level, the only differences observed were more severe signs of smoke intoxication in the American smoke exposed animals which, at least in part, was attributed to the higher concentrations of carbon monoxide (CO) to which these animals were exposed; CO concentrations in the American smoke atmospheres were 2–2.5 times higher than the corresponding kretek smoke atmospheres. Comparison of any delayed response was made by observation and measurement of body weight, food and water consumption for a sub-population maintained for 14 days following exposures. This comparison revealed no differences between the groups which could be attributed to the smoke exposures. Comparison of any lung changes induced were made at two intervals, 24h and 14 days following smoke exposures. These intervals were selected to provide information on any damage to the lung attributable to the smoke exposures and any subsequent development or repair. Lung changes were assessed by measurement of lung weights and by histopathological examination. Comparison of lung weights revealed no substantial differences between the groups which could be attributed to the smoke exposures. No qualitative histopathological differences were detected between the different types of cigarette either at 24 h or 14 days after exposure. However, a slight increase in the incidence and severity of focal alveolar haemorrhage was present in the high dose American group at 24 h compared with the high dose kretek group killed at the same time interval.