Higher cytotoxicity and genotoxicity of cultivated versus natural agarwood incense smoke

Agarwood is used as incense around the world. Natural agarwood being in short supply, cultivated agarwood is now produced in many countries, especially in China. Burning agarwood emits fine particulate matter, which enter human lungs and, in turn, elicit illnesses such as cancer. There is actually no knowledge on the differences of hazards posed by the particulate matter released from either cultivated or natural agarwood burning. Here, we measured the diameter and weight of particulates emitted by cultivated and natural agarwood, using an electrical low-pressure impactor. We measured the mutagenicity of particulates using the salmonella reversion test, and the cytotoxicity of each sample of particulates was determined using the 3-4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide assay. Results show that more than 99 % of total particles were ultrafine and fine particles. The cultivated agarwoods emitted a higher proportion of ultrafine particles than the natural agarwoods. The smoke produced by the cultivated agarwood was more mutagenic and more cytotoxic than natural agarwood.