camellia kucha/nicotine

The World Health Organization (W.H.O). defines oral potentially malignant disorders (OPMDs) as "A histologically proven lesion that is associated with a significantly increased risk of malignant transformation."Oral leukoplakia is the most commonly occurring oral potentially malignant disorder.

The idea of identifying oral lesions with a precancerous nature, that is, in the sense of pertaining to a pathologic process with an increased risk for future malignant development, of course, is to prevent frank malignancy to occur in the affected area. In 2005, WHO categorized any lesion or

1. Background Asthma constitutes a significant health problem both in Hong Kong and worldwide (1). Different risk factors for asthma have been identified. These include atopy (2), family history of asthma, exposure to indoor aeroallergens (3) air pollution (4) and exposure to environmental tobacco

Cigarette smoking has been linked to many life threatening diseases including heart diseases, cancer and chronic obstructive pulmonary disease. There are about 1.25 billion smokers in the world. Five million people die every year because of smoking-related diseases. This rate exceeds many other