Hashish smoking is becoming more prevalent while the controversy centered around marihuana continues. It is a potent product of the plant, Cannabis sativa and is produced by scraping resin from the tops of the leaves. Hashish contains five to ten times more tetrahydrocannabinol per weight than marihuana. Two hundred hashish smokers presented with symptoms of pharyngitis, rhinitis, bronchitis, or asthma. They directly and temporally related these symptoms to hashish smoking. Six patients with bronchitis, who smoked 50 gm or more of hashish a month, underwent bronchoscopy and biopsy. Microscopic examination showed abnormal respiratory mucosae with atypical cells, loss of cilia, and epithelial cell hyperplasia in all six patients.
Robert L. Henderson, Forest S. Tennant, Roderick Guerry. Respiratory Manifestations of Hashish Smoking. Arch Otolaryngol. 1972;95(3):248–251. doi:10.1001/archotol.1972.00770080390012