Smoked Marijuana as a Cause of Lung Injury

Abstract

P. Tashkin. In many societies, marijuana is the second most commonly smoked substance after tobacco. While Δ9-tetrahydrocannabinol (THC) is unique to marijuana and nicotine to tobacco, the smoke of marijuana, like that of tobacco, consists of a toxic mixture of gases and particulates, many of which are known to be harmful to the lung. Although far fewer marijuana than tobacco cigarettes are generally smoked on a daily basis, the pulmonary consequences of marijuana smoking may be magnified by the greater deposition of smoke particulates in the lung due to the differing manner in which marijuana is smoked. Whereas THC causes modest short-term bronchodilation, regular marijuana smoking produces a number of long-term pulmonary consequences, including chronic cough and sputum, histopathologic evidence of widespread airway inflammation and injury and immunohistochemical evidence of dysregulated growth of respiratory epithelial cells, that may be precursors to lung cancer. The THC in marijuana could contribute to some of these injurious changes through its ability to augment oxidative stress, cause mitochondrial dysfunction, and inhibit apoptosis. On the other hand, physiologic, clinical or epidemiologic evidence that marijuana smoking may lead to chronic obstructive pulmonary disease or respiratory cancer is limited and inconsistent. Habitual use of marijuana is also associated with abnormalities in the structure and function of alveolar macrophages, including impairment in microbial phagocytosis and killing that is associated with defective production of immunostimulatory cytokines and nitric oxide, thereby potentially predisposing to pulmonary infection. In view of the growing interest in medicinal marijuana, further epidemiologic studies are needed to clarify the true risks of regular marijuana smoking on respiratory health.

General Anxiety Disorder Symptoms, Tension Reduction, and Marijuana Use Among Young Adult Females

“…Considering that young adults have the highest rates of marijuana use 1 and use of marijuana is associated with a number of physical health [2][3][4][5] and psychosocial problems, [6][7][8][9][10][11] findings from the current study may have public health implications. Our findings can be used to further refine and develop treatment interventions for young women with more heterogeneous levels of marijuana use and who struggle with symptoms of GAD.…”

“…In 2007, approximately 6% of Americans over the age of 12 reported using marijuana at least once in the past month. 1 Regular marijuana use is associated with respiratory illnesses, such as bronchitis, emphysema, and lung infections, [2][3][4] as well as neurocognitive deficits. 2,5 The use of marijuana has also been linked with psychosocial problems, including occupational absenteeism, work-related accidents, [6][7] poor educational achievement, 2,8,9 and increased likelihood of mental health conditions, including anxiety, depression, and suicidal behavior.…”

Does cannabis use predispose to chronic airflow obstruction?

“…Conversely, marijuana use appears to lead to a modest degree of hyperinflation neither the mechanism nor the clinical significance of which is clear. It is possible, however, that the hyperinflation may have played a role in some of the instances of spontaneous pneumothorax and/or pneumomediastinum and of the peripheral apical lung bullae that have been reported in isolated cases of marijuana smokers (reviewed in [18]). …”

Differences Between African-American and European- American Women in the Association of Childhood Sexual Abuse With Initiation of Marijuana Use and Progression to Problem Use

“…More than one third of marijuana users in that study endorsed at least one CUD symptom (Nocon et al, 2006). CUD is associated with elevated risk for use and misuse of other illicit substances (Hall & Lynskey, 2005;Macleod et al, 2004) in addition to physical health problems such as bronchitis and lung damage (Tashkin, 2005;Taylor et al, 2000). Adolescent and young adult female marijuana users face other risks as well, including increased likelihood of experiencing physical or sexual assault (Kilpatrick et al, 1997;Martino et al, 2004;Testa et al, 2003).…”