Since Cannabis smoke contains many of the same components as tobacco smoke, there are valid concerns about the adverse pulmonary effects of inhaled Cannabis. A longitudinal study in a noncancer population evaluated repeated measurements of pulmonary function over 20 years in 5,115 men and women whose smoking histories were known.[5] While tobacco exposure was associated with decreased pulmonary function, the investigators concluded that occasional and low-cumulative Cannabis use was not associated with adverse effects on pulmonary function (forced expiratory volume in the first second of expiration [FEV1] and forced vital capacity [FVC]).

In late 2017, researchers with the University of Guelph in Canada published the first-ever study to document the ideal growing conditions for cannabis. Using liquid organic fertilizer with a PKN ratio of 1.3P–1.7K-4.0N, the experiment tested five increasing rates of fertilization. They also tested two coir-based soil-less growing media, or “substrates.”
One of the most curious uses of hemp is as a fence to prevent pollen transfer in commercial production of seeds. Isolation distances for ensuring that seeds produced are pure are considerable for many plants, and often impractical. At one point in the 1980s, the only permitted use of hemp in Germany was as a fence or hedge to prevent plots of beets being used for seed production from being contaminated by pollen from ruderal beets. The high and rather inpenetrable hedge that hemp can produce was considered unsurpassed by any other species for the purpose. As well, the sticky leaves of hemp were thought to trap pollen. However, Saeglitz et al. (2000) demonstrated that the spread of beet pollen is not effectively prevented by hemp hedges. Fiber (i.e. tall) cultivars of hemp were also once used in Europe as wind-breaks, protecting vulnerable crops against wind damage. Although hemp plants can lodge, on the whole very tall hemp is remarkably resistant against wind.

A population-based case-control study of 611 lung cancer patients revealed that chronic low Cannabis exposure was not associated with an increased risk of lung cancer or other upper aerodigestive tract cancers and found no positive associations with any cancer type (oral, pharyngeal, laryngeal, lung, or esophagus) when adjusting for several confounders, including cigarette smoking.[7]

I have digenerative disc disease/4 bulgin discs was taking 9---10mg hydrocodones a day... i started with 3 drops of 300mg and within 5 mins started feeling better than i have theses last 6 years or so... not only that, the inflamation has decrease substantially, i wake up with energy and have begun to work out again... if im making it seem like a miracle drug... its because it is... so the first week i took 3 drops twice a day... now 3 weeks in... im taking about 5 drops 3 times a day and zero pain pills... for the first time in years i have taken control of my life agin... not depending on doctor scripts/bills etc....

Cannabis by Product