Today's marijuana isn't what you see in funny movies. It has been genetically modified; in fact, Monsanto, the corporation that produces weed killer, obtained the first genetically modified strain of marijuana. The federal government has said that the THC content of today's marijuana has increased from 0.3%-4% to 10%-30%.
Researchers in New Zealand administered IQ tests to over 1,000 individuals at age 13 (born in 1972 and 1973) and assessed their patterns of cannabis use at several points as they aged. Participants were again IQ tested at age 38, and their two scores were compared as a function of their marijuana use. Participants who used cannabis heavily in their teens and continued through adulthood showed a significant drop in IQ between the ages of 13 and 38—an average of eight points for those who met criteria for cannabis dependence. Keep in mind that the average potency of marijuana has more than tripled in the past two decades (Source: National Institute on Drug Abuse).
Is Marijuana Addictive?
Science has shown that Marijuana rewires your brain. You build tolerance. Pretty soon, you don't enjoy life without the drug. Additionally, research indicates that regular marijuana use changes the way the brain responds to rewards. As a person continues to use, the brain makes less dopamine and/or reduces the ability of cells in the brain's reward circuit to respond. This makes the user rely on the drug to feel pleasure and replaces natural pleasure from watching a funny movie or hanging out with friends.
Recent data suggest that 30 percent of those who use marijuana may have some degree of marijuana use disorder. People who begin using marijuana before the age of 18 are four to seven times more likely to develop a marijuana use disorder than adults.
Secondhand Marijuana Smoke
“The biggest reason that people believe marijuana second-hand smoke is harmless is because the public health community . . . hadn’t done the experiments, so I think there is definitely an underestimation of how harmful marijuana smoke is." Matthew Springer, Ph.D., Professor of Medicine, UC San Francisco.
We now have scientific studies about secondhand marijuana smoke which indicates:
THC was present in the blood of nonsmoking participants who had spent 3 hours in a well-ventilated space with people casually smoking marijuana.
Some nonsmoking participants exposed for an hour to 11.3 percent THC smoke in a non-ventilated room showed positive urine tests in the hours directly following exposure
Nonsmoking people in a confined space with people smoking high-THC marijuana reported a "contact high" and displayed mild impairments on performance in motor tasks.
Consider the impact of Secondhand Marijuana Smoke similar to Secondhand Tobacco Smoke:
". . . If you're at a sidewalk café, and you sit within 18 inches of a person who smokes two cigarettes over the course of an hour, your exposure to secondhand smoke could be the same as if you sat one hour inside a tavern with smokers. . . . A child in close proximity to adult smokers at a backyard party also could receive substantial exposure to secondhand smoke."
While more studies may be necessary to measure the long-term impact of secondhand marijuana smoke, recent science has shown:
Marijuana and tobacco smoke are chemically similar and have some of the same cancer-causing and toxic chemicals: acetaldehyde, ammonia arsenic, benzene, cadmium, chromium, formaldehyde, hydrogen cyanide, isoprene, lead, mercury, nickel, and quinoline.
One minute of exposure to second-hand smoke (SHS) from marijuana diminishes blood vessel function to the same extent as tobacco, but the harmful cardiovascular effects last three times longer.
Indoor ventilation will not solve the problem. According to the Centers for Disease Control:
Current heating, ventilating, and air conditioning systems alone do not control secondhand smoke exposure. In fact, these systems may distribute secondhand smoke throughout a building.
Even separately enclosed, separately exhausted, negative-pressure smoking rooms do not keep secondhand smoke from spilling into adjacent areas.
Conventional air cleaning systems can remove large particles but not the smaller particles or the gases found in secondhand smoke.
One in six infants and toddlers admitted to a Colorado hospital with coughing, wheezing, and other symptoms of bronchiolitis tested positive for marijuana exposure. The study, "Marijuana Exposure in Children Hospitalized for Bronchiolitis," recruited parents of previously healthy children between one month of age and two years old bronchiolitis were admitted to Children's Hospital Colorado (CHC) between January 2013 and April 2014 with an inflammation of the smallest air passages in the lung.
Marijuana Use During Pregnancy
Research has shown that pregnant women who use marijuana have a 2.3 times greater risk of stillbirth.
One in six infants and toddlers admitted to a Colorado hospital with coughing, wheezing, and other symptoms of bronchiolitis tested positive for marijuana exposure. The study, "Marijuana Exposure in Children Hospitalized for Bronchiolitis," recruited parents of previously healthy children between one month of age and two years old who were admitted to Children's Hospital Colorado (CHC) between January 2013 and April 2014 with bronchiolitis, an inflammation of the smallest air passages in the lung.
Human research has shown that some babies born to women who used marijuana during their pregnancies display altered responses to visual stimuli, increased trembling, and a high-pitched cry, which could indicate problems with neurological development.
6-year-olds born to mothers who had smoked one joint or more In Pittsburgh, daily in the first trimester showed a decreased ability to understand concepts in listening and reading. At age 10, children exposed to THC in utero were more impulsive than other children and less able to focus their attention.
Prenatal marijuana exposure is also associated with an increased likelihood of a person using marijuana as a young adult, even when other factors that influence drug use are considered.
Some associations have been found between marijuana use during pregnancy and future developmental and hyperactivity disorders in children.
What about Medical Marijuana Use?