Marijuana smoke damages lung health.
Marijuana has about 50 percent more of some toxins than cigarette smoke. Because of how it is typically smoked (deeper inhale, held for longer time periods), marijuana smoking leads to four times the deposition of tar compared to cigarette smoking.
Within a few minutes after inhaling marijuana smoke, a person’s heart rate speeds up, or may even double.
One Minute of Second-Hand Marijuana Smoke Impairs Cardiovascular Functions. Effects Are Like Tobacco’s, but last three times longer.
Damage is especially damaging to children and teens, according to CDC.
Article relevant to California's smoking laws: https://www.politifact.com/california/article/2018/jul/17/pot-101-update-are-there-limits-smoking-pot-home-w/
In California, it is illegal to smoke (or vape) marijuana in public places, cars or anywhere where tobacco smoke is prohibited (even if it is medical marijuana).
See above links that explain that there is no marijuana smoking or vaping in areas where tobacco use is regulated.