Marijuana products that contain tetrahydrocannabinol (THC) can have health risks regardless of how they are used because THC is impairing and can affect memory, attention, decision-making, and risk-taking. Health and safety risks exist for each of the different ways of consuming marijuana, and scientists do not have enough evidence to say that consuming marijuana in one way is safer than another. For example, smoking marijuana can expose you and those around you to harmful chemicals. Oils and concentrates used in vaping and dabbing (which is a specific method of inhaling THC concentrates) often have highly concentrated forms of THC and may contain additives or be contaminated with other substances.The effects of using these more concentrated forms of THC are not well understood but may include higher risk of developing cannabis use disorder. Vaping has also been linked to lung injury. Marijuana and E-cigarette, or Vaping Use-Associated with Lung Injury (EVALI) In 2019, a national outbreak of lung injury associated with vaping occurred. Data from patient reports and product testing showed tetrahydrocannabinol (THC)-containing vaping products that also contained vitamin E acetate were linked to most cases. This outbreak resulted in over 2,800 emergency department visits and 68 confirmed deaths. More information about the outbreak can be found here.