Batches of marijuana being sold by state dispensaries and provisioning centers are failing to meet state standards.
New York and New Jersey race to become the 11th state to legalize recreational cannabis in the US.
Dangerous levels of lead contamination have been found in vape cartridges. California's newly revised and strict regulations mean that many vape carts are failing at the point of testing.
The fungal disease responsible for the 2017 and 2018 hemp blight has been identified.
A recent study from Purdue University highlights the problems and obstacles preventing the regulation of pesticide use in cannabis cultivation.
South Carolina is still against the legalization of medicinal and recreational cannabis within the state, but this has not stopped them from supporting scientific research into the therapeutic uses of the plant.
Young people in conservative states may use cannabis very differently to their peers in liberal regions - even if they all have legal access.