New measures put in place by Health Canada to screen medical marijuana companies for contaminants have turned up further problems in the industry, with the discovery of a banned pesticide at Hydropothecary Corp.

The company, one of more than three dozen federally licensed cannabis producers, was told by Health Canada on Monday that leaf samples taken during an inspection of its Gatineau facility contained myclobutanil. The chemical, which is used to kill mildew, is a known carcinogen that is strictly prohibited for use on plants that are smoked because it produces hydrogen cyanide when heated.

​The three state agencies that will oversee California’s medical cannabis industry released their proposed rules for the state system late last week. There are a lot of them. Rules, that is. It took us a while to comb through them all, but we managed. The result: Below you will find the single most insightful, comprehensive, legalese-free insider’s guide to California’s proposed regs.

Ever wanted to use weed to treat what ails you, but found yourself wading through multitudes of semi-convincing blog posts and abstracts for medical papers that require a subscription to view in full? You're not alone.

The good news is, as cannabis becomes increasingly mainstream, comprehensive sources of information are emerging.

The Cannabis Health Index (North Atlantic Books, 660 pages, $20) is a new reference text by mind-body medicine author Uwe Blesching that combines evidence-based, scientific cannabis research with mindfulness techniques to help readers heal themselves of "100 chronic symptoms and diseases."

UK research into cannabidiol (CBD) comes after surge in parents administering it to children without medical advice.

British scientists are investigating whether a compound found in cannabis could be used to shrink brain tumours in children.

The study of the effects of cannabidiol (CBD), the non-psychoactive ingredient in marijuana, was prompted by a growing number of parents giving it to children with a brain tumour after buying it online. The lead researcher, Prof Richard Grundy of Nottingham University’s children’s brain tumour centre, said in the last six months there had been a surge in parents administering it without medical advice in the belief it might help.

The best remedy to treat cannabis psychosis is legalization, according to a researcher who recently pored over 50+ years of studies on marijuana and mental health. University of York lecturer Ian Hamilton says that the incidence of cannabis users experiencing psychotic episodes is relatively low, but the best way to reduce the number of those incidents even further is to legalize and regulate marijuana.

The first two commercial shipments of medicinal cannabis products to be legally imported to Australia have arrived in Melbourne and Perth.

It means that if you already have approval to use medicinal cannabis, you no longer have to wait for the product you need to be imported. Until now, medicinal cannabis was imported into Australia on a case-by-case basis. Each bottle of the drug was destined for a specific patient. Now pharmacists are able to stockpile the drug for anyone with a prescription. 

But actually getting that prescription can be a slow process, and sometimes take months, depending on the state where you apply. 

Observers point out that new state rules proposed for medical marijuana sales would govern just about every aspect of retailing, including possibly tracking weed patients' purchases.

The rules would require that "patient identification numbers" be entered into a state "track and trace" database and state that: "Upon request from the bureau, a licensed dispensary shall provide the name of the medical cannabis patient associated with the patient identification number listed on the delivery request receipt."

North Carolinians overwhelmingly want to see medical marijuana legalized, according to a new Elon University poll. 

Twenty-nine states have signed off on the medical use of marijuana, and a majority of North Carolina voters polled say they want their state to become the 30th – 80 percent say they approve of legalizing it. Seventeen percent of those polled opposed legalization.

Democrats and independent voters were the most likely to support medical marijuana legalization, with 83 percent approval. Republicans weren’t that far behind, with 73 percent approval.

A tray of tempting pastel-coloured candies sits on a countertop inside AmeriCanna's production facility. Although shaped like pot leaves and stamped with Colorado's universal symbol for the mind-altering ingredient in cannabis – a diamond containing the letters "THC" – the gummies would only provide a sugar high at this point.

Working with precision and speed, the kitchen supervisor uses a device to soak each candy with marijuana extract, so each piece contains exactly 10 milligrams of THC, a single dose under the state's regulations.

The entire process takes seconds, but it represents the culmination of a long regulatory journey for Colorado's edible marijuana industry – one that AmeriCanna owner Dan Anglin is urging Canada to learn from.

A further person has been granted a licence to use marijuana for medical purposes in Sweden three months after an historic decision from the country's Medical Products Agency (Läkemedelsverket) to allow the first prescriptions of the drug in the country.

The first two Swedish licences to use parts of the cannabis plants to relieve chronic pain were granted last February, and since then there have been ten further applications. One of those has now been approved, newspaper Svenska Dagbladet (SvD) reports.