Recently, Science Magazine posted a few articles about the connection between Air Pollution and Cannabis. At first, the idea seems ripe for all sorts of puns: Denver is under a haze, people are lighting up trees, hotboxing the city, etc. But researchers are actually exploring a specific kind of air pollution: Ozone.

Ball-and-stick model of Ozone. Image courtesy of Wikipedia.

Ozone (O₃) is a highly-reactive, strong-smelling, blue gas that is incredibly toxic to most life. In controlled applications, it can be used very effectively to sanitize surfaces of microbial life. But when ozone is floating around in the environment, it can start causing indiscriminate harm. Ozone can be formed in several different ways, but the one most relevant to researchers is how it can form in sunlight by mixing Nitrogen Oxides (abbreviated as NO_x) and hydrocarbon compounds.

And this is where cannabis comes into the picture. Cannabis is well-known for its pungent smell, sometimes called “skunk” or “dank.” The compounds responsible for these strong smells are known as terpenes. Terpenes belong to a larger group of compounds referred to as “Volatile Organic Compounds” or VOCs for short. VOCs are hydrocarbons, so their presence in the air, when mixed with NO_x in sunlight could theoretically cause the formation of environmental ozone.

Author’s Note: The NO_x generally comes from vehicle emissions or plastics off-gassing.

So what does the research say? Well, not much yet. They’re still conducting trials. But we know that terpenes are getting into the air, because virtually anybody who visits a grow operation can smell what’s coming out of them.

There are a few different methods to avoid contributing to an ozone problem, but the simplest one is to not even grow in an area where it would be a problem. In order for ozone to form in the lower atmosphere, NO_x has to mix with VOCs in sunlight. Rural areas generally have very low levels of NO_x, and thus growing out in farmland or rural locations will reliably avoid the formation of ozone.

But let’s say you’re growing in a city, and you can’t afford to move, or it would be otherwise unreasonable to do so, and you still want to avoid contributing to ozone production. Lucky for you, there’s a solution there too!

It’s called carbon filtration. Your facility can be designed in such a way that any gases emitted from it can be pulled through a carbon filter. Carbon filters pull 98-99% of VOCs out of the air, meaning that your facility won’t be a major contributor to Ozone production. A lot of commercial grows are already using this technology to control the smell of cannabis, and in so doing, are also protecting the environment.

So if you’re worried about the environment, and you grow in a big city, consider installing carbon filters if you haven’t already done so. It’s nice to your neighbors, and can help everyone breathe easy!