Woof! Something in the air doesn't smell right! WDRB has received several calls and comments on social media about a foul smell outside and we are trying to solve the mystery for you. While we have not been able to get confirmation from authorities yet, I have some theories for you in today's blog.

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Theory #1

It seems history may be repeating itself. That's right! Reports of foul odors have happened in the Louisville area before. The cause is likely something organic or the weather could even be to blame. More specifically, it is likely an organic compound called "geosmin" that is created by microorganisms in the soil dying. It's usually strongest when it's been raining for a while. The trashy smell typically comes to life in wet, muddy conditions. That's why geosmin is also the earthy smell most of us think of when we think of rain. We have seen more rain than normal this year and it has been consistently wet with shorter periods of dry time between rounds of rain.

Some researchers call geosmin "The Earth's Perfume." It is also largely responsible for the earthy or musty smell/taste you get from beets, dirt, and even wine. Additionally, humans are very sensitive to geosmin; the average person can detect 0.7 parts per billion!  If this is indeed the cause there is some good news. It's not toxic and not coming from the city's industrial sites. Also, due to the fact it has happened before, it would not be caused from the ongoing pandemic. 

Theory #2

Another theory is blooming trees or mulch. There are two species of trees that are particularly...fragrant. The first is Pyrus calleryana, also known as Callery pear, and resembles a cheery blossom. The weather warms and its flowers begin to bloom, the tree emits chemical compounds that smell of fish, decayed flesh or semen. 

The second tree is the Ginkgo biloba and it has a very smelly molecule present in the fermentation process. It is called Butyric acid and people actually smell it slightly differently. Descriptions include "poop", "vomit", "farts", "smelly feet" and "Parmesan cheese" (LOL).

Theory #3

The National Weather Service also thought it could be geosmin. They also mentioned the possibility that it could be coming from the Louisville landfill. Meteorologist Joe Sullivan said he can always tell which direction the wind is blowing when he is driving on I-65, south of the airport, due to the contents of the landfill. 

Stay Tuned!

Hannah Strong and I both reached out to a few officials to get some answers. As of last night, Metrosafe said they had not received any calls or complaints. I also left a message with the Air Pollution Control Board (who identified foul smells across the area in the past) and I have not heard back from them yet.  We will keep you posted if the mystery is officially solved. Remember: You can report smells around Louisville with a new app...Follow this link for more information!