Ozone Levels in Los Angeles

Ozone is great at protecting people from UV rays, however, it can also be harmful to human health. For my analysis, I will be looking at ground-level ozone. Ground-level ozone has several harmful effects on human health, but is especially serious to those with preexisting lung conditions. Los Angeles has the worst ozone levels in the U.S., so my focus will be on its current state and where it will likely be over the next few years.

The goal of my project is to trend the ozone levels out 3 years, then make a recommendation on what the city should do to combat the rising levels. I want my recommendation to take locations into consideration, so they will target the worst spots of Los Angeles.

The data I worked with is EPA air quality data, and NOAA weather data. The EPA data can be pulled in several ways, but I used the Los Angeles county to pull my dataset. This had a bit more data than I needed, so I dropped a few sites that I considered outside the realm of Los Angeles and was left with 11 sites.

LA Air Quality Monitoring Sites

The red points on the map are areas with high levels of ozone, and the green points are sites with ‘healthy’ levels of ozone. Refer to this guide if you are interested in what qualifies as hazardous levels.

Using the open-source tool, Facebook Prophet, I used the base data to create a 3 year forecast.

Ozone PPB as a function of Time

The markers are the data points used to train the model, while the blue lines are the forecasted levels. The RMSE on the trend is 9.08 ppb. The trend is steadily increasing, but the levels aren’t entirely unhealthy, or are they? Since the trend is a daily average across all 11 sites, it is not telling us the whole story.

I dove into each site to add some granularity, and forecasted the concentrations out 3 years. The main results are in the map below.

The points circled in black have high concentrations of ozone, and the points circled in red have high rates of increasing ozone. Taking a look at Site 60370002, the trend looks like this.

Now this is concerning. The overall trend has no days in the unhealthy levels, but here we not only have a handful of unhealthy days, but also have a few very unhealthy days. What is the most likely cause of this? One solution might be that the mountain range is blocking the ozone from moving out of the city, and its just pooling there.

After some research, we start to understand that this uptick in ozone concentrations is after a decrease in ozone since 2004. Is there a bigger trend, or were the efforts of getting the ozone problem under control not strict enough?

Either way, instead of focusing on reducing emissions, which would then need to be enforced, we can add new technology to curb and reverse this trend. I chose CityTrees because of there cost effectiveness. They are also self-sustaining except for occasional maintenance. I choose the following locations based on weather data and ozone concentration levels.

CityTree Locations L.A.

With these in place, we can use research literature and the company’s numbers to created a projected trend for the site we looked at previously.

Ozone concentration for Site

The light blue line shows how the trend would react to the new technology. Its important to note that the trend will never flatline, there will always be periods where the ozone generation rate outpaces the ozone scrubbing rate. However, the ozone levels will no longer be hazardous for human health. Note, these are also theoretical rates, and I had to make certain assumptions to create this model.

I hope you enjoyed reading my post! Please leave a comment on what you thought, and any constructive feedback is nice!