Photo by Call Me Fred on Unsplash

Caravela started monitoring the air quality outside of our location close to the Molson Coors and Harley-Davidson facilities on the west side of Milwaukee, a mile or so north of the industrial Menomonee River and Miller Valleys.

We have had sensors collecting data for our weather dashboard for a few months, and have now added a 2.5 micrometer (PM2.5) particle sensor. This sensor has particular importance in detecting potentially hazardous airborne particulates. Of specific interest to us is how particulate concentration measurements vary from one neighborhood to another.

Exposure to fine particles causes short-term adverse effects to the nose, eyes, throat and lungs. Longer-term exposure affects lung function and worsens pre-existing medical conditions such as asthma and heart disease, particularly impacting children and the elderly.

Indoor sources of fine particles include tobacco smoke, candles, fireplaces or stove-top cooking. At this moment, Caravela is more concerned with outdoor sources of fine particles. While that includes diesel and gasoline-powered vehicles or construction equipment, heating oil or burned wood, it also includes particles from power plants or from wildfires that may be hundreds of miles away.

The current US EPA guidance regards the safe annual PM2.5 standard at 12.0 micrograms per cubic meter, and the 24-hour standard safe level of 35 micrograms per cubic meter.

You can see the current 7-day history of air quality on Milwaukee’s west side in the link here: to contrast recommended guidance with actual numbers. 

For comparative purposes, the five-day long disaster of London Smog of 1952 resulted in over 12,000 deaths in the period of just a few weeks after the event, that saw hundreds of cows collapsing and dying in their fields, had PM 2.5 levels as high as 4,500 micrograms. This was caused by the perfect storm of cold weather, coal-hearth fires due to lack of central heating and an almost total lack of wind, and it led to a complete nation-wide change in how homes were heated.

Citizens of Chinese industrial cities regularly experience multiple times the safe level of particulate matter, due to the comparative lack of regulation and the percentage of energy produced from coal-burning power plants. Higher than average pandemic mortality rates in the Italian industrial region of Lombardy are also linked to poor air quality and high particulate levels.

Different pollutants affect the body in different ways. Asthmatics are most at risk from high levels of sulfur dioxide (from burning fossil fuels, chemical preparation, and fuel refining) and people with heart disease are most at risk from carbon monoxide (from gasoline and diesel-powered vehicles, some paint types, and other fossil fuel burning sources). 

At present there is no relevant US government agency providing the public with a reliable specific breakdown of what the atmospheric PM2.5 ‘haze’ chemically comprises. Our goal is to add specific sensor types to parse out particle types and provide a more detailed picture of exactly what makes up our air quality in specific neighborhoods and work with partners to fuse that data with other data that tracks the incidence of respiratory disease within a locality.

We’ll provide updates via the blog as we make progress. Thanks for reading!