Support better monitoring


With the official TCEQ monitor down, Midlothian Breathe is working to complete our citizens' grid of air quality sensors. Current particulate matter (PM) levels are close to exceeding safe air standards, and they already exceed levels recommended by former EPA advisory scientists

Why do citizens need to take action?

TCEQ — the state regulating agency — employs a single monitor to capture particulate matter (PM) data used to confirm whether industry in our area is complying with current EPA standards. But that monitor was taken down in April 2022 and may not be reinstalled until late 2023. The reinstated monitor will still be upwind of the Holcim plant, which is the worst polluter of the three cement plants in our area and one of the worst in Texas. We need a more representative sampling of air — the health of our children, seniors and medically at-risk population is at stake.

Can you help us find hosts in those areas? Midlothian Breathe can provide a PurpleAir sensor free of charge to our hosts. All that's needed is an outdoor electrical outlet and reliable WiFi — it plugs in with no further maintenance required for continuous real-time readings of air quality. Please email us at if you or someone you know can help cover these target sites.

Using PurpleAir sensors, we can create a grid that provides publicly available data in locations that TCEQ does not cover.

What are PurpleAir sensors?

PurpleAir sensors record real-time air quality data that is shared and mapped on At about the size of a softball, these sensors are mounted outside and are connected to the internet. They use laser particle count technology to measure particulate matter in the air (like cement plant emissions, dust, smoke and other suspended particles).

Information collected with the air sensors is aligned with the EPA Air Quality Index, and is represented using color indicators for different pollutant levels. Graphs of averages over time and comparisons between sensors will provide baselines to identify issues with our local air quality. 

What can you do?

An engineer set up a grid of targeted locations for the PurpleAir sensors based on geography, wind and other information. We’re currently asking for community support in identifying potential PurpleAir sensor locations. We want to place monitors with hosts who are close to our target locations, determined by our engineer-designed monitoring grid (see map below).

Please help. You'll breathe easier!

Volunteer by emailing And follow us on Facebook.

Overview map of target sites needing air sensors


RED Marker = High priority location, no hosts identified yet

BLUE Marker = Hosts identified but monitors not yet placed

GREEN Marker = Host identified and monitor in the process of being placed

Click below to see target locations by quadrant