About
Air pollution affects the health of everyone in San Antonio. Metro Health is working to protect our community from air pollution, and we need your help.
San Antonio's air may look clean, but it does not meet the U.S. Environmental Protection Agency's (EPA) health standards for ground-level ozone. Ozone is a gas that can hurt your lungs when you breathe it in.
Ozone forms when nitrogen oxides, largely from car exhaust and burning fuel, mix with other chemicals called Volatile Organic Compounds (VOCs), plus sunlight and heat. This is why ozone is worse on hot, sunny days. It is also why ozone levels are highest from March through November, when San Antonio has more hot, sunny days.
The good news: ozone pollution can be reduced. When we drive less and make cleaner choices, we lower ozone levels and protect the health of everyone in our community.
How Air Pollution Affects Your Health
Breathing polluted air can hurt your body much like secondhand smoke does. Children, older adults, people with asthma or heart disease, and outdoor workers are at the highest risk. Air pollution can:
- Trigger asthma attacks
- Make heart and lung disease worse
- Raise the risk of heart attack and stroke
- Make it hard to breathe, sometimes bad enough for an ER visit
- Lead to lung cancer over time
Even low levels of ozone can cause these problems, especially for people with asthma or other breathing conditions.
A 2017 City of San Antonio study found that about 24 deaths each year could be prevented if our ground-level ozone met the EPA's health standard. That is close to $220 million in avoided health costs.
Read the full report: How Ozone Pollution Affects Public Health in San Antonio.
Understanding the Air Quality Index
The Air Quality Index (AQI) tells you how clean or dirty the air is each day. It also tells you what health problems you might expect within a few hours or days of breathing that air.
The EPA tracks five main pollutants for the AQI. In San Antonio, ground-level ozone is the pollutant that poses the biggest health risk. Some rows below mention "sensitive groups." That means children, older adults and people with asthma or heart disease.
| AQI Levels of Health Concern |
Numerical Value |
Meaning |
| Good |
0 to 50 |
Air quality is safe for everyone. |
| Moderate |
51 to 100 |
Air is okay, but a few very sensitive people may feel effects. |
| Unhealthy for Sensitive Groups |
101 to 150 |
People with asthma, heart disease, kids, and older adults may feel effects. |
| Unhealthy |
151 to 200 |
Everyone may start to feel effects. Sensitive groups may feel worse effects. |
| Very Unhealthy |
201 to 300 |
Health alert. Everyone may feel serious effects. |
| Hazardous |
301 to 500 |
Emergency conditions. Everyone is at risk. |
You can check San Antonio’s daily AQI at Air Now.
Ways to Reduce Ozone
Small changes in daily habits add up. Here is how you can help lower ozone and protect your health and your neighbors' health:
- When You Drive
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- Drive less. Carpool, combine errands into one trip, take the bus, bike or walk.
- Avoid quick starts and stops. Drive at the speed limit.
- Turn off your engine when waiting, instead of idling.
- Keep your vehicle tuned up, including your tires.
- Fill your gas tank in the late afternoon or evening. Stop pumping when it clicks off, and tighten the gas cap.
- Around Your Home
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- Skip gas-powered yard tools when you can. Try a push mower, shears, or an electric tool instead.
- Do not burn yard waste.
- Choose paint and cleaning products labeled low-VOC or zero-VOC.
- Plan Ahead
-
- Try to avoid rush hour traffic when you can.
- Sign up for free air quality alerts from the Texas Commission on Environmental Quality.
Ozone Action Days
Ozone season runs from March through November. On some days during this season, ozone is expected to reach unhealthy levels. These are called Ozone Action Days.
You can find out if today is an Ozone Action Day by checking the EPA's air quality website, or by signing up for free ozone action day alerts from the Texas Commission on Environmental Quality.
On Ozone Action Days, the City asks everyone to take extra steps to reduce pollution, like driving less and avoiding vehicle idling. City departments also follow the Ozone Action Day Plan and adjust their own activities to help cut down on emissions.
Read more about the Ozone Action Day Plan.
Put it Into Practice
- Check the AQI before you plan outdoor activities.
- Know if today is an Ozone Action Day.
- Act to protect your health and reduce pollution.
On high ozone days, limit hard outdoor exercise, drive less, and avoid idling your car. See Ways to Reduce Ozone above for more ideas.
Regulations & Local Action
This section covers the rules and legal steps behind our air quality efforts.
Nonattainment Status
Bexar County is in what the EPA calls "nonattainment" for ozone. This means air quality here does not meet the EPA's health standard. The EPA has moved Bexar County from Moderate to Serious Nonattainment, a stricter category. This new status means businesses and residents in Bexar County must follow additional EPA air quality rules.
The Texas Commission on Environmental Quality (TCEQ) enforces these rules under the federal Clean Air Act, which regulates air emissions from both stationary sources, like factories, and mobile sources, like vehicles.
TCEQ is required to prepare a State Implementation Plan (SIP) for Bexar County by a deadline set by the EPA. The SIP is a comprehensive plan laying out how the region will reduce emissions and meet federal air quality standards.
The City of San Antonio does not have a regulatory role in enforcing the SIP or these state and federal rules. Instead, Metro Health focuses on educating the public and working with local businesses to help reduce emissions.
Many local partners are working together on this effort, including Bexar County, the Alamo Area Council of Governments, VIA Metropolitan Transit, CPS Energy, Joint Base San Antonio, area school districts, and community groups.
Funding is available for businesses and residents who want to reduce emissions:
Resources & Partners
TCEQ Resources
- Texas Emissions Reduction Program (TERP)
- Provides financial incentives to eligible individuals, businesses or local governments to reduce emissions from polluting vehicles and equipment.
- Current Ozone 1-Hour Levels
- Map showing current ozone level at Texas monitors.
- Four Highest Eight-Hour Ozone Concentrations
- Table of these concentrations arranged by areas in Texas.
- Compliance with Eight-Hour Ozone Standard
- Ozone design values.
- TCEQ Air Information
- Find information about permits, monitoring and emissions.
Partners
- Alamo Area Council of Governments
- Enhance the lives of all residents of the Alamo Region by working in mutual respect and partnership with all levels of government, the business sector and the community at large to meet regional challenges and to create regional strengths.
- Texas Commission on Environmental Quality (TCEQ)
- Protects the state's human and natural resources consistent with sustainable economic development. TCEQ’s goal is clean air, clean water and the safe management of waste.
- U.S. Environmental Protection Agency
- Protects human health and safeguards the natural environment - air, water and land - upon which life depends with its partners, pursues innovative solutions that will serve generations to come.