National Ambient Air Quality Standards (NAAQS) are a set of standards for six air pollutants, known as criteria pollutants: particulate matter ground level ozone carbon monoxide sulfur dioxide nitrogen dioxide lead Criteria pollutants are common air pollutants that are found worldwide at varying levels and can be harmful to human health and the environment. The NAAQS are established by the U.S. Environmental Protection Agency (EPA) under the Clean Air Act. … Continued
Air pollutants may exist as solid particles, liquid droplets or gases and may originate from: 1 – large stationary sources – refineries, power plants, smelters, boilers, and smaller sources such as dry cleaners and degreasing operations 2 – mobile sources – cars, construction equipment, buses, planes, trucks, marine vessels and trains 3 – naturally occurring sources – wildfires [link to blog post on haze/smoke], wind-blown dust, some tree species, and … Continued
Houston’s air quality has dramatically improved since the late 1980s, and it’s no accident. Despite hot, humid summer weather that makes for ideal ground level ozone formation and being home to the largest concentration of petrochemical and refining facilities in the nation, Houston remains compliant with five out of the six federal health-based standards for common air pollutants. Furthermore, since 2010, the Houston region has added more than 736,000 residents, … Continued
We often think of air pollution as being a concern in the hot summer months. However, one type of indoor air pollution is more troublesome in the winter—carbon monoxide poisoning.
The greater Houston region has been working for many years to meet EPA’s health-based standard for ozone. Over the past 15 years, we have seen significant decreases in both ozone levels and the number of days that the standard was exceeded in Houston. In fact, 2014 was our cleanest year on record.
The greater Houston region has been working for many years to meet EPA’s health-based standard for ozone. Over the past 15 years, we have seen significant decreases in both ozone levels and the number of days that the standard was exceeded in Houston.
Scientists are still working to understand the reason for the higher ozone. We know that weather is a key factor that drives ozone formation. Some years have more days with hot, dry, stagnant weather that can contribute to more days with high ozone.
In Houston, we are proud of the significant improvements in air quality that we have achieved over the past decade. We made those improvements by reducing ozone-forming emissions like oxides of nitrogen (NOx) in every sector—industry, small business, motor vehicles and heavy-duty equipment.
This graph illustrates the changes to the National Ambient Air Quality Standard for ozone pollution over the past 26 years and Houston’s compliance with this standard.
What is Sulfur Dioxide? Sulfur dioxide (SO2) is one of a group of highly reactive gasses known as “oxides of sulfur.” Short-term exposures to SO2 can harm the human respiratory system and make breathing difficult. Children, the elderly, and those who suffer from asthma are particularly sensitive to effects of SO2. Where is Sulfur Dioxide Found? The largest sources of SO2 emissions are from fossil fuel combustion at power plants (73%) and … Continued