Mark Twain State Park Air Monitoring Site

The air monitoring station at Mark Twain State Park is not close to urban areas or large air pollution sources. Therefore, it provides important information on regional background levels of air pollutant concentrations.

Pollutants

Ozone Pollutant

The primary National Ambient Air Quality Standard for ozone is 0.070 parts per million averaged over eight hours (annual fourth-highest daily maximum 8-hour concentration, averaged over three years). The federal ozone season for monitoring runs from March 1 to Oct. 31.

Departmental information about ozone (O₃)

Description
Health effects
Tips to reduce ozone
2008 and 2015 standards plus related documents

Air Quality Analysis Ozone - Weekly Monitor Data

Eight-hour ozone design values
Four highest eight-hour ozone values from beginning of ozone season
Running list of sites with exceedances from beginning of season
Monthly number of exceedances, 2022 and 2023
Daily maximum average eight-hour concentration for each site from beginning of season
Map of Missouri's ozone monitoring sites

Preliminary one-hour ozone averages from all sites in parts per million

Preliminary eight-hour ozone averages from all sites in parts per million

Air Pollutant Design Values - Quarterly Report

Additional information about ground-level ozone and state planning efforts

Table of Symbols - Flags Air Monitoring Data

Technical issues can affect ability to deliver quality data. Access a table of symbols with explanation of the problems they represent.

Ozone preliminary one-hour averages from Mark Twain State Park

Ozone data in fifth and six columns
"P" stands for primary monitor. "S" stands for secondary monitor
Data from previous 10 days through current date
Central Standard Time
Concentrations of ozone in parts per million (ppm)

Sulfur Dioxide

EPA not only established a new one-hour standard in 2010, but it also introduced a new form for determining compliance. The new form requires three years of data — the average SO₂ concentration from each hour of the year. The department and EPA calculate the design value, using the 99th percentile of one-hour daily maximum concentrations, averaged over three years.

Departmental information about sulfur dioxide (SO₂)

Description
2010 standard and related documents

Air Quality Analysis Sulfur Dioxide - Weekly Monitor Data

One-hour SO₂ design values
Four highest one-hour SO₂ values year-to-date
Map of monitoring sites

Preliminary one-hour SO2 data from state-operated sites, parts per billion, CST

Air Pollutant Design Values - Quarterly Report - Sulfur Dioxide

Additional information about sulfur dioxide and state planning efforts

Table of Symbols - Flags Air Monitoring Data

Technical issues can affect ability to deliver quality data. Access a table of symbols with explanation of the problems they represent.

Sulfur dioxide preliminary one-hour averages from Mark Twain State Park

SO₂ data in eighth column
Data from 10 days ago through current date
Central Standard Time

Nitrogen Dioxide

Nitrogen dioxide is a foul-smelling gas. It comes primarily from the burning of fossil fuels — coal, oil and gas. NO₂combines with volatile organic compounds (VOCs) in the presence of sunlight and heat to create ozone. (VOCs are compounds with carbon that easily become vapors or gases.)

In 2010, EPA revised the one-hour NO₂ standard to 100 parts per billion. An area is in compliance if the design value is at or below the standard. The one-hour standard is based on a three-year design value, which is calculated by taking the 98th percentile of the daily high one-hour average concentrations recorded each year, for three years, and averaging the three years together. The annual standard of 0.053 parts per million is based on the annual arithmetic mean and is not to be exceeded.

Departmental information about nitrogen dioxide (NO₂)