Cancer risk pollutants are air pollutants that increase the lifetime risk of developing cancer. Each location lists every cancer risk pollutant measured at that site and its average concentration as a multiple of the Screening Level. The bottom Total (Combined) row sums the pollutant risks, matching the combined cancer total reported on the main dashboard.
A value below 1.00x is below the screening level.
CHATTER analyzes air pollutants measured with automatic gas chromatograph (AutoGC) equipment. In Beaumont-Port-Arthur, there are only two AutoGC monitor sites that measure cancer risk pollutants analyzed by CHATTER: Beaumont-Downtown and Nederland 17th Street.
How to read this plot (click to expand)
Each row is a cancer risk pollutant, with its health effect listed beside it. Each column is a period of time — the calendar years, the year so far (2026 YTD), the most recent 365 days, and the most recent month. The bottom row, Total (Combined), adds the pollutants together for that period.
The number in each square is the measured level divided by the Screening Level, written as a multiple with an “x.” An asterisk after a number means that period had between 60% and 75% of its possible hourly readings, so the average rests on thinner data; periods below 60% are left blank.
A clarifying example.On the Beaumont-Downtown card, find the row for 1,3-Butadiene and the column for 2024. The square reads 1.72x. Breathing 1,3-butadiene increases the risk of cancer. That number means the average level of 1,3-butadiene in 2024 was a little over one and a half times the screening level. Looking at the color scale on the right, the square falls in the band that begins at the Screening Level — the range from one to five times the screening level, values in this range are considered acceptable risk levels for human health.
Squares paler than that band are below the screening level. In the same column, Beaumont’s Total (Combined) for 2024 is 2.90x: adding both cancer pollutants together, the combined level was nearly three times the screening level.
For a general explanation of heat maps, see the Frequently Asked Questions.
