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Air Home > Meteorology > Air Quality Trends

Air Quality Trends

Maine DEP staff analyzes data gathered at our various monitoring sites. There are many different things one can learn when analyzing data. One important part of air pollution data analyses is information about trends. DEP staff are interested in various trends such as:

  • hourly (diurnal) -- how does a given pollutant tend to 'behave' during an average day
  • annual -- how a given pollutant 'behaves' during the course of the year
  • seasonal -- in the case of ozone, there is a season so it is important to know how ozone 'behaves' during the course of a season
  • regional -- there are different factors that contribute to pollutant levels so it is important to learn how pollutant levels differ by region within the State
  • historical -- this is the trend over many years

Looking at pollution data in different ways is a good approach to learn more about how it behaves over time and space. So we have presented the data in different ways to help you learn more about ozone and particle pollution in Maine . We have a number of charts that you can view. You may want to view them all or you may want to look at some and not others.

DEP is interested in trends for many reasons. They include helping to decide where to deploy monitors and knowing the effectiveness of national and state pollution control legislation.

Individuals who are sensitive to pollutants will want to understand more about trends so they know how and when to protect themselves. For instance, someone who is sensitive to ozone will want to know when they should take precautions. In this case, annual and hourly trend information will help them to know when they should be checking the Air Quality Forecast and taking precautions to protect their health.

Teachers are interested in local pollutant trends to supplement national scientific textbook information in their classes.

There are many others who are interested in pollutant trends in Maine for various reasons.

On these pages, DEP has presented trend information for ozone and particle pollution (aka particle matter, fine particles, and PM). Use the links in the column to the left to navigate through the pages. Each page will contain a brief discussion and a graph or two illustrating a particular pollutant and trend.