The overall goal of this page is to explore the National Emissions Inventory database and see what it say about fine particulate matter pollution in the United states over the 10-year period 1999–2008. It presents answers and justifications to the following questions:
- Have total emissions from PM2.5 decreased in the United States from 1999 to 2008?
- Have total emissions from PM2.5 decreased in the Baltimore City, Maryland (fips == "24510") from 1999 to 2008?
- Of the four types of sources indicated by the type (point, nonpoint, onroad, nonroad) variable, which of these four sources have seen decreases in emissions from 1999–2008 for Baltimore City? Which have seen increases in emissions from 1999–2008?
- Across the United States, how have emissions from coal combustion-related sources changed from 1999–2008?
- How have emissions from motor vehicle sources changed from 1999–2008 in Baltimore City?
- Compare emissions from motor vehicle sources in Baltimore City with emissions from motor vehicle sources in Los Angeles County, California (fips == "06037"). Which city has seen greater changes over time in motor vehicle emissions?
The negative slope of the regression line in below shows that total emissions from PM2.5 decreased in the United States between 1999 and 2008.
again, by regressing the annual volumes of PM2.5, the slope appears to be negative, indicating an overall decline of total emissions from PM2.5
There have been a decrease of volume of all types of pollutant (point, nonpoint, onroad, nonroad) over the city of Baltimore over this period.
The plot below shows an overall decline in the volume of coal related pollution in the US between 1999 and 2008.
The plot shows a decline of motor vehicle pollution in Baltimore City between 1999 and 2008.
As plot 5 below shows, While motor vehicle pollution in Baltimore City stayed almost constant, Los angeles County had a considerable increase between 1999 and 2008.
