Dataset: The dataset for this question is available here. The dataset contains two files, the PM2.5 emissions table and the Source Classification Code table.
Description: The PM2.5 emissions table contains the data from years 1999, 2002, 2005 and 2008 of fine particulate matter emissions in tons by several sources across the United States. There are five fields in this table:
- fips: The five-digit number indicating the conty where the emissions were recorded;
- SCC: The name of the source as indicated by the Source Classification Code table;
- Pollutant: The type of pollutant;
- Emissions: The ammount of PM2.5 emissions recorded (in tons);
- type: The type of source for the emissions (
point,non-point,on-road,non-road); - year: The year that the emissions were recorded.
The following questions are addressed by this project:
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Have total emissions from PM2.5 decreased in the United States from 1999 to 2008?
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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 to 2008 for Baltimore City? Which have seen increases in emissions from 1999 to 2008? -
Across the United States, how have emissions from coal combustion-related sources changed from 1999 to 2008?
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How have emissions from motor vehicle sources changed from 1999 to 2008 in Baltimore City?
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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 source code to answer each question is named plotN.R, where N is the question number as stated in the previous section. Each script loads the datasets, filters it as necessary and produces the plots included in each answer.
- Have total emissions from PM2.5 decreased in the United States from 1999 to 2008?
The figure above shows the emissions of fine particulate matter in the United States between the years 1999 and 2008 at 3 year intervals. The graphic shows that the emissions have decreased.
- Have total emissions from PM2.5 decreased in the Baltimore City, Maryland (
fips == "24510") from 1999 to 2008?
The figure shows that the emissions of fine particulate matter in Baltimore City have decreased between the years 1999 and 2002, and from 2005 to 2008, with a sharp increase from 2002 to 2005.
- 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 to 2008 for Baltimore City? Which have seen increases in emissions from 1999 to 2008?
As the figure shows, except for point type emissions, all particulate emissions have decreased in the time frame considered. For point type emissions, there is a general increase in emissions, with a sharp increase from 1999 to 2005.
- Across the United States, how have emissions from coal combustion-related sources changed from 1999 to 2008?
The figure shows that the emissions of fine particulate matter from coal combustion-related sources across the U.S. has decreased from 1999 to 2008, with a slight increase from 2002 to 2005 and a sharp decrease from 2005 to 2008.
- How have emissions from motor vehicle sources changed from 1999 to 2008 in Baltimore City?
From years 1999 to 2008, the fine particulate emissions from motor vehicle-related sources has decreased, with a sharp decrease from 1999 to 2002 and a slight decrease from 2002 to 2008.
- 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 figure shows that the greater changes of emissions from motor vehicle-related sources occur in Los Angeles County, however, they have increased. In Baltimore City the levels have decreased in the considered time frame.