Intro

PM2.5 is a type of air pollution that is of greatest concern to public health as its microscopic size allows it to enter the bloodstream. The PM2.5 particle can cause different diseases, such as heart and lung diseases, stroke, and cancer.

The leading causes of death in the United States are heart disease and cancer, so it is important to understand how much our health is affected by air pollution.

This analysis aims to explore the relationship between the PM2.5 level in the air and life expectancy across the US in 2020 and 2019.

Data

Life Expectancy by State

The dataset contains the life expectancy at birth of people in all the US states.

Life Expectancy by County

The dataset contains life expectancy in all the US counties from 2015 to 2019.

Air Pollution Datasets

The datasets contain air pollution information from 2019 and 2020 from different monitoring stations in the US.

Counties Coordinates

The dataset contains the coordinates of all the US counties as well as their populations.

Objectives

The main objective of this analysis is to determine whether there is a correlation between PM2.5 pollution and life expectancy, that is, whether people live shorter in the most polluted areas of the US compared to the less polluted ones. This project could be interesting for:

• Ordinary people who are considering where to live in the US,

• Environmental policy makers, who might consider applying stricter policies in certain US states to prevent pollution,

• Big corporations, which are responsible for a large part of air pollution.

Weaknesses of the Analysis

• The analysis takes air pollution as the only independent variable, while there are other factors affecting life expectancy.

• The analysis focuses only on PM2.5 pollution particles while disregarding others (e.g., ozone).

• Only one point in time is considered, while air pollution levels change. The current levels of air pollution might have a greater effect on future generations.

• The analysis has a narrow geographic focus. It considers only the US.

State Level Analysis

US Average Pollution per State, 2020

US Average Life Expectancy per State, 2020

Trend between Life Expectancy and Air Pollution by State, 2020

Trend Without Influential Observations

The graph shows a stronger trend between air pollution and life expectancy at birth after excluding California, Oregon, and Washington.

Most Polluted Area Approximation

After selecting the most polluted US states, I approximated the most polluted areas in the country and created buffers around them.

Lowest Life Exp Area Approximation

After selecting the states with the lowest life expectancy, I approximated the area in the US with the lowest average life expectancy at birth and created a buffer around it.

Comparing the two maps

County Level Analysis

County Pollution-Life Exp Trend, 2019

The negative slope of the trend indicates a negative relationship between life expectancy at birth and air pollution on a county level.

Life Expectancy and Distance from the Most Polluted Counties in the US, 2019

Stevens County, Washington

Benewah County and Shoshone County (both in Idaho) decrease the slope of the trend as they both have a much lower average life expectancy compared to other counties within 200 km of Stevens County. Both of them have air pollution measurement stations that show relatively high levels of pollution (10.114920 and 9.638841).

Stevens County, Washington

Tulare County, California

Again, the trend shows a positive relationship between the average life expectancy and distance from the most polluted county.

Kings County, California

Gwinnett County, Georgia

The trend shows a negative relationship between life expectancy and distance from Gwinnett County, Georgia.

Webb County, Texas

The trend shows a slight negative relationship.

Butler County, Ohio

The trend shows a slight positive relationship.

Winnebago County, Illinois

The trend shows a negative relationship.

Plumas County, California

The trend shows a slight positive relationship.

Average Pollution by County in Different States

California

Average air pollution in Californian counties ranges from 3.14 (Lake County) to 12.89 (Tulare County). There is a lot of variation in average air pollution among different counties in California.

Washington

Average air pollution in Washington counties ranges from 4.54 (Whatcom County) to 13.09 (Stevens County).

Ohio

Average air pollution in Ohio counties ranges from 6.39 (Whatcom County) to 10.31 (Butler County). All observations on the graph are close together, which indicates less variation in air pollution levels across the state.

Georgia

Average air pollution in Georgian counties ranges from 7.18 (Coffee County) to 10.8 (Gwinnett County). The graph suggests little variation in the counties’ average air pollution levels in the state.

Conclusion

• Spatial analysis can help understand the effect that different types of environmental pollution (in this case, air pollution) have on life expectancy at birth.

• This analysis has explored the correlation between life expectancy at birth and air pollution in different parts of the US.

• The conclusion drawn from the analysis suggests a positive relationship between life expectancy and distance from extremely polluted counties, while this relationship varies in less extreme cases.

• The analysis can be further expanded with other variables that affect life expectancy, and it can also be applied to other parts of the world.

Technical Appendix

The code to replicate this study is in the appendix of the memo.

Thank you for your attention!