The water crisis in Flint, Michigan has served as a stark reminder that the aging infrastructure that delivers drinking water to millions of people throughout the country's major metro regions can in fact be dangerous, and the recent events in Flint have caused nation-wide concern about lead exposure from drinking water. And while the drinking water that is produced from Lake Michigan may be some of the safest in the country, Chicago is a city with a large inventory of aging homes that still contain lead paint and pipes.

The Chicago Tribune also recently reported that the city has not been painting the complete picture when it comes to testing for lead contamination in drinking water throughout the city's neighborhoods. The Tribune found that the city has a pattern of focusing its testing of tap water that comes from homes located in the far northwest and southwest sides — areas where lead contamination and poisoning is low.

In coordination with Washington State Department of Health, our colleagues at Vox have created a nation-wide map that illustrates which communities are most at risk for lead exposure. According to Vox, the methodology used to illustrate the map "combines Census housing and poverty data to calculate a lead risk score for each census tract and then maps the scores as deciles from 1 to 10, where 1 is the lowest risk and 10 is the highest risk." In other words, the map looks at the populations of individual census tracts that lives in poverty along with the age of the houses in these areas to determine which communities are most at risk of lead contamination. According to Vox's assessment, one in five census tracts in the Chicago metro area "have very high risks of lead exposure."

The map does not attempt to make an assessment on the level of lead in drinking water, but instead highlights the general risk of lead exposure in individual communities.

Much of Chicago's downtown area ranks very low when it comes to risk of lead exposure. According to the data, the only census tract that is that has any remote risk is the western half of the Loop. Areas like Streeterville and River North have virtually no risk for lead exposure.

However, once you begin to look beyond the city's downtown, the picture begins to change. Here's a snapshot of the city's south and southwest sides.

According to the map, many areas found throughout Chicago's West Side have a high risk of lead exposure. The further west you go, the higher the risk.

The Northwest Side paints a similar portrait as the south and west sides, however, there are some pockets that may be less at risk for lead exposure. One notable example is a section of the Dunning neighborhood that has a very low risk of lead exposure.

Finally, the Far North Side is also colored in various shades of red, indicating that large sections of the population may be at risk for lead exposure.