Air conditioners have been running non-stop this summer, from those small window units in homes to the large cooling towers found in crowded city apartments. While they offer a welcome break from the heat, these systems also create environments where harmful bacteria can thrive.
Right now, New York City is facing an outbreak of Legionnaire’s disease, a serious bacterial pneumonia that tends to flare up every summer in the city. More than 100 individuals have fallen ill, and tragically, five lives have been lost due to this growing concern.
If you’re not from New York City or the Northeast, you might not know much about Legionnaire’s disease, but it seems to be a growing public health issue that could soon affect more places.
Climate change is playing a significant role in this brewing storm, making Legionnaire’s disease more common in areas where it was already present, and potentially creating the conditions for it to appear in new locations where people aren’t used to dealing with it. Cities in the Northeast and Midwest, especially those with older infrastructure, have seen an uptick in reported cases recently. For example, the Legionella bacteria was found in the water system of a nursing home in Dearborn, Michigan—one of several states that have noticed increased activity in the last few years.
Contracting Legionnaire’s disease is unfortunately easy; it usually happens when someone breathes in tiny droplets containing the bacteria. Symptoms like fever, headache, and shortness of breath can appear within days, and it can lead to serious lung infections. The illness has a roughly 10 percent fatality rate.
Interestingly, while healthy individuals might only experience mild symptoms, vulnerable populations—including young children, the elderly, pregnant people, and those with weakened immune systems—are at a much greater risk. In fact, about 5,000 people die from Legionnaire’s disease in the United States each year, many from lower-income backgrounds living in older housing with outdated cooling systems where the bacteria can thrive.
This situation illustrates how climate change intersects with economic disparities. As warming temperatures boost the spread of disease, it’s often the most socially vulnerable who end up suffering the most.
The Overlap of Legionnaire’s Disease, Climate Change, and Economic Inequality
Legionnaire’s disease first came to light after a pneumonia outbreak at an American Legion conference in Philadelphia in 1976. Investigations revealed the culprit: a previously unknown bacteria named Legionella. This bacteria is widespread, found in various water sources, but it typically exists in such small amounts that it doesn’t pose a risk.
However, that’s not always the case.
City health officials have recently detected the bacteria in the cooling towers used by large apartment complexes in New York City, particularly in Harlem. These towers, filled with stagnant warm water, create ideal conditions for the bacteria to grow. The systems then convert this water into cool air, potentially releasing bacterial mists into the environment, putting residents at risk when they inhale. According to the Environmental Protection Agency, a staggering 80 percent of Legionnaire’s cases are linked to potable water systems.
