The World Trade Center attacks in New York City on September 11, 2001 were the immediate cause of over 2,800 deaths of people in planes, in buildings, and first responders who got caught in the collapse of the North Tower and South Tower.

This was an unprecedented event in terms of the scope of destruction and magnitude of air pollution, including dust cloud from the building collapse and burning building material for days afterward. Since then, the health of many survivors has been shown to be compromised, especially among those with greatest exposure to 9/11 hazards.

Detecting long term health effects

In a recently published study, we investigated the relationship between exposure to the 9/11 attacks with later development of chronic diseases, specifically heart disease, asthma, and non-cancerous lung diseases for up to 11 years after the disaster.

Many latent health chronic effects develop several years after exposure, as people age

Our study differs from previous research in several ways. Prior studies examined the effects of 9/11 only up to 5-6 years after the attacks, while our study investigated the consequences of 9/11 up to 10-11 years afterwards. Our intent was to focus on “same-day” exposures, in contrast to exposure to hazardous materials that may have lasted for an extended period of time during the lengthy cleanup period.

In addition, our study focused on people with acute exposure to the 9/11 attacks, meaning they were primarily in the affected area on 9/11/2001, less so afterwards.  Most previous research has focused on people who could have been present both on the day of 9/11 or after.

Finally, a lot of previous research included people who had health issues before 9/11. Our study did not include people who reported a diagnosed chronic disease before the 9/11 attacks.

We hypothesized that people who were present or in the vicinity of the 9/11 attacks, and who were in the dust cloud or were injured, would be more likely to develop chronic disease than those with less exposure or trauma. Many latent health chronic effects develop several years after exposure, as people age. In addition, our follow-up period is many times greater than the first published studies, nearly twice that of most others, and therefore more likely to detect long-term health impact.

Dust exposure, injury and chronic diseases

Intense exposure to a man-made disaster on a single day can have significant individual and public health consequences many years later

The main results of our study concerned two aspects of exposure to the 9/11 attacks: being injured and being caught in the dust cloud. We found a strong relationship between injury and later development of heart disease. People who suffered a larger number of injury types, such as head injuries or fractures on 9/11, were linked to earlier development of heart disease compared to people who sustained no injuries.

In particular, people who reported three or more injuries developed heart disease much earlier and as much as seven times more rapidly than those with no injuries. We found the strength of the impact of injuries on heart disease to be surprising, since it was somewhat greater than found in previous research.

We also found that intense exposure to the dust cloud from the collapse of the buildings was related to the earlier development of asthma and non-cancerous lung disease, compared to having some/no dust cloud exposure.

Our study demonstrates that intense exposure to a man-made disaster on a single day can have significant individual and public health consequences many years later.  Clinicians treating people exposed “only” on the day of a disaster should be educated about the potential for development of chronic disease in such cases, even many years later.