9/11 responders much more likely to suffer early onset dementia

A new study has identified a link between responders to 2001’s attack on World Trade Centre and an increased incidence of dementia before 65 years of age.

It also found that the incidence of early onset dementia was higher among those responders who were more severely exposed or did not wear personal protective equipment (PPE).

The cohort study involved 5,010 World Trade Center responders aged 60 or younger who did not have dementia at the time of their first cognitive assessment. The responders, who were an average of 53 years old at the start, were followed up with a cognitive assessment every 18 months for up to five years.

Long-term exposure to air pollution is known to be a potential risk factor for cognitive decline, however exposures in the aftermath of the Twin Tower’s collapse was relatively short-term, while the incidence of dementia before the age of 65 years is relatively rare.

To qualify for the cohort, the subjects had to have worked in lower Manhattan or at cleanup sites for at least (i) four hours during the first three days, (ii) for 24 hours at any other time in September, or (iii) for at least 80 hours in the period to July 31, 2002.

A low exposure category was created to include responders such as those who worked in clean rooms and those who routinely wore PPE, such as Hazmat suits and respirators or masks.

The researchers found the subjects outside this low exposure group had a significantly greater risk of dementia before age 65 years..

Overall, the team found that 228 responders developed dementia over the five year period, representing 4.6% of the responders in the study. In the general population the likelihood of developing early onset  dementia would only be around 0.5%.

Lead author Sean Clouston, professor in the Program in Public Health and in the Department of Family, Population, and Preventive Medicine in the Renaissance School of Medicine at New York’s Stony Brook University said: ‘This rate of dementia in those reporting many exposures and limited protection is not only statistically significant, it is alarming for a patient cohort that clearly shows a strong association between exposure and the incidence of dementia under the age of 65.

‘Also, the rates remained statistically significant over the less exposed group even after adjusting for social, medical, and demographic factors.’

Benjamin Luft, MD, co-author and director of the Stony Brook WTC Health and Wellness Program, who has been monitoring the health of responders for 20 years, said: ‘These findings are a major step forward in establishing that the dust and toxins which were released as a result of the calamitous terrorist attacks on 9/11 continue to have devastating consequences on the responders. The full extent of neurodegenerative disease still needs to be determined.’

The full research can be read here